Wikipedia:Reference desk/Archives/Science/2011 June 30

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June 30

The universe, consciousness and the anthropic principle

Hi. Can a property of the universe be said in the following manner? This is not meant to advertise some cranky or crackpotting idea but just for discussion although the following ideas may induce semantic headache. Consider the following.

The product of human consciousness and sapience has been an anthropogenic proliferation in tools, eventually evolving to higher forms of technology, including artificial intelligence. This can potentially be characterized as a localized decrease in entropy, in which energy of chaos is re-positioned to form ordered substances. Although the second law of thermodynamics dictates that entropy must increase over time, localized increases in order via the self-ordering nature of matter are allowed, which is accelerated when consciousness is present.

Given the Big Bang theory of the formation of the universe, matter and antimatter were composed of high energies, infinite temperature and a primordial soup. After this initial energy forced inflation (cosmology) at rates approaching Plank velocities, the matter-antimatter asymmetry allowed the prevailing of matter over antimatter through the help of bosons and other factors. The matter assembled into stars, which later formed planetary systems and were components of quasars and later galaxies, which in turn became ordered into superclusters in bubble-like forms. Complex molecules arose on Earth, eventually forming into prokaryotes, then into complex life, which eventually evolved to humans today, which carry a form of conscious self-awareness.

In this context, the universe over time becomes more and more ordered, and although all matter such as stars eventually explode, the resulting debris forms into new stars and new order. Since both humans and the universe share this locally accelerated ordering capacity, could it be said that the Universe is dually conscious?

Alternatively, does the hypothesized supersymmetry breaking and multiverse scenario more than make up for this local decrease in entropy? Considering a multiverse, supose that its consistuents are order and chaos. Similar to the matter-antimatter duality within our universe, the scenario could either unfold where order prevails (a universe forms), or chaos does (a nearby universe is destroyed). Thus, would the passage of time result in the formation of more universes, so that the total heat contained in all universes increases over time, thus increasing total entropy on a quantum level? Or, can something about dark matter change this effect?

The anthropic principle proposes an almost infinitely long list of requirements for life to exist on Earth, so that the chance of such a universe existing is one over infinity. However, this is easily resolved given a multiverse, in which an infinite number of universes is created and destroyed. Of course, we don't know whether this is the correct infinity.

However, humans have succeeded in creating the basic building blocks of life. If the universe and humans are both conscious, depending on how consciousness is defined, could the existence of conscious life be considered a fractal subset of the macro-scale universe's consciousness? Or, would this only be true in retrospect, as the existence of conscious life itself is required for any realization of the anthropic principle?

Is time thus a non-material dimension, one that results in the conversion between matter and energy to cause the diversion of macro-scale and micro-scale entropies? There is also a human sense of time, which is potentially distinct from the actual flow of time relative to the conscious observer. Can this somehow make sense of the aforementioned context, provided that simultaneity is relative based on different observers in spacetime, so that each observer is positioned so that all other observers' futures in spacetime already exist?

Does any of this make meaningful sense? Thanks. ~AH1 ^(discuss!) 00:36, 30 June 2011 (UTC)

Not really, no. There's no evidence that the universe is conscious. The final few paragraphs look more like rubbing a set of random concepts together than anything else. --Tagishsimon (talk) 00:42, 30 June 2011 (UTC)

(edit conflict)I don't have the mental energy right now to fully wrap my mind around your whole argument, and you touch on a large number of highly-speculative and non-falsifiable topics (thus your whole argument here may be more philosophy than science), but I do have a few points:

1. You make the assertion that human consciousness is "accelerating" a local decrease in entropy (increase in "order") on Earth which you take as truth; all of this without citation. Now, this may be true, but it would be nice to see some quantification of this before I take it as fact. We may be decreasing entropy on earth by refining metals from ores and extracting other pure materials from nature, but we are doing so primarily through the combustion of fossil fuels, which is a process which results in an overall increase in entropy.
2. Even using "renewable energy" such as solar power, wind power, and geothermal power, this energy is ultimately all derived from solar fusion from the Sun, a process which results in a huge increase in entropy.
3. You make the further assertion that "the universe over time becomes more and more ordered". This is demonstrably untrue: as I say above, fusion in stars results in an enormous increase in entropy as primordial hydrogen is fused into helium on astronomical scales. If I had some more time I'd do some scale-analysis to give some rough numbers, but it is safe to say it is enormously beyond the scale of any potential local decrease in entropy by humans (which, as I've said above, may not even be true).
4. I'm no good on the philosophy front, but I do believe that most definitions of consciousness at least require a conscious entity to present the appearance of self-determinism; the Universe as a whole does not appear to demonstrate this feature.
5. Almost infinity is not even close to infinity; the two are not even comparable. The odds of the existence of a universe where humans can live can not be zero because it does exist.-RunningOnBrains^(talk) 01:08, 30 June 2011 (UTC)
6. You also seem to be trying to think of the anthropic principle as a causal mechanism; this is nonsensical, as the anthropic principle is essentially answering the question of "Why are we here?" with "Because we are here." This is an over-simplification of the topic; the anthropic principle is really the only branch of philosophy I've done serious reading and thinking on. It is my favorite principle, since it really allows us to avoid the need to ask the question of why we are here. It helps me sleep better at night.-RunningOnBrains^(talk) 01:16, 30 June 2011 (UTC)

