this is written like a traditional blood pressure measurement. an example is a pulmonary artery pressure 90 / 40. the mean pap is a function of the upper ( systolic ) and lower ( diastolic ) number. see also pulmonary artery pressure magnetic resonance imaging ( mri ) : an imaging technique that uses a strong magnetic field and low - energy radio waves to make pictures of the inside of the body. mri images usually have great detail, and can allow doctors to make some diagnoses much easier. in ph, mri is currently being used to capture better pictures of the heart, heart valves and the functioning of the heart than seen on an echocardiogram. sometimes used with radiopaque dye. read more about common tests in ph back to top of page - n - national heart, lung, and blood institute ( nhlbi ) : a government institute that is part of the national institutes of health. the nhlbi coordinates basic research, clinical investigations and trials, observational studies, and education projects related to the causes, prevention, diagnosis, and treatment of heart, blood vessel, lung and blood diseases as well as sleep disorders. pha interacts with the nhlbi through the agency ’ s public interest organizations group. learn more about the nhlbi national institutes of health ( nih ) : the national institutes of health, a part of the u. s. department of health and human services whose mission is “ to seek fundamental knowledge about the nature and behavior of living systems and the application of that knowledge to enhance health, lengthen life, and reduce the burdens of illness and disability. ” learn more about the nih nebulizer : a machine that can aerosolize medications so that they can be inhaled. nitric oxide ( no ) : a potent vasodilator in gas form. ( not the same thing as nitrous oxide, which is “ laughing gas ” used during dental procedures. ) it is delivered through a face mask or nasal cannula like oxygen. it has been approved by the fda for use in newborn babies with persistent pulmonary hypertension. it is being used experimentally for adults with pah. back to top of page - o - oximeter / pulse oximeter : a device to measure the concentration of oxygen in your blood by measuring the color in your skin ( usually finger or earlobe ). normal saturation is around 97 - 100 percent. in patients with lung disease, it is generally desirable to be above 90 percent “ saturated. ” some patients with congenital heart disease have


phineas parkhurst quimby whence is it - of matter or wisdom? errors & misery resulting from the misapplication of the wordnovember 1861 what is strength? this question sounds as though it might be easily answered, but on consideration, it is not so easy. words are so misused that it it impossible to get at the original meaning of the person who applied the word - or at the feeling ( or state of mind ) when the word was first introduced. if you choose to apply the word " strength " to machinery - then i have no fault to find with the definition. but if it means will, then it is wrongly applied - for will is independent of the thing you call strong. if you say, " that is a strong lever " - then it does not include the force that is applied to it. if the person who first used the word applied it to his wisdom as a powerful intellect - then it will only apply where there is some intellect - the quality of which is not taken into account. this confusion of meaning makes a great deal of trouble, for we put intelligence into everything that has resistance - instead of in the intelligence having the strength. as far as man is concerned the word " strength " has no meaning at all - unless you call it " will. " a man ' s legs are a combined lever - and if you mean that they have strength - you might as well say that a lever has strength ; for one is as much alive as the other - and neither, of itself, can do anything. the word " strength " does not convey the author ' s feelings when he made the expression. he either meant to apply it to wisdom - or to matter. if the author meant to give a name to the phenomenon called " will " - then it makes a vast difference in reasoning about strength. for instance, a person is " weak, " as it is called, in the back or limbs. now the medical faculty goes to work to rub on all kinds of strengthening medicines - just as though there were intelligence in the medicine, and it imparted strength to the weak part. the absurd idea is carried out all through our lives - and it deprives man of the true wisdom that might make him happy and intelligent. my theory gives the lie to all the above, for i have seen that the word " strength " is a mere word with no more meaning than to lead man astray - and the whole medical science is based on this word " strength. " this or


atmospheric sciences & global change division dust achieves lofty aspirations disposition to form ice crystals is measured and modeled for a new - fangled framework this conceptual model illustrates the path pnnl researchers used to steer multiple data points into one flexible calculation, efficiently simulating how ice forms on dust particles and produces clouds. this universal calculation will help them describe how ice crystals are formed on other particles, such as atmospheric soot, organic, and biological particles. enlarge image results : instead of dust - bunnies under the sofa, this dust helps form ice crystals that are at the heart of clouds. researchers at pacific northwest national laboratory used dust ’ s loftier disposition to create a new way to calculate how all particles, not just dust, attract and form ice crystals in clouds. steering multiple data points into one flexible calculation, they efficiently simulated how ice forms on dust particles, a calculation that will help them nail down how ice latches on to atmospheric soot, organic, and biological particles as well. their research was published in the august issue of atmospheric chemistry and physics. why it matters : the u. s. and other parts of the world are suffering record drought this year. looking at the genesis of rain and snow, and how the earth warms and cools are crucial to daily life. tiny ice crystals in the clouds can be instigators of rain and snow. ice crystals can reflect and scatter sunlight away from the earth, cooling the surface. thus, ice crystals are tiny provocateurs for both precipitation and earth ’ s warming and cooling. scientists in this study are tracking down the very basics of how ice forms in the atmosphere, beginning with its attraction to dust – one of several ways that ice crystals form. their finding of a universal calculation for how this happens will enable them to model and predict other ways that ice crystals are formed. methods : previously, scientists had to rely on individual data points to represent the process of ice forming on dust particles. in this study, pnnl researchers developed a new way to translate multiple observation data points into one efficient parameterization framework used in cloud and climate models. parameterizations are calculations that allow scientists to represent field or laboratory observations in computer simulations. this framework not only works on dust particles shown in this study, it can be used with many different data sets. the framework takes into account a standard way to measure how efficiently ice forms on a substance and calculated the probability that a seed particle — in this case dust — will form an ice crystal. the higher the contact angle,


the basic requirements for a synthetic motor are repetitive 360° motion, the consumption of energy and unidirectional rotation. two efforts in this direction were published in 1999 in the same issue of nature. for the two reports below, it is unknown whether these molecules are capable of generating torque. it is expected that reports of more efforts in this field will increase, as understanding of chemistry and physics at the nanolevel improves. this rotation takes place in five steps. first, the amine group present on the triptycene moiety is converted to an isocyanate group by condensation with a phosgene molecule ( a ). thermal or spontaneous rotation around the central bond then brings the isocyanate group in proximity of the hydroxyl group located on the helicene moiety ( b ), thereby allowing these two groups to react with each other ( c ). this reaction irreversibly traps the system as a strained cyclic urethane that is higher in energy and thus energetically closer to the rotational energy barrier than the original state. further rotation of the triptycene moiety therefore requires only a relatively small amount of thermal activation in order to overcome this barrier, thereby releasing the strain ( d ). finally, cleavage of the urethane group restores the amine and alcohol functionalities of the molecule ( e ). the result of this sequence of events is a unidirectional 120° rotation of the triptycene moiety with respect to the helicene moiety. additional forward or backward rotation of the triptycene rotor is inhibited by the helicene moiety, which serves a function similar to that of the pawl of a ratchet. the unidirectionality of the system is a result from both the asymmetric skew of the helicene moiety as well as the strain of the cyclic urethane which is formed in c. this strain can be only be lowered by the clockwise rotation of the triptycene rotor in d, as both counterclockwise rotation as well as the inverse process of d are energetically unfavorable. in this respect, the preference for the rotation direction is determined by both the positions of the functional groups and the shape of the helicene, and is thus built into the design of the molecule instead of dictated by external factors. the motor by kelly and co - workers is an elegant example of how chemical energy can be used to induce controlled, unidirectional rotational motion


software developers are racing to patch a recently discovered vulnerability that allows attackers to recover the plaintext of authentication cookies and other encrypted data as they travel over the internet and other unsecured networks. the discovery is significant because in many cases it makes it possible for attackers to completely subvert the protection provided by the secure sockets layer and transport layer protocols. together, ssl, tls, and a close tls relative known as datagram transport layer security are the sole cryptographic means for websites to prove their authenticity and to encrypt data as it travels between end users and web servers. the so - called " lucky thirteen " attacks devised by computer scientists to exploit the weaknesses work against virtually all open - source tls implementations, and possibly implementations supported by apple and cisco systems as well. ( microsoft told the researchers it has determined its software isn ' t susceptible. ) the attacks are extremely complex, so for the time being, average end users are probably more susceptible to attacks that use phishing e - mails or rely on fraudulently issued digital certificates to defeat the web encryption protection. nonetheless, the success of the cryptographers ' exploits — including the full plaintext recovery of data protected by the widely used openssl implementation — has clearly gotten the attention of the developers who maintain those programs. already, the opera browser and polarssl have been patched to plug the hole, and developers for openssl, nss, and cyassl are expected to issue updates soon. " the attacks can only be carried out by a determined attacker who is located close to the machine being attacked and who can generate sufficient sessions for the attacks, " nadhem j. alfardan and kenneth g. paterson researchers wrote in a web post that accompanied their research. " in this sense, the attacks do not pose a significant danger to ordinary users of tls in their current form. however, it is a truism that attacks only get better with time, and we cannot anticipate what improvements to our attacks, or entirely new attacks, may yet be discovered. " a pdf of their paper is here. how it works lucky thirteen uses a technique known as a padding oracle that works against the main cryptographic engine in tls that performs encryption and ensures the integrity of data. it processes data into 16 - byte chunks using a routine known as mee, which runs data through a mac ( message authentication code ) algorithm, then encodes and encrypts it. the routine adds " padding " data to the cipher


