passengers the same distance. the low supersonic efficiency of the concorde, which has a cruise speed of mach 2, is not a result of poor design but a fundamental consequence of supersonic aerodynamics. for a supersonic aircraft, the maximum achievable l / d depends on several aircraft characteristics and drops as mach ocr for page 19 commercial supersonic technology : the way ahead figure 3 - 1 typical variation in l / d with mach number. source : boeing ( 1989 ). number is increased. figure 3 - 1 shows the typical variation in l / d with mach number. 3 the requirement for low cruise drag generally leads to supersonic vehicles that are much longer than subsonic aircraft with a comparable payload capacity. this, in turn, leads to penalties in the form of degraded vehicle performance at low speed and increased structural weight. as the cruise mach number is increased, the optimal slenderness of the vehicle increases as well, creating even further disparity between the best cruise design and the best low - speed design. another critical design conflict arises because the optimum engine bypass ratio decreases as mach increases. design compromises result in degraded subsonic performance and lower usable maximum lift during low - speed flight. for example, the concorde achieves an l / d of only about 5 to 9 in low - speed flight ( rech and leyman, 1980 ). as a result, almost 40 percent of the fuel carried at takeoff is devoted to low - speed flight and reserve fuel. offsetting the difficulties associated with higher mach numbers is the increased utilization ( distance flown per year ) that higher speeds make possible. also, the range achievable in long - range cruise at constant speed is proportional to where v is the cruise speed, c is the specific fuel consumption, and w1 / w2 is the ratio of the initial weight ( at takeoff ) to the final weight ( at landing ). compared with more aerodynamically efficient subsonic aircraft, the aerodynamic penalty ( in terms of lower l / d ) for flying at mach 2. 0 to 2. 4 is about 10 percent greater than the penalty at mach 1. 6 to 3 the minimum drag of a supersonic aircraft may be expressed as follows ( jones and cohen, 1960 ) : ( 1 ) where b is the wingspan, is the parasite drag at zero lift ( i. e., skin - friction drag and all other drag except induced drag ), l is the effective length of the vehicle, m is the mach number, q is the dynamic pressure, s is


, is the parasite drag at zero lift ( i. e., skin - friction drag and all other drag except induced drag ), l is the effective length of the vehicle, m is the mach number, q is the dynamic pressure, s is the reference wing area, vol is the total volume, and w is the total weight of the aircraft. if the altitude is chosen to be optimal at the given mach number, the l / d can be written as follows : ( 2 ) where ar, the aspect ratio, is given by b2 / s ; arl, the length aspect ratio, is l2 / s ; and, the zero lift wave drag, is a function of aircraft length, volume, and wing area. equation 2 is plotted in figure 3 - 1, assuming that and have values of 0. 01 and 0. 006, respectively, and that ar and arl have values of 2. 7 and 10, respectively. ( the wave drag terms,, and the term containing arl are set to 0 below mach 1. ) ocr for page 20 commercial supersonic technology : the way ahead 1. 8 ( see figure 3 - 1 ). as the cruise speed of a supersonic aircraft increases, specific fuel consumption also increases. however, in principle, the parameter v / c actually increases with speed by a factor of about v¼4 over the range of interest here. an increase of this magnitude would largely offset the drop in l / d that occurs at higher speeds. however, this increase has not been demonstrated in operational engines. furthermore, parametric design studies of supersonic airplanes show that designers have much less freedom to make necessary compromises than with subsonic aircraft. thus, a net reduction of a few percent in [ v / c × l / d ] may have a serious cascading effect on the ability to meet other design goals at higher speeds. regardless of the cruise speed of interest, increases in l / d are vital to enabling an economically viable supersonic aircraft, and meeting l / d goals ( see table 2 - 1 ) should remain the focus of aerodynamic research for commercial supersonic aircraft. most work to date has focused on the higher speeds to increase the benefit in terms of utilization. based on more recent estimates of environmental constraints, however, a range of 1. 4 to 2. 0 seems more reasonable and would open the possibility for new benefits from advances in vehicle configuration and aerodynamics. as described in the preceding section, improved vehicle configuration designs are also likely to be a key part


, a range of 1. 4 to 2. 0 seems more reasonable and would open the possibility for new benefits from advances in vehicle configuration and aerodynamics. as described in the preceding section, improved vehicle configuration designs are also likely to be a key part of reducing sonic boom to levels that might permit overland supersonic flight. state of the art research in supersonic aircraft aerodynamics, which has been ongoing for almost 50 years, has been marked by intermittent efforts — first in the late 1960s and early 1970s when the concorde was developed and a u. s. sst was worked on, then again in the 1990s as part of nasa ’ s hsr program and concurrent work by u. s. industry to develop designs for an hsct. currently attention is being given to smaller supersonic aircraft by the darpa qsp program, and industry ( e. g., gulfstream and dassault ) is exploring the development of an sbj ( george, 2000 ). one view of the progress that has been achieved is shown in figure 3 - 1, which compares the l / d of a recent boeing hsct design with that of the concorde. although the estimates for the hsct are somewhat optimistic, the improvements in cruise performance and particularly in subsonic performance are significant. although a change in cruise l / d from 7. 5 to 9 represents only a 20 percent improvement in drag at a given weight, supersonic aircraft are more sensitive to such changes than are conventional subsonic aircraft. for a design range of 5, 000 nm and with an assumed engine efficiency of 45 percent and an empty weight fraction of 0. 25, a 20 percent increase in l / d corresponds to a 40 percent reduction in the required takeoff weight for a 100 - passenger aircraft. several promising concepts, while immature, may become key features of a successful future commercial supersonic aircraft. related promising technologies supersonic aerodynamics could be revolutionized by successful technologies in any of four areas : supersonic laminar flow, other methods for modifying the flow field around the aircraft, unconventional vehicle configurations, and detailed, computational systems for high - fidelity analysis. supersonic laminar flow has long been recognized as a potential breakthrough that might reduce skin friction drag by as much as 90 percent. but achieving extensive laminar flow has been an elusive goal. substantial efforts are being made to achieve laminar flow for subsonic aircraft, but results have not been particularly encouraging. research on suppressing the transition from laminar to turbulent flow using active flow control ( via su


has been an elusive goal. substantial efforts are being made to achieve laminar flow for subsonic aircraft, but results have not been particularly encouraging. research on suppressing the transition from laminar to turbulent flow using active flow control ( via suction, blowing, or time - dependent boundary - layer manipulation ) continues in many laboratories, but the prospect of developing an economically viable system of this sort remains remote. perhaps more intriguing is the possibility that laminar flow may be more easily maintained at supersonic speeds than at lower speeds. a few related approaches involve the careful design of wing surfaces to achieve favorable streamwise pressure gradients and minimize cross - flow transition. these approaches range from those described by tracy et al. ( 1995 ), in which wings with low leading - edge sweep and favorable chordwise pressure gradients are integrated into the aircraft concept, to recent work at the national aerospace laboratory of japan, which emphasizes more highly swept wings with low upper - surface cross - flow achieved with rather flat streamwise pressures ( yoshida et al., 2000 ). the latter concept, while more sensitive to disturbances and aimed at achieving laminar flow over 25 percent of the wing surface, permits the use of substantial wing sweep. the more mildly swept natural laminar flow concept has demonstrated much larger extents of laminar flow in recent flight tests but may incur structural penalties because of the need for very thin wings. in addition, the short lifting length of the reference concept is difficult to reconcile with the requirement for shaped sonic boom signatures. research on each of these concepts is in its infancy but, if successful, may have a dramatic effect on achievable supersonic aircraft performance. it appears feasible to extend these ideas with additional measures for cross - flow suppression. active cooling or passive techniques for suppressing the initial cross - flow instability ( white and saric, 2000 ) may permit additional sweep on the supersonic leading - edge natural laminar flow concept or more extensive laminarity for the subsonic concept. the second area of general interest for dramatic improvements in supersonic aerodynamics involves much more speculative approaches to the modification of the flow field. active flow control, virtual shaping, and energy addition in various forms have been proposed for many years as a possible means for reducing wave drag or sonic boom amplitude. the committee does not believe that any of these approaches promise near - term breakthroughs in supersonic ocr for page 21 commercial supersonic technology : the way ahead performance or boom reduction. indeed, some of them appear to have


or sonic boom amplitude. the committee does not believe that any of these approaches promise near - term breakthroughs in supersonic ocr for page 21 commercial supersonic technology : the way ahead performance or boom reduction. indeed, some of them appear to have no reasonable physical basis, while others are either too complex to evaluate at this time or feature concepts whose practical implementation is hard to imagine ( see, for example, rethorst and kantner, 1996 ; rising and vadyak, 1999 ; and soloviev et al., 1999 ). future research programs should consider investigating such concepts, with the understanding that success, while unlikely, would be important. a third alternative is to investigate unconventional designs that attempt to address some of the fundamental problems encountered with supersonic aerodynamics. these range from nonplanar and multiple - surface configurations to asymmetric, oblique wings. several of these ideas are based on fundamentally sound aerodynamics, but integrating them into practical aircraft designs has been difficult. in some cases, this is due to a basic limitation of the concept. for example, the oblique all - wing concept that accommodates passengers inside the wing structure appears to offer spectacular aerodynamic performance and great potential for reducing sonic boom, but it is difficult to configure as a passenger aircraft unless it is scaled up to accommodate 500 passengers ( jones, 1991 ; seebass, 1994 ). in other cases, the complexity of the configuration may limit the applicability of simple analyses, and the associated risk and large amount of work required to develop appropriate analysis methodologies cannot be accommodated within the time and resource constraints of ongoing supersonic research programs. immature vehicle configurations also have a hard time competing against vehicle configurations that have long histories of wind tunnel testing and computational design analyses. the solution to this dilemma may lie in the development of analytical methods that permit higher - fidelity analysis of new concepts early in the design cycle. high - fidelity analysis of unconventional vehicle configurations is just now becoming feasible and represents a true opportunity for breakthrough technology. advances in computational algorithms for aerodynamic analysis and shape optimization, together with a revolution in computer hardware capabilities, now make it possible to consider a much wider range of design possibilities at a level of detail formerly restricted to a single baseline design. more mature flow solvers, improved representations of boundary layer turbulence, and methods for efficient calculation of flow field sensitivities to design changes make the evaluation of alternative design concepts feasible. coupled with advances in techniques for multidisciplinary optimization, such capabilities hold out the promise that unconventional concepts can be


