De Broglie Wavelength - Can a Person Move Slow Enough?

[Arctic]

Just a random thought: is it not possible for a person to move slow enough to have an observable de Broglie wavelength? For example a person moving at around 10^-30 m/s should have a wave nature that is very observable.

 

[Phrak]

That's an interesting thought. A person is a rather large object, difficult to experiment with, so how about a few atoms instead? The first thing that comes to mind is coherence. Do incoherent assemblies of atoms display interference, or do they all have to be indistinguishable for this to happen?

To be clear, take a few dozen bound atoms, thermally agitated, and send them through a double slit. What will we measure on the other side? Will we measure bands of intensity as we would expect from the wavelength associated with total momentum or something else?

 

[t_barlow]

Sure, in principle everything is quantum mechanical. But try and work out how cold you'd have to be: use $E = (1/2)mv^2 = Nk_B T$. You won't ever get that cold because you can't decouple from the environment enough. You'll always be hit by radiation - even in space - making you so warm you can't notice the quantum effects.

 

[PhilDSP]

One thing to consider that might make a person's de Broglie wave very hard to detect are that the strength or spatial sharpness of the EM fluctuations must diminish with speed even though the wavelength grows longer. If you spread the same amount of energy into a larger area the density and resolution goes down.

Another thing to think about is that most likely the waves or ripples are dependent on the spatial extension of the associated particle. The empty (or rather particle-less) space around the particle doesn't itself generate the wave. Since a person very largely consists of empty space, there will not be a single large wave but a mesh of tiny, tiny waves generated by the particles.

 

[mariush]

What about the uncertainty relations? Wouldn't the uncertainty in position be very large as the speed approached 0?