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56fa97178f12f31900630182
Strict notation is required with HD fractional rates to avoid what?
ambiguity
[ "High-definition_television\n\n50 Hz systems support three scanning rates: 50i, 25p and 50p. 60 Hz systems support a much wider set of frame rates: 59.94i, 60i, 23.976p, 24p, 29.97p, 30p, 59.94p and 60p. In the days of standard definition television, the fractional rates were often rounded up to whole numbers, e.g....
56fa995df34c681400b0c0f9
What is usually dropped for the commercial naming of an HDTV product?
the frame rate
[ "High-definition_television\n\nFor the commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames...
56fa995df34c681400b0c0fa
What does 24p mean?
24 progressive scan frames per second
[ "High-definition_television\n\nFor the commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames...
56fa995df34c681400b0c0fb
What does 50i mean?
25 interlaced frames per second
[ "High-definition_television\n\nFor the commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames...
56fa995df34c681400b0c0fc
When naming a commercial HDTV product, a frame rate can be specified without what?
a resolution
[ "High-definition_television\n\nFor the commercial naming of a product, the frame rate is often dropped and is implied from context (e.g., a 1080i television set). A frame rate can also be specified without a resolution. For example, 24p means 24 progressive scan frames per second, and 50i means 25 interlaced frames...
56fa9afa8f12f31900630187
Is there a single standard for HDTV color support?
no
[ "High-definition_television\n\nThere is no single standard for HDTV color support. Colors are typically broadcast using a (10-bits per channel) YUV color space but, depending on the underlying image generating technologies of the receiver, are then subsequently converted to a RGB color space using standardized algo...
56fa9afa8f12f31900630188
Before being converted to RGB, colors are ususally broadcasted using what color space?
YUV
[ "High-definition_television\n\nThere is no single standard for HDTV color support. Colors are typically broadcast using a (10-bits per channel) YUV color space but, depending on the underlying image generating technologies of the receiver, are then subsequently converted to a RGB color space using standardized algo...
56fa9afa8f12f31900630189
Colors are typically broadcast using YUV and then converted to what?
a RGB color space
[ "High-definition_television\n\nThere is no single standard for HDTV color support. Colors are typically broadcast using a (10-bits per channel) YUV color space but, depending on the underlying image generating technologies of the receiver, are then subsequently converted to a RGB color space using standardized algo...
56fa9afa8f12f3190063018a
When transmitted over the internet, colors are typically to what?
8-bit RGB channels
[ "High-definition_television\n\nThere is no single standard for HDTV color support. Colors are typically broadcast using a (10-bits per channel) YUV color space but, depending on the underlying image generating technologies of the receiver, are then subsequently converted to a RGB color space using standardized algo...
56fa9afa8f12f3190063018b
What assumption is made with colors being transmitted over the internet?
it will only be viewed only on a (sRGB) computer screen
[ "High-definition_television\n\nThere is no single standard for HDTV color support. Colors are typically broadcast using a (10-bits per channel) YUV color space but, depending on the underlying image generating technologies of the receiver, are then subsequently converted to a RGB color space using standardized algo...
56fa9f9df34c681400b0c101
At least how many times more linear resolution does HDTV have over SDTV?
twice
[ "High-definition_television\n\nAt a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or a...
56fa9f9df34c681400b0c102
HDTV increases the effective image resolution by not using what?
letterboxing or anamorphic stretching
[ "High-definition_television\n\nAt a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or a...
56fa9f9df34c681400b0c103
What does SDTV stand for?
standard-definition television
[ "High-definition_television\n\nAt a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or a...
56fa9f9df34c681400b0c104
HDTV handles what aspect ratio without using letterboxing or anamorphic stretching?
16:9
[ "High-definition_television\n\nAt a minimum, HDTV has twice the linear resolution of standard-definition television (SDTV), thus showing greater detail than either analog television or regular DVD. The technical standards for broadcasting HDTV also handle the 16:9 aspect ratio images without using letterboxing or a...
56faa8ff8f12f31900630191
If more bandwith is required than is available, a very high resolution source my not be able to transmitted without loss of what?
fidelity
[ "High-definition_television\n\nA very high resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The lossy compression that is used in all digital HDTV storage and transmission systems will distort the received picture, when compared to the uncompressed sou...
56faa8ff8f12f31900630192
The compression used in all HDTV storage and transmission systems will do what if resolution is too high?
distort the received picture
[ "High-definition_television\n\nA very high resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The lossy compression that is used in all digital HDTV storage and transmission systems will distort the received picture, when compared to the uncompressed sou...