a treatise on electricity and magnetism / part i / chapter i | ←part i : electrostatics | | a treatise on electricity and magnetism by part i, chapter i : description of phenomena | chapter ii : elementary mathematical theory of electricity→ | | scanned pages for this section can be found starting here. | description of phenomena. electrification by friction. 27. ] experiment i. let a piece of glass and a piece of resin, neither of which exhibits any electrical properties, be rubbed together and left with the rubbed surfaces in contact. they will still exhibit no electrical properties. let them be separated. they will now attract each other. if a second piece of glass be rubbed with a second piece of resin, and if the pieces be then separated and suspended in the neighbourhood of the former pieces of glass and resin, it may be observed — - that the two pieces of glass repel each other. - that each piece of glass attracts each piece of resin. - that the two pieces of resin repel each other. these phenomena of attraction and repulsion are called electrical phenomena, and the bodies which exhibit them are said to be electrified, or to be charged with electricity bodies may be electrified in many other ways, as well as by friction. the electrical properties of the two pieces of glass are similar to each other but opposite to those of the two pieces of resin, the glass attracts what the resin repels and repels what the resin attracts. if a body electrified in any manner whatever behaves as the glass does, that is, if it repels the glass and attracts the resin, the body is said to be vitreously electrified, and if it attracts the glass and repels the resin it is said to be resinously electrified. all electrified bodies are found to be either vitreously or resinously electrified. it is the established practice of men of science to call the vitreous electrification positive, and the resinous electrification negative. the exactly opposite properties of the two kinds of electrification justify us in indicating them by opposite signs, but the application of the positive sign to one rather than to the other kind must be considered as a matter of arbitrary convention, just as it is a matter of convention in mathematical diagrams to reckon positive distances towards the right hand. no force, either of attraction or of repulsion, can be observed between an electrified body and a body not electrified. when, in any case, bodies not previously electrified are observed to be acted on by an electrified body, it is because they have become electrified by induction


of attraction or of repulsion, can be observed between an electrified body and a body not electrified. when, in any case, bodies not previously electrified are observed to be acted on by an electrified body, it is because they have become electrified by induction. electrification by induction 28. ] experiment ii. let a hollow vessel of metal be hung up by white silk threads, and let a similar thread be attached to the lid of the vessel so that the vessel may be opened or closed without touching it. let the pieces of glass and resin be similarly suspended and electrified as before. let the vessel be originally unelectrified, then if an electrified piece of glass is hung up within it by its thread without touching the vessel, and the lid closed, the outside of the vessel will be found to be vitreously electrified, and it may be shewn that the electrification outside of the vessel is exactly the same in whatever part of the interior space the glass is suspended. if the glass is now taken out of the vessel without touching it, the electrification of the glass will be the same as before it was put in, and that of the vessel will have disappeared. this electrification of the vessel, which depends on the glass being within it, and which vanishes when the glass is removed, is called electrification by induction. similar effects would be produced if the glass were suspended near the vessel on the outside, but in that case we should find an electrification vitreous in one part of the outside of the vessel and resinous in another, when the glass is inside the vessel the whole of the outside is vitreously and the whole of the inside resinously electrified. electrification by conduction. 29 ] experiment iii. let the metal vessel he electrified by induction, as in the last experiment, let a second metallic body be suspended by white silk threads near it, and let a metal wire, similarly suspended, he brought so as to touch simultaneously the electrified vessel and the second body. the second body will now be found to be vitreously electrified, and the vitreous electrification of the vessel will have diminished. the electrical condition has been transferred from the vessel to the second body by means of the wire. the wire is called a conductor of electricity, and the second body is said to be electrified by conduction. conductors and insulators. experiment iv. if a glass rod, a stick of resin or gutta - percha, or a white silk thread, had been used instead of the metal wire, no transfer of electricity would have taken


conduction. conductors and insulators. experiment iv. if a glass rod, a stick of resin or gutta - percha, or a white silk thread, had been used instead of the metal wire, no transfer of electricity would have taken place. hence these latter substances are called non - conductors of electricity. non - conductors are used in electrical experiments to support electrified bodies without carrying off their electricity. they are then called insulators. the metals are good conductors ; air, glass, resins, gutta - percha, vulcanite, paraffin, & c. are good insulators ; but, as we shall see afterwards, all substances resist the passage of electricity, and all substances allow it to pass, though in exceedingly different degrees. this subject will be considered when we come to treat of the motion of electricity. for the present we shall consider only two classes of bodies, good conductors, and good insulators. in experiment ii an electrified body produced electrification in the metal vessel while separated from it by air, a non - conducting medium. such a medium, considered as transmitting these electrical effects without conduction, has been called by faraday a dielectric medium, and the action which takes place through it is called induction. in experiment iii the electrified vessel produced electrification in the second metallic body through the medium of the wire. let us suppose the wire removed, and the electrified piece of glass taken out of the vessel without touching it, and removed to a sufficient distance. the second body will still exhibit vitreous electrification, but the vessel, when the glass is removed, will have resinous electrification. if we now bring the wire into contact with both bodies, conduction will take place along the wire, and all electrification will disappear from both bodies, showing that the electrification of the two bodies was equal and opposite, 30. ] experiment v. in experiment ii it was shown that if a piece of glass, electrified by rubbing it with resin, is hung up in an insulated metal vessel, the electrification observed outside does not depend on the position of the glass. if we now introduce the piece of resin with which the glass was rubbled into the same vessel, without touching it or the vessel, it will be found that there is no electrification outside the vessel. from this we conclude that the electrification of the resin is exactly equal and opposite to that of the glass. by putting in any number of bodies, electrified in any way, it may be shown that the electrification of the outside of the vessel is


is expressed by the equation known as the equation of continuity in hydrodynamics. it is not true of heat, for heat may be increased or diminished within a closed surface, without passing in or out through the surface, by the transformation of some other form of energy into heat, or of heat into some other form of energy. it is not true even of energy in general if we admit the immediate action of bodies at a distance. for a body outside the closed surface may make an exchange of energy with a body within the surface. but if all apparent action at a distance is the result of the action between the parts of an intervening medium, and if the nature of this action of the parts of the medium is clearly understood, then it is conceivable that in all cases of the increases or diminution of the energy within a closed surface we may be able to trace the passage of the energy in or out through that surface. there is, however, another reason which warrants us in asserting that electricity, as a physical quantity, synonymous with the total electrification of a body, is not, like heat, a form of energy. an electrified system has a certain amount or energy, and this energy can be calculated by multiplying the quantity of electricity in each of its parts by another physical quantity, called the potential, of that part, and taking half the sum of the products. the quantities ' electricity ' and ' potential, ' when multiplied together, produce the quantity ' energy. ' it is impossible, therefore, that electricity and energy should be quantities of the same category, for electricity is only one of the factors of energy, the other factor being ' potential. ' energy, which is the product of these factors, may also be considered as the product of several other pairs of factors, such as | a force | | × | | a distance through which the force is to act. | | a mass | | × | | gravitation acting through a certain height. | | a mass | | × | | half the square of its velocity, | | a pressure | | × | | a volume of fluid introduced into a vessal at that pressure | | a chemical affinity | | × | | a chemical change, measured by the number of electro - chemical equivalents which enter into combination. | if we obtain distinct mechanical ideas of the nature of electric potential, we may combine these with the idea of energy to determine the physical category in which ' electricity ' is to be placed. 36. ] in most


equivalents which enter into combination. | if we obtain distinct mechanical ideas of the nature of electric potential, we may combine these with the idea of energy to determine the physical category in which ' electricity ' is to be placed. 36. ] in most theories on the subject, electricity is treated as a substance, but inasmuch as there are two kinds of electrification which, being combined, annul each other, and since we cannot conceive of two substances annulling each other, a distinction has been drawn between free electricity and combined electricity. theory of two fluidsin the theory called that of two fluids, all bodies, in their un - electrified state, are supposed to be charged with equal quantities of positive and negative electricity. these quantities are supposed to be so great that no process of electrification has ever yet deprived a body of all the electricity of either kind. the process of electrification, according to this theory, consists in taking a certain quantity p of positive electricity from the body a and communicating it to b, or in taking a quantity n of negative electricity from b and communicating it to a, or in some combination or these processes. the result will be that a will have p + n units of negative electricity over and above its remaining positive electricity, which is supposed to be in a state of combination with an equal quantity of negative electricity. this quantity p + n is called the free electricity, the rest is called the combined, latent, or fixed electricity. in most expositions of this theory the two electricities are called ' fluids, ' because they are capable of being transferred from one body to another, and are, within conducting bodies, extremely mobile. the other properties of fluids, such as their inertia, weight, and elasticity, are not attributed to them by those who have used the theory for merely mathematical purposes ; but the use of the word fluid has been apt to mislead the vulgar, including many men of science who are not natural philosophers, and who have seized on the word fluid as the only term in the statement of the theory which seemed intelligible to them. we shall see that the mathematical treatment of the subject has been greatly developed by writers who express themselves in terms of the ' two fluids ' theory. their results, however, have been deduced entirely from data which can be proved by experiment, and which must therefore be true, whether we adopt the theory of two fluids or not. the experimental verification of the mathematical results therefore is no evidence for or against the peculiar doctrines of this theory


