Science desk
< March 29	<< Feb \| March \| Apr >>	March 31 >

Welcome to the Wikipedia Science Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

March 30

Things without Mass

These are probably straightforward questions for any physicists out there, but:

Have we found or identified things without mass (or matter, if you prefer) in the universe?
If not, are there not-unproven theories that allow for or expect to find massless or matterless things?
Where do forces and waves (and torques and etc.) fit in? Are they considered things, or effects of things? 207.6.208.66 (talk) 01:35, 30 March 2012 (UTC)[reply]

Well, photons have zero rest mass, or at least that's the current thinking, and by default mass means "rest mass" these days.

If you mean that the things have no mass-energy, I suppose that depends on what you mean by a "thing". I am not aware of any way that a physical object can be detected if it has no mass-energy. But the number seven doesn't seem to have any mass-energy, and has arguably been "found", at least if you're a mathematical realist. --Trovatore (talk) 02:06, 30 March 2012 (UTC)[reply]

This question might even boil down to metaphysical naturalism, the theory that the only kind of things that "exist" are made of "physical stuff", i.e. mass and energy. In that respect, nothing has been found which conclusivley proves "non-physical" things exist, but a few things, perhaps the most well known being consciousness, present as yet unsolved problems to the position. Vespine (talk) 03:28, 30 March 2012 (UTC)[reply]

Maybe just add that it's probably a question of philosophy as much as physics. Specifically metaphysics. Vespine (talk)

Last one. As to the "not unproven theories that allow massless or matterles things"; Cartesian dualism, or more specifically Substance dualism would fall into that category. Vespine (talk) 03:36, 30 March 2012 (UTC)[reply]

See, and I thought only the Catholics had a Mass... --Jayron32 03:50, 30 March 2012 (UTC)[reply]

Look up wikt:Mass and wikt:Mess. The original meaning is simply the amount of food put out for a meal. (The symbolic wafer has apparently wandered a way from the Last Supper) But Newton's mass has a different etymology entirely. Wnt (talk) 04:25, 30 March 2012 (UTC)[reply]

Er, no. The Wiktionary entry for 'mass' clearly indicates that the name for the church ritual derives from the dismissal sentence 'Ite, missa est'. This has nothing to do with amounts of food; it just means "(You can/should) go, it (our prayer) has been sent." AlexTiefling (talk) 13:23, 30 March 2012 (UTC)[reply]

Actually, for 'Mass', which I hadn't read (I guess I should have remembered article names over there are case sensitive!). I find myself very skeptical of this interpretation but it's off topic, and not my field. Wnt (talk) 14:28, 30 March 2012 (UTC)[reply]

Hmmm, agreed that all particles have a finite mass-energy. Photons would have zero mass-energy if they stood still, while massive particles would have infinite energy at the speed of light, so we don't see these things. Fundamental forces are mediated by particles - with the possible exception if quantum gravity can't be worked out, and anything else a real physicist might think of... These particles, and forces, have mass, or release mass. For example the binding energy of a nucleus makes it less massive so energy has to go in to bring out the protons and ~~electrons~~ doh! neutrons. Or the negative energy of the Casimir effect (maybe lack of virtual particles?). But potential energy e.g. between two charged objects brought together can also have positive mass...

Hypothetically, if you had a "zero mass electron", and you brought it near a regular electron, I'd expect it to go accelerating away at an infinite rate (zero inertia). But with access to a proton I suppose it would zip to it from any distance based on the most infinitesimal force. It would certainly be very weird - I wonder if there's a stronger way to refute the possibility. Wnt (talk) 04:09, 30 March 2012 (UTC)[reply]

Thanks for the responses: I suppose I should have clarified that I was considering detectable phenomena rather than concepts or ideas. Are zero-mass electrons possible? I was lead to believe (by a school no less!) that they had a fixed mass. They also decided that Newtonian physics sufficiently explained how things worked, so I wouldn't be surprised that they were wrong.