turbulence, and methods for efficient calculation of flow field sensitivities to design changes make the evaluation of alternative design concepts feasible. coupled with advances in techniques for multidisciplinary optimization, such capabilities hold out the promise that unconventional concepts can be transformed into practical breakthrough technologies. as an example, consider the concept of natural laminar flow. until recently, the ability to predict transition of a three - dimensional boundary layer and use this prediction to design a wing with extensive laminar flow was a remote possibility. indeed, tests on an f - 104 in the late 1950s showed that limited laminar flow could be achieved, but tools were not available to analyze the results, let alone use them to design a wing. more recently, a specified wing design was analyzed to assess its potential for extensive natural laminar flow ( agrawal and powell, 1991 ). the conclusion was that despite the small sweep, little laminar flow would occur. current computations including nonlinear computational fluid dynamics, three - dimensional boundary layer analysis, and stability calculations have made it possible to successfully optimize a wing for extensive laminar flow. combining this capability with structural analysis and more comprehensive aircraft performance calculations would greatly advance the prospects for using natural laminar flow to significantly improve the performance of a commercial supersonic aircraft. basic and applied aeronautics research future research programs that would support the development of the technologies described above should include the following : techniques to predict and control the transition from laminar to turbulent flow, including supersonic natural laminar flow, passive control techniques, cooling, periodic roughness, and active control methods improved, design - oriented computational fluid dynamics for improved multipoint performance and sonic boom reduction, including adaptive, unstructured methods that achieve the efficiency of current multigrid structured methods and low dissipation methods that can be used in combination with boom propagation codes multidisciplinary design methods compatible with high - fidelity modeling, as well as optimization, decomposition, and methods that exploit parallel computing architectures flight r & t demonstrations to help investigate technologies of interest that remain difficult to validate computationally, or even in existing wind tunnel facilities ( nrc, 1994 ) flight experiments will play an important role in the development of new concepts, and methods for more efficient flight tests, including the development of sensors for flow diagnostics, will be especially important. new supersonic wind tunnel capability may also be needed. vehicle dynamics and control problem description to achieve the required aerodynamic performance, next - generation supersonic transport aircraft will likely exhibit


, including the development of sensors for flow diagnostics, will be especially important. new supersonic wind tunnel capability may also be needed. vehicle dynamics and control problem description to achieve the required aerodynamic performance, next - generation supersonic transport aircraft will likely exhibit greater aerodynamic instabilities than any other existing or planned transport aircraft. these instabilities must be stabilized using high - authority, flight - critical feedback control ocr for page 22 commercial supersonic technology : the way ahead systems. furthermore, owing to their size and shape, large commercial supersonic aircraft will also exhibit unusually low structural - vibration modal frequencies. for example, the 1 - to 1. 5 - hz first - fuselage modes predicted for the baseline hsct designs considered by the hsr program would be significantly lower than those for any manned aircraft, commercial or military ( nrc, 1997 ). either aerodynamic instability or structural flexibility considered separately would present significant technical challenges. taken together, they create severe frequency coalescence ( between the rigid - body and structural modes ) that must be carefully examined before developing the flight - and structural - mode control systems. the combination of aerodynamic instability and structural flexibility also creates two forms of multidisciplinary feedback phenomena involving the elastic airframe, flight - control systems, and either the pilot or the aircraft ’ s propulsion systems. hence, both phenomena are encompassed by the acronym apse, which can refer to either aircraft - pilot servo - elastic or aero - propulsive servo - elastic phenomena. although both apse phenomena fundamentally depend on structural deformations, apse is not an aeroelastic problem per se and it cannot be solved by methods used to counter classical aeroelastic flutter. the aero - propulsive servo - elastic phenomenon was discussed in some detail in a previous nrc report that reviewed nasa ’ s hsr program ( nrc, 1997 ). that report concluded that this phenomenon was “ completely outside industry ’ s experience base, ” and the hsr program had not found a solution to the problems created by the phenomenon. regarding the aircraft - pilot servo - elastic phenomenon, the excitation of the elastic modes of aircraft with structural modal frequencies below 2 hz ( which is a natural consequence of turbulence and pilot control inputs ) will be orders of magnitudes greater than that encountered in other transport aircraft. if left unmitigated, these modal excitations would create unacceptable handling quality and ride quality. in particular, pilot excitation of low - frequency structural modes, coupled with the pilot ’ s biodynami


in other transport aircraft. if left unmitigated, these modal excitations would create unacceptable handling quality and ride quality. in particular, pilot excitation of low - frequency structural modes, coupled with the pilot ’ s biodynamic response to these excitations, has been recently demonstrated to lead to aircraft - pilot coupling instabilities ( see box 3 - 1 ) ( raney et al., 2001 ). configuration design implications both forms of apse phenomena are exacerbated by vehicle configurations with long and slender fuselages and thin or highly swept wings, by lightweight ( hence low stiffness ) structural design, and by increased aerodynamic instability, all of which are key factors in achieving high - performance, low - boom commercial supersonic aircraft. thus, even though apse effects are likely to be a major factor in defining the vehicle configuration for next - generation commercial supersonic aircraft, their importance in this regard is not generally recognized and they are rarely incorporated into the early stages of aircraft design. consequently, research into apse phenomena and their causes, along with new analysis and synthesis tools, is required. these tools include new active - control concepts, new control - system synthesis techniques, and aeroelastic modeling approaches that may be used in the vehicle configuration - design phase and integrated into multidisciplinary optimization techniques. additional research required low - frequency structural vibration modes will require active structural mode control systems that are highly integrated with the primary flight - control systems. success in this effort will be particularly beneficial because solving the control problems associated with low - frequency structural vibration modes is one key to resolving both forms of apse phenomena. new techniques must be developed and validated for designing affordable, certifiable, highly integrated, high - authority flight - and structural - mode control systems. research in handling qualities is necessary to develop design criteria for aircraft control systems. additionally, novel sensors and actuation devices, along with novel distributed control approaches, must be considered. 4, 5 new structural design approaches are also required, and new tools and technology must be developed and validated for designing affordable, advanced structural systems that can be certificated for use on commercial aircraft. options include ( 1 ) multidisciplinary configuration optimization techniques that capture both types of apse phenomena, ( 2 ) active or smart structures, and ( 3 ) viscoelectric or electrorheological materials. 4, 5 finally, current practice in the industry creates functionally separate flight controls engineering organizations and structural dynamics engineering organizations. this is not


( 2 ) active or smart structures, and ( 3 ) viscoelectric or electrorheological materials. 4, 5 finally, current practice in the industry creates functionally separate flight controls engineering organizations and structural dynamics engineering organizations. this is not an appropriate organizational structure for handling the issues associated with these apse phenomena. as previously recommended by the nrc in an assessment of the hsr program, interdisciplinary teams should be formed to fully address relevant aspects of the apse problem, and the organizational distance between groups responsible for ( 1 ) guidance and control systems and ( 2 ) structural - mode control laws should be reduced or eliminated ( nrc, 1997 ). experimental programs should be initiated as a first step in establishing better handling - and ride - quality requirements for highly unstable and highly flexible aircraft and associated flight control and structural - mode control systems. real - time, manned simulations of the dynamics of these vehicles, however, would severely tax both fixed - base and inflight simulation facilities, limiting the ability to establish 4 anna - maria mcgowan, nasa langley research center, personal communication with david schmidt, 2001. 5 terrance weisshaar, purdue university, personal communication with david schmidt, 2001. ocr for page 23 commercial supersonic technology : the way ahead box 3 - 1 demonstration of aircraft - pilot coupling instability in a ground - based simulation the upper graph shows the time histories of lateral cockpit acceleration and pilot lateral stick input for a moving - base piloted simulation of a demanding landing - approach task. these time histories reveal an undamped oscillatory instability beginning at about 19 normalized time units. the cause of this instability is revealed in the power spectra of these two time histories, shown in the three lower graphs, where curves labeled “ 1 ” show lateral stick power spectral density and curves labeled “ 2 ” show lateral acceleration power spectral density. in the first power - spectra plot, on the left, calculated early in the time history, there is little correlation between the peak - power frequency of the stick input and the lateral accelerations. but in the power - spectra plot on the right, which is calculated from the traces in which the instability is evident, the peak power of the stick input shows a strong correlation with the peak power of the lateral acceleration. this indicates a feedback process is present between the cockpit accelerations and the stick input. that is, the accelerations are driving the stick inputs, through the dynamic responses of the pilot ’ s body to the stick, and these stick inputs are in turn driving the accelerations.


