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MattC

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About MattC

  • Rank
    Baryon
  • Birthday 02/20/1981

Profile Information

  • Location
    Berkeley
  • Interests
    Learning!
  • College Major/Degree
    UCR - B.S. ENSC
  • Occupation
    GC Chemist
  1. Thank you guys for your input! Regarding the light being used by plants not turning into heat - it doesn't turn into heat till I eat it!! Then it'll probably be used to heat my body while I'm outside, so you're right - some of the light won't heat the house. However, assuming you want to heat your house AND grow a plant indoors (which for some people is very rewarding, strange though it is), then the energy is used at 100% efficiency (it's either used in photosynthesis, a desired application, or heating - not counting any light that escapes through a window, of course. That idea of converting a gas heater to a generator is simply brilliant! __________________________________________________________ One flaw with my plant growing plans is that there are plenty of days where I won't be interested in heating my house - so I'm torn between a desire to build the simplest, cheapest configuration that grows and warms (that would be T8 fluorescent fixtures, 4', with a variety of bulb types - right now I'm using only one (T12) with a wide spectrum (an aquarium bulb)) and a desire to build the most energy efficient plant growing system (which would not produce significant heat and would cost much more). The energy efficient method involves LED lighting, which currently is very expensive (but dropping fast, I bet). I have read numerous reviews and tests and even seen one test in person, so I'm confident that LED lights will grow plants, but it's still a developing field that needs research ... so I want to do the research! I've spent the last few weeks re-reading some circuitry material in preparation for a custom LED project, and these are the key points that I feel need to be considered: Spectrum - Looking at the absorption spectrum of chlorophyll A and B, it looks like I should be targeting these wavelengths (all in units of nm): Red - ~640 and ~660 (for Chl. B and A, respectively) Blue - ~430 and ~450 (A and B) Unfortunately, most of the red LEDs I have found for sale as individual components (not ready-to-use lights) are in the lower 600s - for instance, luxeon makes some reds that peak around 627. Also, there are blues that peak at around 455, but none that I've found in the 430 range. Of course, these are peak wavelengths, so the output will actually be in a range around these peaks. I've got a lot of work to do before I solder anything, because I suspect that the specific ratio of red to blue, as well as the actual frequencies that peak, will have dramatic effects on the plant growth patterns. I'm a little on the poor side now, so I want to get it right the first time. All of the manufacturers of LED grow lights seem to use a large ratio of red to blue (usually 80/20 red/blue, it seems), but I can't help wondering if I want more blue light for my indoor plants, as blue light encourages short internodes (distance between leaf sets) and shorter, more compact plants (though red lights are supposed to encourage blooming/fruiting). In addition to figuring out exactly which LEDs I will use, I've got some circuitry challenges ahead of me. I'm a bit of a novice at building circuits, so I don't know the tricks of the trade that will allow maximum efficiency. For instance, all of the LEDs I need to use will require much lower voltage than 12 volts (and yet it seems likely that I'll end up using a 12v DC adapter, or something similar). What's the most efficient way to convert the voltage to something I need? I don't want to use resistors, as that's just wasted energy, but the only way I know of, off-hand, to drop voltage is through the use of resistors. Current, of course, isn't such an issue, as it's easy to split current through parallel designs. I wonder if there's a way to replace the resistor that I'd use to drop the voltage with a light producing resistor - theoretically it should be possible, and it would be ok if the light was not narrow-band (as I fully intend to have at least some wide spectrum lighting). Hmm.