deduced entirely from data which can be proved by experiment, and which must therefore be true, whether we adopt the theory of two fluids or not. the experimental verification of the mathematical results therefore is no evidence for or against the peculiar doctrines of this theory. the introduction of two fluids permits us to consider the negative electrification of a and the positive electrification of b as the effect of any one of three different processes which would lead to the same result. we have already supposed it produced by the transfer of p units of positive electricity from a to b, together with the transfer of n units of negative electricity from b to a. but if ' p + n ' units of positive electricity had been transferred from a to b, or if p + n units of negative electricity had been transferred from b to a, the resulting ' free electricity ' on a and on b would have been the same as before, but the quantity of ' combined electricity ' in a would have been less in the second case and greater in the third than it was in the first. it would appear therefore, according to this theory, that it is possible to alter not only the amount of free electricity in a body, but the amount of combined electricity. but no phenomena have ever been observed in electrified bodies which can be traced to the varying amount of their combined electricities. hence either the combined electricities have no observable properties, or the amount of the combined electricities is incapable of variation. the first of these alternatives presents no difficulty to the mere mathematician, who attributes no properties to the fluids except those of attraction and repulsion, for in this point of view the two fluids simply annul one another, and their combination is a true mathematical zero. but to those who cannot use the word fluid without thinking of a substance it is difficult to conceive that the combination of the two fluids shall have no properties at all, so that the addition of more or less of the combination to a body shall not in any way affect it, either by increasing its mass or its weight, or altering some or its other properties. hence it has been supposed by some, that in every process of electrification exactly equal quantities of the two fluids are transferred in opposite directions, so that the total quantity of the two fluids in any body taken together remains always the same. by this new law they ' contrive to save appearances, ' forgetting that there would have been no need of the law except to reconcile the ' two fluids ' theory with facts, and to prevent it from predicting non - existent phenomena


the same. by this new law they ' contrive to save appearances, ' forgetting that there would have been no need of the law except to reconcile the ' two fluids ' theory with facts, and to prevent it from predicting non - existent phenomena. theory of one fluid 37. ] in the theory of one fluid everything is the same as in the theory of two fluids except that, instead of supposing the two substances equal and opposite in all respects, one of them, generally the negative one, has been endowed with the properties and name of ordinary matter, while the other retains the name of the electric fluid. the particles of the fluid are supposed to repel one another according to the law of the inverse square of the distance, and to attract those of matter according to the same law. those of matter are supposed to repel each other and attract those of electricity. the attraction, however, between units of the different substances at unit of distance is supposed to be a very little greater than the repulsion between units of the same kind, so that a unit of matter combined with a unit of electricity will exert a force of attraction on a similar combination at a distance, this force, however, being exceedingly small compared with the force between two uncombined units. this residual force is supposed to account for the attraction of gravitation. unelectrified bodies are supposed to be charged with as many units of electricity as they contain of ordinary matter. when they contain more electricity or less, they are said to be positively or negatively electrified. this theory does not, like the two - field theory, explain too much. it requires us, however, to suppose the mass of the electric fluid so small that no attainable positive or negative electrification has yet perceptibly increased or diminished either the mass or the weight of a body, and it has not yet been able to assign sufficient reasons why the vitreous rather than the resinous electrification should be supposed due to an excess of electricity. one objection has sometimes been urged against this theory by men who ought to have reasoned better. it has been said that the doctrine that the particles of matter uncombined with electricity repel one another, is in direct antagonism with the well established fact that every particle of matter attracts every other particle throughout the universe. if the theory of one fluid were true we should have the heavenly bodies repelling one another. but it is manifest that the heavenly bodies, according to this theory, if they consisted of matter uncombined with electricity


every other particle throughout the universe. if the theory of one fluid were true we should have the heavenly bodies repelling one another. but it is manifest that the heavenly bodies, according to this theory, if they consisted of matter uncombined with electricity, would be in the highest state of negative electrification, and would repel each other. we have no reason to believe that they are in such a highly electrified state, or could be maintained in that state. the earth and all the bodies whose attraction has been observed are rather in an unelectrified state, that is, they contain the normal charge of electricity, and the only action between them is the residual force lately mentioned. the artificial manner, however, in which this residual force is introduced is a much more valid objection to the theory. in the present treatise i propose, at different stages of the investigation, to test the different theories in the light of additional classes of phenomena. for my own part, i look for additional light on the nature of electricity from a study of what takes place in the space intervening between the electrified bodies. such is the essential character of the mode of investigation pursued by faraday in his experimental researches, and as we go on i intend to exhibit the results, as developed by faraday, w. thomson, & c., in a connected and mathematical form, so that we may perceive what phenomena are explained equally well by all the theories, and what phenomena indicate the peculiar difficulties of each theory. measurement of the force between electrified bodies. 38. ] forces may be measured in various ways. for instance, one of the bodies may be suspended from one arm of a delicate balance, and weights suspended from the other arm, till the body, when unelectrified, is in equilibrium. the other body may then be placed at a known distance beneath the first, so that the attraction or repulsion of the bodies when electrified may increase or diminish the apparent weight of the first. the weight which must be added to or taken from the other arm, when expressed in dynamical measure, will measure the force between the bodies. this arrangement was used by sir w. snow harris, and is that adopted in sir w. thomson ' s absolute electrometers. see art. 217. it is sometimes more convenient to use a torsion - balance in which a horizontal arm is suspended by a fine wire or fibre, so as to be capable of vibrating about the vertical wire as an axis, and the body is attached to one end of the arm and acted


each of the positive units in will repel each of the positive units in with a certain force, say, making a total effect equal to. since the effect of negative electricity is exactly equal and opposite to that of positive electricity, each of the positive units in will attract each of the negative units in with the same force, making a total effect equal to. similarly the negative units in will attract the positive units in with a force, and will repel the negative units in with a force the total repulsion will therefore be ; and the total attraction will be the resultant repulsion will be now is the algebraical value of the charge on, and is that of the charge on, so that the resultant repulsion may be written, the quantities and being always understood to be taken with their proper signs. variation of the force with the distance. 40. ] having established the law of force at a fixed distance, we may measure the force between bodies charged in a constant manner and placed at different distances. it is found by direct measurement that the force, whether of attraction or repulsion, varies inversely as the square of the distance, so that if is the repulsion between two units at unit distance, the repulsion at distance will be and the general expression for the repulsion between units and units at distance will be definition of the electrostatic unit of electricity. 41. ] we have hitherto used a wholly arbitrary standard for our unit of electricity, namely, the electrification of a certain piece of glass as it happened to be electrified at the commencement of our experiments. we are now able to select a unit on a definite principle, and in order that this unit may belong to a general system we define it so that may be unity, or in other words — the electrostatic unit of electricity is that quantity of electricity which, when placed at unit of distance from an equal quantity, repels it with unit of force. this unit is called the electrostatic unit to distinguish it from the electromagnetic unit, to be afterwards defined. we may now write the general law of electrical action in the simple form dimensions of the electrostatic unit of quantity. 42. ] if is the concrete electrostatic unit of quantity itself, and, the numerical values of particular quantities ; if is the unit of length, and the numerical value of the distance ; and if is the unit of force, and the numerical value of the force, then the equation becomes. this unit is called the electrostatic unit of electricity. other units may be employed for practical purposes, and in