is present between the cockpit accelerations and the stick input. that is, the accelerations are driving the stick inputs, through the dynamic responses of the pilot ’ s body to the stick, and these stick inputs are in turn driving the accelerations. these data further indicate that the instability is inadvertent — the pilot could not avoid the instability despite — or because of — stick inputs intended to maintain stable flight. source : raney et al. ( 2001 ) handling - and ride - quality requirements and to design and verify the performance of control systems. the ability of national simulation facilities to deliver high - fidelity manned simulations of highly flexible aircraft may need to be upgraded. high - fidelity integrated design tools highly integrated designs are required for virtually all new aerospace systems. for aircraft, the importance of integration increases with flight speed. supersonic aircraft are much more sensitive to how components and disciplines are ocr for page 24 commercial supersonic technology : the way ahead combined than subsonic aircraft, particularly with regard to apse effects and sonic boom, as already discussed. stringent requirements for component performance ( with attendant development, manufacturing, cost, and operational issues ), coupled with the economic and environmental challenges faced by commercial supersonic aircraft, leave little room for inefficiencies in the design of the airframe, engine, flight controls system, or other performance - critical systems. design integration tools should allow design teams to interact in the design of complex systems where technical and other factors ( including cost ) can be appropriately traded ; to compress the design cycle time by concurrently considering all critical constraints and disciplines ; to adapt quickly to changes in design and manufacturing processes ; to easily accept new and improved tools ; and to provide databases with levels of complexity appropriate to each task. fortunately, a substantial national investment has been made in tools for integrated design, including system engineering methods, multidisciplinary optimization methods, detailed discipline methods and interfaces, and design - integration frameworks. the aircraft design and manufacturing industry is heavily committed to improving such tools. universities and the government also have critical roles in advancing the state of the art in many of these areas. nasa and the department of defense have both made significant investments in the development of advanced integration environments and tools, although nasa ’ s flagship program in this area, the integrated synthesis environments initiative, was recently cancelled. despite the progress that has been made, important work remains to be done. existing tools cannot model some key technologies ( e. g., active controls ), nor do they have sufficient model validity in all important


synthesis environments initiative, was recently cancelled. despite the progress that has been made, important work remains to be done. existing tools cannot model some key technologies ( e. g., active controls ), nor do they have sufficient model validity in all important disciplinary areas. at the broad technical scale, it is extremely important to begin with a full understanding of the design objectives and constraints, such as payload, range, takeoff gross weight ( togw ), noise, sonic boom, and cost, and to identify all the critical disciplines. this will prevent suboptimization and the debilitating effects of discovering, too late, that a first - order design driver ( such as apse in the hsr program ) has not been fully appreciated or adequately addressed. many existing design schemes do not fit well with integration / optimization algorithms, and user - friendly frameworks that accommodate such schemes are not available. off - the - shelf software and interface mindsets are needed. faster mechanisms for geometric modeling are required for improved efficiency at both the conceptual and detailed design levels. for design teams that might be geographically dispersed, mechanisms for sharing the geometric models are lacking. indeed, the management and sharing of information and data are themselves first - order issues, as is reducing the time for each design cycle. very large quantities of data must be transferred ; presently, both modeling and data management are much too labor - intensive. analytical design tools, such as computational fluid dynamics and finite element modeling, have been greatly improved, but they often take so long to run that they are impractical in an iterative design context, and they are not robust enough to be fully integrated into a design framework. other important issues for the development of advanced integrated tools are associated with uncertainties : how they propagate through a design and how to develop calibration and validation processes that quantify them. too often, even after an optimization calculation has been made, new designs can be evaluated only by comparing them against a previous baseline rather than by making an absolute measurement of expected performance and comparing it against a validation metric. major benefits could be realized from the development and effective use of advanced design and integration tools, but there are significant barriers to achieving these benefits. on the nontechnical front, nasa could help by creating a new culture of collaboration, which is required for the most effective utilization of university, government, and industry talent in the realm of integration tools. nasa also has the charter and opportunity to provide much of the technology that is needed to enable viable supersonic aircraft designs.


of collaboration, which is required for the most effective utilization of university, government, and industry talent in the realm of integration tools. nasa also has the charter and opportunity to provide much of the technology that is needed to enable viable supersonic aircraft designs. first, it will be vital to develop advanced, high - fidelity methodologies and tools for intradiscipline analysis in areas such as computational fluid dynamics and finite element modeling for structures. interdisciplinary and multidisciplinary tools are also crucial for integrated design of complex systems and entire vehicles. particular attention should be given to ( 1 ) integrating the design of mechanical systems with the design of electrical systems and software development and ( 2 ) factors such as computational speed and robustness that will increase the utility of new tools in an integrated design context. speed should come naturally with advances in computer hardware capability, but algorithms must be tailored to take advantage of the massively parallel computing environment. second, to realize the potential for design improvements through advanced tools, substantial new efforts must be focused on the automation of integration and validation. today, design processes can require weeks to a couple of months to set up and compute the aerodynamic, weight, stability and control, aeroelastic, and other performance characteristics resulting from a configuration change. optimizing in any context takes a number of such cycles. while multidisciplinary optimization techniques can reduce the optimization time dramatically, the setup time for the basic configuration is still counted in weeks and the validation of designs resulting from multidisciplinary optimization techniques, at least in the usual context of experimental verification, is extremely difficult because of the highly integrated nature of the process ( it typically involves the use of sophisticated analyses to check design calculations ). there is, as a result, a great need for focused research on how to validate highly integrated design capabilities. clever combinations of analytical, computational, and experimental approaches ocr for page 25 commercial supersonic technology : the way ahead may be necessary. where experimental approaches are needed, it is very likely that current ground test capabilities are inadequate. in any case, only after successful application of these newly developed validation methods will confidence be high enough to encourage the widespread use of the new tools. third, design and integration frameworks should be developed to allow teams of analysts and designers at different locations to come together and immerse themselves in a user - friendly design environment. such frameworks must be able to achieve a wide range of design and integration objectives and accommodate discipline - specific analyses at varying levels of breadth and depth. having a common framework


to come together and immerse themselves in a user - friendly design environment. such frameworks must be able to achieve a wide range of design and integration objectives and accommodate discipline - specific analyses at varying levels of breadth and depth. having a common framework to carry out the conceptual, preliminary, and detailed design phases is important, and approaches ranging from approximate to high - fidelity must be accommodated. framework technologies should also facilitate the exchange and management of large databases. design team members must have access to the same data, new data must be readily transferable and modifiable, and the entire process must take place in a secure environment with user - friendly methods for preventing unauthorized alteration of or access to information. this requires emphasis on system - user interfaces and data - management tools. frameworks should also allow the inclusion of manufacturing and operations parameters, which are important to affordability. nasa should work closely with engine and airframe manufacturers and other industries, government agencies, and universities engaged in the development of integrated design tools and methods to define the specific characteristics required of advanced technology collaboration infrastructures and to develop a comprehensive plan for meeting those needs. an expanded discussion of the above issues and a comprehensive set of recommendations for action is contained in design in the new millennium ( nrc, 2000 ). variable cycle engines a variable cycle engine would, in theory, allow the propulsion system to be optimized for different flight conditions ( e. g., takeoff, supersonic cruise, subsonic cruise, and landing ). a variable cycle engine is similar to a conventional mixed - flow turbofan, except that it has an additional secondary outer bypass duct to increase the overall bypass ratio and, thus, the air flow handling capability. the second bypass stream improves tsfc and improves fan surge control by allowing the fan to pass a maximum amount of air throughout a broader flight regime. unlike conventional turbofans, a variable cycle engine varies the bypass ratio to optimize performance for different flight conditions. reducing the bypass ratio during cruise improves fuel efficiency, whereas increasing it during takeoff and landing reduces community noise. ejector nozzles would still be needed to mix ambient air with the jet exhaust to reduce noise enough to meet community noise standards. with a variable cycle engine, however, the nozzle can be smaller, which reduces aircraft weight and improves the economic viability of the design. one of the leading design approaches for a variable cycle engine has a core - driven fan stage directly in front of the high - pressure compressor to supercharge both the core and inner bypass flow streams


weight and improves the economic viability of the design. one of the leading design approaches for a variable cycle engine has a core - driven fan stage directly in front of the high - pressure compressor to supercharge both the core and inner bypass flow streams. the term “ variable cycle engine ” has come to apply narrowly to this type of engine. however, other engine cycles can also adjust their bypass ratio during operations and thus fall within the general class of “ variable cycle engines. ” these include the fan - on blade ( “ flade ” ) cycle and the turbine bypass engine with an inlet flow valve ( tbe / ifv ) cycle, both of which were investigated by nasa ’ s hsr program ( nasa, 2001 ). initial studies at nasa indicated that the additional design complexity of variable cycle engines outweighed the benefits ( berton, 1992 ). research has continued, but most of it has been proprietary. continued development of engines with advanced cycles, such as the variable cycle engine, that are compatible with high cruise efficiency, low community noise, and small, lightweight nozzles could lead to important breakthroughs in the realization of commercial supersonic aircraft. references agrawal, s., and a. g. powell. 1991. “ supersonic boundary - layer stability analysis of an aircraft wing. ” journal of aircraft 28 ( november ) : 721 - 727. berton, j., w. haller, p. senick, s. jones, and j. seidel. 1992. comparative propulsion system analysis for the high speed civil transport. cleveland, ohio : national aeronautics and space administration. boeing commercial airplane group. 1989. high speed civil transport study, summary, nasa contractor report 4234, september. george, f. 2000. “ the supersonic business jet, ” business and commercial aviation ( july ) : 44 - 48. jones, r., and d. cohen. 1960. high speed wing theory. princeton, n. j. : princeton university press. jones, r., 1991. “ the flying wing supersonic transport. ” aeronautical journal, march. nasa ( national aeronautics and space administration ). 2001. available online at < http : / / www. lerc. nasa. gov / www / hsr / psi. html >. nrc ( national research council ), aeronautics and space engineering board. 1994. aeronautical facilities : assessing the national plan for aeronautical ground test facilities. available online at < http : / / www. nap. edu / catalog / 908


