Hello, future

http://www.technologyreview.com/blog/arxiv/26448/ I got totally lost by the actual paper, but the article is enough to see what's going on.

A photon has a small momentum which it can impart to anything it hits, as Arthur Compton and Peter Lebedev discovered at the beginning of the last century. We now know that photons can be used to push anything from electrons to solar sails.

Today, Jun Chen from Fudan University in China and a few pals demonstrate the counterintuitive result that photons can pull things too. In other words, they've worked out how to generate a backward pulling force from a forward propagating beam.

Hoorah, we're that much closer to moving things with our MINDS.

I like how various wild sci-fi concepts actually work perfectly: IF you adjust your sense of perspective.

Wanna travel to the stars? Slow your metabolism and sense of time so a thousand years is like a day, and it doesn't matter what percentage of c you travel, you'll get there in no time.

Want teleportation or (as in this article) tractor beams? If you're working with nanomachines, it's not only possible, but with teleportation (aka Quantum Tunnelling), essential.

DO WANT.

When can we have this thing in hand held form.

It'll make an awesome grabby tool for getting stuff off the fridge.

^^Was just about to bitch about how the future is here but only on the particle scale.

What is all this technobabble? Where's my jet pack? Where's my flying car?

But seriously, possible development of tractor beams? I'm intrigued.

There must be an alternate universe in which people possess flying cars and jetpacks who continually bitch about how there's no worldwide computer network.

They've already made jetpacks. They just aren't as awesome as you might think. Or you know, useful. As for flying cars, they've managed to get cars off the ground for several minutes at a time but it's too fuel costly right now to be feasible.

When can we start scaling up these effects of quantum tunneling and tractor beams to the perceptible level? Can we simply not generate enough power?

No, it's not about the amount of power. Quantum tunneling relies on the inherent uncertainty in the position of subatomic particles, which only happens on a very small scale compared to our everyday existence. At any level that could remotely be called perceptible, a quantum tunneling event is so unlikely as to be for any practical purpose impossible. I don't know how the tractor beam works, but it probably also relies on small-scale effects.

It only works on a small scale guys.

Same thing for nuclear explosions. At best, you'd get a slight bump on the graph when setting off only one atom.

Then they eventually used that to make bombs. Same principle applies here, we've just got to figure out how to apply the small case in a large enough manner to make it relevant to our daily lives and to jobs.

edited 2nd Mar '11 7:37:45 AM by Usht

You don't set off an atom.

Nah, you split it. Which is close enough to setting off an atom for me.

You don't split it either.

You do something that makes an itty bitty boom.

Two things:

1) You're derailing this.

2) Atomic fission. Nukes run on it.

edited 2nd Mar '11 8:40:54 AM by Usht

Also, it's true that this only works on the scale of individual atoms/molecules (as do optic tweezers) but guess what machine also does?

The term is "decay" not split, it's just a very rapid chain reaction, done by getting the material to a high enough density.

It actually says on there that it only works for small scale stuff.

They thought the atom was full of smaller stuff but when they cut it open they found out it was really just full of explosions.