Interesting point on the rest mass of photons: though I can't find exactly where in the speed of light article it outright states that photons move at a fixed speed, I'm inferring it from everyone above. Theoretically speaking, then, what would happen to photons caught in black holes? Would they no longer be able to move? (Or if preferred, what do current theories stipulate might happen to photons when they meet with a black hole?) 207.6.208.66 (talk) 05:19, 30 March 2012 (UTC)[reply]

Emphatically no, no zero mass electrons have ever been suggested. Photons move at the speed of light, always; this is the key axiom underlying the theory of relativity. Even in black holes they move at the speed of light, relative to the space they're in, until the singularity is reached; and the mathematical description just ends there without explanation. Wnt (talk) 05:36, 30 March 2012 (UTC)[reply]

Well, I guess that makes sense then. Thanks a bunch to everyone, especially Wnt! 207.6.208.66 (talk) 05:45, 30 March 2012 (UTC)[reply]

Flat, empty spacetime is something that physically exists, yet in non-quantum physics at least doesn't inherently have any mass to it, even if you take the ambiguous term "mass" to mean "relativistic mass". However, in quantum physics spacetime does inherently have a vacuum energy (which is equivalent to a "vacuum relativistic mass"), although how much of that "vacuum relativistic mass" spacetime has is unclear, since looking at vacuum energy from the perspective of quantum field theory or from the perspective of the cosmological constant gives wildly different values for that, for reasons that aren't understood. Red Act (talk) 06:59, 30 March 2012 (UTC)[reply]

Photons always move at the speed of light, true, but what that speed is depends on the medium the photons are passing through. When people refer to "the speed of light" without elaboration they mean the speed of light in a vacuum. But scientists can slow down light dramatically, using low temperature mediums. Just recently I read (maybe in Scientific American?) that in a recent experiment light was slowed down to about 38 miles per hour.

Is it conceptually possible to slow light to 0 miles per hour? Would it be massless/energyless then? Duoduoduo (talk) 19:43, 30 March 2012 (UTC)[reply]

Look at slow light. The distinction between phase velocity, group velocity, and signal velocity gets really tricky. I've seen different takes on the situation with photons subject to a refractive index - as I understand it, though, all the "slowing" of light has to do with properties of the wave model; whenever you're looking at an actual photon that thing should be moving at the honest to God vacuum speed of light. Note I could well be wrong/confused on that point - I've seen explanations up to and including modeling electric field as a curvature of space to explain the slower speed. Wnt (talk) 21:01, 30 March 2012 (UTC)[reply]

eco-friendly utopia

Imagine everything about pollution, greenhouse effect, blah blah... is magically fixed. Now how can we start again and build cities that are completely eco-friendly, without giving up all the technology we have now (like, say, going back into caves). I mean do we have a theoretical idea of what an eco-friendly city, town, whatever, looks like? I mean we scream about global warming and pollution all the time, but what is it that we ultimately want to reach exactly?--Irrational number (talk) 07:41, 30 March 2012 (UTC)[reply]

If you have a subscription to New Scientist, this article on "Rebuilding civilisation from scratch" explores this. The engineer's dream (if not necessarily the sociologist's) is an arcology - a largely self-contained planned city which attempts to be as efficient as possible to heat and cool, to water and feed, to light, and to provide transport around. "What we want to reach" is more of a political question, and it'll depend on who you ask, but the technological approach is roughly bright green environmentalism. Smurrayinchester 08:31, 30 March 2012 (UTC)[reply]

I believe population is the real problem. If 99% of the people would be good enough to disintegrate, we would still have enough to maintain a technological society yet not enough to create ecological catastrophes. StuRat (talk) 08:37, 30 March 2012 (UTC)[reply]

So what your saying is, is that we ought to nuke Zuccotti Park? 203.27.72.5 (talk) 21:00, 30 March 2012 (UTC)[reply]

There are many who would argue that anything less than giving up all technology is pollution. --145.94.77.43 (talk) 09:35, 30 March 2012 (UTC)[reply]