>. nrc ( national research council ), aeronautics and space engineering board. 1994. aeronautical facilities : assessing the national plan for aeronautical ground test facilities. available online at < http : / / www. nap. edu / catalog / 9088. html >. accessed on september 13, 2001. nrc, aeronautics and space engineering board. 1997. u. s. supersonic commercial aircraft. available online at < http : / / www. nap. edu / catalog / 5848. html >. accessed on september 13, 2001. nrc. 2000. design in the new millennium — advanced engineering environments ( phase 2 ). available online at < http : / / www. nap. edu / catalog / 9876. html >. accessed on september 13, 2001. raney, david l., e. bruce jackson, carey s. buttrill, and william m. adams. 2001. the impact of structural vibrations on flying qualities of a supersonic transport. aiaa paper 201 - 4006, presented at the aiaa flight mechanics guidance, navigation, and control conference, montreal, august. rech, j., and c. leyman. 1980. “ concorde aerodynamics and associated systems development. ” in aiaa case studies in aircraft design. reston, va. : aiaa. rethorst, s., and m. kantner, 1996. underwing traveling wave / feedback control system, vehicle research corp., pd 135, august. ocr for page 26 commercial supersonic technology : the way ahead rising, j., and j. vadyak. 1999. shock suppression supersonic aircraft. u. s. patent 5934607, august. seebass, a. 1994. the prospects for commercial transport at supersonic speeds, aiaa 94 - 0017, sixth biannual w. f. durand lecture, arlington, va. : may 1994. soloviev, v., v. krivstov, a. konchakov, and n. malmuth. 1999. mechanisms of shock wave dispersion and attenuation in weakly ionized cold discharge plasmas. ivtan perspectives of mhd and plasma technologies in proceeding of aerospace applications conference, moscow, russia, march 24 - 25, 1999. tracy, r., i. kroo, j. chase, and j. viken. 1995. exploiting natural laminar flow for economical supersonic transport. sae paper


in 2008, barack obama campaigned for the white house on the promise that he would pass a sweeping energy and climate - change law and move the country from dependence on fossil fuels to clean, renewable energy that reduced carbon pollution and addressed global warming. in his first term, obama inched in that direction : the president rolled out regulations to reduce pollution from tailpipes and coal plants, and his stimulus program pumped $ 40 billion into clean - energy development. but so far, he has failed to enact comprehensive reform. “ cap - and - trade ” crashed in the senate, energy and climate change became partisan fodder in 2012 campaign attack ads, and even minor energy bills stalled in the gridlocked congress. meanwhile, the u. s. still depends on fossil fuels for the vast majority of its energy needs, while the latest scientific reports show that the planet is speeding toward a temperature hike of 2 degrees celsius or more, which scientists say will melt polar ice sheets, rapidly raise sea levels, induce more destructive storms and droughts, and turn vast swaths of land into places where crops cannot grow. so what can washington do on energy and climate change in the second obama term? the president says that the problem is urgent — and that solving it is an important component of his legacy. “ we want our children to live in an america that isn ’ t … threatened by the destructive power of a warming planet, ” obama said on election night. and at his postelection press conference, he said, “ you ’ ll hear more from me in the coming months and years about how we can shape an [ energy ] agenda that gains bipartisan support and helps move this agenda forward. ” meanwhile, the partisan impasse may be about to end. quietly, lawmakers and lobbyists say they can envision a grand bargain on energy and climate change — cutting fossil - fuel use and investing in clean energy in exchange for new offshore drilling or approval of the controversial keystone xl pipeline. the biggest if, and the heaviest lift, will be getting congress to enact the policy that economists say would do the most to transform the nation ’ s energy economy : taxing or pricing fossil carbon pollution. a price on carbon, say economists across the ideological spectrum, will increase the price of fossil fuels and decisively drive the free market toward clean energy. yet any lawmaker who supports the plan could be accused of supporting an energy tax. still, a combination of events — including more droughts, floods, and extreme weather like superstorm sandy — has increased


( naturalnews ) a japanese study found that drinking green tea can lower the risk of death from a variety of illnesses, including cardiovascular disease. the tohoku university study - - started in 1994 - - looked at 40, 530 healthy adults aged 40 to 79 who lived in northeastern japan, where roughly 80 percent of people drink green tea and more than half drink three or more cups daily. over the course of the 11 - year study, people who drank five or more cups of green tea per day had a 16 percent lowered risk of dying from any cause and, during the seven - year follow - up, had a 26 percent lower risk of dying from cardiovascular disease when compared to people who drank fewer than one cup a day. the study found no association between green tea consumption and death from cancer. the study noted that women seemed to get a greater benefit from the tea than men, as the risk of death from cardiovascular disease was reduced by 31 percent in women who drank more than five cups of green tea a day. " the most important finding is that green tea may prolong people ' s lives through reducing the risk of cardiovascular disease, " said lead researcher dr. shinichi kuriyama. ellen mason, a cardiac nurse at the british heart foundation, said the results may not apply to people who consume western diets because the japanese diet as a whole is recognized for its healthy properties. " the rate of heart disease in japan is already one of the lowest in the world, and the japanese diet is believed to play a substantial role in keeping this low, " she said. " the average british diet contains more saturated fat than the average japanese diet, and our levels of heart disease are relatively high compared with many other countries in the world. " it is questionable whether drinking the same amount of green tea a day in the uk would have a significant impact on levels of heart disease, " mason said, adding that subsequent clinical trials would be needed to prove whether green tea can prevent deaths from heart disease. " i reach the exact opposition conclusion, " said mike adams, a consumer health advocate and creator of the herbreference. com website. " if green tea can significantly reduce the risk of heart disease in japanese people who already have excellent cardiovascular health, the herb may be even more beneficial in westerners who don ' t follow heart - healthy diets, " he said. " americans have more room for improvement. " more than 3 million tons of tea is produced annually worldwide, and it is hailed as the most consumed beverage on earth after water


cartographers and surveyors performed in the heat of battle as the nation prepares to observe the 150th anniversary of the civil war in 2011, noaa has assembled a special historical collection of maps, charts, and documents prepared by the u. s. coast survey during the war years. the collection, “ charting a more perfect union, ” contains over 400 documents, available free to the public. in the nation ' s early years, the u. s. lost more ships to accidents than to war. in 1807, president thomas jefferson established the survey of the coast to produce the nautical charts necessary for maritime safety, defense, and the establishment of national boundaries. by 1860, the united states coast survey was the government ’ s leading scientific agency. teams of men were surveying coastlines, determining land elevations, and producing maps and nautical charts for an expanding nation experiencing growing trade relationships between states and with other countries. u. s. coast survey goes on a war footing under coast survey superintendent alexander bache, the agency was quick to apply its resources to the war effort. in addition to setting up additional lithographic presses to produce the thousands of charts required by the navy and other vessels in government service, bache made a critical decision to send coast survey parties to work with blockading squadrons and armies in the field. bache detailed these activities in his annual reports to congress. bache was also one of four members of the union ’ s blockade board, planning strategy to essentially strangle the south, economically and militarily. on april 16, 1861, president lincoln issued a proclamation declaring the blockade of ports from south carolina to texas. bache ’ s notes on the coast provided valuable information for union naval forces. in the centuries before google earth, maps in wartime had special military significance. as superintendent alexander bache pointed out in his annual report, on nov 7, 1862 : “ it is certain that accurate maps must form the basis of well - conducted military operations, and that the best time to procure them is not when an attack is impending, or when the army waits, but when there is no hindrance to, or pressure upon, the surveyors. that no coast can be effectively attacked, defended, or blockaded without accurate maps and charts, has been fully proved by the events of the last two years, if, indeed, such a proposition required practical proof. ” today ’ s coast survey honors its forebears today, the office of coast survey still meets its maritime responsibilities as a part of noaa, surveying america


events of the last two years, if, indeed, such a proposition required practical proof. ” today ’ s coast survey honors its forebears today, the office of coast survey still meets its maritime responsibilities as a part of noaa, surveying america ’ s coast and producing the nation ’ s nautical charts. to honor its legacy and to inform the public, coast survey maintains a digital historical map & chart collection, with over 21, 000 maps and charts from 1747 to 2001. the collection also maintains historical coast pilots. coast survey ’ s collection includes 394 civil war - era maps, including nautical charts used for naval campaigns, and maps of troop movements and battlefields. rarely seen publications include “ notes on the coast, ” prepared by coast survey to help union forces plan naval blockades against the confederacy, and the annual report summaries by superintendent bache as he detailed the trials and tribulations of producing the maps and charts needed to meet growing military demands. the civil war special collection is accessible through a searchable database at http : / / www. nauticalcharts. noaa. gov / history / civilwar. this project was supported by the noaa preserve america initiative, part of preserve america, a federal initiative to preserve, protect and promote our nation ' s rich heritage.


