New Proton Measurements: 4% Smaller - Implications

[Trexman89]

First of all, do you believe the new measurements are accurate and the proton is actually 4% smaller. If you do, What implications do you think this will have?

 

[stevenb]

First of all, do you believe the new measurements are accurate and the proton is actually 4% smaller. If you do, What implications do you think this will have?

Hmmm, the old "does size matter?" question. Why not ask the electron, since she is his natural mate?

 

[Curl]

Hmmm, the old "does size matter?" question. Why not ask the electron, since she is his natural mate?

lol, I don't think she'd notice if he's 4% smaller.

 

[exploding]

lmao... nice guys... hey all first post.

honestly i think its too soon to go around saying the new size is accurate.

 

[Acut]

Hm, I've always thought quantum mechanics didn't allow precise length measurements.
If it is hard to define what is the size of an atom, I'm wondering how to define a proton's size.

Where have you found this news?

 

[Pengwuino]

Hm, I've always thought quantum mechanics didn't allow precise length measurements.
If it is hard to define what is the size of an atom, I'm wondering how to define a proton's size.

Where have you found this news?

It doesn't allow simultaneous precise measurements of observables that don't commute.

 

[Acut]

@Pengwuino

I know that. In fact, I've just posted it somewhere else: https://www.physicsforums.com/showthread.php?t=419945

I meant to say "precise length measurements of the proton". At such small scales, it is hard to define boundaries.

 

[zhermes]

I meant to say "precise length measurements of the proton". At such small scales, it is hard to define boundaries.

Its an operational definition, see: http://en.wikipedia.org/wiki/Charge_radius

 

[Acut]

@zhermes
Thank you! I didn't know such definitions existed - I know very little QM, indeed.

 

[zhermes]

@Acut
np. The concept of "boundaries" in general is pretty wild. The table I'm writing on, has no clear boundaries: the surface is just the average location at which the electrons in my hands strongly repel the electrons in the wood. Our E&M fields interact at all distances, and with enough force we could become arbitrarily "close."
Crazy stuff! :)

 

[Acut]

@zhermes
Yes, there are no sharp boundaries. In one of Feynman's lectures on Physics, a entire section is used to illustrate those blurred definitions.

By the way, I forgot asking... @ OP: where have you read about those new measurements?

 

[adaptation]

By the way, I forgot asking... @ OP: where have you read about those new measurements?

I'm not the OP (obviously), but I read about it http://www.physorg.com/news197727820.html" last month.

 

[alxm]

Already discussed in threads https://www.physicsforums.com/showthread.php?t=414787".