why there is more matter than antimatter...

ML1
ML1
Joined: 20 Feb 05
Posts: 340
Credit: 75,344,819
RAC: 28,291

RE: ...Still not quite sure

Message 86919 in response to message 86917

Quote:
...Still not quite sure what to make of it ...


Good experimenting!

One thought: Does the interference pattern survive being deflected by a reflective surface or being put through a lens? I suspect so...

Cheers,
Martin

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,284
Credit: 150,712,340
RAC: 124,053

I'd think that C60 at typical

I'd think that C60 at typical room temperature molecular speeds would have a momentum too high and thus wavelength too small to yield a discernible pattern with the gear you have. There'd be plenty of extraneous disturbances to boot.

Those subsequent optics after formation of the interference pattern would not change the basic behaviour. That's how Chipper showed us the results - by photographing them! :-)

Or put another way, from a photon's point of view, it's all optics/interference. Even transmission of light through free space can be analysed as interference amongst pathways. That's the beauty of QED as it replicates all prior knowledge ( waves models, particle models, ray tracing etc ) and encompasses ( experimentally, to date ) all known scenarios.

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

Chipper Q
Chipper Q
Joined: 20 Feb 05
Posts: 1,540
Credit: 708,571
RAC: 0

RE: I'd think that C60 at

Quote:
I'd think that C60 at typical room temperature molecular speeds would have a momentum too high and thus wavelength too small to yield a discernible pattern with the gear you have. There'd be plenty of extraneous disturbances to boot.


Well, I had to do some checking on how it's currently being done by some of the pioneers in the field, and it really is amazing. Guess what material can be used for the slits – light itself, in the form of a standing wave, can be used! Wow!! And that's not all – (quoting from here)

Quote:
It is intriguing that C60 can almost be considered to be a body obeying classical physics in view of its many excited internal degrees of freedom. Leaving the source, it has as much as 7 eV of internal energy stored in 174 vibrational modes, and highly excited rotational states with quantum numbers greater than 100. Fullerenes can emit and absorb blackbody radiation very much like a solid and they can no longer be treated as a simple few level system.


Most surprising is how they impart the kinetic energy to form the particle-beam of buckyballs in the first place – they use a very hot oven with everything inside a vacuum chamber! The buckyballs are heated in powder form to a temperature of 600-700 degrees C and the ones that ricochet out a narrow slit get collimated into a beam by height and lateral limiters and end up having a most probable velocity of around 210 meters per second. It's amazing that the buckyballs must be vibrating and rotating to the hilt!

More amazing still is being able to measure/observe the effect of the van Der Waals interaction between the molecules and the gratings! (See Figure 2 here). Not only that, it seems apparent (well, to me) that including the geometry of the edges will lead to an even better fit of the numerical model with the experimental results.

Perhaps most amazing is that even the effects of gravity have to be accounted for, which means being able to make some precise measurements of the gravitational acceleration component in the interferometer plane (on the order of 10^-3 g) within a short integration time ... I wonder if it could be used to detect, say, the current position of the moon? Other solar system gravitational perturbations? Could two or more be used to measure the how fast the force of gravity propagates?

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,284
Credit: 150,712,340
RAC: 124,053

Ah, back of the envelope time

Message 86922 in response to message 86921

Ah, back of the envelope time :[pre]
m = mass of C60 molecule

~ 60 * 12 * 1 ( AMU's )

~ 720 * 1.67 * 10^(-27)

~ 1.2 * 10^(-24) kg

v = velocity of C60 molecule

~ 210 m/sec

p = momentum of C60 molecule

~ m * v

~ 2.52 * 10^(-22) kg m/sec

h = Planck's constant

~ 6.63 * 10^(-34) m^2 kg/sec

l = QM wavelength of C60 molecule

~ h / p

~ 6.63 * 10^(-34) / 2.52 * 10^(-22)

~ 2.63 * 10^(-12) m

[/pre]That is about 2.5 pico-meters. What an experiment! It's amazing to see the side peaks and diffraction minima. There is absolutely no classical way around this.

Makes you want to rush out and buy a high quality optics bench and stuff ( mirrors, polarisers, diffraction gratings, multichannel analyser ) with a power stabilised laser. :-)

Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

ML1
ML1
Joined: 20 Feb 05
Posts: 340
Credit: 75,344,819
RAC: 28,291

Still deep in various

Still deep in various cogitations... And here's a little more physics for thought:

Bouncing atoms take a measure of gravity

Entanglement goes mechanical

Soo... There's the chance to finely measure gravity effects at a very small scale. (Including utilising atomic interference.)

And to my mind the mechanical entanglement suggests that perhaps entanglement depends on multiple small oscillations that must coincide (heterodyne) to 'poke up a peak' that can then be observed. The entanglement tricks may just be a synchronisation of the underlaying (multiple small) oscillations. In effect, the 'hidden variables'?

Still yet to work through the original Young's slits!

Cheers,
Martin

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.