Friday 15 April 2011

Science! Molecular Octopi!

One from Science Daily. I need some cheering up after all the struggle vs stupidity, ignorance and malice.

First, The 'molecular octopus': A little brother of 'Schroedinger’s cat'
For the first time, the quantum behaviour of molecules consisting of more than 400 atoms was demonstrated by quantum physicists based at the University of Vienna in collaboration with chemists from Basel and Delaware. The international and interdisciplinary team of scientists has set a new record in the verification of the quantum properties of nanoparticles.



In quantum physics, the propagation of massive particles is described by means of matter waves. In a certain sense, this means that the particles loose their classical property of a well-defined position and their quantum wave function can extend simultaneously over a large area. Formally, this state resembles that of a cat that is at the same time dead and alive. In quantum physics this is called a 'superposition'.
...
The use of specifically synthesized organic molecules consisting of complexes of up to 430 atoms enabled the researchers to demonstrate the quantum wave nature in mass and size regimes that hitherto had been experimentally inaccessible. These particles are comparable in size, mass and complexity to Insulin molecules and exhibit many features of classical objects. Nevertheless, in the current experiment the tailor-made molecules can exist in a superposition of clearly distinguishable positions and therefore -- similar to 'Schroedinger's cat' -- in a state that is excluded in classical physics.
So it's both there and somewhere else at the same time. Now it's OK for subatomic particles to do this, even individual atoms, bose-einstein condensates where bosons all occupy the same place, but now we're demonstrating it in molecules big enough to comprehend.

3 comments:

Zimbel said...

Very poorly written article (not yours - ScienceDaily's).

Here's the original paper; while my quantum mechanics is weak, at least I don't have to figure out what a thought experiment about radioactive decay has to do with quantum interference:

Quantum interference of large organic molecules

Zimbel said...

Very poorly written article (not yours - ScienceDaily's).

Here's the original paper:

Quantum interference of large organic molecules

Zimbel said...

From the paper:

In our experiment, the superposition consists of having
all 430 atoms simultaneously 'in the left arm' and 'in the right arm' of
our interferometer, that is, two possibilities that are
macroscopically distinct. The path separation is about two orders of
magnitude larger than the size of the molecules.