There are lots of positions one could take as to the outcome, but the essential goal of all of them is some form of sustainability — e.g., a system that can continue without eventually destroying itself. The problems with global warming and pollution in their current forms is that they are rapidly becoming unsustainable, and the consequences of that are going to be massive in terms of human health, lived environments, and human economies. There are practical solutions, for example, towards reducing carbon dioxide output substantially that would keep the base temperature deviation within holocene levels, for example. They don't involve becoming an eco-topia or anything like that; they involve capturing emissions, improving efficiency, using other forms of energy generation, etc. (e.g. the Stabilization Wedge Game). --Mr.98 (talk) 13:24, 30 March 2012 (UTC)[reply]

Tangential, but I wanted to pull this quote from Mr.98's link (emphasis mine):

"A final criticism is that the Wedge Game focuses on technological fixes rather than fundamentally challenging the endless growth economy that is at the heart of global climate change.The 2007 IPCC reports state clearly that economic and demographic growth are the fundamental drivers of global climate change." I think this aspect is often overlooked. Our basic economic principles which equate growth with wealth and prosperity inherently lead to unstable, unstustainable resource exploitation. SemanticMantis (talk) 15:09, 30 March 2012 (UTC)[reply]

I was looking for something more... detailed. I mean I know an eco-friendly system is such that it won't destroy itself and all of those things, but what exactly would it be like? Do we know enough about what it must look like?--Irrational number (talk) 17:39, 30 March 2012 (UTC)[reply]

With a lower population, it would work pretty much like it does now. That is, people would continue to cut down trees to plant crops, but this would now only take a small portion of the total land, because of the much smaller population. Fossil fuels would still be unsustainable, though, in that we are currently using them up at something like a million times the rate at which they are formed, and we can't cut our usage to 1 millionth merely by reducing population. The good news is, renewable energy sources like solar and hydro work far better with lower populations. That is, there's just as much sunlight and water, but far less energy is needed. Creating greenhouse gases would no longer be a concern at 1% of our current population, as that lower rate wouldn't have a measurable effect on the climate. Of course, if population began to grow, then the ecology would again be threatened, so we would need controls in place to prevent that. My point is, that it's fundamentally our current population which is unsustainable, and the effects on the environment are just a symptom of this problem. StuRat (talk) 17:54, 30 March 2012 (UTC)[reply]

StuRat, you make a good point about population. However, it's not just our population, it's our population and our rate of resource use. There are indeed two factors that can in principle be adjusted. SemanticMantis (talk) 18:12, 30 March 2012 (UTC)[reply]

True, but we often make this mistake of thinking that, say, American Indians, lived in a totally sustainable way, when, if they had the same population we do, they would have had environmental problems, too. For example, all those feces, if not sent through a sewage treatment plant, would pollute all the rivers, lakes, and aquifers. That population would also quickly kill off all the wild game. StuRat (talk) 20:07, 30 March 2012 (UTC)[reply]

Then we are agreed. While per capita rate of resource usage is the important factor for a fixed population size, the total resource usage rate goes up linearly with population, if they use resources at a fixed per capita rate. Given a certain total target usage rate (which is really what sustainability is), we must then use less per capita to support more people. SemanticMantis (talk) 20:18, 30 March 2012 (UTC)[reply]

Right, but I don't know if it's possible to reduce our level of consumption per capita to be sustainable at the current population, much less with an ever-expanding population. At out current pop, about the best we can do is use up one resource, then move on to the next, like from oil to natural gas, to coal, and hope global warming isn't too bad. There's basically no hope we can maintain our current population without having a major ecological impact. StuRat (talk) 00:50, 31 March 2012 (UTC)[reply]

The answers to your revised question have more to do with sociology and culture than engineering and hard science. As such, you're basically asking for a political and cultural philosophy that supports sustainable practices. This is basically the realm of speculative fiction. If that angle interests you, I highly recommend this book [1], which (in great detail) posits a societal system that is truly sustainable. Spoiler alert: it involves no urban/rural divide, no cars or fossil fuels, no beasts of burden, and no eating meat ;) SemanticMantis (talk) 20:26, 30 March 2012 (UTC)[reply]

