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I'd never say "never", but:
  • Chemical Vapour Deposition (CVD) usually has a solid substrate (with matching crystal lattice) onto which to deposit a layer of the substance in the vapour phase.
  • The channel formed by passing a laser through the air does not provide a stable, crystal lattice onto which to grow a perfectly crystalline graphene tube (or carbon nanotube, which is effectively the same thing)
  • Graphene tends to fold up into a compact shape as soon as it forms, so some sort of substrate or spool with tension is needed to keep it in a useablel shape.
  • Carbon is not ferromagnetic, so it would have trouble aligning with a magnetic field
Technology in this area is advancing rapidly. CVD on nickel and copper substrates is one current technique. See: http://en.wikipedia.org/wiki/Graphene#Exfoliation
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Thanks for interesting replies.
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New Theories / Re: Post Orgasmic Illness Syndrome (POIS)
« Last post by fornicationDENIED2 on 30/09/2014 23:54:14 »
I learned a new trick, after months of doing kegels (rather inconsistenly Im ashamed to admit) I have learned to orgasm without ejaculation, its very hard though. You basically have to contract your pelvic floor muscles VERY HARD when you reach the point of no return and hold the contraction for a long time, 5 minutes approx., I used to let go quicker of the contraction at first and failed, it is great, no POIS, just hard as hell to achieve.
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Physics, Astronomy & Cosmology / Re: Is infinity a misconception?
« Last post by PmbPhy on 30/09/2014 23:49:58 »
If the universe was flat then Sean Carroll would not disagree with me.
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Alan, I have to respectfully disagree.

There are many spontaneous local reversals of entropy, including crystallization, condensation, accretion (even on planet scale). There are also many patterns that self propagate. There's more to it than that.

Also, a tortoise in the galapagos could be forgiven for thinking that all life was particularly well evolved for life on his rock, and therefore must have begun there. I'm not saying that I know of any evidence that we originated elsewhere, but the possibility cannot be dismissed just because it looks like life is too well adapted, and requires conditions found only on Earth (as far as we know for certain so far).
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Physics, Astronomy & Cosmology / Re: Is infinity a misconception?
« Last post by chiralSPO on 30/09/2014 23:23:41 »
The only way would be able to prove something is infinite would be by abstraction. I don't think we could ever claim to have measured or experimentally determined an infinite value, countable or uncountable.

In the same way, zero is also kind of an infinity. Reciprocal and logarithmic relationships abound in physice. For instance, one cannot actually actually achieve absolute zero on the Kelvin scale (for many reasons!), only arbitrarily close to it; the distance between two particles cannot really be zero or infinite, only arbitrarily far or close. Yet there are also laws of conservation--meaning a derivative implied to be precisely zero, but verified to be zero within some small, but obviously nonzero confidence interval.


Does the fact that we cannot experimentally verify something make it untrue through?

The math predicts infinities or zeros, but we must be careful here, also to remember that our beloved equations are ALL MODELS. And all models have implicit assumptions and limitations. So an equation having a nonsensical infinite or zero value could  just as much signify a problem with the model as reflect reality. Often these ridiculous failures of our equations happens at boundaries or limits (absolute zero, speed of light, discontinuity in another parameter [phase change], etc.) But overall, we can do amazing things with infinities in models, giving real predictive power for experimental physics, chemistry and cosmology.

Most people have misconceptions about infinities, myself included--little is intuitive, only protracted analysis and mathematical rigor works here. One can do some really crazy things with them mathematically, or by logical induction (Cantor actually went crazy, but that's another story).
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The essence of life seems to be a local reversal of mesoscopic entropy.

Where did it come from? Why would anyone think it came from anywhere else? The conditions for the continuation of life seem to be fairly narrow, yet widely available on the surface of this planet, so evolution is most likely to have begun here. The question is whether it started first on the hard surface or (more likely in my uninformed opinion) on the sea bed.
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I have found intelligent life that is not human..

On Earth.

Try beating chimps in this task:

https://www.youtube.com/watch?v=zsXP8qeFF6A
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Quote from: Bill S
Pete and ChiralSPO, I would not argue with your logic, but I still think starving people might not feel the same about the logic.
I disagree. Most of my life I've spent being poor and having a lack of money. Many times going without food too. But never once did I think that we should stop the search for life outside our solar system. Finding such life would mean a great deal to my existence and that would mean a great deal to me. And I know as a fact that I'd be no better off or worse off depending if the did or didn't do that kind of searching. It would change absolutely nothing in my life. If other people who are starving don't think that way then that's there problem because they're living an illusion. Why? you may ask? Because, as I said, there would be absolutely no difference in their life. And just because they're starving it doesn't mean they had access to the same education up to high school that I had. At least for Americans. And just because the US does this research it doesn't mean that every country in the world needs to do it or even should do it.

I've heard this kind of argument all of my life. There's always someone arguing that certain research shouldn't be done because people are starving somewhere when in fact it's never that simple. A lot of the time nothing would be different for the starving people because less money is going into that kind of research. It's not like that direct it into food for starving people.

If you take a look at who it is that's really starving you'll see that its people in countries in Asia and the Pacific, Africa, Latin American and the Caribbean and Developed Countries. See http://www.wfp.org/hunger/who-are

And it's not as if the world doesn't produce enough food for everyone either. There's plenty to go around. http://www.wfp.org/hunger/causes

So I think that it's very na´ve to think that we can stop looking for aliens and put that money into food and that would make a noticeable dent in the world hunger problem. And if someone disagrees with me then that's fine. If they want to prove that I'm wrong then it would do them a world of good because it would help them learn about some of the realities that we have to live with in modern society.

I don't mean to be unfeeling. And believe me, if I thought it'd help then my feelings would be radically different.
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I can do no better than copy my response to a related question:

Quote
As has been said in another context, it's the kind of thing that makes a nation worth defending.

I think there are two distinct questions: extraterrestrial life and extrasolar intelligence. The search for selfreplicating mechanisms or the remains of such, is more likely to bear fruit within the solar system, but there's very little likelihood of finding anything we might communicate with. On the other hand it is quite likely that if extraterrestrial life has ever existed in the universe, something outside the solar system may have produced a broadcast signal to that effect. 
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