  2. Hello! I'm not sure this doesn't belong in the engineering thread. Admins should feel free to move it, of course! I have an idea I'd like to run past you guys. I have been interested in energy efficiency for a number of years (along with pretty much anyone else who pays bills), but my interest is usually not in reducing power use (though I do use energy efficient devices where possible). Instead, I'm interested in simply using the energy we already use more intelligently. One example of this that I've been meaning to implement for years is perfect for warm places like California: a refrigerator radiator that is exposed to the outside (leaving the bulk of the unit in the kitchen) would reduce the amount of heat pumped into the house - it seems silly to produce so much heat in a house with an AC running! But that's not the idea that's been consuming my thoughts lately. Instead, I'm interested in gardening ... indoors! Before I make my case for indoor gardening (and before you say that I should just save energy and use the sun to grow things), let me point out two things: (1) Light bulbs, whether they're LEDs with very narrow output spectrums, CFL which claim low heat output, MH, HPS, or hot incandescent lights, light bulbs share something in common with the average space heater: 100% efficiency (ignoring line losses outside of the home) at producing heat. In the case of lighting, heat is a byproduct that is often not wanted (hence the popularity of CFL bulbs which produce intense light without the intense heat). In the case of the heater, of course, heat is the goal. (2) The average american home uses between 400 and 4800 KWH of energy per year on heating bills. Much of this is natural gas, some is electricity, and some comes from other sources. The range is a rough estimate, taken from the following sources (and is not intended to be a truly accurate estimate, nor to be representative of every individual home, as some people heat much more than others): http://www.physics.uci.edu/~silverma/actions/HouseholdEnergy.html http://www.eia.doe.gov/emeu/reps/enduse/er01_us.html Again, let me stress that this is a rough estimate ... no, it's not even that. It's just a guess, based upon two sources. The lower estimate comes from a source that isn't even taking into account non-electric heating (gas heating), so take it with a pound of salt. The fact is that while heating bills range quite a bit, many people use many KWH of energy to heat their home - especially in the winter. Especially in the winter ... when we're growing the least amount of food locally ... and driving/boating/training the most food in from often distant places. My idea is simple. It doesn't matter whether you heat your home with a 500W heater running all day (unrealistic, of course, but that's irrelevant, as we're dealing with average energy use and we can easily convert between the energy use of a 1.5kw heater used for a few hours and a few hundreds watts of lighting used for 17 hours) or a 500W light bulb running all day - the energy use is the same and the heat out-put is the same. The only difference is that the heat just heats stuff up - we can shave a small number of those photons off the total coming from that 500W bulb to power photosynthesis in an indoor garden without significantly altering the temperature. Furthermore, if people produce some food at home, less food will need to be driven in from distant locations. Consider, for example, my parents. They live in southern california ... but not in sunny LA! Instead, they live in the mountains, in a ski-resort town. It's very beautiful, but it's in the middle of (almost) nowhere, and every bit of food they eat has to be trucked up. Well water, on the other hand, is local ... and to my knowledge there is no real cost, aside from line losses, to pumping electricity uphill. They have a large house (too large, now that the kids are gone, but that's a different story) and their heater (this is an educated guess) probably consumes at least a couple KWH per day for a chunk of the year. Let's assume they use a measly 2 KWH per day during the winter. If they converted a sunny room into a garden, or a few sunny rooms into gardens, the plants could get enough light from the windows during the summer to survive - I doubt they'd flourish without help. In the winter, they'd probably die, except for a few plants by the few windows that would actually get a few hours of decent winter light. During the winter, those 2,000 KWHs of energy could be used to power around 130W worth of grow lights (on for between 12 and 17 hours, depending upon the plant.). That's enough light for a tomato plant - actually, if used well with good reflectors, that's enough for a BIG tomato plant, or a tomato plant and a couple square feet of vegetables (lettuce or spinach or the like). It may not seem like that much, but in reality my parents use more energy than that. I would guess twice as much, at least, because even in their well insulated house it gets cold when the heater stops. The real solution for them is a smaller house, but that's aside from the point. Still, there are some issues. Heat distribution is very different when you run a space heater - often vents transport warm air throughout the house. Those vents could still be used, but a truly efficient design would NOT entail simply putting all the plants in one room with all the lights. The heat loss through windows would be larger and some rooms would just not be warmed enough (at least, in their house). With good planning and design, an indoor garden could be made to produce and disperse the desired heat while simultaneously producing some food - thereby reducing the power used to transport food from distant places. The work required to maintain such a garden would depend upon the design - in my small (75W) indoor garden, there is very little work. Basically, we just pick off herbs and veggies while cooking, but that's because it's a small garden. More work would be required in a larger garden, but with a good self-watering design next to no daily work is required. For a home like my parents, I suspect that a sizable amount of food could be produced (and good design could easily eliminate all of the problems that I've discussed here). For an apartment like mine, a small garden, sufficient for producing herbs and some tomatoes, is feasible. Comments? Thoughts?