paris — a day after the european space agency warned its demise was near, an ice bridge connecting a massive ice shelf to an island collapsed on saturday, sending hundreds of icebergs out to sea. the paris - based agency on friday published satellite images showing the bridge barely intact. " the beginning of what appears to be the demise of the ice bridge began this week when new rifts " appeared and a large block of ice broke away, it said in a statement. the bridge helped stabilize the wilkins ice shelf and experts now fear the shelf itself will start to disintegrate over time. the wilkins ice shelf — which like the rest of antarctic ' s ice sheet " was formed by thousands of years of accumulated and compacted snow " — had been stable for most of the last century before it began retreating in the 1990s, the statement said. the shelf, which is now about the size of connecticut, is located on the western side of the antarctic peninsula, which thrusts up from the continent toward the southern tip of south america. video : disintegrating originally covering about 5, 000 square miles, the ice shelf lost 14 percent of its mass last year alone, the statement quotes a scientist angelika humbert of germany ' s munster university as saying. in two 2008 incidents, large chunks of the ice bridge fell away, shaving it down to just 985 yards across at its narrowest, the statement said. scientist are examining whether global warming is behind the shelf ' s breakup, the statement said. average temperatures in the antarctic peninsula have risen by 3. 8 degrees fahrenheit over the past half century, the statement said — higher than the average global rise. ice shelves do not add to sea level rise since they are already in the ocean, but they do hold back ice that is grounded on antarctica and greenland. so as ice shelves there break up, grounded ice flows toward the seas more quickly. copyright 2009 the associated press. all rights reserved. this material may not be published, broadcast, rewritten or redistributed.


home > health library > neuroscience > neurological conditions and diseases > other neurological conditions other neurological conditions acoustic neuroma is a noncancerous tumor that may develop from an overproduction of schwann cells that press on the hearing and balance nerves in the inner ear. bell ' s palsy is an unexplained weakness or paralysis of the facial muscle that begins suddenly and worsens over three to five days. it can strike at any age, but it occurs most often in pregnant women, and in people who have diabetes, influenza, or another upper respiratory ailment. meniere ' s disease is a balance disorder caused by an abnormality found in a section of the inner ear called the labyrinth. multiple cranial neuropathies neuropathy is a disorder that affects the nerves. the cranial nerves are those that arise directly from your brain or brainstem and often affect areas like the face and eyes. neurocutaneous syndrome is a broad term for a group of disorders. these diseases are life - long conditions that can cause tumors to grow inside the brain, spinal cord, organs, skin, and skeletal bones. neuromyelitis optica, sometimes called nmo, is a rare condition that affects the spinal cord and the nerves that carry signals from the eyes to the brain, causing paralysis and blindness. normal pressure hydrocephalus the ventricles are chambers in the brain that normally contain cerebrospinal fluid. sometimes, too much fluid can build up in the ventricles. this accumulation of fluid leads to a condition is called normal pressure hydrocephalus ( nph ). pseudotumor cerebri is a disorder related to high pressure in the brain that causes signs and symptoms of a brain tumor — hence the term “ pseudo ” or false tumor. transverse myelitis is a neurological condition that happens when both sides of the same section of the spinal cord become inflamed. trigeminal neuralgia is a type of nerve pain that affects your face.


by dr. tina wellman, ph. d, pne article published in " total health for longevity " | | dr. wellman is the author of psychoneuroendocrinology : copper toxicity and premenstrual syndrome. she blends nutritional support with environmental detoxification to achieve wellness. her efforts in this field are groundbreaking, and provide hope for healing and wellness. | what is the weakest force in the universe and has the most profound effect on the human body? gravity. as we age, the relentless pull of gravity causes our body to sag in a southerly direction. we develop wrinkles, flabby forearms, portly midriffs, vericosities, edemic feet and ankles, stooped shoulders, turkey necks, and compressed spines, to name a few multifarious insults to our body shape. to compensate for this " g - force " we must continually work against it through body movement. regular exercise is essential to maintain optimal health. apiarian royden brown noted, " it has been scientifically documented that exercising regularly increases longevity and enhanced quality of life. " 1 the proverbial expression " either use it or lose it " applies to the body ' s need for daily exercise as well as to maintain musculoskeletal strength, immunity, and psychobiological balance. the best nutrition in the world cannot sustain us if our circulation is stagnant and we do not receive oxygen - rich blood to our body ' s three trillion cells. 2 gravitational force is key to understanding resistive rebounding ' s health benefits. by combining the forces of acceleration and deceleration, body cells are tricked into believing they are being subjected to increased gravity. 3 nasa clearly demonstrated the virtues of rebounding when they designed an exercise protocol in the zero gravity of space. loss of bone density and muscle mass are the negative results incurred to astronauts soaring through the cosmos at zero gravity. scientific blood analysis that included subjecting weakened blood cells ( of returning astronauts ) to increased g - force evidenced an increase in cellular strength. it is this increase in g - force during rebounding ( specifically during deceleration ) that challenges body cells to strengthen. 4 an exercise for all ages rebounding knows no social boundaries and has no age limitations. exercise guru jack lalanne often demonstrated rebounding on his popular t. v. exercise program. comedian bob hope once noted " i keep my rebounder at the foot of my bed and use it daily. " morning talk show host regis philbin


apes have food, will share for a social payoff people have been sharing food with strangers since ancient days, offering up the household ' s finest fare to mysterious travelers. think abraham and the three men of mamre in the bible and the folks who take in strangers after natural disasters like hurricane sandy. that deep tradition of generous hospitality has long been thought uniquely human. if so, then bonobos, those gregarious african apes, may be more like us than we thought. " the pairs that are unfamiliar with each other are the ones that shared most often, " says jingzhi tan, a graduate student at duke university who tested bonobos ' penchant for sharing food and discovered that they not only share with strangers, they even offer their fruit and nuts to an unfamiliar bonobo faster than they will feed one they know well. bonobos, like humans, are acutely social, and often eat together. with both species, it works. children and other vulnerable relatives get fed, social ties are strengthened and alliances formed. but humans also developed a rich tradition of feeding strangers, one that ' s embedded in religion and literature – the xenia of ancient greece, promoted by zeus, the god of travelers. back then there were practical reasons for selfless hospitality. it allowed people to travel far from home in the days long before holiday inns and drive - throughs. stingy hosts were reviled, but so were guests who failed to be properly grateful. when paris made off with his host ' s wife, helen, in the iliad, that faux pas kicked off the trojan war. but could hospitality be important to apes? tan and his colleagues at duke had done experiments with bonobos two years ago that showed that bonobos would share food with unrelated bonobos, rather than hoard it. now they wanted to find out just how far that spirit of sharing went. so they created a series of experiments with bonobos living in a sanctuary in kinshasa, democratic republic of congo. the series of experiments gave bonobos the ability to decide whether they would share their apples, bananas, papayas, and peanuts by giving them control over doors in a room. ( see how the researchers did it in this video. ) in the first experiment, the scientists created a setup where one bonobo was put in a room with food. that bonobo could choose to open two doors leading to two other rooms – one housing a friend, the other, a stranger. all of the bonobos opened a door to let in another,


one bonobo was put in a room with food. that bonobo could choose to open two doors leading to two other rooms – one housing a friend, the other, a stranger. all of the bonobos opened a door to let in another, rather than dine alone. and nine of the 14 animals chose dining with the stranger over the familiar face – the ape equivalent of a restaurant ' s communal table. what ' s more, when the familiar bonobo was invited to join the feast, it was almost always by the stranger, who would have considered that bonobo a new face. none of the animals fought over the food, and there was quite a bit of the friendly genital rubbing that ' s made bonobos renowned in animal behavior - land. then the scientists tweaked the layout. in another experiment, the bonobos were isolated in separate cages, with food in a compartment in between. offered the option of sharing the food without physical contact, not one of the seven bonobos tested pulled a rope that would have let another reach through to the food. the results were published online in the journal plos one. so it looks like if you ' re a bonobo, sharing food is only worth it if it ' s a social event. bonus points if you ' re meeting someone new. it ' s fascinating behavior, but the researchers say it ' s not clear that this is altruism. " if you ' re being nice to a stranger, it ' s not necessarily unselfish, " tan told the salt. it ' s easy to see the benefits to humans in sharing a meal with a stranger, even in modern times. good conversation, future business partners, a broader social network – maybe even romance. perhaps bonobos see those potential payoffs in a meal shared, too.