and measurements ( which may be used as illustrations of the law ), but by a mathematical consideration of the phenomenon described as experiment vii, namely, that an electrified conductor, if made to touch the inside of a hollow closed conductor and then withdrawn without touching, is perfectly discharged, in whatever manner the outside of may be electrified. by means of delicate electroscopes it is easy to show that no electricity remains on after the operation, and by the mathematical theory given at art. 74, this can only be the case if the force varies inversely as the square of the distance, for if the law had been of any different form would have been electrified. the electric field. 44. ] the electric field is the portion of space in the neighbourhood of electrified bodies, considered with reference to electric phenomena. it may be occupied by air or other bodies, or it may be a so - called vacuum, from which we have withdrawn every substance which we can act upon with the means at our disposal. if an electrified body be placed at any part of the electric field it will be acted on by a force which will depend, in general, on the shape of the body and on its charge, if the body is so highly charged as to produce a sensible disturbance in the previous electrification of the other bodies. but if the body is very small and its charge also very small, the electrification of the other bodies will not be sensibly disturbed, and we may consider the body as indicating by its centre of gravity a certain point of the field. the force acting on the body will then be proportional to its charge, and will be reversed when the charge is reversed. let be the charge of the body, and the force acting on the body in a certain direction, then when is very small is proportional to, or where is a quantity depending on the other bodies in the field. if the charge could be made equal to unity without disturbing the electrification of other bodies we should have. we shall call the resultant electric force at the given point of the field. 45. ] if the small body carrying the small charge be moved from the given point to an indefinite distance from the electrified bodies, it will experience at each point of its course a force, where varies from point to point of the course. let the whole work done on the body by these electrical forces be, then is the potential at the point of the field from which the body started. if the charge could be made equal to unity without disturbing the electrification of other bodies, we might define the potential at any


done on the body by these electrical forces be, then is the potential at the point of the field from which the body started. if the charge could be made equal to unity without disturbing the electrification of other bodies, we might define the potential at any point as the work done on a body charged with unit of electricity in moving from that point to an infinite distance. a body electrified positively tends to move from places of greater positive potential to places of smaller positive, or of negative potential, and a body negatively electrified tends to move in the opposite direction. in a conductor the electrification is distributed exactly as if it were free to move in the conductor according to the same law. if therefore two parts of a conductor have different potentials, positive electricity will move from the part having greater potential to the part having less potential as long as that difference continues. a conductor therefore cannot be in electrical equilibrium unless every point in it has the same potential. this potential is called the potential of the conductor. 46. ] if a surface described or supposed to be described in the electric field is such that the electric potential is the same at every point of the surface it is called an equipotential surface. an electrified point constrained to rest upon such a surface will have no tendency to move from one part of the surface to another, because the potential is the same at every point. an equipotential surface is therefore a surface of equilibrium or a level surface. the resultant force at any point of the surface is in the direction of the normal to the surface, and the magnitude of the force is such that the work done on an electrical unit in passing from the surface v to the surface v ' is v - v '. no two equipotential surfaces having different potentials can meet one another, because the same point cannot have more than one potential, but one equipotential surface may meet itself, and this takes place at all points and lines of equilibrium. the surface of a conductor in electrical equilibrium is necessarily an equipotential surface. if the electrification of the conductor is the whole surface, then the potential will diminish as we move away from the surface on every side, and the conductor will be surrounded by a series of surfaces of lower potential. but if ( owing to the action of external electrified bodies ) some regions of the conductor are electrified positively and others negatively, the complete equipotential surface will consist of the surface of the conductor itself together with a system of other surfaces, meeting the surface of the conductor in the lines which


proportional to the superficial density of the electrification. hence the electricity on any small area of the surface will be acted on by a force tending from the conductor and proportional to the product of the resultant force and the density, that is, proportional to the square of the resultant force. this force which acts outwards as a tension on every part of the conductor will be called electric tension. it is measured like ordinary mechanical tension, by the force exerted on unit of area. the word tension has been used by electricians in several vague senses, and it has been attempted to adopt it in mathematical language as a synonym for potential ; but on examining the cases in which the word has been used, i think it will be more consistent with usage and with mechanical analogy to understand by tension a pulling force of so many pounds per square inch exerted on the surface of a conductor or elsewhere. we shall find that the conception of faraday, that this electric tension exists not only at the electrified surface but all along the lines of force, leads to a theory of electric action as a phenomenon of stress in a medium. 49. ] when two conductors at different potentials are connected by a thin conducting wire, the tendency of electricity to flow along the wire is measured by the difference of the potentials of the two bodies. the difference of potentials between two conductors or two points is therefore called the electromotive force between them. electromotive force may arise from other causes than difference of potential, but these causes are not considered in treating of statical electricity. we shall consider them when we come to chemical actions, motions of magnets, inequalities of temperature, & c. capacity of a conductor. 50. ] if one conductor is insulated while all the surrounding conductors are kept at the zero potential by being put in communication with the earth, and if the conductor, when charged with a quantity of electricity, has a potential, the ratio of to is called the capacity of the conductor. if the conductor is completely enclosed within a conducting vessel without touching it, then the charge on the inner conductor will be equal and opposite to the charge on the inner surface of the outer conductor, and will be equal to the capacity of the inner conductor multiplied by the difference of the potentials of the two conductors. a system consisting of two conductors whose opposed surfaces are separated from each other by a thin stratum of an insulating medium is called an electric accumulator. its capacity is directly proportional to the area of the opposed surfaces and inversely proportional to


a system consisting of two conductors whose opposed surfaces are separated from each other by a thin stratum of an insulating medium is called an electric accumulator. its capacity is directly proportional to the area of the opposed surfaces and inversely proportional to the thickness of the stratum between them. a leyden jar is an accumulator in which glass is the insulating medium. accumulators are sometimes called condensers, but i prefer to restrict the term condenser to an instrument which is used not to hold electricity but to increase its superficial density. resistance to the passage of electricity through a body. 51. ] when a charge of electricity is communicated to any part of a mass of metal the electricity is rapidly transferred from places of high to places of low potential till the potential of the whole mass becomes the same. in the case of pieces of metal used in ordinary experiments this process is completed in a time too short to be observed, but in the case of very long and thin wires, such as those used in telegraphs, the potential does not become uniform till after a sensible time, on account of the resistance of the wire to the passage of electricity through it. the resistance to the passage of electricity is exceedingly different in different substances, as may be seen from the tables at arts. 362, 366, and 369, which will be explained in treating of electric currents. all the metals are good conductors, though the resistance of lead is 12 times that of copper or silver, that of iron 6 times, and that of mercury 60 times that of copper. the resistance of all metals increases as their temperature rises. selenium in its crystalline state may also be regarded as a conductor, though its resistance is 3. 7×1012 times that of a piece of copper of the same dimensions. its resistance increases as the temperature rises. selenium in the amorphous form is a good insulator, like sulphur. many liquids conduct electricity by electrolysis. this mode of conduction will be considered in part ii. for the present, we may regard all liquids containing water and all damp bodies as conductors, far inferior to the metals, but incapable of insulating a charge of electricity for a sufficient time to be observed. on the other hand, the gases at the atmospheric pressure, whether dry or moist, are insulators so nearly perfect when the electric tension is small that we have as yet obtained no evidence of electricity passing through them by ordinary conduction. the gradual loss of charge


hand, the gases at the atmospheric pressure, whether dry or moist, are insulators so nearly perfect when the electric tension is small that we have as yet obtained no evidence of electricity passing through them by ordinary conduction. the gradual loss of charge by electrified bodies may in every case be traced to imperfect insulation in the supports, the electricity either passing through the substance of the support or creeping over its surface. hence, when two charged bodies are hung up near each other, they will preserve their charges longer if they are electrified in opposite ways, than if they are electrified in the same way. for though the electromotive force tending to make the electricity pass through the air between them is much greater when they are oppositely electrified, no perceptible loss occurs in this way. the actual loss takes place through the supports, and the electromotive force through the supports is greatest when the bodies are electrified in the same way. the result appears anomalous only when we expect the loss to occur by the passage of electricity through the air between the bodies. certain kinds of glass when cold are marvelously perfect insulators, and sir w. thomson has preserved charges of electricity for years in bulbs hermetically sealed. the same glass, however, becomes a conductor at a temperature below that of boiling water. gutta - percha, caoutchoue, vulcanite, paraffin, and resins are good insulators, the resistance of gutta - percha at 75°f. being about 6×1019 times that of copper. ice, crystals, and solidified electrolytes, are also insulators. certain liquids, such as naphtha, turpentine, and some oils, are insulators, but inferior to most of the solid insulators. the resistance of most substances, except the metals, and selenium and carbon, seems to diminish as the temperature rises. specific inductive capacity. 52. ] all bodies whose insulating power is such that when they are placed between two conductors at different potentials the electromotive force acting on them does not immediately distribute their electricity so as to reduce the potential to a constant value, are called by faraday dielectrics. faraday discovered that the capacity of an accumulator depends on the nature of the insulating medium between the two conductors, as well as on the dimensions and relative position of the conductors themselves. by substituting other insulating media for air as the dielectric of the