On the issue of conscious entities lowering entropy: this dos not happen. If you clean up your desk, putting things that were initially randomly distributed, in some neat order, then the information needed to specify the initially disordered state is not lost. You have to act on that intial state to get to the final state, so the information about the initial state ends up in your brain. So, as your desk becomes more and more neatly ordered, your brain accumulates more and more random information. You can later forget about what you exactly did to clean up your desk, but then the information gets dumped into the environment. Count Iblis (talk) 01:17, 30 June 2011 (UTC)

Supposing the universe had some form of consciousness, could we somehow potentially test for it? The final paragraphs supposed that if the universe was conscious, then conscious life could be a fractal-like microcosm of the consciousness, or not. ~AH1 ^(discuss!) 01:51, 30 June 2011 (UTC)

Entropy, as a quantified theory, is defined on the molecular and atomic scale. Reordering macro objects will not result in a quantifiable decrease in entropy, though it may intuitively seem so to our consciousness. Calling it "localized" implies that the volume in question is less than typical entropy measurements, which is not the case. Keep in mind that moving objects, and even thinking of moving objects, increases entropy by converting food to more basic molecules (much like the fossil fuel reference mentioned). Mamyles (talk) 02:59, 30 June 2011 (UTC)

More importantly, it increases entropy because it decreases free energy; some food energy is always lost as heating the environment in addition to making muscles move; and that environmental heating is also an increase in entropy. --Jayron32 03:10, 30 June 2011 (UTC)

There's a common fallacy which is the notion that the complex can't naturally arise from the simple. It's often evoked for instance by proponents of intelligent design. They argue that the world is complicated and beautiful, which proves that it can't adequately be explained by reducing things to simple laws of nature. The world has to have been caused by something equally complex and beautiful (god). It's understandable where this misconception comes from. There are a lot of situations in our lives where we're actively maintaining some sort of order, and when we neglect things they break down. But as anyone who's ever spent any quality time with math can tell you, beauty readily sprouts from mundane beginnings all the time without the guiding hand of any conscious being, and we've found that this remarkable trend tends to carry over to our study of the universe (for more on that see the recent question on the math desk).

Here you seem to be making a similar argument about the impossibility of an interesting universe arising naturally without some "consciousness" guiding it, wrapped in (an incorrect reading of) the concept of entropy. Entropy doesn't measure how boring the universe is. With all the galaxies and stars and planets and life engaged in their beautiful dance, entropy is much higher than at the start of the universe when everything was a single boring (but maximally ordered) point. The magic is that bunch of deceptively simple laws (including the second law of thermodynamics) got us from there to here. Rckrone (talk) 04:04, 30 June 2011 (UTC)

Let's consider the life of "Adam", the first conscious being. In the interests of simplicity I will neglect to define whether Adam was man, mouse, or microbe; but his brain (or processing center of similar function) possessed the bare minimum requirement for what we define as a conscious observer. Thus there is one moment at which Adam is aware of consciousness, but ignorant of all else.

In that moment, Adam is, I would suppose, in a superposition of states, like Schroedinger's Cat. He might be Earthling or alien, with any number of possible biochemistries, in any number of universes with any number of laws - all existing as a mad superposition of states. But he stirs his limbs, and the state-vector collapses - as if struck by the divine spark, he becomes carbon-based life, with arms and legs; he takes on a defined form. Many others no doubt were possible. He opens his eyes and looks up to the darkened heavens - and at once, the state-vector of the skies collapses, and the stars, once a homogeneous smear of probability, take on their fixed and immovable positions. Wnt (talk) 05:53, 30 June 2011 (UTC)

Then he turns to the ominously fertile apparition at his side and simultaneously presents himself and enunciates the first palindrome: "Madam I'm Adam". Cuddlyable3 (talk) 12:00, 30 June 2011 (UTC)