file - in this jan. 24, 1972, file photo, a teenager relights the remainder of a marijuana joint. in 1972 a commission appointed by president richard nixon to study marijuana said it should be decriminalized and regulated. nixon rejected that, but a dozen states in the 1970s went on to eliminate jail time as a punishment for pot arrests. on the occasion of ' legalization day, ' thursday, dec. 6, 2012, when washington ' s new law takes effect, ap takes a look back at the cultural and legal status of the ' evil weed ' in american history. ( ap photo / jerry mosey, file ) / ap seattle ( ap ) the grass is no greener. but, finally, it ' s legal at least somewhere in america. it ' s been a long, strange trip for marijuana. washington state and colorado voted to legalize and regulate its recreational use last month. but before that, the plant, renowned since ancient times for its strong fibers, medical use and mind - altering properties, was a staple crop of the colonies, an " assassin of youth, " a counterculture emblem and a widely accepted if often abused medicine. on the occasion of thursday ' s " legalization day, " when washington ' s new law takes effect, here ' s a look back at the cultural and legal status of the " evil weed " in american history. cannabis in the colonies george washington and thomas jefferson both grew hemp and puzzled over the best ways to process it for clothing and rope. indeed, cannabis has been grown in america since soon after the british arrived. in 1619 the crown ordered the colonists at jamestown to grow hemp to satisfy england ' s incessant demand for maritime ropes, wayne state university professor ernest abel wrote in " marihuana : the first twelve thousand years. " hemp became more important to the colonies as new england ' s own shipping industry developed, and homespun hemp helped clothe american soldiers during the revolutionary war. some colonies offered farmers " bounties " for growing it. " we have manufactured within our families the most necessary articles of cloathing, " jefferson said in " notes on the state of virginia. " ' ' those of wool, flax and hemp are very coarse, unsightly, and unpleasant. " jefferson went on to invent a device for processing hemp in 1815. taste the hashish books such as " the arabian nights " and alexandre dumas ' " the count of monte cristo, " with its vol


urged legalization in a letter to president dwight eisenhower. reefer madness, hemp for victory after the repeal of alcohol prohibition in 1933, harry anslinger, who headed the federal bureau of narcotics, turned his attention to pot. he told of sensational crimes reportedly committed by marijuana addicts. " no one knows, when he places a marijuana cigarette to his lips, whether he will become a philosopher, a joyous reveler in a musical heaven, a mad insensate, a calm philosopher, or a murderer, " he wrote in a 1937 magazine article called " marijuana : assassin of youth. " the hysteria was captured in the propaganda films of the time most famously, " reefer madness, " which depicted young adults descending into violence and insanity after smoking marijuana. the movie found little audience upon its release in 1936 but was rediscovered by pot fans in the 1970s. congress banned marijuana with the marihuana tax act of 1937. anslinger continued his campaign into the ' 40s and ' 50s, sometimes trying without luck to get jazz musicians to inform on each other. " zoot suited hep cats, with their jive lingo and passion for swift, hot music, provide a fertile field for growth of the marijuana habit, narcotics agents have found here, " began a 1943 washington post story about increasing pot use in the nation ' s capital. the department of agriculture promoted a different message. after japanese troops cut off access to asian fiber supplies during world war ii, it released " hemp for victory, " a propaganda film urging farmers to grow hemp and extolling its use in parachutes and rope for the war effort. as the conformity of the postwar era took hold, getting high on marijuana and other drugs emerged as a symbol of the counterculture, with jack kerouac and the rest of the beat generation singing pot ' s praises. it also continued to be popular with actors and musicians. when actor robert mitchum was arrested on a marijuana charge in 1948, people magazine recounted, " the press nationwide branded him a dope fiend. preachers railed against him from pulpits. mothers warned their daughters to shun his films. " congress responded to increasing drug use especially heroin with stiffer penalties in the ' 50s. anslinger began to hype what we now call the " gateway drug " theory : that marijuana had to be controlled because it would eventually lead its users to heroin. then came vietnam. the widespread, open use of marijuana by hippies and war protesters from


ever took place because of the federal prohibition. nevertheless, doctors noted its ability to ease nausea and stimulate appetites of cancer and aids patients. and in 1996, california became the first state to allow the medical use of marijuana. since then, 17 other states and the district of columbia have followed. in recent years, medical marijuana dispensaries readily identifiable by the green crosses on their storefronts have proliferated in many states, including washington, colorado and california. that ' s prompted a backlash from some who suggest they are fronts for illicit drug dealing and that most of the people they serve aren ' t really sick. the justice department has shut down some it deems the worst offenders. legal weed at last on nov. 6, washington and colorado pleased aging hippies everywhere and shocked straights of all ages by voting to become the first states to legalize the fun use of marijuana. voters handily approved measures to decriminalize the possession of up to an ounce by adults over 21. colorado ' s measure also permits home - growing of up to six plants. both states are working to set up a regulatory scheme with licensed growers, processors and retail stores. eventually, activists say, grown - ups will be able to walk into a store, buy some marijuana, and walk out with ganja in hand but not before paying the taxman. the states expect to raise hundreds of millions of dollars for schools and other government functions. but it ' s not so simple. the regulatory schemes conflict with the federal government ' s longstanding pot prohibition, according to many legal scholars. the justice department could sue to block those schemes from taking effect but hasn ' t said whether it will do so. the bizarre journey of cannabis in america continues. johnson can be reached at https : / / twitter. com / geneapseattle ap researcher julie reed bell contributed to this report from charlotte, n. c.


how did the universe get its structure? it was very smooth when it was born, with matter distributed incredibly evenly through space. now, thanks to the action of gravity over billions of years, it is very lumpy, with dense clusters of galaxies separated by enormous voids. you can watch the process unfold in a new computer simulation by a group of scientists led by tiziana di matteo of carnegie mellon university in pittsburgh, pennsylvania, us. unlike previous simulations, di matteo ' s team included black holes in their simulation. the black holes are not highlighted in the animation, but they do influence their surroundings. increasingly, scientists are realising that supermassive black holes weighing millions or billions of times the mass of the sun may affect their environment more than previously thought. their enormous gravity can capture and swallow vast quantities of matter from their immediate vicinity, but they can also produce jets and radiation that can influence matter much farther away. another cool animation released recently shows the effects of the solar wind on earth ' s magnetosphere. the solar wind constantly buffets the magnetosphere, stretching and bending magnetic field lines until they suddenly snap in what are called magnetic reconnection events. esa ' s four cluster spacecraft have been investigating this phenomenon and esa recently put out an animation illustrating this magnetic field snapping. i ' m fascinated by how a combination of science and computer graphics can show you things that you could never witness firsthand? like cosmic changes that unfold over billions of years in the case of di matteo ' s simulation, and the normally invisible dance of magnetic field lines in the case of the cluster animation. david shiga, online reporter ( image : tiziana di matteo / cmu ) labels : black holes, cluster, large - scale structure, magnetic reconnection


( bpt ) - health conditions in the human body interact in many different and unique ways. what may be surprising to people is how oral health is connected with diabetes. a recent survey conducted by harris interactive reveals a lack of awareness about the various health issues associated with diabetes – particularly oral health. more than one third of people with diabetes aren ’ t aware of the link between diabetes and oral health. while more than half of people with diabetes report one or more symptoms of gum disease, an astounding 67 percent do not discuss their oral health with their doctor. the majority of americans living with diabetes say they don ’ t have enough information about the link between oral health and dental care, and they say they would benefit from more. dr. natalie strand shares five simple tips to help take charge of your diabetes and prevent gum disease. she managed her own diabetes while also winning a popular endurance reality tv show, is an assistant professor in clinical anesthesiology and a practicing physician at university of southern california keck school of medicine. 1. take charge with small steps take small steps to transform your life and your health. walk one extra block before returning home, eat smaller portions of your favorite foods and brush your teeth after every meal. as you slowly make changes, keep your doctor and family informed. they ’ ll help you to keep a positive attitude and stay on the road to a healthier lifestyle. 2. talk to your doctor and your dentist your doctor plays an integral role in helping you to manage your diabetes health, but your dentist can be important too. make sure your doctor and your dentist know how to contact each other and are sharing information, so they can work together on your treatment plan. 3. oral care isn ’ t just about having white teeth people with diabetes are more susceptible to serious gum disease, so it ’ s important to take good care of your teeth and gums by getting regular dental checkups every six months. if you don ’ t have a dentist or dental insurance, a dental school in your area can be a great resource. most dental schools also have clinics where the cost is often lower than visiting a private - practice dentist. 4. glucose and gum disease could be a two - way street research suggests that the relationship between serious gum disease and diabetes can go two ways, and serious gum disease may have the potential to affect blood glucose control and contribute to the progression of diabetes. taking steps recommended by your doctor to control your diabetes can decrease your likelihood of developing gum disease. 5. choose your toothpaste wisely


monday, march 21, 2011 contact : karen aldana new age - focused guidelines help parents make more informed choices the national highway traffic safety administration has revised its child restraint guidelines to be categorized by age rather than by type of child seat in order to keep pace with the latest scientific and medical research and the development of new child restraint technologies. under the new guidelines, issued today, nhtsa is advising parents and caregivers to keep children in each restraint type, including rear - facing, forward - facing and booster seats, for as long as possible before moving them up to the next type of seat. for instance, the safety agency recommends using the restraints in the rear - facing position as long as children fit within the height and weight limits of the car seat as established by the manufacturer. the rear - facing position reduces stresses to the neck and spinal cord and is particularly important for growing babies. nhtsa said that its new guidelines are consistent with the latest advice from the american academy of pediatrics, which advises parents to keep kids in rear - facing restraints until two years of age or until they reach the highest weight or height allowed by their car safety seat ' s manufacturer. there is no need to hurry to transition a child to the next restraint type. " safety is our highest priority, " said transportation secretary ray lahood. " the ' best ' car seat is the one that fits your child, fits your vehicle and one you will use every time your child is in the car. " nhtsa administrator david strickland pointed out that while all car seats sold in the u. s. must meet federal child restraint safety standards, he said, " selecting the right seat for your child can be a challenge for many parents. nhtsa ' s new revised guidelines will help consumers pick the appropriate seat for their child. " administrator strickland said that parents should also consider other factors when selecting a car seat, including their child ' s weight, height, physical development and behavioral needs, as well the family ' s economics and type of vehicle. additional recommendations for child seat use from nhtsa include the following : - always read child seat manufacturers ' instructions and the vehicle owner ' s manual for important information on height and weight limits and how to install the car seat using the seat belt or the latch system. - all children under 13 should ride in the back seat. - children in rear - facing car seats should never ride in front of an active passenger air bag.