Sustainability depends on time horizon. Ultimately, only maximum entropy condition is sustainable. 203.27.72.5 (talk) 21:08, 30 March 2012 (UTC)[reply]

let me put it this way: we leave the earth, and meet a fancy beautiful, non-poluted planet just like our earth, with (for the sake of the question) identical conditions. Now we want to build cities, what would the city be like? I want a picture detailed enough to be able to be analyzed for seeing whether it's practical or not (horrible phrasing, sorry!!)--Irrational number (talk) 21:34, 30 March 2012 (UTC)[reply]

It really depends on what your goals are. If your only consideration is minimising pollution, then fairly obviously the solution is not to build a city at all and just leave the planet alone. Clearly, you want the minimise pollution while still having humans living there, but how many humans? In what level of comfort? If you want a similar population and standard of living as we have now, then your main problem really isn't the design of the cities. It's power generation. Your main priority would be to find a means of power generation that doesn't rely on burning fossil fuels. We have plenty of those now (nuclear, solar, wind, tidal, hydro, biomass, etc.), they just tend to be more expensive and less convenient than fossil fuels so they aren't used as much. There are other forms of pollution, but getting rid of fossil fuels would get you 90% of the way there. --Tango (talk) 21:50, 30 March 2012 (UTC)[reply]

Well, living underground and leaving the surface alone would be nice. I happen to think underground nuclear power is less destructive to the environment than massive solar farms, wind farms, and dams, so I'd go that way. Mines should be the traditional type, not strip mines or mountaintop removal. Food should be grown hydroponically. Transportation would be subways and elevators. StuRat (talk) 01:08, 31 March 2012 (UTC)[reply]

I think that suggestion just belies a subjective preference for protecting superterranean environments. Why is destroying the environment of earthworms, plants' root structures and soil microbes objectively better than destroying that of any other organism? 203.27.72.5 (talk) 04:19, 31 March 2012 (UTC)[reply]

The earthworms and roots would stay relatively close to the surface, so would be safe. I'm talking about hundreds of meters/yards down. StuRat (talk) 05:26, 31 March 2012 (UTC)[reply]

I think what you really need to define (and not just you, but environmentalists in general) is what you want to avoid. Do you want to avoid causing pain, killing individual organisms, causing the extinction of species, influencing behaviours or evolution? Do you only want to avoid affecting life, or are you also adverse to polluting places that don't host life? If you try to take this all to its logical conclusion, you just end up with a paradox; people ought not to exist (as per the Voluntary Human Extinction Movement ) so as to avoid changing the natural environment, but people exist naturally so removing them would in itself be changing the natural environment. 203.27.72.5 (talk) 06:45, 31 March 2012 (UTC)[reply]

If human beings, governed by the laws of nature as are any other form of life, are going to be part of this utopia, the idea of anything being sustained but high population growth is pretty dubious. One would have to modify humans to create a society of people averse to having children above the replacement rate for a society which had a minimal impact on the ecology of this new planet. These modified humans could live in rammed earth and cob houses and bike everywhere, or they could live in brick subdivisions and drive 500cu Eldorados. Regardless of the technology they used, the only thing stopping them from naturally expanding to fill the space available would be genetic engineering or some kind of mandated psychological programming. Even these measures would fail given enough generations of mutation. Nevard (talk) 20:53, 31 March 2012 (UTC)[reply]

Ironic how all attempts to preserve nature inherently involve fighting against the natural processes that tend to destroy it. 203.27.72.5 (talk) 02:07, 1 April 2012 (UTC)[reply]

Two questions about plastic bag bans

The city where I live banned plastic bags in June last year, and so far it seems to have good public support. Plastic bag bans seem to be all the rage in the Philippines right now, with cities like Angeles, Muntinlupa, Pasig and Makati implementing them. I have two questions about such bans:

1. What are the short-term and long-term ecological effects of such bans? (both good and bad)

One of the advantages of plastic bag bans is that it cleans up the environment, or does it? I read somewhere that in the long-term, plastic bag bans are actually harmful to the environment, since making paper bags takes up more water and cuts more trees. However, at least they biodegrade easily. So, have there ever been studies about the effects of bans, both short-term and long-term? I'm not asking for opinions, but actual results from studies or experiences.