a discharge, will be too great. the accumulator if charged and left insulated appears to lose its charge by conduction, but it is found that the proportionate rate of loss is much greater at first than it is afterwards, so that the measure of conductivity, if deduced from what takes place at first, would be too great. thus, when the insulation of a submarine cable is tested, the insulation appears to improve as the electrification continues. thermal phenomena of a kind at first sight analogous take place in the case of the conduction of heat when the opposite sides of a body are kept at different temperatures. in the case of heat we know that they depend on the heat taken in and given out by the body itself. hence, in the case of the electrical phenomena, it has been supposed that electricity is absorbed and emitted by the parts of the body. we shall see, however, in art. 329, that the phenomena can be explained without the hypothesis of absorption of electricity, by supposing the dielectric in some degree heterogeneous. that the phenomenon called electric absorption is not an actual absorption of electricity by the substance may be shewn by charging the substance in any manner with electricity while it is surrounded by a closed metallic insulated vessel. if, when the substance is charged and insulated, the vessel be instantaneously discharged and then left insulated, no charge is ever communicated to the vessel by the gradual dissipation of the electrification of the charged substance within it. 54. ] this fact is expressed by the statement of faraday that it is impossible to charge matter with an absolute and independent charge of one kind of electricity. in fact it appears from the result of every experiment which has been tried that in whatever way electrical actions may take place among a system of bodies surrounded by a metallic vessel, the charge on the outside of that vessel is not altered. now if any portion of electricity could be forced into a body so as to be absorbed in it, or to become latent, or in any way to exist in it, without being connected with an equal portion of the opposite electricity by lines of induction, or if, after having being absorbed, it could gradually emerge and return to its ordinary mode of action, we should find some change of electrification in the surrounding vessel. as this is never found to be the case, faraday concluded that it is impossible to communicate an absolute charge to matter, and that no portion of matter can by any change of state evolve or render latent one


its surface. let its temperature be now raised, the crystal remaining insulated. one end will be found positively and the other end negatively electrified. let the surface be deprived of this apparent electrification by means of a flame or other wise, then if the crystal be made still hotter, electrification of the same kind as before will appear, but if the crystal be cooled the end which was positive when the crystal was heated will become negative. these electrifications are observed at the extremities of the crystallographic axis. some crystals are terminated by a six - sided pyramid at one end and by a three - sided pyramid at the other. in these the end having the six - sided pyramid becomes positive when the crystal is heated. sir w. thomson supposes every portion of these and other hemihedral crystals to have a definite electric polarity, the intensity of which depends on the temperature. when the surface is passed through a flame, every part of the surface becomes electrified to such an extent as to exactly neutralize, for all external points, the effect of the internal polarity. the crystal then has no external electrical action, nor any tendency to change its mode of electrification. but if it be heated or cooled the interior polarization of each particle of the crystal is altered, and can no longer be balanced by the superficial electrification, so that there is a resultant external action. plan of this treatise. 59. ] in the following treatise i propose first to explain the ordinary theory of electrical action, which considers it as depending only on the electrified bodies and on their relative position, without taking account of any phenomena which may take place in the surrounding media. in this way we shall establish the law of the inverse square, the theory of the potential, and the equations of laplace and poisson. we shall next consider the charges and potentials of a system of electrified conductors as connected by a system of equations, the coefficients of which may be supposed to be determined by experiment in those cases in which our present mathematical methods are not applicable, and from these we shall determine the mechanical forces acting between the different electrified bodies. we shall then investigate certain general theorems by which green, gauss, and thomson have indicated the conditions of solution of problems in the distribution of electricity. one result of these theorems is, that if poisson ' s equation is satisfied by any function, and if at the surface of every conductor the function has the value of the potential of that conductor, then the function expresses the actual potential of the system at every point.


, we shall find it equal to the energy due to the electrification of the conductors on the hypothesis of direct action at a distance. hence the two hypotheses are mathematically equivalent. if we now proceed to investigate the mechanical state of the medium on the hypothesis that the mechanical action observed between electrified bodies is exerted through and by means of the medium, as in the familiar instances of the action of one body on another by means of the tension of a rope or the pressure of a rod, we find that the medium must be in a state of mechanical stress. the nature of this stress is, as faraday pointed out, a tension along the lines of force combined with an equal pressure in all directions at right angles to these lines. the magnitude of these stresses is proportional to the energy of the electrification, or, in other words, to the square of the resultant electromotive force multiplied by the specific inductive capacity of the medium. this distribution of stress is the only one consistent with the observed mechanical action on the electrified bodies, and also with the observed equilibrium of the fluid dielectric which surrounds them. i have therefore thought it a warrantable step in scientific procedure to assume the actual existence of this state of stress, and to follow the assumption into its consequences. finding the phrase electric tension used in several vague senses, i have attempted to confine it to what i conceive to have been in the mind of some of those who have used it, namely, the state of stress in the dielectric medium which causes motion of the electrified bodies, and leads, when continually augmented, to disruptive discharge. electric tension, in this sense, is a tension of exactly the same kind, and measured in the same way, as the tension of a rope, and the dielectric medium, which can support a certain tension and no more, may be said to have a certain strength in exactly the same sense as the rope is said to have a certain strength. thus, for example, thomson has found that air at the ordinary pressure and temperature can support an electric tension of 9600 grains weight per square foot before a spark passes. 60. ] from the hypothesis that electric action is not a direct action between bodies at a distance, but is exerted by means of the medium between the bodies, we have deduced that this medium must be in a state of stress. we have also ascertained the character of the stress, and compared it with the stresses which may occur in solid bodies. along the lines of force


medium between the bodies, we have deduced that this medium must be in a state of stress. we have also ascertained the character of the stress, and compared it with the stresses which may occur in solid bodies. along the lines of force there is tension, and perpendicular to them there is pressure, the numerical magnitude of these forces being equal, and each proportional to the square of the resultant force at the point. having established these results, we are prepared to take another step, and to form an idea of the nature of the electric polarization of the dielectric medium. an elementary portion of a body may be said to be polarized when it acquires equal and opposite properties on two opposite sides. the idea of internal polarity may be studied to the greatest advantage as exemplified in permanent magnets, and it will be explained at greater length when we come to treat of magnetism. the electric polarization of an elementary portion of a dielectric is a forced state into which the medium is thrown by the action of electromotive force, and which disappears when that force is removed. we may conceive it to consist in what we may call an electrical displacement, produced by the electromotive force. when the electromotive force acts on a conducting medium it produces a current through it, but if the medium is a non - conductor or dielectric, the current cannot flow through the medium, but the electricity is displaced within the medium in the direction of the electromotive force, the extent of this displacement depending on the magnitude of the electromotive force, so that if the electromotive force increases or diminishes the electric displacement increases and diminishes in the same ratio. the amount of the displacement is measured by the quantity of electricity which crosses unit of area, while the displacement increases from zero to its actual amount. this, therefore, is the measure of the electric polarization. the analogy between the action of electromotive force in producing electric displacement and of ordinary mechanical force in producing the displacement of an elastic body is so obvious that i have ventured to call the ratio of the electromotive force to the corresponding electric displacement the coefficient of electric elasticity of the medium. this coefficient is different in different media, and varies inversely as the specific inductive capacity of each medium. the variations of electric displacement evidently constitute electric currents. these currents, however, can only exist during the variation of the displacement, and therefore, since the displacement cannot exceed a certain value without causing disrupt


as the specific inductive capacity of each medium. the variations of electric displacement evidently constitute electric currents. these currents, however, can only exist during the variation of the displacement, and therefore, since the displacement cannot exceed a certain value without causing disruptive discharge, they cannot be continued indefinitely in the same direction, like the currents through conductors. in tourmaline, and other pyro - electric crystals, it is probable that a state of electric polarization exists, which depends upon temperature, and does not require an external electromotive force to produce it if the interior of a body were in a state of permanent electric polarization, the outside would gradually become charged in such a manner as to neutralize the action of the internal electrification for all points outside the body. this external superficial charge could not be detected by any of the ordinary tests, and could not be removed by any of the ordinary methods for dis charging superficial electrification. the internal polarization of the substance would therefore never be discovered unless by some means, such as change of temperature, the amount of the internal polarization could be increased or diminished. the external electrification would then be no longer capable of neutralizing the external effect of the internal polarization, and an apparent electrification would be observed, as in the case of tourmaline. if a charge is uniformly distributed over the surface of a sphere, the resultant force at any point of the medium surrounding the sphere is numerically equal to the charge e divided by the square of the distance from the centre of the sphere. this resultant force, according to our theory, is accompanied by a displacement of electricity in a direction outwards from the sphere. if we now draw a concentric spherical surface of radius, the whole displacement,, through this surface will be proportional to the resultant force multiplied by the area of the spherical surface. but the resultant force is directly as the charge e and inversely as the square of the radius, while the area of the surface is directly as the square of the radius. hence the whole displacement,, is proportional to the charge, and is independent of the radius. to determine the ratio between the charge, and the quantity of electricity,, displaced outwards through the spherical surface, let us consider the work done upon the medium in the region between two concentric spherical surfaces, while the displacement is increased from to. if and denote the potentials at the inner and the outer of these surfaces respectively, the electromotive force by which the additional displacement is produced is, so that the work spent in