It seems like a rather awkward QM interpretation to sharply distinguish between living and non-living objects. Rckrone (talk) 16:49, 30 June 2011 (UTC)

Carl Sagan liked to say that conscious life is the way in which the universe eventually knows itself — we are made from the universe, we have evolved to the point where we can study the universe, and so in a very holistic way, this makes the universe "conscious" (in the sense that it contains consciousness, in the form of us, among other critters). It is indeed a fairly deep idea if you take the time to really contemplate it, and don't just dismiss it as wordplay. This is separate from many of your other questions. --Mr.98 (talk) 16:45, 4 July 2011 (UTC)

The idea of a multiverse is not something requiring new physics. Consider a slightly altered version of Schroedinger's cat in a box: you place a completely automated in vitro fertilization clinic into the box, complete with an artificial womb, and don't bother opening the box later on. Now the box exists in a superposition of states: in some the equipment broke down and nothing happened, but in a few, it successfully reared an infant. Doesn't the anthropic principle apply, namely, that the successfully conceived infant's perspective prevails over the other possibilities ... from the infant's perspective, at least? Wnt (talk) 13:40, 6 July 2011 (UTC)

String theory and time travel

Collapsing -- Wikipedia RefDesks are not a forum for presentation of original speculation
The following discussion has been closed. Please do not modify it.
Hi. Assume for the purposes of this question that String theory is correct. The theory makes the assumption of 11 dimensions, some of which are branes. Suppose three of these dimensions are the spatial dimensions, and that time is the fourth dimension. Since strings are said to vibrate in the eleven dimensions, could a string in itself travel back and forwards in time, similar to quantum teleportation, except that these sub-quantum entities travel in the fourth rather than the 1-3 dimensions? If a particle collider were to harness enough energy to isolate strings, if they exist, let's say through the use of a Dyson sphere or some type of Higgs boson technology, could time travel or time-teleportation theoretically be achieved? Since string theory supposes an infinite number of particles, far more than the current Standard Model, the mathematical singularity of a black hole would transcend some of these particles and reduce matter to infinite density at the string level. Since this requires energies capable of producing strings, could this allow time travel in the context of a wormhole via the tapping of the string energies? Could the black hole itself time travel to an earlier state in which it did not exist, thus evaporating into Hawking radiation and dissapating into dark energy? Also, if time is one of the dimensions in which strings vibrate, how can the vibration occur without the flow of time? If strings were to travel in the fourth dimension, would the vibrations stop, or would this induce a parity in the time reversal symmetry present in any oscillation? Is this thus a form of supersymmetry breaking? If strings vibrate based on an infinite particle number, could some high energy cause the vibrational frequency to change, and thus turning a neutron into a photon plus some energy, let's say? Or, perhaps create gravitons or other particles responsible for the other fundamental forces, so that the strings themselves impart force when enough energy is applied? There are still many theories for light, including wave-particle duality and the neutrino theory. Apart from the existence of some disproven aether, would light simply be a form of converted energy, similar to the way that photons carrying energy cause electrons to jump to a higher level, releasing more energetic photons? Could strings facilitate this conversion, and generate new energy from particles? At quantum levels, the observer effect becomes amplified, as seen in the quantum Zeno effect for the Heisenberg uncertainty principle. Is it conceivable that human observation is adjusting the vibrational frequencies of the strings, thus quantum-teleporting this string-information onto the later-observed states and momentum of the observed particles? Also, is it possible for an observer in the future, through this mechanism, to influence the quantum states of particles in the past, providing ostensible evidence of retrocausality and other retrospective mechanisms? Responses welcome. Thanks. ~AH1 (discuss!) 00:59, 30 June 2011 (UTC)

Can I ask one question: can strings theoretically time travel? ~AH1 ^(discuss!) 01:51, 30 June 2011 (UTC)

So far as I know, all subatomic particles, real or proposed, exist in four dimensions, time being one. And most of them exist in a way which is in some sense symmetric over time (CPT symmetry). So when you ask if strings can time travel, well, you might have a string at one time, which exists in another time, earlier or later. Now can a change to a string later "cause" a change in the string earlier? That depends on the nature of "causation", which seems to me to be essentially religious, if not superstitious. Wnt (talk) 05:59, 30 June 2011 (UTC)

Request for RDS regulars to help with a teensy problem on another board...