2. Which was the first location in the world to ban plastic bags, and where?

I know San Francisco was the first city in the United States to ban plastic bags, and Bangladesh was among the first countries to ban their use, but where was the first place in the world to ban them, and when? I could not find enough information about this online, but according to some sources, it was a small village in Australia (whose name I forgot), but is this true?

Narutolovehinata5 ^tccsdnew 13:55, 30 March 2012 (UTC)[reply]

I think that more information with regard to the proposed legal status of alternatives, as explained in Oxo Biodegradable, Biodegradable bag, and Bioplastic, is necessary to evaluate the effect of such a ban. Presently it appears that degradability is not well defined with some international standard (and more importantly, there's no clear logical dividing line either), so exactly where the line is drawn is important. Wnt (talk) 14:18, 30 March 2012 (UTC)[reply]

I read somewhere (unfortunately I can't remember where) that paper bags take a very long time to degrade, which would mean that biodegradability is at best a long term but not short term advantage of paper over plastic.

My understanding is that paper is made of some pretty nasty chemicals. Would that mean that biodegradability is a bad thing?

A disadvantage of plastic bags is that animals eat them and die as a result of a clogged up digestive system. Duoduoduo (talk) 14:57, 30 March 2012 (UTC)[reply]

Paper is made with some nasty chemicals more than of them, depending in part on what is done with it - see environmental impact of paper, bleaching of wood pulp. In landfill conditions, denied access to oxygen and nutrients, biodegradation of many things is difficult.

In practice, I think that the urban dweller's main objection to plastic bags is when they end up in every tree, crinkling away in the wind like the flag of some small trashy nation, or when they appear visibly at the shoreline of a river. Any sort of photo- or bio-degradation is enough to help with that. Wnt (talk) 15:23, 30 March 2012 (UTC)[reply]

I think the best idea is to get everyone to use reusable bags. (Of course, if they feel the need to wash them after each use, with detergent, this has a high environmental cost, too.) Brown paper bags aren't bleached, which is better for the environment and they biodegrade quickly. The glossy, bleached and dyed paper bags from high-end stores are more of a problem. One other advantage of paper bags is that they quickly get soaked and flattened and thus stop blowing around, unlike plastic bags, which seems to blow around until they hit a chain linked fence or something like that. StuRat (talk) 15:29, 30 March 2012 (UTC)[reply]

Actually guys, I'm asking about the effects of plastic bag bans, not about the bags themselves. I'm asking what are the good and bad short and long-term effects of plastic bag bans, not arguments in favor and against recyclable bags. Narutolovehinata5 ^tccsdnew 15:34, 30 March 2012 (UTC)[reply]

Well, to reiterate, the specifics depend on the ban. Will a patchwork of overbroad local bans damage demand for oxydegradable bags and thus create more long-term trash elsewhere? Will they encourage the use of paper which then leads to more deforestation? Even with a single known law in your hands it is very hard to work out what it will do, and when it is unspecified... Wnt (talk) 16:55, 30 March 2012 (UTC)[reply]

Belgium banned "free" shopping bags years ago, customers have to ask specifically for them and shops have to charge for them. Not sure if they were the first to do it. Since then most shops only have "reusable" bags, though you could question the reusability of the cheapest ones (0.10€), they're made from that stretchable plastic that you know won't last too long if you carry something heavy. This only appies to supermarkets, other shops like fashion, electronics etc. don't mind paying for the bags themselves. Ever since the Greens were in the government some 10 to 15 years ago (??), an eco-tax was introduced on all "avoidable" non-recyclable packaging. That meant 0.50€ for plastic bottles, since recycled glass is an alternative, high taxes on non-rechargeable batteries, on razors with a fixed handle and so on. Basically, all the cheapest products got much more expensive... Ssscienccce (84.197.178.75) (talk) 21:38, 2 April 2012 (UTC)[reply]

Duck with face texture like a chicken's wattle

The other day at a pond in northern Virginia I saw a duck and instead of feathers on the front of its head above its bill and around its eyes there was red bumpy skin like unto a chicken's wattle or a turkey's head. This was only around the face area; it had feathers on the rest of its head. What species of duck have red skin on their faces? 20.137.18.53 (talk) 14:09, 30 March 2012 (UTC)[reply]

