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Shower thoughts: Plants perform photosynthesis by absorbing sunlight and using it to create sugar. By having the colour green the leaves must be reflecting some of the spectrum of sunlight, losing potential energy that the plant could be using. Why haven't all plants evolved to be black, absorbing more sunlight to maximize their energy intake?
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Dec 27, 2015 08:10
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Pigments that absorb energy efficiently are really complex and difficult to arrive at by random mutation, I believe the current theory is that chlorophyll evolved once in the entire timespan of life on Earth and has spread since. There are I believe certain rare plant strains with black pigments, but most of the visible spectrum is indeed covered (cholorphyll absorbs red and blue light, reflecting green in the middle, while other pigments absorb small amounts of green light.) Outside of visible, lower-frequency photons don't have enough energy to be worth harvesting, while higher-frequency (primarily UV, with some x-ray and gamma) are so energetic they cause tissue damage. The reason they're not more efficient is that they're efficient enough to reproduce, and that's all the "natural selection" portion of evolutionary mechanisms select for. Numbers I find are about .2% conversion efficiency from radiant to chemical energy for plants on average, up to about 8% peak for cultivated strains like sugarcane. It's dismally low compared to even solar panels, but it's enough to get the job done, so plants don't naturally evolve the (more complex and likely energy-intensive to produce) sorts of traits that would boost photosynthetic efficiency above that.
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Dec 27, 2015 08:45
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Enourmo posted:Pigments that absorb energy efficiently are really complex and difficult to arrive at by random mutation, I believe the current theory is that chlorophyll evolved once in the entire timespan of life on Earth and has spread since. To be fair, once photosynthesis popped up, it was a really nasty way to ensure survival of the fittest, since at the time chlorophyll producing plants started farting Oxygen, it was essentially germs spewing out poison gasses and committing what we would think of as warcrimes by polluting the atmosphere with O2. Oxygen is a fairly reactive gas, not quite as bad as Fluorine or Chlorine, but pumping tons of Oxygen into the air probably lead to the Earth's first mass extinction event. It also probably lead to the formation of multicelular organisms. So you know, no harm no foul.
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Dec 27, 2015 10:06
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Matte black plants would be the best for absorbing photons but in most places of the earth they would get too hot for at least part of the year for the enzymes that control photosynthesis to still work. Over 40°C the enzymes lose efficiency and past a certain point I can't remember off hand they denature and then the plant will die. If you've ever touched a black car that has sat in the sun you know how hot surfaces like that can get.
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Dec 27, 2015 10:14
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Memento posted:Matte black plants would be the best for absorbing photons but in most places of the earth they would get too hot for at least part of the year for the enzymes that control photosynthesis to still work. Over 40°C the enzymes lose efficiency and past a certain point I can't remember off hand they denature and then the plant will die. If you've ever touched a black car that has sat in the sun you know how hot surfaces like that can get. I was under the impression that the 'over 40 degrees' only applies to human enzymes. The exact temperature will depend on the organism (things with lower body temperatures will have lower maximum temperatures). There's no reason to assume 40C would be the maximum temperature for all of them.
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Dec 27, 2015 10:18
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Namarrgon posted:I was under the impression that the 'over 40 degrees' only applies to human enzymes. The exact temperature will depend on the organism (things with lower body temperatures will have lower maximum temperatures). There's no reason to assume 40C would be the maximum temperature for all of them. Plant enzymes are just as susceptible to temperature-driven denaturing. Phone posting right now but the search term you're after is "temperature denaturation of RuBisCo activase". There's an (I think) Eckhardt paper that is pretty good from (I think) around the mid-late 90s.
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Dec 27, 2015 11:37
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Memento posted:Plant enzymes are just as susceptible to temperature-driven denaturing. Phone posting right now but the search term you're after is "temperature denaturation of RuBisCo activase". There's an (I think) Eckhardt paper that is pretty good from (I think) around the mid-late 90s. Found it. Dangerous temperatures were around 55C and 33C for Rubisco and Rubisco activase respectively. Nevertheless, there is no reason why an enzyme couldn't have evolved to work in higher temperatures, as we have organisms that can survive boiling conditions. So that only moves the question around a bit.
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Dec 27, 2015 13:29
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I guess the same reason any other beneficial genetic anomaly never evolved. The random DNA mutant lottery never produced a black plant, or if it existed it wasn't better enough at being a plant for its mutation to propagate?
