MattC

Mass extinction can occur for many reasons. I suspect that, if we survive a million more years (not so long a time, really), we will be able to prevent objects from space from impacting earth. That's one less mass extinction. If there is a supervolcanic eruption or two, and the earth is dusted over, that may be a different story. Or perhaps by then humans will be able to survive under the earth? Let's see... what are some other plausable causes of mass extinction? Anyway, while it's a nice idea, it's a bit of a stretch to assume that, should another mass extinction come, huge reptiles would end up dominating the Earth. There are many other possibilities.

Sounds like you have OCD, obsessive compusive disorder. But if that's all you do, then either you have a really, really mild case, or you are just anal-retentive and that happens to be a habit of yours. If it's just a habit, you can probabily condition yourself by looking at pointy objects and not doing what you do. If it's OCD, see a professional, if you really need to stop.

Hmmm... I wonder if you are asking the right question. Why are you interested in artificial photosynthesis? If you are interested in it as a means of turning solar energy into something useful, we have a few types of photovoltaic cells that convert sun energy to electricity. Honestly, I can't think of any good reason to make artificial photosynthesis, as any products we might want are (probably .. but not certainly) already widely available. Photosynthesis is, specifically, how plants turn sunlight into energy to convert atmospheric carbon (carbon dioxide) into organic carbon. We have plenty of sources of organic carbon, in fact the products of photosynthesis are as abundant as plants themselves. But as far as a truly artificial form of photosynthesis, which utilizes sunlight to convert inorganic carbon to organic carbon, I don't think such a thing exists, or if it does it is not in widespread use. I'm sure it could be invented, though - there are chemical reactions that can break carbon-oxygen bonds and rebond the carbon to hydrogen, oxygen, and I suspect many other elements, and a solar panel could be used to generate a current to drive these reactions.

When I first read about this, it seemed exciting and interesting... quite an idea. The more I think about it, the more wild and crazy ... and dangerous it seems to me. If they do this, I hope they study their asses off, because the benefits if it works well are much smaller, in my opinion, than the worst case costs if it goes terribly wrong.

There are some excellent replies here, but I'll add a little anyway The 10% rule, which is not exact by any standard, as another poster pointed out, means that a vegetarian diet requires less energy to produce - meaning, a vegetarian eats the same amount of calories, perhaps, but the sun energy required to produce those calories is much less. A cow eats many, many pounds of grains to produce a single pound of meat. Additionally, that grain needs to be transported, except in those relatively rare cases where the cows simply graze (despite what you see in commercials for california cheese, the vast majority of cows are in crowded lots, where there is no grass, just piles of dung, and piles of imported (locally, I imagine) grain food). While transportation costs are not factored into the 10% rule, it's important with regards to humans. And as far as water goes .... 1 pound of beef requires over 2,000 gallons of water (estimates vary, but the ones not produced by the obviously biased meat industry cite figures in this range, whereas beef producers claim that beef is much more efficient in terms of water; I suspect the actual average amount is significantly higher than 2,000, but I wanted to cite an extremely conservative value)), whereas 1 pound of, say, wheat, takes under 30 gallons of water. That one pound of wheat is a tiny fraction of the amount of grain a cow needs over it's life, up to the point it is ready for the slaughter. Of course, the whole picture is much more complicated, but I hope this helps. So no, a vegetarian needs to eat just as much, possibly more, as meat is chock full of calories, while vegetables are low on calories. Of course, if a meat eater doesn't get his veggies, he gets sick.

Perhaps I am misunderstanding your idea of conservation of information (as that could be interpreted a number of ways), but here's my two cents: matter has a direction, velocity, mass, etc - various properties which can be considered "information." In normal space, this information is conserved - for instance, a baseball flying through the atmosphere contains "information" about where it came from, it's initial velocity, etc, down to the spin directions of all the electrons. Granted, we may not be able to access most of this information, due to the uncertainty principle, but it's there. Some people have argued that when matter is sucked into a black hole, it is converted to some sort of informationless sludge, and since all matter presumably (or at least some matter) will end up in a black hole, information will be lost. Steven Hawking recently suggested or decided (I don't recall the exact details, but if you're really interested a quick google will fill in the gaps) that information sucked into a black hole actually does retain the information, and perhaps that information is actually emitted by black holes (in the form of the matter or antimatter that escapes from the border of the event horizon, or in the form of the entire black hole, which may eventually evaporate completely as it leaches matter via the matter-antimatter processes on the edge of the (potentially shrinking?) event horizon. If that is the case, then indeed all information is preserved, from the moment of "creation," however we define that, to the "end," if there is such a thing. My understanding of this stuff is only in the abstract, and I have to take the word of experts like Hawking, and who knows how much of this I truly understand - it's one thing to read a book and maybe even be able to regurgitate some of it in a meaningful way, and it's another thing entirely to be able to grasp the mechanics of processes that occur on such vast or minute scales. If the human mind is even able to grasp these things at all, there is the question of whether or not I read it all right. I'm just an environmental scientist, after all, not a physicist. But I hope this helps to answer your question, or at least lead you down a path that might lead you to an answer.

When you burn a piece of wood, you are taking the carbon and hydrogen bonds in the wood, combining them with oxygen in the air, and producing water, carbon dioxide, and heat (a gross simplification -there are many other products, but these are the ones of interest to us). When you breath in, you take in air, with oxygen. Your lungs take up some of that oxygen, your blood delivers it to cells, and your cells use that oxygen and the food that you eat (which, like wood, has carbon and hydrogen molecules - another gross simplification, but hey it's 2 am, what do you expect?) in a process similar to the burning of the wood to produce heat, water, and carbon dioxide (which you breath out). The heat is either sent out through the body as heat, or used to turn ADP into ATP - ADP and ATP are the same thing, in a sense, they are just like a battery in a charged and uncharged state. ATP is charged. So you breath in, burn food, use some energy to turn ADP (uncharged energy molecules in your cells) into ATP, and some of the heat is "lost" as heat which just radiates out of your body. Also, as your body uses the energy in ATP, some of the energy is "lost" as heat, instead of work, much the same way a car loses some of it's fuel energy to heat (most of it, actually - most of the fuel your car burns doesn't make it move, but instead is wasted as heat loss, or entropy as it is called). I hope that was helpful!

