

Electrons Are Near-Perfect Spheres - spottiness
http://www.wired.com/wiredscience/2011/05/electrons-are-near-perfect-spheres/

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Afton
'Near-Perfect' == 'Perfect to within our ability to measure'

That is, the headline might lead you to believe that they are not perfect
spheres, but that is not known to be the case.

Also: cool.

~~~
ansy
Note that whether electrons are spherical or not is important to theoretical
physics. Right now we do NOT want them to be perfect spheres. But, as you say,
our ability to measure this is limited by our instruments.

Keep in mind that many important scientific theories had to wait a very long
time until our instruments could reliably measure what was predicted. For
example, theories that the earth rotated around the sun were theorized as far
back as the 5th Century BC and maybe far before that. Actually proving the
Earth rotated around the sun didn't happen until 1728 by measuring aberration
in starlight. But what the ancients actually sought, proof by stellar
parallax, was far beyond the capabilities of optical instruments until 1854.
To be technical, it was actually empirical to believe the sun orbited the
earth during this time. Ancients would say "if the earth orbits, I should see
stars shift. I do not see stars shifting, therefore the earth does not orbit."
Aristotle actually used this very argument!

I was listening to some of the researchers comment on this particular
discovery and they are more hopeful about the technique than the findings.
There is already talk about improving the resolution a couple of orders of
magnitude.

~~~
endtime
>Right now we do NOT want them to be perfect spheres.

Two questions:

1) By "do not want" do you mean that it wouldn't be compatible with current
models? Or something else?

2) Relatedly, what would be the implications if they were to turn out to be
perfect spheres?

~~~
ansy
Aspheric electrons help explain the imbalance between matter and antimatter
under many current models.

I don't know the full implications if electrons were spherical. But two I can
think of are that either our models are wrong or there is something wrong with
the way we are measuring the amounts of matter and antimatter in the universe.

~~~
queensnake
Geez, I'm out of touch - last I knew they were point particles (and not just
in abstract).

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ColinWright
Title and timing are everything - I submitted this story yesterday and got no
upvates, and no comments: <http://news.ycombinator.com/item?id=2584908>

Don't mistake me - this isn't a complaint. It's an observation that although
technically savvy people pride themselves on assessing data purely on its
merits, we are persuaded by words and images in ways we don't fully
understand.

This is then really important in web design, marketing, sales, presentations,
_etc._ You can't rely on your technical superiority.

Timing and presentation matter almost more than content. More than you'd hope.
More than you'd want. More than is reasonable.

But it's not about reason.

~~~
alok-g
I wonder if it helps to submit when a large number of people are active at HN
as opposed to say on a weekend. It seems to me that the sort-order algorithm
is based on up-votes and time elapsed since submission. So if a submission is
made during off hours, it does not get enough attention or votes, yet the time
elapses the same way...

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TGJ
I've always been curious about this. If electrons are spheres and so are
protons and neutrons, what type of matter is filling up the area in between?
Are protons and neutrons not spheres? Can electrons get squished into
different shapes depending on arrangement? Or, does there even have to be
matter in the voids surrounding adjacent spheres?

~~~
icegreentea
There are voids. A lot of voids. A good deal of matter (even solid) are
actually 'nothing'. If you take materials science, you get the 'atoms made of
hard ball' approximation of the world (which usually yields pretty good
answers), and even then, the densest you can get anything like 75% matter or
something. And that's severely high-balling it (the ball radius approximates
the electron cloud as a hard continuous shell, when it's really actually
mostly just empty.

~~~
foob
These voids are actually full of a crazy mess of virtual particles that exist
within time/energy uncertainty. Empty space isn't really a meaningful concept
when you're dealing with field theories.

When you study quantum field theory one of the first mind blowing things that
you learn is that an electron at rest can be thought of as a superposition of
an infinite number of somewhat classical scenarios. For instance, the electron
can shoot of a virtual photon, which creates an electron/positron pair, which
annhilate and create a new photon, which is then absorbed by the original
electron. These processes can be arbitrarily complex; just imagine
substituting in the whole process we just described for the electron that was
pair produced- you can do that as many times as you want. These things are all
ocurring at once. This leads to the necessity of renormalization and in turn a
great joke. What is positive infinity plus negative infinity? If you ask a
mathematician he'll tell you that it's undefined. If you ask a physicist he'll
tell you it's the mass of the electron.

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roadnottaken
_"if an electron was the size of the solar system, it would be out from being
perfectly round by less than the width of a human hair"_

This doesn't seem right:

    
    
      Radius of an electron: 2.8e-15 m
      Off by: 1e-29 m
    
      Thus it's off by 0.0000000000004%
    
      Average distance of pluto from the sun: 5.9e12 m
      Thus "size" of the solar system: 1.18e13 m
    
      1.18e13 * 0.0000000000004% = 4.2e-2 = 4.2cm
    

It's not off by that much , but 4.2cm is way more than the width of a human
hair (17-180um, a factor of ~1000-2000-fold)

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allenp
Are you sure it isn't this:

[http://www.wolframalpha.com/input/?i=width+of+human+hair+%2F...](http://www.wolframalpha.com/input/?i=width+of+human+hair+%2F+size+of+solar+system+%3D&a=*DPClash.MiscellaneousE.size+solar+system-_*PlutoSemimajorAxis-)

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foob
What actually happened was that they placed a new upper limit on the electric
dipole moment of electrons. This has implications for physics beyond the
standard model. You can't be a "sphere" unless you have a finite and well
defined radius, which electrons don't.

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cschmidt
The Economist Science columnist, Babbage, had an article about this today as
well.

<http://www.economist.com/node/21518365>

It has a little more context than the wired article.

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TuxPirate
... and we still can't figure their areas beacause of Pi!

 _facedesk_