Over at Wikipedia:In the news/Candidates, there's a consensus developing to have a blurb about a recently discovered quasar. However, no one has the science background to update or create a target article for the blurb. See the section "Brighest Object in the Galaxy found yet" We could use someone with astrophysics knowledge to pitch in to help work it out. Science is a heavily underrepresented topic in all areas of the main page, and ITN is no exception, so when a particularly good event comes along we don't want to miss the opportunity to use it. --Jayron32 01:56, 30 June 2011 (UTC)

Well, the person who could create that article is certainly not me, but I will make one correction: the object is clearly not in our galaxy. According to the article, it is the most distant object that has ever been observed. Do you think it would make sense simply to correct our quasar article, which currently says that all known quasars have redshifts between 0.056 and 6.5, to an upper limit of 7.085 (as reported in the Nature paper), and cite the paper? Would that be enough to justify a news item? Looie496 (talk) 02:11, 30 June 2011 (UTC)

Superlative objects (biggest, farthest, fastest, brightest, whatever) with good confirmation as to their superlative status are generally good topics for being stand-alone article subjects. Having Nature call you the brightest or farthest object known is a pretty solid aspect of notability, though again I (nor anyone currently working at WP:ITN/C) has the background to take on such a task. --Jayron32 02:24, 30 June 2011 (UTC)

For what it's worth, this Scientific American news piece tells the story in a pretty understandable way. Looie496 (talk) 02:26, 30 June 2011 (UTC)

Good stuff. There's an honest-to-goodness astronomer who has made a few comments, and indicated he may get around to working up an article in the next day or so. Of course, more help is more better. --Jayron32 02:29, 30 June 2011 (UTC)

Well, I just started one, ULAS J1120+0641. I'll say more at the ITN page. Looie496 (talk) 03:11, 30 June 2011 (UTC)

slow neutrinos

Hi, is there any FUNDAMENTAL reason why neutrinos could not be slowed down relative to us on Earth? If some type of exceedingly inelastic collision mechanism could be devised, couldn't scientists start collecting slow neutrinos? Once they are slow, wouldn't they stay slow? Conceivably the neutrino cross section would increase as they slowed down?Thanks, Rich Peterson24.7.28.186 (talk) 04:04, 30 June 2011 (UTC)

In principle they can be slowed down, but their cross-section would decrease. Have a look at formulas - the various cross sections are proportional to the energy or to the square of the energy. Icek (talk) 08:55, 30 June 2011 (UTC)

The link you posted seems to be broken. Dauto (talk) 15:35, 30 June 2011 (UTC)

This is the link to the entire page, which gives various sets of equations. I would guess that the second set is the one you want, but hopefully Icek will reappear and confirm it. I don't have enough background in the mathematics to see what equations on that page have the property he/she describes. Wabbott9 Tell me about it.... 15:51, 30 June 2011 (UTC)

All of them do. Dauto (talk) 22:07, 30 June 2011 (UTC)

thank you.24.7.28.186 (talk) 02:45, 2 July 2011 (UTC)

Plugging in and electrical use

I'm trying to save electricity, for the sake of both the environment and my bills. ;) So two questions:

(1) Do appliances such as fans with a plain adaptor-less power cord and no digital display (e.g. clock) use any electricity when they are turned off but still plugged into the electrical outlet? That is, would I save any energy by unplugging appliances even when they are turned off, or does being plugged in or not make no difference as long as the appliance is already turned off?

(2) What about devices that use AC adaptors? I find that even when I turn off the device, if I leave the adaptor plugged in, then the adaptor stays warm to the touch, suggesting it is still using electricity.

Also, if unplugging does indeed save power, are there any negative side effects to frequent unplugging?

—SeekingAnswers (reply) 05:56, 30 June 2011 (UTC)

The phrase for those adaptors (and myriad other usages) is "power vampire". I still have no idea why corporate idiots decided to get rid of perfectly good 1 - 0 power switches that you could be confident about, and replaced them with things that consume more power while doing nothing than when active. There's just no plausible excuse. Wnt (talk) 06:03, 30 June 2011 (UTC)

Can you give an example of a "thing that consumes more power while doing nothing than when active? Cuddlyable3 (talk) 11:30, 30 June 2011 (UTC)

Consume more energy would be the right phrase. You buy energy not power. The CD-Player in the guest room only ocupied two weeks a year would be a clear point which would consume more during the 56 weeks in stand-by while working for 5 minutes during the guests are in the room. --Stone (talk) 11:44, 30 June 2011 (UTC)

However just being there available to spring into life anytime you want is, like a burglar- or fire alarm that is never triggered, not nothing. Cuddlyable3 (talk) 19:55, 30 June 2011 (UTC)

Mechanical appliances do not normally use power when turned off, but there is an additional element of safety if they are switched off at two places. Appliances with "AC adaptors" (usually switch-mode power supplies) use a tiny amount of electricity when plugged in, but much less than a penny a day when not being used. I leave mine plugged in for convenience, but I live in a cold climate where the tiny amount of heat is beneficial. People who are fanatical about energy conservation always turn them off when not in use. Dbfirs 07:18, 30 June 2011 (UTC)