Vibrations travel very well through solids, but in your example, they are not traveling from the speakers, to your hands, to your ears - the waves are traveleing through air from the speakers, to your hands (and probably around them, as well, through small gaps in your coverage), and through your hands to some degree, and then again through air ... before reaching the hairs in your ear that receive the sound. In other words, you are buffering the sound, not amplifying it, as ultimately the sound travels to the end-destination in your ears through air. The only way around that last air passage would be to use something to bridge the air outside of your ears and away from your head directly with the hairs in your ears (or your ear drums), and this would cause damage, most likely. It's more likely, in my opinion, that the sound was unpleasantly loud, and that by muffling it you were able to focus on the pleasant aspects of the sound. Alternately, you may have a personal preference for certain sound frequencies, and you were probably not affecting all frequences equally with what you were doing. After all, much of the low freq sound waves are probably traveling through the ground more than through the air, as the speakers are sitting on the ground. Hope that helps

I could be mistaken but I believe that even P3's have some measure of protection against overheating ... I believe I read that on Tom's Hardware, when they tested a whole bunch of CPU's to see which ones they could burn out.

I suppose I could be missing out on something important here, but it seems to me that there is very little science in this thread. Fly's perceiving time faster or slower than humans? It seems rediculous to me. I suspect that our perception of how "fast" time is is dependent upon factors such as mood (are we happy where we are, or are we busy anticipating some future event ... and eager for time to "move faster") and reaction times. An event would appear to be "fast" if we do not have time to react - our reaction times are determined by various pathway lengths ... the distance chemicals and light and such have to travel to make the machinary of our brains get to the stage in response where the chemical signals to respond are sent out. That response may be physical, as in a movement, or emotional ... or otherwise. But ultimately our perception of time is hardly fixed, it is relative to so many factors. It seems silly to me to compare our perception of time with a fly's - fly's cannot respond in the ways that we can respond, they cannot (presumably) contemplate events like we can, they cannot (presumably) perceive events as being linear in "time," they cannot (presumably) predict the future. Fly's almost certainly do not "perceive time" in any way that resembles the intellectual concept of time that is being bandied about on this thread - they, like us, are just machines, and in the case of a fly, I'd say it's fairly likely that the closest thing they have to "perception of time" is very, very basic, and limited to action-reaction. If you swat at a fly and miss, will the fly think ... "gee, that human's hand moved slow! ...? Or will the fly just do whatever it was doing, respond however it is able, and not "think" at all, in any sense of the word as we humans use it. I suspect the latter. Therefor perception of time is irrelevant. Furthermore, to clarify something about relatively - The Theory of Relativity should not come up in a discussion of perception of time rates unless you talk about the movement of light. The theory states that light must move at the same rate (distance per time) and that for objects moving faster than others, the curvature of space and time allow for that object (that is moving faster than another) to exist in a "slow" bubble in time - by slowing it's time factor down, light is able to hit it at the same speed it hits everything else. So relatively only affects perception of time if a creature is physically MOVING faster, and the differences in speed that you will see between a fly and a person will not allow for significant (I suspect) dilation of time. If you want to talk about time being perceived at different rates, talk about objects or people moving at vastly different rates, or talk about different people with significantly different intellectual abilities ... then you'll have something. That's my perspective on this strange thread.

Metal may corrode slowly from the inside, but it could be easily coated with something that wouldn't.

You probably don't need to make up anything far-fetched. As it is, the world is overpopulated and filled with strife, valuable resources are being over- and mis-used, and the environment (and thus the ability of the environment to sustain life) is being broadly degraded. You can argue, in your story, that poor land use has lead to the near-permanent destruction of most of the worlds arable land - pick a country you want out of the picture, and say that over-irrigation using river water, lake water, or partially desalted ocean water has lead to a build up of salts. The development of new, salt resistent plants encouraged the people in that country to ignore the warnings of concerned environmentalists and continue to irrigate without proper drainage (which can be impossible, without pumping, in some areas). At some point the fertile lands of that country became simply too salty to grow anything, and the people starve or go to war with a neighbor. Perhaps you can use the spread of AIDs as a vehicle for fictional mass die-offs. If you want something a little fartherfetched.. Or a massive earthquake in antarctica could knock both ice sheets off in a matter of days, causing an increase in sea levels large enough to kill off huge swaths of people living along the coasts and displace (and concentrate) many more. The increased surface area of the now larger oceans of the world mean that the albedo of the Earth is greater - the Earth would warm up, humidity, precipitation, and retention of solar energy would all increase. Before the process becomes irreversible, it's plausable that ocean currents would shift, leading to less heat transfer between the warm equatorial regions and the cooler polar regions - this would lead to significant cooling in polar regions, and the increased vapor in the atmosphere (atmospheric mixing would occur just as much as normally, even though oceanic mixing between the equator and the poles would stop) would lead to clouds and snowfall, both of which would increase the Albedo of the Earth and cause a decrease in temperature, back to levels below pre-earthquake levels. In the frigid, wet northern regions of the world, agriculture would be difficult if not impossible without advanced technology, and in the equatorial regions rain and fertile land would be available, but the increased concentration of people and the higher temperatures could lead to massive outbreaks of disease that might wipe out entire populations in some cases, and leave others crippled.