[sourcery]

FYI

[jennyp]

Breakin' the law!
Breakin' the law!

[nightdriver]

All sorts of things like this can be supposed when we get down to the quantum level. One problem is that we have to be nano-sized observers to make any use of it.

[DH]

The researchers used optical tweezers to grab hold of a micron-sized bead and drag it through water.

By measuring the motion of the bead and calculating the minuscule forces on it, the researchers were able to show that the bead was sometimes kicked by the water molecules in such a way that energy was transferred from the water to the bead. In effect, heat energy was extracted from the reservoir and used to do work (helping to move the bead) in apparent violation of the second law.

Something doesn't sound right here.  I could have sworn the tweezers were moving the bead.

[boris]

"One of the simplest is to note that it's impossible simply to extract the heat energy from some reservoir and use it to do work."

It's also wrong. You can indeed extract the heat energy from a reservoir and use it to do work. You just can't get it all and you have to reject some of it to the environment, so you have an efficiency lower than some upper limit (the Carnot efficiency). But when did we expect journalists to get things right?

--Boris

[Free the USA]

Index Bump

[anymouse]

Physics ping.

[gcruse]

This description of the experiment is easier to visualize than the one from the first article.