similar to the petroleum industry, the wind power industry uses data from many different types of surveys and studies. however, the wind industry currently lacks both methods and tools to process and make concerted use of the available data for planning purposes. developing planning tools that use integrated models of the physical environment will be an important step towards cutting installation costs and increasing the profitability of wind farm projects. “ a common platform for descriptions, planning and impact assessment, integrating information from all disciplines involved, provides a comprehensive picture of the interaction between the various environmental parameters and the planned installations. use of common models has already proven itself to be a very effective way of organising, analysing and communicating data between the various specialist groups involved in the development of petroleum fields, ” says jan tveranger, research leader of the geoscience section at uni cipr. testing at havsul the work on developing a common platform and analytical tools for site characterization and optimization of offshore wind farms is part of an innovation project supported by the research council of norway ’ s clean energy for the future ( renergi ) programme. here uni cipr is part of a broad partnership ( see the “ facts ” box ), the purpose of which is to streamline the planning, design and installation of seabed foundations for wind turbines. the project has a budget of nok 14 million, and the results will be published in summer 2013 and ready for use in the large, growing market for offshore wind farm projects from 2014 onwards. the the planned wind farm havsul off the møre coast in northwestern norway, owned by vestavind offshore as, will act as a test side for demonstrating the new technology. costs must be cut much of the norwegian coast is characterized by a challenging climate as well as highly variable water depths and seabed conditions. this type of environment imposes major constraints on marine operations, positioning of turbine towers and the choice of foundation designs for the towers. this in turns may send the material costs and construction time through the roof. installation costs must be reduced for offshore wind farms to become an attractive industry. norwegian companies and research institutions are working on developing new technology and new methods to overcome these challenges. integrated site characterization the single most important prerequisite for cost - effective development of wind farms is detailed knowledge and good understanding of the local environmental conditions : meteorological, oceanographic, biological and geological. the description of the environmental conditions forms the basis for the design of the turbines and towers and constrains where they can be positioned to achieve optimal power generation


knowledge and good understanding of the local environmental conditions : meteorological, oceanographic, biological and geological. the description of the environmental conditions forms the basis for the design of the turbines and towers and constrains where they can be positioned to achieve optimal power generation. although environmental surveying is already a key part of planning work in connection with offshore wind farms, there is currently no common software or methodology that allows integrated treatment of the whole suite of environmental data. in addition, since most of the existing offshore wind farms have been built in areas with simple, relatively uniform seabed conditions, methods have not yet been developed for installation of wind power plants in areas with complex seabed geology, discontinuous cover of surficial deposits, and large variations in water depth. this can pose significant problems during installation, if the tower foundations have not been designed for and adapted to the local seabed conditions. the centre for integrated petroleum research at uni research ( uni cipr ) and its partners norwind installer as ( project owner ), owec tower as, vestavind offshore as, menck gmbh, bauer spezialtiefbau gmbh and the university of strathclyde, glasgow have been awarded support from the research council of norway for an innovation project in the field of renewable energy. norwind installer as, which installed the first jacket foundations in the german sector in 2009, will primarily focus on the installation of the new designs using their planned purpose - built installation vessels. owec tower as, the market leader in jacket - based foundation design for offshore wind turbines, is collaborating with the other partners to develop new design solutions for pre - installed seabed foundations. the solutions will cover a broad spectrum of designs from drilled and screwed piles to suction buckets and gravity bases, using the current system of piles in sand as a reference. the foreign partners, which have a great deal of experience from offshore wind research and industrial projects in germany and the uk, are contributing expertise in the fields of design and installation activities.


general knowledge - quiz general facts on world affairs. athletics 01 - warming up lesson plan that introduces children to the concept of warming up. children are provided with opportunities to practice running over distance, sprinting and jumping. their knowledge and understanding of athletics is promoted as they find out about sprinting. how do i get to work by public transport? op het einde van deze les kun je opzoeken hoe een persoon het best naar zijn werk gaat met het openbaar vervoer. the senses : hearing - by studyjams the ear is specially designed to change sound waves into signals that the brain can understand, allowing you to hear. that is not all they do, though. your ears also help you balance. learn more about your sense of hearing with this cartoon animation from studyjams. a short, self - checking quiz is also included with this link. dear 16 - year - old me this professionally - made video was made possible thanks to the generosity of real canadians and americans whose lives have been touched by melanoma. these are not actors. the video encourages early detection of skin cancer and provides suggestions for prevention. the " p. i. t. a " expression is used at counter 2 : 19, but it does not overshadow the powerful message directed towards teens about the serious matter of melanoma. ( 05 : 04 ) " the needs of a plant " - song about what plants need to thrive this computer - animated video contains a lively song which teaches young children the needs of a plant : water, soil, space, sun, and air. ( 1 : 04 ) " they were the pilgrims " - a song about the journey of the pilgrims this computer - animated video features a song which traces the journey of the pilgrims to america. the selection includes maps and describes challenges faced by the pilgrims. ( 2 : 24 ) counting by fives song this cute animated video will help students learn to count by 5 ' s. the lyrics repeat themselves several times. the numbers appear on the screen as they are said. ( 3 : 04 ) animal life cycles by studyjams every animal ' s life goes through the same cycle : reproduction, growth, maturity, and finally, death. learn more about the animal life cycle with this slide show from studyjams. vibrant images are set to music with information written under each photo. a short, self - checking quiz is also included with this link. these are mayans and they were part of south


the animal life cycle with this slide show from studyjams. vibrant images are set to music with information written under each photo. a short, self - checking quiz is also included with this link. these are mayans and they were part of south america and they were one of the many important civilizations in the continent and the topic of this 48 minute video. it is slow loading so it should be downloaded before viewing online. there are images shown that may be offensive to some so a preview is a must. provides students with a better perspective of how progressive these people were and adds to the mystery of what happened to them. how to identify a white pine this 1 : 35 video explains what a white pine looks like and ways to identify it. its vitamin content is explained and how to use it needles to make a tea is also shown. the spread of the apple tree from the romans this 12 minute video traces how the apple tree came to the new world and its uses. there is some mention of sex, but the video ' s subject matter is overwhelming fit for most classrooms. sometimes the speaker wanders from the topic. 25 years later : nuclear expert robert alvarez speaks on chernobyl and fukushima on april 26, 1986, a reactor at the chernobyl nuclear power plant in ukraine exploded. the resulting meltdown became the world ' s worst nuclear disaster. 25 years later, as japan struggles to contain its own nuclear disaster, institute for policy studies nuclear expert robert alvarez discusses health effects from the chernobyl disaster, what we can expect for japan and what we have learned about nuclear power. a state - of - the - art relative navigation system will be demonstrated on the sts - 134 mission to the international space station called the sensor test for orion relative navigation risk mitigation or storrm. the goal of storrm is to validate a new relative navigation sensor based on advanced laser and detector technology that will make docking and undocking to the international space station and other spacecraft easier and safer. the demonstration is a test - run of the technology, and the sts - 134 cr sts - 134 daily mission recap - flight day 2 a video recap of flight day 2 of the sts - 134 mission of space shuttle endeavour to the international space station. first spaceflight recreated read more : http : / / www. newscientist. com / blogs / nstv / 2011 / 04 / experience - the - first - spaceflight. html robot with corkscrew legs read more : http : / / www. newscie


: http : / / www. newscientist. com / blogs / nstv / 2011 / 04 / experience - the - first - spaceflight. html robot with corkscrew legs read more : http : / / www. newscientist. com / blogs / nstv / 2011 / 05 / corkscrew - legs - make - robot - more - versatile. html now at moma : looking at music 3. 0 | lee quinones looking at music 3. 0 : lee quinones on graffiti february 16 - may 30, 2011 images courtesy of lee quinones filmed by the people ' s dp, inc. authors @ google : mary roach mary roach spoke to googlers in mountain view on april 22, 2011 about her book packing for mars : the curious science of life in the void. about the book : space is a world devoid of the things we need to live and thrive : air, gravity, hot showers, fresh produce, privacy, beer. how much can a person give up? how much weirdness can they take? what happens to you when you can ' t walk for a year? what happens if you vomit in your helmet during a space walk? is it possible for the human body to survi authors @ google : gary taubes gary taubes spoke to googlers in mountain view on may 2, 2011 about his book why we get fat : and what to do about it. about the book : an eye - opening, myth - shattering examination of what makes us fat, from acclaimed science writer gary taubes. building upon this critical work in good calories, bad calories, taubes revisits the urgent question of what ' s making us fat and how we can change in this exciting new book. persuasive, straightforward, and practical, why we get fat makes taubess crucial


showcase of amazing paper made artworks and sculptures paper is a medium that most of us only use for jotting down our ideas and writing down notes, and think that there is no other use of paper except writing. however, some imaginative artists out there have created spectacular pieces of artwork out of paper. they refer to it as paper craft or paper artwork. we have already published a post about awesome works of art made from paper and that was greatly appreciated by our readers. now we have gathered another great collection of amazing paper made artworks and sculptures. this post is meant to pay accolade to those artists who have created such phenomenal pieces of artwork. all the examples presented in this post have been created only by using papers from delicate cut outs to the most comprehensive and realistic models. enjoy! wanrayen - paper modeling this paper artwork looks so realistic that your brain struggles to grasp whether you are looking at a piece of paper created art or an actual photograph. a most beautiful example of paper art, demonstrating the appropriate use of colors to give the work a real unique and appealing look. this is truly amazing to see how paper can be used to fabricate such a huge sculpture. a beautiful and colorful vase made out of papers. see how wonderfully the artist has added the necessary detail. quilling in a fishbowl a hard type of paper is used in this artwork to express the hard nature of the fishbowl. paper lantern art a beautiful example of a paper lantern creation that looks so imaginative and attractive. the artist has taken special care with the folds and light indentions in the paper to craft this beautiful paper sculpture of a lion. this piece was made with great concentration and skill as the artist carefully carved the words from the paper to preserve the integrity and flow of the letters. see how creatively paper is used to portray the perfect shape of a sunflower. paper quilling doily this piece is an amazing example of the intricate and delicate nature of working with paper as your medium, demonstrating another wonderful way in which artists use it. this one is an epic masterpiece among the collection. using over 20 books to carve and arrange an artistic and transformative spectacle. here the artist molded and folded their way to a scene that is a little bit rock ‘ n ’ roll, and a whole lot of artistry. the roots of heaven the artist of this spectacular cut out was devoted enough to pay close attention to even the minute details in this piece. o ero he ’ ll fight ( detail ) this next piece is an abstract creation