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Dec 27, 2015 13:36
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My wife's brother is my brother-in-law. Is there an English term for his wife? Is she my sister-in-law?
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Dec 27, 2015 14:39
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hooah posted:My wife's brother is my brother-in-law. Is there an English term for his wife? Is she my sister-in-law? Co-sister-in-law?
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Dec 27, 2015 15:08
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hooah posted:My wife's brother is my brother-in-law. Is there an English term for his wife? Is she my sister-in-law? Would that imply they are siblings? 
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Dec 27, 2015 15:36
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Wedemeyer posted:Why do royal bedrooms sometimes have those tiny dumb fences around the bed area? These are places where the public is allowed.
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Dec 27, 2015 15:40
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EVERYTHING I SAY ABOUT JAPAN OR LIVING IN JAPAN IS COMPLETELY WRONG, BUT YOU BETTER BELIEVE I'LL 
ABOUT IT.
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Memento posted:Matte black plants would be the best for absorbing photons but in most places of the earth they would get too hot for at least part of the year for the enzymes that control photosynthesis to still work. Over 40°C the enzymes lose efficiency and past a certain point I can't remember off hand they denature and then the plant will die. If you've ever touched a black car that has sat in the sun you know how hot surfaces like that can get. The sun produces a majority of green photons. This is why green is an advantageous color.
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Dec 27, 2015 15:46
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XmasGiftFromWife posted:The sun produces a majority of green photons. This is why green is an advantageous color. We see green because it is reflected. The plant doesn't use it.
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Dec 27, 2015 15:54
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XmasGiftFromWife posted:The sun produces a majority of green photons. This is why green is an advantageous color. Mak0rz posted:We see green because it is reflected. The plant doesn't use it. These two posts are, almost word-for-word, one of the examples of "unanswered questions in science" that Carl Sagan gave in his book The Demon-Haunted World (which is an awesome book and well worth tracking down). I honestly don't know if progress has been made on the matter in the 20 years since he wrote the book; I'm not a plantpigmentevolutionologist, even in my spare time.
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Dec 27, 2015 17:37
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Namarrgon posted:Found it. Dangerous temperatures were around 55C and 33C for Rubisco and Rubisco activase respectively. Well, there is a good reason, the "green" plants reproduced well enough that they nudged out the other plants. This has been covered.
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Dec 27, 2015 19:21
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Is it possible to hide certain subforums? E.g. FYAD since it's users and moderators are apparently fuckwits who don't care about spoiling one of the biggest movies of the decade.
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Dec 27, 2015 20:37
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Shakugan posted:Is it possible to hide certain subforums? E.g. FYAD since it's users and moderators are apparently fuckwits who don't care about spoiling one of the biggest movies of the decade. Welcome to something awful dot com.
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Dec 27, 2015 20:40
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XmasGiftFromWife posted:Welcome to something awful dot com. Something Awful is generally much better than 4-chan, Reddit and the like, since its dickheads are contained to two forums (GBS and FYAD) by generally strict moderating. It shouldn't be an expected thing that a moderator would allow that forum title.
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Dec 27, 2015 20:47
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Shakugan posted:Is it possible to hide certain subforums? E.g. FYAD since it's users and moderators are apparently fuckwits who don't care about spoiling one of the biggest movies of the decade. Thanks for confirming it rear end in a top hat.
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Dec 27, 2015 20:55
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uBlock allows me to block specific elements of a website, in this case the FYAD title.
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Dec 27, 2015 21:03
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I like to take my dickheads in moderation.
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Dec 27, 2015 21:03
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What did it say? edit: spoiler it of course, I'm just curious, I have no interest in the movie
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Dec 27, 2015 21:13
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Shakugan posted:Is it possible to hide certain subforums? E.g. FYAD since it's users and moderators are apparently fuckwits who don't care about spoiling one of the biggest movies of the decade. If you're up for learning a new skill, it shouldn't be too hard to make yourself a greasemonkey script that will hide the table row that shows FYAD on the forums list page.
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Dec 27, 2015 21:17
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snape kills dumbledore
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Dec 27, 2015 21:30
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Is there any current way to get AMC a la carte? Preferably watchable with a PS4 or Chromcast.
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Dec 27, 2015 21:41
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Shakugan posted:Is it possible to hide certain subforums? E.g. FYAD since it's users and moderators are apparently fuckwits who don't care about spoiling one of the biggest movies of the decade. Oh, I know the answer to this one! "You have so much spare time that you are able to care about movies, and you squander it getting angry about movies."