  3. Is it possible to prove that an equation exists to describe any possible graph? Specifically, can an equation exist which yields a graph that, for instance, is identical to a sine wave with a certain magnitude for the x= a to b, then some random exponential graph from b to c, and then maybe some holes (limits) and such? I'm not asking about any specific graph ... I'm just wondering if, short of graphs with infinite, non-repeating patterns, everything that can be drawn on a graph has an equation that corresponds to it. Thank you in advance for your thoughts! If you're curious as to why I ask this, my girlfriend had a question for me about a homework question for calculus. The question regarded limits and it went a little like this: If the limit as f(x) approaches 5 is 2, can f(5)= 4? The answer is yes, because the graph may approach the limit, but have a hole there and leap to another part of the graph, whereat it continues on it's path. I said no, thinking that the only way to get a limit in an equation is to have some undefined point, whereat a certain x value yields an undefined function. If the function is undefined at that value, it cannot, by definition, have a value (4, in the case of my example of f(5)=4). My best guess is that the only reason that the answer is "yes" is because graphs can have range-specific functions, e.g. for x values between -infinity and 0, f(x) = x + 1 for x values at 0 or above 0, f(x) = x + 3
  4. Fix a mans computer, and he knows where to go to get his computer fixed. Teach a man to fix his computer, and you just destroyed your market base!
  5. MattC

    Vista

    If Microsoft's previous OS's are any indication, Vista will be bug-ridden at launch. I won't be surprised if it takes more than a year for Vista's stability to rival that of XP. The only compelling reason I have heard to adopt Vista early is DX 10 - and that's *only* compelling if you own DX 10 compliant hardware (which is brand new and very expensive) and play games that utilize it. In fact, unless there's some software that you use that requires Windows, linux is the way to go (If there are drivers for all of your components). That's my 2 cents!
  6. It seems to me that a perfectly stable orbit for an orbiting photon would be affected by any increase in mass - something to be expected with black holes. Instead of a very thin sphere, there would just be a photon cloud containing photons heading toward the black hole, photons on orbits that are collapsing but were recently/once in stable orbits, and a (small, I would guess) layer of photons in what is currently the stable orbital distance.
  7. I like the idea of a car that runs on both hydrogen fuel (fuel cell or otherwise) AND gas, as a stepping stone toward a different fuel economy. The car could be sold along with a kit to generate fuel from solar energy - yes, it would take a long time, but it may very well be enough to satisfy the energy needs of many drivers who do not commute long distances. Certainly it would be enough for people like me, who walk or bike any short distances, and drive only when necessary. Ultimately, that's the best solution for the short term - not only to energy problem, but also to the obesity problem. I really would feel bad, though, for people biking around in cities that aren't bike friendly. Even in the best of places, cars will chug past you leaving a foul-smelling smoke while you ride along, and in the worst places you may be regularly run off the road, honked at (even though you may obey the law and act curteously), and in general treated horribly.
  8. Do any magnetic fields in the universe, regardless of how weak they are, ever completely fade to nothing? I have always imagined that the gravity and magnetic field of my body has some effect, however imperceptibly small, on every other piece of mass (by gravity) and every magnetic field in the universe. While it may never be possible to measure such a tiny effect, it should have some effect - perhaps because of me an entire star will move (during my lifetime) by 10^-1,000,000,000,000 meters.