A Muscovy Duck. (+)H₃N-Protein\Chemist-CO₂(-) 14:16, 30 March 2012 (UTC)[reply]

Thank you. 20.137.18.53 (talk) 14:46, 30 March 2012 (UTC)[reply]

Or possibly a churkendoose.[2] ←Baseball Bugs ^{What's up, Doc?} carrots→ 01:37, 31 March 2012 (UTC)[reply]

Visual range of animals that differs from humans

I understand that some birds can see into the UV spectrum. Do they have a wider visual range than humans, or is their whole visual range just shifted up a bit? To put it another way, can birds see all the same colors as us plus UV light, or are they "missing" some of the colors we can see? I'd also like to know about other animals that have a different range than us. Are there any that go the other way, seeing infrared instead of UV? And what do you think it would look like to have such different kinds of vision? 151.163.2.8 (talk) 15:36, 30 March 2012 (UTC)[reply]

You could try to follow references from Bruce MacEvoy,'s Color vision pages, chapter 1. – b_jonas 16:07, 30 March 2012 (UTC)[reply]

Humans can see ultraviolet after cataract surgery. Reputedly this was used by British intelligence, which recruited such people to "coastwatch" for signalling by German submarines - but the truth of that story seems to be hard to determine. [3] Wnt (talk) 16:52, 30 March 2012 (UTC)[reply]

For infrared, lots of animals can see that, like the pit viper. I imagine it looks similar to what we see when using an infrared scope. StuRat (talk) 19:58, 30 March 2012 (UTC)[reply]

I believe pit vipers can just detect what direction heat is coming from in a fairly vague way. They don't have any kind of lens, so they won't get a clear image. --Tango (talk) 21:53, 30 March 2012 (UTC)[reply]

Fair web info at [4] [5] . The latter sort of gets my imagination going, because it points out that the pits of a pit viper work more by their structure than any special heat receptors. It makes me wonder whether using a tissue printer and doing nothing more absurd than existing sex-change 'therapy', you might take a sensitive area of a blind person (e.g. fingertip) and replace it with a functioning pit sensor. Not saying that's a winning idea, just interesting. Wnt (talk) 20:30, 30 March 2012 (UTC)[reply]

That page says pit vipers have a resolution of about 5 degrees, or roughly the your hand held at arm's length. That kind of resolution would be a lot better than nothing for a blind person, but it wouldn't be any near a replacement for sight. And remember, you're just seeing heat, which isn't a very precise way of seeing things anyway (the long wavelength doesn't help). I don't think a pit-fingered blind person would be able to do much more than identify where doors and windows are, which many of them can do with their eyes anyway (what we call "blind" isn't usually no sight at all, although it can be in some cases). --Tango (talk) 22:03, 30 March 2012 (UTC)[reply]

Another thing is that many animals are sensitive to polarization of light, so they can see visual structure that is invisible to us. Looie496 (talk) 21:42, 30 March 2012 (UTC)[reply]

Most Birds have four types of pigments unlike the the three that humans have. So they don't have any missing colours. In fact with more receptors, they can distinguish more colours. ( mathematically, i think of it this way: with three receptors, all the colours you can see fall in a 3D space; for a given intensity, all the possible shades will fall on 2D space. see RGB-> HSV coding of colours; with more receptors, you get more shades) As a concrete example, you don't distinguish blue+yellow light from green as they both activate red, green and blue receptors, maximally activating the green receptors. birds will be able to tell apart certain pure shades from a mixture that humans can't tell apart. As an aside, birds have two types of red receptors: both have the same rhodopsin sensor, but each has a differently coloured oil droplet that gives the whole cell a different sensitivity. So the longest wavelength peak for the filtered red cell is around 610nm, a bit lower than ours. But a total of 5 primary colours! hope this answers your questionStaticd (talk) 18:31, 31 March 2012 (UTC)[reply]

There are probably human tetrachromats too. --ColinFine (talk) 11:57, 1 April 2012 (UTC)[reply]