56faa8ff8f12f31900630193
A very high resolution source may require more of what?
bandwidth
[ "High-definition_television\n\nA very high resolution source may require more bandwidth than available in order to be transmitted without loss of fidelity. The lossy compression that is used in all digital HDTV storage and transmission systems will distort the received picture, when compared to the uncompressed sou...
56faaa04f34c681400b0c109
A broadcasts optimum format depends on what two things?
the type of videographic recording medium used and the image's characteristics
[ "High-definition_television\n\nThe optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. For best fidelity to the source the transmitted field ratio, lines, and frame rate should match those of the source." ]
56faaa04f34c681400b0c10a
For best fidelity to the source, what three things should match the source?
transmitted field ratio, lines, and frame rate
[ "High-definition_television\n\nThe optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. For best fidelity to the source the transmitted field ratio, lines, and frame rate should match those of the source." ]
56faaa04f34c681400b0c10b
For best fidelity to the source, the transmitted field ratio, lines, and frame rate should match what?
those of the source
[ "High-definition_television\n\nThe optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. For best fidelity to the source the transmitted field ratio, lines, and frame rate should match those of the source." ]
56faaa04f34c681400b0c10c
The type of videographic recording medium used and the image's characteristics determine what?
The optimum format for a broadcast
[ "High-definition_television\n\nThe optimum format for a broadcast depends upon the type of videographic recording medium used and the image's characteristics. For best fidelity to the source the transmitted field ratio, lines, and frame rate should match those of the source." ]
56faaac38f12f31900630197
PAL, SECAM, and NTSC frame rates apply to what definition televisions?
analogue standard
[ "High-definition_television\n\nPAL, SECAM and NTSC frame rates technically apply only to analogue standard definition television, not to digital or high definition broadcasts. However, with the roll out of digital broadcasting, and later HDTV broadcasting, countries retained their heritage systems. HDTV in former P...
56faaac38f12f31900630198
PAL, SECAM, and NTSC frame rates do not apply to what broadcasts?
digital or high definition
[ "High-definition_television\n\nPAL, SECAM and NTSC frame rates technically apply only to analogue standard definition television, not to digital or high definition broadcasts. However, with the roll out of digital broadcasting, and later HDTV broadcasting, countries retained their heritage systems. HDTV in former P...
56faaac38f12f31900630199
In former PAL and SECAM countries, what frame rate does HDTV operate at?
25/50 Hz
[ "High-definition_television\n\nPAL, SECAM and NTSC frame rates technically apply only to analogue standard definition television, not to digital or high definition broadcasts. However, with the roll out of digital broadcasting, and later HDTV broadcasting, countries retained their heritage systems. HDTV in former P...
56faaac38f12f3190063019a
In former NTSC countries, what frame rate does HDTV operate at?
30/60 Hz
[ "High-definition_television\n\nPAL, SECAM and NTSC frame rates technically apply only to analogue standard definition television, not to digital or high definition broadcasts. However, with the roll out of digital broadcasting, and later HDTV broadcasting, countries retained their heritage systems. HDTV in former P...
56faae57f34c681400b0c111
At what rate is standard 35mm photographic film exposed and projected?
24 frames per second
[ "High-definition_television\n\nStandard 35mm photographic film used for cinema projection has a much higher image resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second (frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate...
56faae57f34c681400b0c112
To be shown on SDTV in PAL-system countries, at what rate is cinema film scanned?
25 frame/s
[ "High-definition_television\n\nStandard 35mm photographic film used for cinema projection has a much higher image resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second (frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate...
56faae57f34c681400b0c113
The technique in which with successive pair of film frames, one is held for three video fields, and the next is held for two, is called what?
3:2 Pulldown
[ "High-definition_television\n\nStandard 35mm photographic film used for cinema projection has a much higher image resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second (frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate...
56faae57f34c681400b0c114
The 3:2 Pulldown techniques gives what total time for two frames?
1/12 of a second
[ "High-definition_television\n\nStandard 35mm photographic film used for cinema projection has a much higher image resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second (frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate...
56faae57f34c681400b0c115
What is achieved by the 3:2 Pulldown technique producing a total time of 1/12 of a second for two frames?
the correct average film frame rate
[ "High-definition_television\n\nStandard 35mm photographic film used for cinema projection has a much higher image resolution than HDTV systems, and is exposed and projected at a rate of 24 frames per second (frame/s). To be shown on standard television, in PAL-system countries, cinema film is scanned at the TV rate...