  9. Cells exposed to a hypotonic solution can take in more water than is expelled, thereby expanding and exploding. It is said that a cell has lysed (sp?) when this occurs. My girlfriend and I were discussing something and this term came up ... but neither of us could remember the term that refers to when a cell shrivels up, as with a cell exposed to a hypertonic solution! Note - I'm not assuming that all cells do this, regardless of cell walls (as in plants) and such, or anything of the sort - really, I'm just curious about the term for cellular implosion. I think there is a term ... and so does my girlfriend. Neither of us can remember it, though, and my googling is all for naught. Someone help us, or else this tip-of-the-tongueism will drive me insane for days, perhaps even years!
  10. Sounds like an O-Chem homework question. Here's a hint: What does pka mean? If you can make the 6.0 equal to something, say some function of certain concentrations, and you can do the similar things with other relevant parts of the question ... and if you can put that together ... you can get a concentration.
  11. MattC

    Animal Testing

    As a vegan, I am not opposed to animal experimentation for medical purposes. This is a tradeoff - we sacrifice a number of organisms in order to save, in the long run, a larger number of organisms from pain and suffering. In the food industry, I think it's an entirely different matter - if you can't find a way to raise and kill animals for food that doesn't cause unnecessary suffering, you shouldn't do it. Plenty of small farms manage to kill animals in a way that doesn't lead to enormous suffering - it's only when people try to make a factory and assembly line out of killing and eating animals that unnecessary suffering enters the equation. For the same reason that I would consider it unethical to *not* use animals for research, in order to save more lives in the long run, I consider it unethical to treat animals with any less dignity than is feasible. I think we would all appreciate the same consideration being given to us when some alien race that just loves how humans taste (and to whom humans are quite nutritious) comes along and decides to start a human farm here. If you think it is fine to eat animals (and I'm definitely not saying it isn't, for all that I'm a vegan), you would be a hypocrite to think it would be wrong for some other equally more advanced race to consume us. In that situation, who would argue that humans shouldn't be treated with dignity and compassion, for all that we are merely food for some other species? I do not have evidence for my next argument, but I think most of you will probably agree with me, regardless. Many people eat meat - this is a fact of our culture and world. Most of the people who eat meat would find it very difficult to kill their own meals - and of those who would be able to do it at all, only a small minority would be willing to do so in an unnecessarily cruel manner. If you wanted chicken soup, would you kill the chicken, then cook it, or pluck it (while it is still alive), cook it (letting it die slowly), and then eat it? The only reason we tolerate the mistreatment of animals, in our society, in this context, is the unfortunate fact that the majority of people are completely detached from the production of their own food. I have challenged many defensive meat-eaters to do their own research into how animals are treated. I cannot count the number of times I have heard someone say, "I will never eat *that* again, not after what I learned." This is not because eating meat is wrong - certainly those people don't feel that way, and I don't even really feel that way. Instead, it is because most humans are programmed or hard-wired to show compassion when it is not terribly inconvenient (or completely undeserved). Factory-style production of meat has nothing to do with compassion and everything to do with maximizing the profit of the company preparing the food.
  12. Not to get too caught up on Trophy, but is that really the case? It can only fire once, at least within a certain section of its view? Or is it just the case that, in a particular segment of it's defense, if it has just fired it cannot fire for a moment or two? Very interesting! If so, it would be very easy to overcome, once the enemy caught on.