I had read somewhere that running one yellow light in your car would save more money than leaving a cell phone charger plugged in all year. Not sure if that is true but it suggests that there is a penny-wise/pound-foolish element to energy savings. Rmhermen (talk) 16:45, 30 June 2011 (UTC)

If the adapter or phone charger feels warm to the touch when idle, then it is wasting a meaningful amount of energy. Edison (talk) 20:18, 30 June 2011 (UTC)

True, but if the warmth provides background heating, then the energy is not being "wasted". I "waste" much more energy by accidentally leaving lights turned on when they are not needed, but these also provide background heat. Of course, if your house is hot enough to need air conditioning then the energy really is being wasted. Dbfirs 07:59, 1 July 2011 (UTC)

The waste energy amounts to electric resistance heat, too expensive for most people in areas with a cold climate. It would be cheaper even in winter to kill the power to the adapter and get the extra heat from a high efficiency gas furnace. In the air conditioning season, waste heat from "vampire power" runs up the air conditioning bill. Edison (talk) 14:39, 1 July 2011 (UTC)

... true if you already have one, but high efficiency gas furnaces are not cheap! Also, the nearest mains gas is five miles away from my house! Dbfirs 17:57, 1 July 2011 (UTC)

More to the point, while the power adapter thing may work (although I'm not even convinced of that, particularly if you don't use heating 24 hours a day), so far I haven't seen any source which has analysed this in a meaningful way. As I say every time this comes up, I would expect there is some stratification of heat in most houses (e.g. [1]). Most analysis even RS like [2] seem to just presume all heat generated by the lights is going to be as useful as heat generated by purpose build heating systems which as I've said given the stratification seems unlikely to be true.

Heaters are generally located close to the floor. Lights are located close to the ceiling. Some of the wasted energy that ends up as heat is in the form of thermal radiation (primarily infrared) which would reach the floor and people but the rest is at the ceiling and is likely to stay there if you don't have some sort of convection system which would suggest an increase in the vertical stratification which may not be useful if you aren't Spiderman. (I'm presuming we all know warmer air is less dense.)

In fact you probably have to consider horizontal stratification too. Many lights are brightest under the light, and humans tend to be away from (but not too far from) the light. But this would also imply a greater amount of the radiative heating happens under the light and while there would be some circulation it seems likely it will be warmest directly under the light which isn't useful if you aren't staying under it. (There's some unrelated discussion here [3] comparing halogen and incandescent infrared lights for heating piglets.)

In other words, as I say every time this comes up, it's obviously true that wasted energy is going to end up as heat eventually and likely also true not all 'wasted' energy from lights is truly wasted when heating is needed. But if your goal is heating for human comfort then it probably isn't true that the wasted energy completely oversets heating requirements (so isn't wasted). So even if you use electrical resistive central heating, there's a good chance using a purposely and hopefully well designed system will use energy more effectively then using light bulbs intended for lighting the home for the same purpose. Some actual sources to help us determine how incandescent lights in a typical home perform for heating compared to such a system would be useful but so far I haven't see any.

As a completely unrelated OR example, I had a cheap oil column heater from The Warehouse. It was 1000W as with many such heaters intended for small rooms in New Zealand. You may think it would therefore be as good (ignoring things like timers and safety functions) as any other such heater. However I found (and so did someone else with the same type) that it was rather ineffective. The heater itself got hot, the room not so much. Similar more expensive name brand oil column heaters were better at heating the room. I never measured energy usage (didn't have a plug-in energy meter at the time) but I presume despite both being 1000W it used less then the other heaters since the thermostat would likely shut it off faster and keep it off longer. But I also suspect if you adjusted the thermostat of the other heater until it used the same amount of energy over a defined period, e.g. 6 hours the other heater would have been better at achieving thermal comfort for the occupants of the room over those 6 hours or even an hour or two more after the heater was switched off (if they weren't right next to it).

Nil Einne (talk) 16:23, 1 July 2011 (UTC)

With light bulbs, some of the energy escapes through the window, of course. In the case of power adaptors, the trick is to place them in a location where the heat will be beneficial, though I agree that the heat will be "wasted" if you didn't want the room to be heated. I don't understand why a more expensive oil-filled heater using the same amount of energy could possibly provide a better "thermal comfort" (unless the surface temperature was higher or lower). A 1000 watt heater would be inadequate for most of the year in the house where I live, but in a well-insulated room in a region with a warmer winter it might provide all the heat needed. Comfort depends on the temperature of the walls, floor and ceiling, not just on air temperature and proximity to the radiator. Dbfirs 11:43, 2 July 2011 (UTC)

Expansion of the universe

Hello,

It is often said that the universe continues to expand, creating new space as it grows. However, this does not seem to fit in with the conservation of energy, since if new space is being created, that means new energy is being created in the form of vacuum energy. Am I missing something?