Bees can see UV light which has led some flowers to evolve patterns which are not visible to humans. Vespine (talk) 23:57, 1 April 2012 (UTC)[reply]

Help with bird identification

I saw this bird at a park in Southern California. It was maybe six inches long, and appears to be a juvenile, though it doesn't resemble the juveniles of the other bird species that were around. Can anyone tell what it is? 69.111.79.119 (talk) 15:47, 30 March 2012 (UTC)[reply]

What were the other adult birds you saw around? Coots?, grebes? My current best guess is Pied-billed_Grebe, note the distinctive dark patch on the beak. (Yes, I know the chick pictured in our article doesn't look much like yours... but this google image search shows how much the chicks can vary [6]) SemanticMantis (talk) 16:01, 30 March 2012 (UTC)[reply]

Heavy water plant

What is the purpose of the pipes running up the hillside at the Vemork plant? I am asssuming they have nothing to do with heavy water production: maybe connected with the factory's original purpose of fertilizer production? Spinning Spark 17:17, 30 March 2012 (UTC)[reply]

Its a hydro-electric plant. These are the pipes delivering the water from the reservoir to the turbines.--Aspro (talk) 17:36, 30 March 2012 (UTC)[reply]

That is, the Penstocks. DMacks (talk) 19:05, 30 March 2012 (UTC)[reply]

second part of question: distributing energy in the world economy via carriers

Guys and gals, thanks for the detailed responses to the first part of my question above. The second part was not addressed at all - could someone answer it? (About depletable/refillable energy carriers for the world economy akin to a biological ATP/ADP energy carrier analogue.) Please assume infinite energy is available at a single point on Earth only, and all these 'atp' analogues have to be routed there to be recharged. what would work in practice? If you have any other ideas for addressing my thinking in the second part of the question, or references, I welcome them. Thank you! 188.157.72.10 (talk) 18:29, 30 March 2012 (UTC)[reply]

"Transporting energy from a single point source" is a perfectly reasonable simplification of our present energy infrastructure. Sure, we've got multiple point sources, but you can generalize it as "one to many" and it makes sense. And we transport energy around. And that's without getting into "infinite" energy; once you posit that, you can do pretty much whatever you feel like doing, because waste becomes an utter non-factor. So yeah, stick the infinite energy thingamabob on the coastline, crack water into hydrogen, ship it, and burn it. Nice clean fuel cycle that'll power more or less anything. Note that we're not talking anything fundamentally distinct from my local swap-a-propane-can program that I use to run my grill, so I don't see the need to reinvent much terminology. — Lomn 18:38, 30 March 2012 (UTC)[reply]

If you want to transport large amounts of energy around the world, I suggest copper wires carrying electricity (your "ATP" could be converted into electricity first). They do lose a bit over the course of the transport, but, so long as you have an infinite energy supply, that's not a problem. This isn't currently done between continents, but I see no reason why oceanic cables similar to the ones which carry phone and Internet signals couldn't also transfer power. Laying all this cable would cost quite a bit, up front, but then we would no longer need to send oil tankers all over the world, endangering the environment, etc. Electricity is also the most useful form of energy for most applications. For those applications where we still need another form, like airplane fuel, it could be created using electricity, close to where it's needed. See synthetic fuel. Electricity would make more sense in cars than gasoline, if it was almost free. Each parking space could then charge you a few pennies to recharge your car as it sits. StuRat (talk) 19:32, 30 March 2012 (UTC)[reply]

having more rem dreaming or at least additive From-dream awakemenment

how could i get this?.. thanks!. 109.65.39.161 (talk) 19:39, 30 March 2012 (UTC)[reply]

You need to ask your question more clearly. I have no idea what "additive from-dream awakenment" is. See REM sleep for basics. I wonder if lucid dreaming is what you're really interested in. Note that we can't give you specific medical advice for treating some sleep related illness, but we can answer general questions about such an illness. Wnt (talk) 20:35, 30 March 2012 (UTC)[reply]

I believe most people dream about the same amount, the main difference is how much they remember their dreams. Keeping a dream diary is supposed to be a good way of learning to remember dreams. --Tango (talk) 20:48, 30 March 2012 (UTC)[reply]