Advanced and Conceptual Physics

[Vasu]

While it's true that we can make everything that's needed to make someone invisible, I disagree that it's as easy as making a processor. Based on the "invisibility cloak" concept in the Harry Potter series, scientists are working on creating precisely that. Something mobile which bends light around itself. So far, they haven't exactly been extremely successful, so I don't see how it's as easy as a processor.


BTW, the plural of index is indices. ^^

[Kyrillos]

While it's true that we can make everything that's needed to make someone invisible, I disagree that it's as easy as making a processor. Based on the "invisibility cloak" concept in the Harry Potter series, scientists are working on creating precisely that. Something mobile which bends light around itself. So far, they haven't exactly been extremely successful, so I don't see how it's as easy as a processor.


BTW, the plural of index is indices. ^^

The technology is a small as one, or at least what they have made. They're having problems creating flexible material that is able to bend all the pigments of natural light around an object, while most of the materials made in the bending process have been made using processor making technology.

Yay for carrying on an intellectual thought process at 1AM.

[Mindspank]

Though because your bending light, and not giving matter the property to have light pass through it, you will never be truly invisible. Not to mention the cloak would probably be heavy as hell and hold alot of heat in. So you couldnt stay under it for too long or you would suffocate.

[Kyrillos]

its not that light isn't passing through it, as so much as the refractive index is negative, so it bends around it.

They also said a "Harry Potter-esque" cloak would be too heavy, cylindrical, and impractical for hundreds of years.

the other problem is that you couldn't see out. xD

[lamchopz]

Any physics book is a nice book, particularly the ones written by theoretical physicists. In fact, it's their job: sitting down and thinking up things, then recording them and collaborating with the experimental physicists to test out new ideas and hopefully discover something novel and useful.

My Physics professor is involved in quantum computing development and he showed us a concept video of the mechanism of such a machine:
http://www.iop.org/EJ/mmedia/1367-2630/10/12/125005/
(Only fragments of the video are released to the public. We were lucky to see the full version.)

It's simply remarkable.

I'm intrigued by the fact that while we don't really know what it is, we use it extensively to accommodate our life. For example, we have no idea what precisely an electron is (e.g., its spin is an obvious given but mysterious nonetheless), we still refer to it in texts that explain its applications. The same goes for light. In the book mentioned, the author refers to it as a wave but it can also act as a particle, hence its dual nature.

This bit interests me: aligned atoms received stimulus, thus vibrate rhythmically which affect the light 'wave' that acts as the current? or did you mean the aligned atoms vibrate upon receiving the light stimulus and these by themselves affect the next set of atoms (recall matter waves concept) in order to transmit the information encoded in the stimulus wavelength?

Sorry I'm a bit unclear about that part. Could you explain it a bit more? =]

[Kyrillos]

Quoting the book here:

The goal of plasmaonics is to "squeeze" light so that one can manipulate objects at the nanoscale, espicially on the surface of metals. The reason metals conduct electricity is that electrons are loosely bound to metal atoms, so they can freely move along the surface of the metal lattice. The electricity flowing in your home represents the smooth flow of these loosely bound electrons on the metal surface. But under certain conditions, when a light beam collides with the metal surface, the electrons can vibrate in unison with the original light beam, creating a wavelike motions of the electrons on the metal surface (called plasmons), and these wavelike motions beat in unison with the original light beam. More important, one can "squeeze" these plasmons so that they have the same frequency as the orignal beam(and hence carry the same information) but have a much smaller wavelength. In principle, one might then cram these squeezed waves into nanowires. As with photonic crystals, the ultimate goal of plasmonics is to create computer chips that compute using light, rather than electricity."

Enjoy your light reading for the day. This is from a segement entitled "Invisibility via plasmonics"

[lamchopz]

Thanks for that.

It makes much more sense now. I was wondering what was meant by "aligning atoms in a rhythm" to create a current. Seems we use the electrons after all in this specific description. By atoms, you probably meant the quasiparticles, aka. plasmons, that result from the excitation by light.