circuit, such that at every section of the circuit the same quantity of electricity crosses in the same time, and this is the case, not only in the voltaic circuit where it has always been recognised, but in those cases in which electricity has been generally supposed to be accumulated in certain places. 61. ] we are thus led to a very remarkable consequence of the theory which we are examining, namely, that the motions of electricity are like those of an incompressible fluid, so that the total quantity within an imaginary fixed closed surface remains always the same. this result appears at first sight in direct contradiction to the fact that we can charge a conductor and then introduce it into the closed space, and so alter the quantity of electricity within that space. but we must remember that the ordinary theory takes no account of the electric displacement in the substance of dielectrics which we have been investigating, but confines its attention to the electrification at the bounding surfaces of the conductors and dielectrics. in the case of the charged conductor let us suppose the charge to be positive, then if the surrounding dielectric extends on all sides beyond the closed surface there will be electric polarization, accompanied with displacement from within outwards all over the closed surface, and the surface - integral of the displacement taken over the surface will be equal to the charge on the conductor within. thus when the charged conductor is introduced into the closed space there is immediately a displacement of a quantity of electricity equal to the charge through the surface from within out wards, and the whole quantity within the surface remains the same. the theory of electric polarization will be discussed at greater length in chapter v, and a mechanical illustration of it will be given in art. 334, but its importance cannot be fully understood till we arrive at the study of electromagnetic phenomena. 62. ] the peculiar features of the theory as we have now developed them are : - that the energy of electrification resides in the dielectric medium, whether that medium be solid, liquid, or gaseous, dense or rare, or even deprived of ordinary gross matter, provided it be still capable of transmitting electrical action. that the energy in any part of the medium is stored up in the form of a state of constraint called electric polarization, the amount of which depends on the resultant electromotive force at the place. that electromotive force acting on a dielectric produces what we have called electric displacement, the relation between the force and the displacement being in the most general case of a kind to be afterwards investigated


is set up, and the resistance depends, not on the total quantity of electricity displaced from its position of equilibrium, but on the quantity which crosses a section of the conductor in a given time. that in every case the motion of electricity is subject to the same condition as that of an incompressible fluid, namely, that at every instant as much must flow out of any given closed space as flows into it. it follows from this that every electric current must form a closed circuit. the importance of this result will be seen when we investigate the laws of electro - magnetism. since, as we have seen, the theory of direct action at a distance is mathematically identical with that of action by means of a medium, the actual phenomena may be explained by the one theory as well as by the other, provided suitable hypotheses be introduced when any difficulty occurs. thus, mossotti has deduced the mathematical theory of dielectrics from the ordinary theory of attraction by merely giving an electric instead of a magnetic interpretation to the symbols in the investigation by which poisson has deduced the theory of magnetic induction from the theory of magnetic fluids. he assumes the existence within the dielectric of small conducting elements, capable of having their opposite surfaces oppositely electrified by induction,, but not capable of losing or gaining electricity on the whole, owing to their being insulated from each other by a non - conducting medium. this theory of dielectrics is consistent with the laws of electricity, and may be actually true. if it is true, the specific inductive capacity of a dielectric may be greater, but cannot be less, than that of air or vacuum. no instance has yet been found of a dielectric having an inductive capacity less than that of air, but if such should be discovered, mossotti ' s theory must be abandoned, although his formulae would all remain exact, and would only require us to alter the sign of a coefficient. in the theory which i propose to develope, the mathematical methods are founded upon the smallest possible amount of hypothesis, and thus equations of the same form are found applicable to phenomena which are certainly of quite different natures, as, for instance, electric induction through dielectrics ; conduction through conductors, and magnetic induction. in all these cases the relation between the force and the effect produced is expressed by a set of equations of the same kind, so that when a problem in one of these subjects is solved, the problem and its solution may be


in our last article we discussed how both the celsius and fahrenheit temperature scales aligned perfectly with the specific structural design of the future holy temple as laid out by ezekiel thousands of years ago, and moreover how the kelvin scale and the surface temperature of the planets aligned with the dates given by the tzaddikim for the final redemption. given that, and returning the the freezing point of water, 32 degrees fahrenheit, we see that the major structural dimensions of the future holy temple centers redundantly and concentrically on the 32 paths of wisdom that comprise the tree - of - life. as we lay out this structure for you in a 2 - dimensional grid, please note that the temple, like the tree - of - life, is multi - dimensional and should always be viewed that way, staring with the fact that 32 is 25, and that 32 represents the 32 edges ( paths ) of what is called in mathematics a 4 - dimensional hypercube. though our modern physicists, by and large, agree with the ancient kabbalists that the greater universe is constructed in 10 dimensions, we cannot even fathom, except mathematically, how a 4 - d cube, or indeed any object would actually look. nevertheless, in the same way that a 3 - d cube casts a 2 - d shadow on our desk, a 4 - d hypercube does the same in our 3 - d world. it ’ s by these shadows, much like plato ’ s cave, that we can glimpse and maybe grasp that upper dimension. the following illustrations are just such shadows of 4 - d hypercubes on our world, and the reason we need to perceive them before getting back to the temperature scales will be clear in a moment, but keep in mind that it ’ s only because of light that we have shadows and thus perception in the first place. one of the shapes that a 3 - d cube casts on a flat 2 - d page is a square, another is a hexagon, and likewise one of the shadows cast by our 4 - d hypercube on our 3 - d world is a cube itself ( if you follow the outlines in the blue image ). others, include the tesseract, as in the image above ( a cube within a cube ), and also the double stacked cubes, which once turned on its axis, forms the exact tree - of - life depiction kabbalists have been elaborating on for thousands of years. since we have a difficult time imagining hyper


1 ) tiny beginnings & the grand unification in the beginning, the universe was smaller and hotter than a mustard seed. it was even smaller than that. smaller than tiny, more miniature than microscopic, and hotter than hot. it was smaller, denser, and had more potential energy than anything that exists today. within this invisible seed, the forces of nature were unified. they travelled bundled together in high energy packages that could be called quofs ( from the quanta of the unified field ), if anyone wanted to give them a name. however, they were only joined in this way due to the extremely extreme and tight conditions they found themselves in. as things began to open up, one by one the forces of nature separated within the primordial little nut. the first to loosen off was the force that holds all the big things together. it even sounds big. its name is gravity, and it shapes our universe on a galactic scale. despite the fact that it is absolutely everywhere, no - one fully understands how it works. it is a mysterious, omnipresent phenomenon. some think gravity is substantially different from the other forces, that it was always a separate entity from the beginning, and its effect can travel and disappear into other universes. whether it was part of the grand unification or not, at some point there were three forces bundled tightly together, which we shall call the strong unification. but these three didn ’ t much like being squeezed together either, and so a powerful member broke off from the trinity – the strong force. the strong force is called the strong force because it is strong. it works invisibly on the tiniest of scales, tightly binding together every object you can see around you. without it, matter would simply fall apart into a gloop of subatomic bits. the strong force ’ s separation from the rest was no casual affair. whilst going its own way, it spilt unprecedented quantities of energy in all directions and set off the most important event of the ever - so - young universe. in the blink of an eye, as quick as a bursting balloon seen in reverse, the universe inflated.


( phys. org ) - - a voltage signal preceding failure of bridges and other structures made of powder has been documented by three researchers in the department of biomedical engineering at rutgers university. their findings, published on monday in proceedings of the national academy of sciences, are an important step forward. the authors note that it has been known for over a century that electrical signals are produced by material failure, for example during crack formation of crystals and glasses, or stick - slip motion of liquid mercury on glass. they say that slip events in cohesive powders also produce electrical signals, and that these signals can appear significantly in advance of slip events. key structural materialsceramics in turbines, chalk in cliffs, and concrete in bridgesare made from powders ; a voltage spike might precede cracking in these structures. the authors of the paper, electrostatic precursors to granular slip events, are troy shinbrot, nam h. kim, and nirmal thyagu, and they discuss their results from lab tests on powders. they documented a voltage signal. they studied how clumps of fine particles emit electrical voltages just before they crack. pulling powders apart seems to produce a voltage. shinbrot and his study team studied scoops of finely ground tylenol in a slowly - spinning cylinder. powder stuck to the sides, built up, and after reaching a certain height, cracked and tumbled down to the bottom. the mini avalanches " created voltages higher than 100 volts. they discovered that the voltage spike sometimes preceded the avalanche by as much as five seconds. outside of rutgers, a doctoral candidate familiar with the electrification of granular systems noted that five seconds might not be meaningful to save people from an earthquake area but would be beneficial in a smart - grid setting in turning off technologies that might cause explosions or fires during a quake. the researchers at rutgers performed several experiments before reaching their conclusions ; they used different containers and different powders. bleached and unbleached flour, plaster and mortar were tried and the team found the same results. similar voltage signals are produced by crack - like defects in several powdered materials. failure of these materials, in turn, may be preceded by telltale electrical signals. they speculate that similar voltage changes could be warning signs of internal defects or of impending catastrophic failures in objects made of consolidated powders. the authors acknowledge that electrical disturbances have been reported in the past to precede major earthquakes and rockbursts, but many of these reports have been anecdot


signs of internal defects or of impending catastrophic failures in objects made of consolidated powders. the authors acknowledge that electrical disturbances have been reported in the past to precede major earthquakes and rockbursts, but many of these reports have been anecdotal. at the same time, a growing body of field measurements will help other research efforts to more fully understand these events. we anticipate that the ability to generate correlated electrical signals and slip events in a controlled setting will enable future research to unveil the mechanisms leading to the curious effects. prof. shinbrot says a better understanding of the particles ' electrical interactions may enable technologies that predict breakages before they cause catastrophic damage. explore further : wearable electronics - the next fashion fad? more information : electrostatic precursors to granular slip events, pnas, published online before print june 11, 2012, doi : 10. 1073 / pnas. 1121596109 it has been known for over a century that electrical signals are produced by material failure, for example during crack formation of crystals and glasses, or stick - slip motion of liquid mercury on glass. we describe here new experiments revealing that slip events in cohesive powders also produce electrical signals, and remarkably these signals can appear significantly in advance of slip events. we have confirmed this effect in two different experimental systems and using two common powdered materials, and in a third experiment we have demonstrated that similar voltage signals are produced by crack - like defects in several powdered materials.


