Posted on 05/30/2005 7:08:57 PM PDT by eagle11
Why cling to any electronics? Why not build photonic systems from scratch, with little or no electronic support?
exactly
They have been working on a photonic computer for at least 20 years. It looks like they are making progress but still a ways away.
Sigh...I guess this means tube type radios really are obsolete.
How large is a photon compared to an electron? How small can the channels practically get?
It's an intermediate step that would allow the new photonic stuff to quickly interface with current (no pun) electronics rather than scrapping everything.
Also, most of the things you want to eventually run are electrical, such as motors, lights, speakers, etc. and they can't (today) be run by the low intensity light that is in the photonic devices.
Large motors and speakers powered by light are quite a stretch for today's technology.
I'd like to place an order for photon torpedos with nanite guidance, please.
Get in line. I've got 25,000 terrorists who want a dozen each.
One, it's a pretty neat idea.
Two, they have been claiming photonics is going to take over from electronics for decades, now. Your PC CPU is going to be electronics for many more decades.
One, it's a pretty neat idea.
Two, they have been claiming photonics is going to take over from electronics for decades, now. Your PC CPU is going to be electronics for many more decades.
Neither one occupies any space. They are "infinitely small" unless space itself is quantized. They are "particles" in the sense that they both have a mathematical definition.
I see. Electrics provide power, photonics produce logic. Got it.
OR:
"Electrons for work, photons for play." -copyright, me
Integrated electronic circuit elements are already significantly smaller than the wavelength of visible light.
The wavelength of an electron depends on its energy, but for energies of the order of atomic binding, 1-10 electron volts, the wavelength is on the order of an atomic size, less than a nanometer, compared to 500 nanometers for visible light.
I'm not sure if this is air-tight reasoning, but to me it implies a big advantage for electronics over photonics.
That's kinda what I was thinking. What is to be gained, except less heat buildup? How fast do electrons travel in Silicon currently?
Storage.
Nobody knows how to store photons.
IIRC, electrons physically travel in semiconductors on the order of a kilometer per second, in electric fields created by typical working voltages. Holes, which are the positively charged quantum counterparts to electrons, propagate somewhat slower.
However, electrons and holes need only travel a few nanometers--partway across a junction or channel--to do their job. The associated electric fields and currents, somewhat paradoxically, travel at an appreciable fraction of the speed of light. The exact fraction depends on the resisitivity and dimensions of the conductor, and the characteristics of the dielectric (insulating) substrate.
(A few years ago, IC makers made the metallurgically difficult transition from aluminum to copper for the interconnect layers, because copper, having higher conductivity, results in faster signal propagation, all other things being equal.)
Interesting. Though I'm confused what you mean by the terms "the" and "voltages".
Well, the vacuum tube is immune to the effects of EMP but transistors and integrated circuits are not. If they get the photonic computer working, then the tube WILL be obsolete.
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