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Dec 27, 2015 21:44
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NESguerilla posted:Is there any current way to get AMC a la carte? Preferably watchable with a PS4 or Chromcast. It's available among other channels via Sling ($20/mo)
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Dec 27, 2015 21:57
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NESguerilla posted:Is there any current way to get AMC a la carte? Preferably watchable with a PS4 or Chromcast. You can also buy most shows on Amazon and stream them on your PS4/Chromecast, if that's your thing.
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Dec 27, 2015 22:46
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Shakugan posted:Is it possible to hide certain subforums? E.g. FYAD since it's users and moderators are apparently fuckwits who don't care about spoiling one of the biggest movies of the decade. If you want to never see the name, use adblock plus or ublock origin to block the link on the forums main page. Won't help you for if you ever use the forum selector drop down I guess.
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Dec 27, 2015 22:53
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mlnhd posted:It's available among other channels via Sling ($20/mo) I signed up for the free trial and do they not keep an on demand library? This service seems bad. I'm basically trying to catch up on TWD without having to drop like $50 for the whole season and that spinoff show.
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Dec 27, 2015 23:56
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hooah posted:My wife's brother is my brother-in-law. Is there an English term for his wife? Is she my sister-in-law? I think the closest may be "sister-in-law by marriage", but English generally doesn't have those neat, efficient words for describing how someone is related to you that some languages have, you generally just have to explain it long form, like "my wife's brother's wife".
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Dec 28, 2015 02:28
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Tiggum posted:I think the closest may be "sister-in-law by marriage", but English generally doesn't have those neat, efficient words for describing how someone is related to you that some languages have, you generally just have to explain it long form, like "my wife's brother's wife". You could always just say "my brother in law's wife."
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Dec 28, 2015 02:32
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I'm having a hard time figuring out what a shearling rug is. I assumed it was a skinned sheep with the coat still attached and the hide tanned on the other side but when I look up shearling it says that it is from a sheep that has been shorn once. Is their coat attached to some other type of leather or material?
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Dec 28, 2015 03:57
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NESguerilla posted:I signed up for the free trial and do they not keep an on demand library? This service seems bad. Sling does not have on demand. It's a replacement for regular cable TV and the price reflects that. If it had an on demand library the. It would just be another Hulu at that point.
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Dec 28, 2015 04:59
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punch drunk posted:I'm having a hard time figuring out what a shearling rug is. I assumed it was a skinned sheep with the coat still attached and the hide tanned on the other side but when I look up shearling it says that it is from a sheep that has been shorn once. Is their coat attached to some other type of leather or material? It's what you immediately assumed. Shearling is used to date the age of the sheep it's made from, it's like the difference between "lamb" and "mutton". A shearling rug is a sheepskin rug that's been made from a sheep between one and two years old. There's a good rundown on it here, if you want more information.
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Dec 28, 2015 13:43
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NESguerilla posted:I'm basically trying to catch up on TWD without having to drop like $50 for the whole season and that spinoff show. You can catch every season except the current one (6) on Netflix. If you obtain season 6 legally, you're probably going to end up paying about that much no matter how you do it.
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Dec 28, 2015 17:08
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Are there any U.S. zoos with quokkas? Is there a site that catalogs where you can find certain animals?
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Dec 28, 2015 19:10
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I'm having serious difficulty uploading a gif into a thread. I found one on tumblr that I'm trying to post but I can't figure it out can someone walk me through this cause I'm a retard
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Dec 28, 2015 20:50
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Grody posted:I'm having serious difficulty uploading a gif into a thread. I found one on tumblr that I'm trying to post but I can't figure it out can someone walk me through this cause I'm a retard Save the picture to a local drive. Open a web browser and surf your way to imgur.com. Upload (you can literally drag the file from Windows Explorer to the imgur browser window, it will begin the upload process...I think there is also an Upload link somewhere). Copy the BBCode link once it is uploaded, paste into your post. If the dimensions of the image are large you can add a "t" before the "img" in the opening and closing tags so it reads code:If none of this works just post the link here and I'll give you an imgur link, provided it's not too large, the original file is downloadable, etc. uwaeve fucked around with this message at 21:04 on Dec 28, 2015 |
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Dec 28, 2015 21:00
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