56fab555f34c681400b0c11b
What two formats are typically used to recorde non-cinematic HDTV video intended for broadcast?
720p or 1080i
[ "High-definition_television\n\nNon-cinematic HDTV video recordings intended for broadcast are typically recorded either in 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet distribution of high-definition video, because most computer monitors operate in progressive-scan mode....
56fab555f34c681400b0c11c
Which format is typically used for internet distribution of HD video?
720p
[ "High-definition_television\n\nNon-cinematic HDTV video recordings intended for broadcast are typically recorded either in 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet distribution of high-definition video, because most computer monitors operate in progressive-scan mode....
56fab555f34c681400b0c11d
Most computer monitors operate in what mode?
progressive-scan
[ "High-definition_television\n\nNon-cinematic HDTV video recordings intended for broadcast are typically recorded either in 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet distribution of high-definition video, because most computer monitors operate in progressive-scan mode....
56fab555f34c681400b0c11e
1080i, 1080p, and 720p are often used on what kind of disc.
Blu-ray
[ "High-definition_television\n\nNon-cinematic HDTV video recordings intended for broadcast are typically recorded either in 720p or 1080i format as determined by the broadcaster. 720p is commonly used for Internet distribution of high-definition video, because most computer monitors operate in progressive-scan mode....
56fac6d48f12f3190063019f
In the US, what kind of tuner is needed for residents to receive free, over the air programming?
ATSC
[ "High-definition_television\n\nIn the US, residents in the line of sight of television station broadcast antennas can receive free, over the air programming with a television set with an ATSC tuner (most sets sold since 2009 have this). This is achieved with a TV aerial, just as it has been since the 1940s except n...
56fac6d48f12f319006301a0
Laws regarding antennas were upated before what?
the change to digital terrestrial broadcasts
[ "High-definition_television\n\nIn the US, residents in the line of sight of television station broadcast antennas can receive free, over the air programming with a television set with an ATSC tuner (most sets sold since 2009 have this). This is achieved with a TV aerial, just as it has been since the 1940s except n...
56fac6d48f12f319006301a1
Who do these laws prohibit from banning the installation of antennas?
home owners' associations and city government
[ "High-definition_television\n\nIn the US, residents in the line of sight of television station broadcast antennas can receive free, over the air programming with a television set with an ATSC tuner (most sets sold since 2009 have this). This is achieved with a TV aerial, just as it has been since the 1940s except n...
56fac6d48f12f319006301a2
Laws about antennas keep home owners' associations and city government from banning what?
the installation of antennas
[ "High-definition_television\n\nIn the US, residents in the line of sight of television station broadcast antennas can receive free, over the air programming with a television set with an ATSC tuner (most sets sold since 2009 have this). This is achieved with a TV aerial, just as it has been since the 1940s except n...
56fac6d48f12f319006301a3
Most television sets sold since what year have an ATSC tuner?
2009
[ "High-definition_television\n\nIn the US, residents in the line of sight of television station broadcast antennas can receive free, over the air programming with a television set with an ATSC tuner (most sets sold since 2009 have this). This is achieved with a TV aerial, just as it has been since the 1940s except n...
56fac7ddf34c681400b0c123
HD content can be displayed by cable-ready TVs without using what?
an external box
[ "High-definition_television\n\nAdditionally, cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD." ]
56fac7ddf34c681400b0c124
Without using an external box, cable-ready TVs can display what?
HD content
[ "High-definition_television\n\nAdditionally, cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD." ]
56fac7ddf34c681400b0c125
What features allow the cable-ready TVs to display HD content without an external box?
a QAM tuner built-in and/or a card slot for inserting a CableCARD
[ "High-definition_television\n\nAdditionally, cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD." ]
56fac7ddf34c681400b0c126
What kind of built-in tuner will allow a cable-ready TV to display HD content without an external box?
QAM
[ "High-definition_television\n\nAdditionally, cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD." ]
56fac7ddf34c681400b0c127
What kind of card will allow a cable-ready TV to display HD content without an external box?
CableCARD
[ "High-definition_television\n\nAdditionally, cable-ready TV sets can display HD content without using an external box. They have a QAM tuner built-in and/or a card slot for inserting a CableCARD." ]
56fac8e58f12f319006301a9
Roku and AppleTV are examples of what?