how can i decrypt a message that was encrypted with a one - time pad? would i need to get that pad, and then reverse the process? i ' m confused here. one - time pad is unbreakable, assuming the pad is perfectly random, kept secret, used only once, and no plaintext is known. this is due to the properties of the exclusive - or ( xor ) operation. here ' s its truth table : note that it introduces no bit - skew - the number of 0s and 1s in the inputs are equal to the number of 0s and 1s in the output, i. e. two of each. furthermore, if you know only one element from a row, you cannot predict the values of the other two, since they are equally probable. for example, let ' s say we know that x is 0. there ' s an equal probability that a = 0 and b = 0, or a = 1 and b = 1. now let ' s say we know that x is 1. there ' s an equal probability that a = 0 and b = 1, or a = 1 and b = 0. it ' s impossible to predict. so, if you only know one element, you cannot possibly determine any information about a or b. the next interesting property is that it is reversible, i. e. so, if we take any value and xor it with itself, the result is cancelled out and it always results in 0. this means that, if we xor a value a with a value b, then later xor that result with either a or b, we get b or a respectively. the operation is reversible. this lends well to cryptography, because : as such, the following is perfectly secure : but only if message is the same length as key, key is perfectly random, key is only used once, and only one element is known to an attacker. if they know the ciphertext, but not the key or message, it ' s useless to them. they cannot possibly break it. in order to decrypt the message, you must know the entire key and the ciphertext. keep in mind that the key must be completely random, i. e. every bit must have an equal probability of being 1 or 0, and be completely independent of all other bits in the key. this actually turns out to be rather impractical, for a few reasons : the weak link here is your


. e. every bit must have an equal probability of being 1 or 0, and be completely independent of all other bits in the key. this actually turns out to be rather impractical, for a few reasons : the weak link here is your random number generator. the security of the one time pad is entirely limited by the security of your generator. since a perfect generator is almost impossible, a perfect one - time pad is almost impossible too. the final problem is that the key can only be used once. if you use it for two different messages, and the attacker knows both ciphertexts, he can xor them together to get the xor of the two plaintexts. this leaks all sorts of information ( e. g. which bits are equal ) and completely breaks the cipher. so, in conclusion, in a perfect one - time pad you need to know the ciphertext and key in order to decrypt it, but perfect one - time pads are almost impossible. one - time pads are extremely hard to break, in fact they are still used in some situations as if they are done correctly then they are essentially unbreakable. in a one - time pad system every character is changed by a stream of random data which is shared by both sides, without a copy of the pad you will not be able to break the code. one of the few weaknesses in the system is the random data source. in wwii british one - time pads were being broken and they traced it to a worker whose job it was to pull random numbered balls out of a drum. the way it was supposed to work was that the worker would spin the drum, pull out a ball at random without looking at it, spin again, pick again, etc, etc. the worker started taking shortcuts by pulling out more than one ball after each spin and looking at the numbers, picking out favorites. it introduced patterns which enabled the opposition to break the pads, and lives were lost as a result. the same is true today with pseudo - random number sources. encryption protocols that should take millennia to break will really only last for years or decades without a true random data source. assuming the encryption was competently done, the only way to decrypt is to get the pad. while one - time - pad encryption is provably impossible to break, note that it is also extraordinarily rare. part of the definition of otp is that the pad must contain truly random data, and truly random data can be hard to come by for


| biomimetic dye molecules for solar cells | pressing energy problems provide opportunities for solid - state physicists and chemists to solve a major challenge : solar cell adoption. though solar cells can use energy directly from the sun to produce electricity that can be converted efficiently into other kinds of energy, they are currently too costly to compete with traditional ( polluting ) energy sources. the most cost - effective solar cells are not high - end, high - efficiency single - crystal devices, but rather low - end cells based on organic molecules or conducting polymers. vital information for making organic solar cells more competitive for widespread implementation was obtained using near - edge x - ray absorption fine structure ( nexafs ) spectroscopy performed at als beamline 8. 0. 1. the relevant energy levels of biomimetic dye molecules were mapped out systematically by determining their unoccupied molecular orbitals and their orientation. organic molecules in dye - sensitized solar cells exhibit great potential to increase the efficiency and reduce the cost of photovoltaic power generation by allowing a wide variety of chemical modifications and combinations with inorganic nanocrystals. researchers investigated the x - ray absorption spectra of two classes of candidate dye molecules for dye - sensitized solar cells : phthalocyanines and porphyrins. these cloverleaf shaped molecules have a metal atom at the center, surrounded by a ring of nitrogen atoms ( in porphyrins, two rings in phthalocyanines ). in each, the metal atom can be exchanged for other atoms among the transition metals. but, how does this substitution affect the energy levels of the molecule? can these molecules be tailored to optimize their performance in solar cells? the highest energy efficiency is currently obtained with dyes based on ruthenium, a rare and expensive metal. in nature, the chemically similar but much more abundant element iron facilitates electron transfer, for example in hemoglobin and cytochrome c. the active center of these dyes — the heme — is similar to that of porphyrin molecules, but it contains additional atoms that form a three - dimensional cage around the central iron atom. it would be advantageous to understand such biomolecules, what makes them so efficient, and how to mimic them with smaller, more robust molecules for use in organic solar cells. in an organic solar cell, sunlight is absorbed by an optical transition between a molecule ' s highest occupied and lowest unoccupied molecular orbitals ( homo and lumo ). in the molecules


, more robust molecules for use in organic solar cells. in an organic solar cell, sunlight is absorbed by an optical transition between a molecule ' s highest occupied and lowest unoccupied molecular orbitals ( homo and lumo ). in the molecules discussed here, the nitrogen cage and the central transition metal atom form the homo and lumo, whose close proximity and significant overlap facilitate electron transfer, which can be controlled by adjusting the orbital energies. the absorption of sunlight produces electrons and holes, which are ultimately responsible for producing electrical power at the solar cells ' electrodes. biomolecules are particularly good at separating electron – hole pairs produced by sunlight in a dye molecule and pulling them towards their destination with minimal energy loss, enabling optimal use of solar energy. x - ray absorption spectroscopy provides much more information than just that about energy levels : it monitors oxidation states, and when coupled with polarized synchrotron radiation, it reveals the orientation of the molecular orbitals. the multiplet structure of the metal spectra reveals the oxidation state of the metal atom in a dye molecule, which is crucial for electron transfer. in the course of this work, researchers found that iron and manganese ( two important transition metals in biomolecules ) easily change between + 2 and + 3 during the preparation of thin films such as those used in solar cells. this requires close monitoring to obtain reproducible solar cells. the polarization dependence of the spectra reveals the orientation of the molecules, which also varies depending on film preparation. this is critical for optimizing electron transport from dye molecules to electrodes. molecular conductivity is commonly poor, but can be mitigated by orienting the molecular orbitals of neighboring molecules such that they overlap optimally. research conducted by p. l. cook, f. j. himpsel and x. liu ( university of wisconsin madison ) ; and w. yang ( berkeley lab ). research funding : u. s. department of energy and the national science foundation. operation of the als and ssrl are supported by the u. s. department of energy, office of basic energy sciences. publication about this research : p. l. cook, x. liu, w. yang, and f. j. himpsel, " x - ray absorption spectroscopy of biomimetic dye molecules for solar cells, " j. chem. phys. 131, 194701 ( 2009 ).