whole lot of artistry. the roots of heaven the artist of this spectacular cut out was devoted enough to pay close attention to even the minute details in this piece. o ero he ’ ll fight ( detail ) this next piece is an abstract creation with layers upon intricate layers of creepy cut outs that give the work an underlying wave of discomfort even with its somewhat whimsical appearance. out of narnia how beautifully a carved sculpture is created and springs to life purely from the pages of the book from which they have come. in this piece, the artist has tried to portray the ninth day of dasara and has wonderfully and playfully succeeded. in this piece we see a a beautiful girl wearing a retro looking skirt and top with long curly hair all crafted purely with paper. you will surely be amazed with this piece featuring a truly innovative artist ’ s creativity and limitless thinking. here an entire dress has been crafted from paper alone. mr. ivo opstelten this is yet another masterpiece of paper work. see how wonderfully the facial lines are created to give it a more realistic look. so much character is given to the piece. here is a sad owl sitting on a branch of a tree for you to see how imaginatively you can use paper in paper artwork. toilet roll face here the artist has ingeniously made use of toilet rolls to create a realistic face by careful folding and scrunching the paper. holding on to myself in this artwork, see how the artist has imaginatively used paper to create this illusion, as if the person is holding on to himself. mckimens has successfully brought cartoon drawings to life via hand - drawn and colored sculptures out of paper, for example ; clapped - out old truck. this piece is one of the most vividly colored in the showcase. such a cheerful and celebratory tone exudes from this paper made creation. another creative and brilliant example of paper sculpture that looks as if it is made up of feathers. girl with dog a detail oriented and meticulous paper sculpture of a dog which fashionably fits with his owner. life size onitsuka tiger it is inspiring to see how paper sculpture can be used to fashion a life sized portrayal one of the toughest creatures in the world. under the cedar another beautiful example of colorful paper art work where the artist has playfully crafted a businessman sitting on the bench. this is simply astonishing to see how the feeling of love and affection can also be depicted through the pieces of papers. these beautiful and refreshing flowers made out of simple colored


colorful paper art work where the artist has playfully crafted a businessman sitting on the bench. this is simply astonishing to see how the feeling of love and affection can also be depicted through the pieces of papers. these beautiful and refreshing flowers made out of simple colored papers are enough to please your eyes with their beauty, and stimulate your mind with their complex construct. 3 spine concertina – single sheet zero waste this artwork shows that a complete 3 spine concertina can be created without wasting a single piece of paper. in this simple and poignant piece, the artist has crafted a nativity scene from paper sculptures. beautiful paper lanterns of different colors and shapes are created purely with papers. mr. chop : sounds from the cave 12 ″ ep this is such a creative display of paper artwork skills featuring a complete music system made of papers. paper is folded and twisted with special care to breathe life into this sculpture of the mythical hippocampus. this paper art work delightfully represents a group of pigeons that have just started their flight from the ground. paper wall art a stunning and impressive wall piece created out of papers only. buscando a la serpiente don ’ t get tempted with its soft and wavy look because this sculpture is made up of nothing but the papers. paper book necklace as a little something different, here we have a highly unique approach to jewelry using paper art in the process. quilling paper picture flowers although this would not be difficult at all to discern as paper, it is still such a compelling and alluring piece of quilled paper art. about the author nousheen aquil is a web graphic designer. she loves photography, drawing and painting. she also is a contributing member of webdesigncore, a platform that focuses on free web resources and inspiration for designers and developers.


easter celebrations through the centuries michel martin, host : i ' m michel martin, and this is tell me more from npr news. in a few minutes, your chance to talk back about what you ' ve heard on the air or read on our blog. it ' s our friday backtalk segment. and that ' s coming up. but first, to another of our friday features, faith matters. that ' s where we talk about matters of faith and spirituality. today is good friday, one of the most important christian holy days. it commemorates the crucifixion of jesus. in jerusalem today, christians marched through the old city retracing jesus ' last steps. ( soundbite of singing ) martin : this sunday of course marks easter, which is the celebration of the resurrection of jesus, who is now called the christ. we wanted to learn more about the rituals of easter and how those have changed over the centuries, so we ' ve called upon mary elizabeth sperry. she ' s worked for the u. s. conference of catholic bishops since 1994. she holds a master ' s in liturgical studies from the catholic university of america, as well as a master ' s in political science. i don ' t know how those work together. but we ' re happy about that. welcome. thanks so much for joining us. ms. mary elizabeth sperry ( associate director of bible utilization, u. s. conference of catholic bishops ) : nice to be here. thank you. martin : now, you were telling us earlier that easter actually used to be celebrated at night. ms. sperry : yes. in the early centuries, up until about the fourth century, easter was a night celebration. you would start after sunset on saturday and finish before the dawn on sunday. and there ' s really a reason for it. there was no weekend in the second and third and early fourth centuries. until christianity became the religion of the empire, you had to do it after your workday was done. and we know that it was a nighttime celebration always because one of the early authors in the church tertullian, who lived in africa, used to write that this was a reason that non - christians and christians shouldn ' t marry, because what non - christian husband would let his wife be out all night celebrating easter? martin : what about sunday? was easter always on sunday? ms. sperry : that was actually a very important debate in the early years of the church, because some people always celebrated it in relationship to the


wife be out all night celebrating easter? martin : what about sunday? was easter always on sunday? ms. sperry : that was actually a very important debate in the early years of the church, because some people always celebrated it in relationship to the jewish passover on the 14th of nisan, which is the date in the jewish calendar of passover. others had note, it always had to be celebrated on a sunday and they would debate this back and forth for almost 200 years. and, finally, pope victor from carthage, north africa - another african again - said, no, we ' re always going to celebrate it on sunday. and it wasn ' t definitively established until 325. and even as late as 1960, there have been debates about, should we fix a date for easter? should we allow it to go back and forth? even today not all christians celebrate at the same time every year. this year we do. martin : yeah, this year and last year, in fact. what would you call it? ms. sperry : the orthodox christians and other christians celebrate on the same day. martin : same day. but that is unusual. ms. sperry : it is somewhat unusual and so there have been debates back and forth. we just fix it and all pick a date. but that ' s just gone nowhere, you know. easter is now defined as the sunday after the first full moon after the spring equinox. so the first full moon was monday, april 18th. so easter is the 24th. the latest it can possibly be is the 25th. so we ' re pushing the limit this year. martin : ok. talk to me, if you would, about the spiritual and theological importance of the holy week and easter. i mean, i think for people who are non - christian, i think they might think that christmas is kind of the big deal for christians. but that ' s not the case. talk a little bit about that, if you would. ms. sperry : nothing in christianity is as important as the passion, death and resurrection of jesus. for christians, it ' s the death and resurrection of jesus, which opens the possibility to us for eternal life. it is the night that gives mourners joy, restores lost innocence that breaks the gates of death and allows life to happen. so, for christians, nothing is as important as easter. we go from this sadness of good friday to the hope of eternal joy. and so it ' s the most important feast of


innocence that breaks the gates of death and allows life to happen. so, for christians, nothing is as important as easter. we go from this sadness of good friday to the hope of eternal joy. and so it ' s the most important feast of our year. and it was the first feast that christians celebrated. martin : if you ' re just joining us, this is tell me more from npr news. we ' re having an easter primer with mary elizabeth sperry. she ' s with the u. s. conference of catholic bishops. she also has a master ' s in liturgical studies. and she ' s talking about the rituals of easter and how it was first celebrated and how their celebrations have changed over the years. all celebrations become metaphors for other themes and people find new meaning in them. i ' m thinking people who have been suffering around the world, say, for example, who have suffered for political - have sort of found great meaning in easter and the idea of hope and an ongoing hope. ms. sperry : the idea of redemptive suffering is a very important part of easter. it ' s the sense that you join jesus in his suffering and death on the cross and you hope to share in his victory. theologically that ' s the meaning of baptism, which is why baptism has always been very closely tied to this weekend. in his letters to the romans, chapter six, saying - paul talks about we die with christ in baptism so that we will live with him forever through resurrection. and so, there ' s a sense that if we enter into suffering of christ, if we combine our suffering to his, we can share the same ultimate victory that he will. and so, there ' s a sense that people who are suffering throughout the world, that by taking on a part of their suffering, by helping them, somehow we combine our suffering with jesus, so as we can share in his victory. martin : now, obviously christianity is a worldwide religion and it ' s observed, you know, all over the world. in this country, you know, african - americans have been very closely identified with a strong association with the story of jesus because of their own experience and passing through slavery to freedom. and the so - called negro spirituals often capture that sense of, you know, hope in the midst of suffering. and i just wanted to play a short, a little bit of one of the spirituals that i grew up with. it ' s called " were you there? " and i want