TIA. Leptictidium (mt) 08:16, 30 June 2011 (UTC)

This has come up before on the reference desk, but I don't have time to search at the moment. Here's a short version. First, it's problematic to say that "new space is created" in an expanding universe, since technically all of the space at a given time is equally new. Space doesn't persist the way matter does. Second, energy actually isn't conserved in cosmology (or GR in general), at least, not in any straightforward way. (This is actually an unsolved problem; quantum mechanics requires energy conservation, and that conflict is one of the reasons quantum gravity is hard.) -- BenRG (talk) 08:37, 30 June 2011 (UTC)

My understanding is that the purported solution to the problem lies in the so-called dark energy. Looie496 (talk) 15:55, 30 June 2011 (UTC)

It doesn't. You can have expansion without dark energy. DE is only required to explain accelerated expansion. --Wrongfilter (talk) 17:08, 30 June 2011 (UTC)

Regenerating electric energy in motor vehicles

in some motor vehicles electric energy can be stored through regenerative braking. so why cant we use this technology in electric cars to recharge the battery using this technology by an additional battery by providing a switchable control between the two? Since by Newton's Law "energy can neither be created nor be destroyed", i dont think dis is impossible..—Preceding unsigned comment added by 220.225.131.153 (talk) 12:32, 30 June 2011

This is already done in some hybrid carsZzubnik (talk) 12:38, 30 June 2011 (UTC)

Energy can not be created or destroyed, but if you convert some of your energy to heat, your car can't use it anymore, so for your purposes it might as well have been destroyed. Googlemeister (talk) 12:46, 30 June 2011 (UTC)

Indeed, you could convert heat back to electricity, using a Stirling motor. 88.14.198.240 (talk) 19:13, 1 July 2011 (UTC)

There's no reason you need an additional battery, you can recharge the original battery (or batteries) from the regenerative braking. StuRat (talk) 16:14, 30 June 2011 (UTC)

I have a bad feeling that the OP is thinking of using one battery to drive while braking to charge the other battery, then switching batteries to keep on driving forever. Methinks dat is impossible. Newton was wrong too. Cuddlyable3 (talk) 19:48, 30 June 2011 (UTC)

A motor or generator has losses, which convert some of the energy into heat. If you convert 90% of the input energy into useful output energy you are doing very well. 80% or 70% efficiency or even lower would not be surprising, to convert mechanical energy into electrical with a generator, charge a battery, and get the electricity back out of the battery and converted to mechanical energy with a motor. There are limits on cost and weight in any system used in a car, so there are likely some shortcuts from the very most efficient technology. Edison (talk) 20:16, 30 June 2011 (UTC)

color

I don't fully understand why if a meterial absorbs,say,red light it emits blue light (or looks blue). and generally absorbing one color (wavelength,frequency,whatever)causes the object to emit the inverted color. and what is the definition of invert colors anyway? I searched "invert color" on wikipedia but found no satisfying results!thanks in advance.--Irrational number (talk) 12:56, 30 June 2011 (UTC)

The object doesn't emit the inverted colour, it reflects what's left of the incoming light (let's assume that's white) after it has absorbed some of it. Since now some wavelengths are missing from the reflected light, it takes on colour. For example, chlorophyll absorbs red light and blue light. The remainder is reflected, which is why tree leaves appear green. --Wrongfilter (talk) 13:04, 30 June 2011 (UTC)

I'm afraid that's not correct. If the light were reflected, it would only be visible in certain directions, like the light that bounces off a mirror. Unless the object is shiny, the light is actually absorbed and re-emitted. Looie496 (talk) 15:51, 30 June 2011 (UTC)

No, Wrongfilter is correct. The only difference between shiny and non-shiny objects is that shiny objects reflect all the light back at a particular angle while matte objects reflect light back in all directions because the surface isn't smooth. Objects do absorb some radiation, and radiate heat back into the environment, but that radiation is not primarily visible light unless the object is very hot (such as the sun). See Thermal radiation. Rckrone (talk) 17:08, 30 June 2011 (UTC)