IPTV
[ "High-definition_television\n\nHigh-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, IPTV (including GoogleTV Roku boxes and AppleTV or built into \"Smart Televisions\"), Blu-ray video disc (BD), and internet downloads." ]
56fac8e58f12f319006301aa
Internet downloads, Blu-ray videos, and Apple TV are examples of what?
High-definition image sources
[ "High-definition_television\n\nHigh-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, IPTV (including GoogleTV Roku boxes and AppleTV or built into \"Smart Televisions\"), Blu-ray video disc (BD), and internet downloads." ]
56fac8e58f12f319006301ab
Terrestrial broadcast and direct broadcast satellite are examples of what?
High-definition image sources
[ "High-definition_television\n\nHigh-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, IPTV (including GoogleTV Roku boxes and AppleTV or built into \"Smart Televisions\"), Blu-ray video disc (BD), and internet downloads." ]
56fac8e58f12f319006301ac
Digital cable and Roku are examples of what?
High-definition image sources
[ "High-definition_television\n\nHigh-definition image sources include terrestrial broadcast, direct broadcast satellite, digital cable, IPTV (including GoogleTV Roku boxes and AppleTV or built into \"Smart Televisions\"), Blu-ray video disc (BD), and internet downloads." ]
56faca31f34c681400b0c12d
Why does the PlayStation 3 have extensive HD compatibility?
because of its built in Blu-ray disc based player
[ "High-definition_television\n\nSony's PlayStation 3 has extensive HD compatibility because of its built in Blu-ray disc based player, so does Microsoft's Xbox 360 with the addition of Netflix and Windows Media Center HTPC streaming capabilities, and the Zune marketplace where users can rent or purchase digital HD c...
56faca31f34c681400b0c12e
In addition to having a Blu-ray player the Xbox 360 also features what?
Netflix and Windows Media Center HTPC streaming capabilities, and the Zune marketplace
[ "High-definition_television\n\nSony's PlayStation 3 has extensive HD compatibility because of its built in Blu-ray disc based player, so does Microsoft's Xbox 360 with the addition of Netflix and Windows Media Center HTPC streaming capabilities, and the Zune marketplace where users can rent or purchase digital HD c...
56faca31f34c681400b0c12f
What high definition gaming platform did Nintendo recently release?
The Wii U
[ "High-definition_television\n\nSony's PlayStation 3 has extensive HD compatibility because of its built in Blu-ray disc based player, so does Microsoft's Xbox 360 with the addition of Netflix and Windows Media Center HTPC streaming capabilities, and the Zune marketplace where users can rent or purchase digital HD c...
56faca31f34c681400b0c130
The HD capabilities of modern gaming systems has inspired developers to do what?
port games from past consoles onto the PS3, Xbox 360 and Wii U, often with remastered or upscaled graphics
[ "High-definition_television\n\nSony's PlayStation 3 has extensive HD compatibility because of its built in Blu-ray disc based player, so does Microsoft's Xbox 360 with the addition of Netflix and Windows Media Center HTPC streaming capabilities, and the Zune marketplace where users can rent or purchase digital HD c...
56facb5d8f12f319006301b1
Sky HD's set-top box, TiVo's Series 3, and Dish Network's VIP 622 are examples of what?
an HDTV-capable digital video recorder
[ "High-definition_television\n\nHDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receive...
56facb5d8f12f319006301b2
Some cable boxes are capable of doing what?
receiving or recording two or more broadcasts at a time in HDTV format
[ "High-definition_television\n\nHDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receive...
56facb5d8f12f319006301b3
What restriction does W-VHS recordings have?
analog only
[ "High-definition_television\n\nHDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receive...
56facb5d8f12f319006301b4
What does D-VHS stand for?
Digital-VHS or Data-VHS
[ "High-definition_television\n\nHDTV can be recorded to D-VHS (Digital-VHS or Data-VHS), W-VHS (analog only), to an HDTV-capable digital video recorder (for example DirecTV's high-definition Digital video recorder, Sky HD's set-top box, Dish Network's VIP 622 or VIP 722 high-definition Digital video recorder receive...
56facca98f12f319006301b9
When was the Hauppauge 1212 Personal Video Recorder introduced?
2008
[ "High-definition_television\n\nThe massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component vide...
56facca98f12f319006301ba
How does the Personal Video Recorder store content?
in MPEG-2 format in a .ts file or in a Blu-ray compatible format .m2ts file
[ "High-definition_television\n\nThe massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component vide...
56facca98f12f319006301bb
Recent systems can record a broadcast HD program in what format?
'as broadcast' format or transcode to a format more compatible with Blu-ray
[ "High-definition_television\n\nThe massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component vide...