  13. Ah, that's something I can whole-heartedly disagree with, Dak! Human infantry is the bulk of all armies, today, yes - but we must ask why this is! I would argue that this is because, no matter how powerful a weapon is, if it's not controlled by a human (who is there, not controlling it wirelessly), then you have to either rely on AI (which today is not up to the task) or some sort of remote connection (which can always be hacked, presumably). I don't foresee any technology on the near-horizon that will allow 100% secure remote control. I do, however, see what I perceive to be an inevitable explosion in the AI field. Video games are getting more and more cleaver, automated customer service systems (a computer-controlled "human" voice) are clunky but rapidly improving - and the incentive to get them up to the level of your average real-person is immense. Imagine the savings for a company that can replace 1,000 phone operators with a few computers. If we extrapolate from the exponential growth of computer processing power, it would appear that human-brain level computational power will be available at an affordable (that's the key) price in 15 to 20 years. This pattern-recognition ability would also come with the inherantly fast-processing ability of computers - that is, massively parallel computers can, presumably, emulate the pattern recognition abilities (that set humans apart from modern computers) of the human brain, but at the same time, they process millions of times faster. You cannot aim a gun at a person and do more than estimate the trajectory of the bullet - a computer, even a modern computer, can not only do that, but it can do it instantly, and not just for one aim and one trajectory, but for thousands or millions. A tank controlled by a modern computer (with todays abilities) and enough guns and detectors (radar, sonar, cameras and pattern/motion detection) would be an amazingly effective murderer - we don't see this happening because the ability of such a system to distinguish between a friend and a foe would be limited. We can't just release tanks into the wild and *hope* that immature software would keep them from killing allies - so this will have to wait until the AI is capable of making these decisions with the same (or superior) accuracy of a human. And tanks are just one example of this - Toyota has developed a numer of exciting robots. The abilities of these robots are limited, but the technology is in it's infancy. 20 years ago, no one would try to build a robot that could dance and play music. http://www.toyota.co.jp/en/special/robot/ In another 10 years, I think the toys you buy for your children will do these things. Imagine telling your children, "when I was your age toy cars just moved in one direction - the direction you pushed 'em! They certainly didn't have collision detection ... thank god for that! I remember just *ruining* the wooden legs on my parents chairs with my toy cars!" In the longer run, humans will merge with computers and robotics, and we may again see the dominance of the human soldier - this time, outfitted with metal bones and stronger, artificial muscles (allowing for heavy armor), constant wireless communication with headquarters via eye-implants that project data over the field of vision, computers that allow every soldier to calculate *exactly* how far their futuristic bullets will penetrate the armor of an enemy, and so on. Just speculation, of course, but it's speculation I'd be willing to put some money on!
  14. Eh, politics. So, anyway, what does everyone think the future of warfare will be? One author (I forget who - not a particularly famous one) speculated that in the future, corporations would fight the wars, rather than countries, in order to secure resources and people. To save costs, the various corporations of the world would agree to nonviolent combat - a sort of laser tag in which the "battle" is really just a competition, and the winner takes all. Personally, I don't think it's very likely. I think warfare will remain a deadly game, with every side attempting to escalate the situation with new methods of defense (and perhaps new variations of old methods of offense - small nuclear bombs, lasers, etc, rather than larger, more dangerous bombs and such). If the US army doesn't take this trophy system and run with it, it's still plausible that the navy or airforce will. Isreal would love to have it, too, I'm sure - and something tells me the Israeli won't care whether or not Raytheon made it, they'll use it as long as it works (and it seems that it does). The next step may be for some country to develop an RPG or missle that has tracking hardware on it - when the sensors detect an anti-ballistic projectile coming, a small laser will melt enough of the projectile surface to destroy it's aerodynamic properties, throwing it off course. All of that is just wild speculation, of course! I still think that in the long run, nanobot soldiers are where it's at.
  15. Soon, U.S. tanks, APCs, etc, will be equipped with defense capabilities such as this one: http://spikedhumor.com/articles/53036/Anti_RPG_System.html (if it doesn't show, reload the webpage, sometimes there is an ad in place of the video and you just have to reload the page) I'd like to devote this thread to discussing the future of warfare. I think that in the nearterm, conventional weapons, along with some new toys such as sound-based weaponry and lasers, will continue to dominate. Remotely operated or AI-operated tanks and planes will replace manned vehicles. In the not-so-distant future, I expect nanobots to take over the role of defending (and attacking!). What do you think? Will satellite lasers with pin-point accuracy allow some countries to dominate the world? Will biological warfare make all other weapons look like pleasant houseguests? Or something else entirely?
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