This distinction between "reflected/re-emitted" is really just semantics. "Reflection" is a macroscopic concept; specular reflection and diffuse reflection are statistical descriptions that are relevant for large surfaces and lots of photons. Any individual photon interaction with an individual atom on the surface is a quantum photoelectric behavior. Thomson scattering is commonly used to explain one photon hitting one atom. If the surface is large (compared to the wavelength of light), the aggregate effect of many many individual photon-atom collisions can be either specular or diffuse. It's a bit meaningless to debate whether the photons are absorbed and re-emitted, or merely "bounce off." If the wavelength of an individual photon changed, we usually say it was absorbed and re-emitted; but the same description loses meaning when describing the ensemble of billions of photons. Large quantities of light are better described as a wavefield. Nimur (talk) 21:02, 1 July 2011 (UTC)

Did you see Color#Color_of_objects ? Sean.hoyland - talk 13:10, 30 June 2011 (UTC)

Also, there are two confounding issues here:

• 1) There are certain wavelengths of light which are absorbed, and others that are reflected. Sometimes, objects do "re-emit" light (see fluorescence and phosphorescence) but reflected light and emitted light are distinctly different and can be readily identified in most situations. For normal (non fluorescing) objects, reflected light determines what wavelengths reach our eyes.
• 2) Human color perception determines how the incoming wavelengths of light strike our eye and are processed by our brain to produce a distinct color in our eyes. It is not always obvious; for example there are actually two different ways that yellow can be produced for us: a single wavelength of light in the yellow range can look yellow, but light composed of a mixture of wavelengths of light from the red and green ranges, with no actual wavelengths from the yellow range will still look yellow to us. That sort of thing is why we can create a full pallete of colors from a limited number of pigments, see RGB and CMYK for some more info on that. --Jayron32 13:11, 30 June 2011 (UTC)

(Edit Conflicts) Despite having studied some Color theory in connection with printing, I've never encountered the term "invert[ed] color. You may however find further enlightenment at the articles Complementary color, Primary colors and Secondary colors. {The poster formerly known as 87.81.230.195} 90.197.66.166 (talk) 13:14, 30 June 2011 (UTC)

I think the definition is approximately the same as a photographic negative: in computer terms, you just subtract the color from the highest value. So for 256 colors, inversion from (X,Y,Z) is (256-X, 256-Y, 256-Z). Am I wrong? Wnt (talk) 23:41, 30 June 2011 (UTC)

Yes, the highest value is 255. Icek (talk) 09:24, 1 July 2011 (UTC)

Ack, I knew that... thanks. Wnt (talk) 16:20, 1 July 2011 (UTC)

This usage of "color inversion" is a very useful and standard concept; but it's based on a perceptually-constructed colorspace (...an abstract mathematical model describing the way colors can be represented...). Thus, this usage of color "inversion" is not related to any fundamental physical properties of light. Nimur (talk) 21:05, 1 July 2011 (UTC)

What is this little white bug?

I was photographing insects in Colonial Williamsburg, Virginia this past weekend when I noticed this little one. I have never seen anything like it, I'm guessing it is a nymph of some sort? It looks like a miniature, white dinosaur.

http://keeganm.com/gallery/2011_06_26/images/large/DSC_3345.jpg

Thanks! Keegstr (talk) 13:33, 30 June 2011 (UTC)

An Aphid of some sort? There are dozens and dozens of species of aphids, perhaps one of them? --Jayron32 14:28, 30 June 2011 (UTC)

Cool photo! It is somewhat uncommon to see a singular wingless aphid (because they rapidly form clonal aggregations), and aphids are usually seen with their stylets inserted into stems or leaves. What kind of plant was it on? Did it run away when disturbed, or stay put? I think you are correct that it is a nymph. I'll keep looking... SemanticMantis (talk) 14:58, 30 June 2011 (UTC)

Awesome. If you think it would be beneficial to post the image to a specific wiki article, I will gladly do so if you can tell me what to title it and where to put it. Here is the full photo (above is a 100% crop) I am unsure of the flower type. http://keeganm.com/tmp/DSC_3345-2.jpg Keegstr (talk) 15:08, 30 June 2011 (UTC)

Thanks. We absolutely should have the image on the commons, and ideally in one or more article. But I guess we might wait for an identification before uploading it. My vote is that it's minizilla. Excellent photo; kudos. --Tagishsimon (talk) 15:10, 30 June 2011 (UTC)

Current best guess: a planthopper nymph_(biology). See a somewhat similar beast here [4]. Note that your photo clearly shows 'thickened, three segmented antennae'. Note also that homoptera has crazy variation in it's defensive/camouflage structures. See extreme/surreal examples here: [5]. If nobody here corroborates my guess or poses a good alternative, you could ask at bugguide.net or whatsthatbug.com. SemanticMantis (talk) 15:31, 30 June 2011 (UTC)