56facca98f12f319006301bc
What uncompressed storage option was introduced in 2008?
the Hauppauge 1212 Personal Video Recorder
[ "High-definition_television\n\nThe massive amount of data storage required to archive uncompressed streams meant that inexpensive uncompressed storage options were not available to the consumer. In 2008, the Hauppauge 1212 Personal Video Recorder was introduced. This device accepts HD content through component vide...
56facd2f8f12f319006301c1
W-VHS recorders are capable of recording what kinds of signals?
analog HD
[ "High-definition_television\n\nAnalog tape recorders with bandwidth capable of recording analog HD signals, such as W-VHS recorders, are no longer produced for the consumer market and are both expensive and scarce in the secondary market." ]
56facd2f8f12f319006301c2
What kind of recorder is no longer produced for the consumer market?
Analog tape
[ "High-definition_television\n\nAnalog tape recorders with bandwidth capable of recording analog HD signals, such as W-VHS recorders, are no longer produced for the consumer market and are both expensive and scarce in the secondary market." ]
56facd2f8f12f319006301c3
In the secondary market, analog tape recorders are considered what?
expensive and scarce
[ "High-definition_television\n\nAnalog tape recorders with bandwidth capable of recording analog HD signals, such as W-VHS recorders, are no longer produced for the consumer market and are both expensive and scarce in the secondary market." ]
56faceb3f34c681400b0c135
Prior to 2004, what were US cable companies required to provide customers who rent HD set-top boxes?
a set-top box with "functional" FireWire (IEEE 1394) on request
[ "High-definition_television\n\nIn the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with \"functional\" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this fe...
56faceb3f34c681400b0c136
When were boxes with "functional" FireWire no longer included in the FCC mandate?
July 2004
[ "High-definition_television\n\nIn the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with \"functional\" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this fe...
56faceb3f34c681400b0c137
Content is now protected by what encryption?
5C
[ "High-definition_television\n\nIn the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with \"functional\" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this fe...
56faceb3f34c681400b0c138
What can 5c encryption prevent?
duplication of content or simply limit the number of copies permitted
[ "High-definition_television\n\nIn the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with \"functional\" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this fe...
56f9e2819b226e1400dd15e8
In addition to being used to build things, what has wood been used for over thousands of years?
fuel
[ "Wood\n\nIt has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems...
56f9e2819b226e1400dd15e9
What kind of strong fibers are part of the composite of wood?
cellulose
[ "Wood\n\nIt has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems...
56f9e2819b226e1400dd15ea
What's the matrix in wood made up of?
lignin
[ "Wood\n\nIt has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems...
56f9e2819b226e1400dd15eb
What one word describes the function wood provides to a tree or plant?
support
[ "Wood\n\nIt has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems...
56f9e2819b226e1400dd15ec
What does wood convey to leaves, roots, and other tissues of a woody plant in addition to water?
nutrients
[ "Wood\n\nIt has been used for thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers (which are strong in tension) embedded in a matrix of lignin which resists compression. Wood is sometimes defined as only the secondary xylem in the stems...
56f9e5219e9bad19000a0b4b
How many cubic meters of growing stock forest are there on the planet?
434 billion
[ "Wood\n\nThe Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Domina...
56f9e5219e9bad19000a0b4c
What percentage of the Earth's stock forest is commercial?
47%
[ "Wood\n\nThe Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Domina...
56f9e5219e9bad19000a0b4d
In addition to buildings, what is wood often used to make?
furniture
[ "Wood\n\nThe Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Domina...
56f9e5219e9bad19000a0b4e
About how many cubic kilometers of the vast stock forest's wood were harvested in 1991?
3.5
[ "Wood\n\nThe Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Domina...
56f9e5219e9bad19000a0b4f
In addition to being carbon neutral, what other adjective describes wood that makes it compelling as a renewable energy source?
abundant
[ "Wood\n\nThe Earth contains about 434 billion cubic meters of growing stock forest, 47% of which is commercial. As an abundant, carbon-neutral renewable resource, woody materials have been of intense interest as a source of renewable energy. In 1991, approximately 3.5 cubic kilometers of wood were harvested. Domina...
56f9e7ba9e9bad19000a0b55
What year were the earliest plants that grew wood discovered?
2011
[ "Wood\n\nA 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created." ]
56f9e7ba9e9bad19000a0b56
In which Canadian province were the oldest woody plants found?
