I'm wondering how I missed Hacking Matter. I'm generally good at keeping up with science fiction and anything interesting in real science, but this one got past me. Quantum dots are real science, but many of their possible applications are science fiction (for now). To make a quantum dot, you take a P-N-P junction and make the top N and P layers much smaller than the bottom P layer. This traps the electrons in 3D space and forces them to form orbitals, as if there is a nucleus. But there is no nucleus and an artificial atom has been created (these are actually real). Researchers merely need to change the voltage to change the type of atom.

Some of the applications of quantum dots are in the same league as FTL drives, teleportation, and time travel. One of those applications is to change "matter" into anything you want merely by writing a computer program. It would be like a very advanced transformer, since the transformers could not change their atoms, only their shape.

One application I can think of would be programmable living spaces. The material in your room would change into the type of surface you needed, depending on what you were doing. With programmable matter you would only need one room. It could also be keyed in with your biological needs. For instance, if you became sleepy, a soft surface would form. If you had to defecate, a small pot to squat upon would form. Your fecal matter would not be programmable, naturally, since you void real atoms. So there would still need to be some sort of drainage/recycling system.

http://www.amazon.com/Hacking-Matter-Le … ef=ed_oe_h

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Hell yeah. You could easily get a cutting board, burner, oven, and sink. Carbon is the champion of thermal conductivity, so you could program a carbon surface and wrap it to make an oven or flatten it to make a burner. You could just simulate steel to get the sink and cutting board. I'll probably be dead long before this technology becomes commonplace, but that doesn't mean I can't get hyped!

Why not eat food made out of quantum dots?

Anyway, wouldn't the programming have to be done within some kind of scaffolding, and wouldn't this rule out the kind of applications you're describing here?

More importantly, it seems to me that you're taking this a step too far. Most organic matter is made from a handful of elements. The difference between a hardwood floor and a featherbed is not so much a matter of what atoms are present*, but rather of how those atoms are arranged into molecules, and how those molecules are arranged into materials, and so on up to the macroscopic level. So quantum dots don't matter much for these applications--what you really need is to be able to break materials down into their constituent atoms and reassemble them into something else.

In principle, I can see how quantom dots could be useful for synthesizing elements which are rare and have important industrial uses--rhodium, platinum, and gold come to mind. Assuming, of course, that they're stable.

*Well, feathers being made mostly of protein, and wood mostly of carbohydrate, the feathers would have more nitrogen, but the atmosphere is 75% nitrogen, so that's by far the least of your problems.

I'm not sure if the body would be able to extract nutrients from them. In fact, I don't think anyone has written a paper about the effects of ingesting quantum dots by biological organisms. Furthermore, I'm not even sure if they would have nutrients. I don't know enough about how nutrients are formed.

I think I understand what you mean. The scaffolding itself would then have to be programmable, in order for it to be morphological.

You're right, I didn't think of that. A good example is carbon, which can be very soft (graphite) or very hard (diamonds).

The author of Hacking Matter proposes that quantum dots could be used to make very heavy transuranic elements more stable, since they do not have nuclei. Most elements heavier than uranium don't last very long, due to radioactivity. They would be useful in devices where radioactivity is required.

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Update:

  I'm still reading the book, so I will have better knowledge about this in the coming weeks. This excerpt answers your question:

"Really, such chips would be capable of doing and being so many different things that it's helpful to reiterate the list of their known limitations. They can't change their mass. They can't change their shape, although they can presumably be mounted on the surface of something that can. They can't create or destroy energy, or operate with perfect thermodynamic efficiency. Also, while their 'chemical' properties are real, they're weak, and limited to highly localized regions on the chip. At best, you'll have an atomically thin programmable dopant layer sitting near the top of a bed of silicon or gallium arsenide. At worst, you'll have discrete programmable islands jutting up from the substrate like stones in a Japanese garden."

  Also, to answer the question about their edibility:

  "We could tile the chip with ersatz glucose molecules, but these would be so oversized and underreactive that our taste buds would never recognize them."

  Clearly, the author has given the issue some thought and indicates food could be made with quantum dots. I'm not sure what would happen to the 'food' if it were separated from the substrate, which means I'm not sure how it could be eaten.