josephson received the 1973 nobel prize in physics for discovery of the josephson effect, which occurs in two superconducting layers separated by an insulating oxide. under certain conditions current can pass through the insulator through tunneling of cooper pairs of electrons. the effect has been used to design superconducting quantum interference devices ( squid ) because switching is very fast, in the order of picoseconds. tunneling in the josephson junctions is very sensitive to magnetic fields and can therefore be used to measure extremely small magnetic fields with thresholds as low as tesla. josephson junctions are also used for other precision measurements. the standard volt is now defined as the voltage required to produce a frequency of 483, 597. 9 ghz in a josephson junction oscillator. a schematic diagram of a circuit with a josephson junction is shown below. the quantum effects can be modeled by the schrodinger equation, but it turns out that the circuit can also be modeled as a system with lumped parameters. let be the flux that is the integral of the voltage across the device, it follows from quantum theory [ feynman, 1970 ] that the current through the device is a function of the flux : where is a device parameter, and the josephson parameter is given by the circuit in the figure has two storage elements : the capacitor and the josephson junction. we choose the states as the voltage across the capacitor and the flux of the josephson junction. let, and be the currents through the resistor, the capacitor and the josephson junction. we have and a current balance gives which can be rewritten as combining this equation with equation for gives the following state equation for the circuit notice that apart from parameter values, this equation is identical to the equation for the inverted pendulum.


used during a concrete pour this small concrete block supports the rebar so it isn ' t forced to the bottom. abbreviation for the word document. 1. structure built into the water from the land providing a facility for boats to tie up. 2. loading area for goods at the rear of a commercial building. legal rule, principle or tenet. recorded materials including letters, photos, reproducible computer files, legal forms, etc. a document is any tangible information including letters, contracts, electronic or paper files, x - rays, receipts or other material evidence. list of documents that a lender requires from a potential borrower, such as paycheck stubs and credit card statements. any written evidence or tangible material that is coherent and related to the subject at hand. this includes documents, contracts, electronic and paper files, photographs and other non - oral evidence. tax imposed by some state and local governments to record property deeds and mortgages into the public records. polygon that is comprised of 12 angles and sides. solid figure comprised of 12 adjoining plane surfaces. heavy metal staple that makes a temporary connection between timbers. wooden fence with top corners of the vertical fence boards cut of at 45 - degree angles. dormer, which is in the shape of a small dog house. brick corners which project from a wall. modification in the amount of money involved for some justifiable reason. 1. any of several kinds of low, flat, wheeled frames for transporting heavy objects. 2. tool that holds a rivet at one end with a head hammered out of the other end. 3. a stick or board for stirring. bevel siding that is made with a rabbet or two - sided groove running along the edge which will overlap the top of the board below it. vertical piling structure which provides support to and contact with each other. a convex vaulted curvature often spherical in shape usually built atop of a building. they can be constructed of any material including masonry, wood, glass or steel and can be decorative or functional in nature. hemispherical ( 1 / 2 of a globe ) ceiling projecting upward. a person ' s permanent primary residence. alternately, the state where on has a permanent legal address. one who is considered the primary and principal estate administrator, being in the state where an individual was domiciled at the time of death. property that has an easement right through another adjoining property. the property through which the easement passes is considered to have the servient tenement. one to whom a


_ 196 ; silverman, 1977 ). in other cases, the ability to discriminate without awareness is minimally above chance and confined to a small number of subjects ( merikle and reingold, 1992, p. 67 ). experiments have similarly failed to corroborate the phenomenon of repression. after reviewing this research holmes has concluded that at the present time there is no controlled laboratory evidence supporting the concept of repression ( holmes, 1990, p. 96 ). in summary, " given the available evidence, it is still possible to argue that unconscious perceptual processes have not been shown to play any important role in directing human behavior " ( merikle and reingold, 1992, p. 76 ). the foregoing critiques of unconscious processes indicate that psychological activity does not proceed by mechanisms independent of consciousness. psychological activity is activity of consciousness. psychological activity is also inseparable from social life. accordingly, the unconscious and its products ( dreams, slips of the tongue, and dysfunctional symptoms ) must be reconceptualized as integral to a social consciousness ( cf. lakoff, 1993 for a social cognitive analysis of dreams ). reconceptualization would be objectified in terminology. the term " the unconscious " would be abandoned because it connotes a physical thing or place outside consciousness. " the unconscious " would be replaced by " unawareness " which connotes a process or state rather than some sort of thing. in the remainder of this paper, i shall attempt to articulate a social conception of unawareness. the most fruitful perspective for guiding this endeavor is sociohistorical psychology. this school was founded by lev vygotsky, alexander luria, and alexei leontiev in the 1920 ' s unawareness according to sociohistorical psychology an overview of sociohistorical psychology space does not permit a full explication of sociohistorical psychology which can be found in ratner ( 1991, 1993a ), van der veer and valsiner ( 1991 ), and wertsch ( 1985a, 1985b ). the cornerstone of this viewpoint is that psychological functions depend upon real social life and bear its imprint. specifically, as individuals participate in economic, political, educational, religious, recreational, familial, and interpersonal activities they form social concepts. social concepts are socially shared knowledge, expectations, and evaluations of objects, people, and events. social concepts are the meanings that things have for a culture ( cf., lutz


. the occupations determine the chief modes of satisfaction, the standards of success and failure. hence they furnish the working classifications and definitions of value ; they control the desire processes. moreover, they decide the sets of objects and relations that are important, and thereby provide the content or material of attention, and the qualities that are interestingly significant. the directions given to mental life thereby extend to emotional and intellectual characteristics. so fundamental and pervasive is the group of occupational activities that it affords the scheme or pattern of the structural organization of mental traits. occupations integrate special elements into a functioning whole. ( dewey, 1902, pp. 219 _ 220 ). moreover, social concepts structure somatic symptoms of psychological dysfunction. smith rosenberg ( 1972 ) concludes that hysterical conversion in nineteenth century middle - class women reflected the social value that women should be weak and spiritual rather than physically active. this social value led frustrated women to deaden their senses and immobilize their limbs, thereby exaggerating the normative gender ideal ( ratner, 1991, p. 274 ). kleinman and kleinman ( 1985, p. 434 ) similarly conclude that social values channel stress into somatic symptoms among precapitalist people and among lower class and rural groups in capitalist societies, while channeling stress into psychological symptoms among people living a more bourgeois life style. the defining features of social concepts are that they are shared by individuals and that they are rooted in concrete social activities of a social system. social concepts originate in particular praxis within particular sectors and classes ( or fields ) of a social system ( cf. bourdieu and wacquant, 1992, pp. 94 _ 115 ). but concepts may migrate to other sectors and classes and become quite general. economic concepts such as competition, individualism, and materialism may permeate family life, education, and the arts ( adorno, 1974 ; bronfenbrenner, 1979 ; henry, 1963 ; leach, 1993 ). religious ideas and scientific concepts may also achieve broad acceptance. wherever social concepts are accepted, they organize perception, emotions, motives, imagination, needs, and bodily functions. research on the cultural - cognitive basis of psychological functions has been summarized by shweder and sullivan ( 1993 ) and ratner ( 1991 ). this research demonstrates that psychological phenomena are integrated with each other, with social life, and with consciousness. unfortunately, little is known about the specific operations by which social concepts organize psychological phenomena. according to sociohistorical psychology, social concepts


1991 ). this research demonstrates that psychological phenomena are integrated with each other, with social life, and with consciousness. unfortunately, little is known about the specific operations by which social concepts organize psychological phenomena. according to sociohistorical psychology, social concepts form psychological activity. they do not simply inhibit pre - social, pre - conscious functions. social concepts reorganize and reconstitute natural, infantile functions into psychological activity. natural functions do not retain their original character and continue to operate independently of social consciousness. in vygotsky ' s words, " culture reworks all the child ' s natural behavior and carves anew his entire course of development " ( 1993, p. 166 ). individual thoughts may be anti - social in content they may oppose certain social norms however they are not pre - social in origin. nor do social concepts influence the mind by operating on one function e. g., sexuality which, in turn, determines all other functions. social concepts directly form all psychological activity ; their impact is broad and systematic. in the same way, social concepts derive from the totality of social relations, not simply from a single domain of sexual mores. social influences on consciousness include economic, political, and other norms. in contrast to freud ' s psychology which narrowed the impact of society and consciousness on psychology, sociohistorical psychology expands their importance. sociohistorical psychological principles of unawareness although vygotsky did not propose a sociohistorical model of unawareness, the foregoing principles can be extended to develop one. indeed, an alternative conception of the unconscious would strengthen the critique which vygotsky levelled against psychoanalysis. while he was initially sympathetic to freud ' s materialistic approach and remained attracted to certain of freud ' s ideas, his mature work repudiated freud ' s overall conceptual system ( van der veer and valsiner, 1991, chapter five ). an exhaustive reconceptualization of the unconscious is beyond the scope of this paper. in what follows i shall only outline some fundamental concepts concerning the nature of unawareness. to begin with, sociohistorical psychology accepts freud ' s distinction between psychological phenomena which are temporarily beyond the focus of attention but are readily accessible ( the preconscious ), versus phenomena which are only accessible through extensive analysis ( the unconscious ). however, sociohistorical psychology constructs this distinction in terms that are significantly different from freud ' s. a more acceptable view of temporary unawareness is the ph