New Brunswick
[ "Wood\n\nA 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created." ]
56f9e7ba9e9bad19000a0b57
If dendrochronology can't be used, what method would scientists employ to date wood?
carbon dating
[ "Wood\n\nA 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created." ]
56f9e7ba9e9bad19000a0b58
How many millions of years old were the plants that were discovered in New Brunswick?
395 to 400
[ "Wood\n\nA 2011 discovery in the Canadian province of New Brunswick uncovered the earliest known plants to have grown wood, approximately 395 to 400 million years ago. Wood can be dated by carbon dating and in some species by dendrochronology to make inferences about when a wooden object was created." ]
56f9e9738f12f3190062ffe7
What has been the primary purpose of wood for millennia other than fuel?
construction material
[ "Wood\n\nPeople have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time." ...
56f9e9738f12f3190062ffe8
What is often made of wood that provides shelter to people?
houses
[ "Wood\n\nPeople have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time." ...
56f9e9738f12f3190062ffe9
For clues about the climate of a place, we can look at variation in isotopic abundances or what other thing?
tree-ring widths
[ "Wood\n\nPeople have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time." ...
56f9e9738f12f3190062ffea
What could be made out of wood that could be used to fight off attackers?
weapons
[ "Wood\n\nPeople have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time." ...
56f9e9738f12f3190062ffeb
What category of items often constructed from wood does a chair belong to?
furniture
[ "Wood\n\nPeople have used wood for millennia for many purposes, primarily as a fuel or as a construction material for making houses, tools, weapons, furniture, packaging, artworks, and paper. The year-to-year variation in tree-ring widths and isotopic abundances gives clues to the prevailing climate at that time." ...
56f9eb0bf34c681400b0bedb
Where does wood come from?
trees
[ "Wood\n\nWood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascu...
56f9eb0bf34c681400b0bedc
What forms in a tree to increase its diameter?
woody layers
[ "Wood\n\nWood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascu...
56f9eb0bf34c681400b0bedd
What is the process of trees growing out to get bigger around called?
secondary growth
[ "Wood\n\nWood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascu...
56f9eb0bf34c681400b0bede
What do many places have four of that would cause growth rings in a tree?
seasons
[ "Wood\n\nWood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascu...
56f9eb0bf34c681400b0bedf
If a place has annual seasons, what are the growth rings on the trees there called?
annual rings
[ "Wood\n\nWood, in the strict sense, is yielded by trees, which increase in diameter by the formation, between the existing wood and the inner bark, of new woody layers which envelop the entire stem, living branches, and roots. This process is known as secondary growth; it is the result of cell division in the vascu...
56f9ecbff34c681400b0bee5
If a growth ring has differences over one season, would the part nearest the tree's center be narrower or wider?
wider
[ "Wood\n\nIf there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earl...
56f9ecbff34c681400b0bee6
What name, besides springwood, is used for the part of a growth ring formed in the beginning of the growing season?
earlywood
[ "Wood\n\nIf there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earl...
56f9ecbff34c681400b0bee7
If the opposite of springwood is summerwood, what's the opposite of earlywood?
latewood
[ "Wood\n\nIf there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earl...
56f9ecbff34c681400b0bee8
Is earlywood usually lighter or darker than the part of the growth ring that forms later in the season?
lighter
[ "Wood\n\nIf there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earl...
56f9ecbff34c681400b0bee9
Is summerwood the inner or outer portion of a growth ring?
outer
[ "Wood\n\nIf there are differences within a growth ring, then the part of a growth ring nearest the center of the tree, and formed early in the growing season when growth is rapid, is usually composed of wider elements. It is usually lighter in color than that near the outer portion of the ring, and is known as earl...
56f9ee81f34c681400b0bef7
What is the sort of circular imperfection in a piece of wood called?
knot
[ "Wood\n\nA knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear...
56f9ee81f34c681400b0bef8
What property of wood does a knot usually reduce in the wood around it?
strength
[ "Wood\n\nA knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear...
56f9ee81f34c681400b0bef9
In what direction is wood often sawn so that a knot appears as a solid circle that the grain flows around?
longitudinally
[ "Wood\n\nA knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear...
56f9ee81f34c681400b0befa
Are knots usually lighter or darker than the surrounding wood?
darker
[ "Wood\n\nA knot is a particular type of imperfection in a piece of wood; it will affect the technical properties of the wood, usually reducing the local strength and increasing the tendency for splitting along the wood grain, but may be exploited for visual effect. In a longitudinally sawn plank, a knot will appear...