I have posted to bugguide, here: http://bugguide.net/node/view/537384 . I will update this if there is any information from that end. Keegstr (talk) 15:47, 30 June 2011 (UTC)

Someone at bugguide.net suggested it might be an Ambush Bug, but was uncertain. Keegstr (talk) 17:01, 30 June 2011 (UTC)

Matches well with this Ambush Bug - http://bugguide.net/node/view/471034 --Tagishsimon (talk) 17:10, 30 June 2011 (UTC)

Judging only by appearance, that looks like the closest match yet. Bus stop (talk) 17:20, 30 June 2011 (UTC)

Is this enough information to post on the wiki article? Or should we wait for more substantial evidence? A google search indicates others call this an ambush bug nymph as well.Keegstr (talk) 17:31, 30 June 2011 (UTC)

I would definitely say we should wait for some more substantial information as to that creature's identity. If we are wrong we would spread misinformation. It is a gem, by the way. Good work photographing it. Bus stop (talk) 17:36, 30 June 2011 (UTC)

I'm changing my vote to ambush bug :). My first thought was actually the related assassin bug (due to the mouth), but I couldn't find any with pale nymphs. Note that your photograph agrees with the other ambush bugs not only in 'look' or appearance, but in specific morphological features such as the large fore-femur, and sturdy, piercing mouthparts which are kept curled under the thorax. Even though I said three-segmented antennae above, on closer inspection I think I see four. Also, a flower is exactly where we would expect to find these critters. I'd say follow wp:bb and add it to our page ambush bug. SemanticMantis (talk) 19:30, 30 June 2011 (UTC)

Ok I added it to he page, i just tucked it in on the right. There isn't a section on life stages so I wasn't sure where to put it, feel free to relocate it. Thanks for all the help!Keegstr (talk) 20:06, 30 June 2011 (UTC)

Photons exchange inside atoms

Hi friends, I have a question about electric charge interaction inside atom. I have read that in standard model, always two electric charge interact, they do this echanging photons. But in atomic model we have see that we only have photons emission or absortion when electrons change of energy level (K to M,N, P or vice versa). My question is: Considering a stable atom without any energy deviation, only with electron around nucleous, is there any photons changing among electorns and protons ? Also, inside nucleus, is there any photons exchanging when we have interactions among two or more protons inside nucleus ?

Thanks for help, — Preceding unsigned comment added by Futurengineer (talk • contribs) 16:30, 30 June 2011 (UTC)

Yes, in quantum electrodynamics, any time there is an electromagnetic force, there are photons to mediate it -- but they are virtual particles, not visible except via their effects. There are also virtual photons exchanged between protons in the nucleus. Looie496 (talk) 16:38, 30 June 2011 (UTC)

How do pigs groom or clean themselves?

I understand that cats groom or clean themselves with their tongues. How do pigs groom or clean themselves? (I am 3 years old, and my father typed this question.)--82.31.133.165 (talk) 21:22, 30 June 2011 (UTC)

According to Van Putten, G. (February 1989). "The pig: A model for discussing animal behaviour and welfare". Applied Animal Behaviour Science. 22 (2): 115–128., pigs groom themselves by taking a mud bath, letting the mud dry, and then rubbing off the mud. The parts that they can't reach are groomed by subordinate pigs, while the dominant pig is laying on its side (See here). ~ Mesoderm (talk) 21:32, 30 June 2011 (UTC)

Who grooms subordinate pigs?--Shantavira|^{feed me} 07:30, 1 July 2011 (UTC)

It's possible that the lowest pig on the totem pole doesn't get groomed at all. StuRat (talk) 07:53, 1 July 2011 (UTC)

This all happens on a totem pole ? Impressive. Sean.hoyland - talk 08:11, 1 July 2011 (UTC)

Please, not while one's eating ;) --Ouro (blah blah) 10:04, 1 July 2011 (UTC)

A pig may lie but only a hen can lay. Cuddlyable3 (talk) 15:53, 1 July 2011 (UTC)

Can anyone translate "Who will groom the subordinate pigs?" into Latin? I think it will make a good motto. 86.181.169.137 (talk) 21:00, 2 July 2011 (UTC)

Fun problem. Qui curam subordinati porci? (Google translate, Latin was a looong time ago) --Ouro (blah blah) 05:53, 3 July 2011 (UTC)

Anyway.... congratulations, you might be the youngest enquirer on these pages ever - unless anyone else knows different! Alansplodge (talk) 15:11, 1 July 2011 (UTC)