are elctrons 3 dimensional? 2 dimensional?

[none]

hello?
what about photons?
electrons, one dimensional? 2 dimensional?

 

[skepticalbip]

Or maybe 11 dimensional?

 

[DBT]

Anything more than four dimensions seems counterintuitive.
.

 

[bilby]

hello?
what about photons?
electrons, one dimensional? 2 dimensional?

Definitely more than that. Everything we observe directly requires at least four dimensions to describe - three to locate a point in space, plus one to locate it in time.

Eleven seems to be the consensus amongst many string theory physicists. I am not qualified to say that they are wrong.

Certainly four is the lower bound. I am not aware that there's any upper bound currently recognised.

 

[lpetrich]

hello?
what about photons?
electrons, one dimensional? 2 dimensional?

That presumes a sort of billiard-ball model.

In actual fact, they are described with quantum field theory. Sort of like waves with some constant total amount. I remember a physics professor who called a photon a "blob of light".

So they are effectively 3-dimensional, being spread over all 3 space dimensions, and changing over the time dimension.

 

[Wiploc]

Certainly four is the lower bound.

That's assuming an electron is bigger than a point.

 

[bilby]

Certainly four is the lower bound.

That's assuming an electron is bigger than a point.

I don't think that's an unreasonable assumption. But even a point has variable position relative to other points, and therefore needs at least four dimensions to describe.

 

[lpetrich]

Wat is quantum field theory? To answer that, I'll consider field theories in general. These are theories that feature some quantity or quantities that vary continuously over all space-time.

The first field theory was gravity. It was originally a theory of forces between particles, but one can express it as a theory of gravitational potential, and do so without any mysterious "action at a distance" (Laplace, Poisson, et al ~ 1800)

The next field theory was electromagnetism, starting out as separate field theories of the electric and magnetic fields. (Maxwell, 1861)

Then general relativity, a theory of gravity that makes it a distortion of space-time. (Einstein, 1915)

Then P.A.M. Dirac's field theory of the electron. (Dirac, 1928)

Plenty of other field theories followed.

 

[Wiploc]

Then P.A.M. Dirac's field theory of the electron. (Dirac, 1928)

If the electron is viewed as a field (rather than as a particle at the center of a field) then not only is it bigger than a point, but it fills all of space, right?

 

[bilby]

Then P.A.M. Dirac's field theory of the electron. (Dirac, 1928)

If the electron is viewed as a field (rather than as a particle at the center of a field) then not only is it bigger than a point, but it fills all of space, right?

That's my understanding.

What we think of as particles at the molecular level are the most probable locations. QFT says that the amplitude (effectively the probability that you will find a particle if you look in that place) is very small but never zero for all locations in spacetime other than close to the location classical models would have us expect to find it. The fun part is that 'close to' is a much larger volume than classical models tell us - leading to fun things like quantum tunnelling.

 

[Jimmy Higgins]

Quantum field theory is complete bullshit, that make little sense, is reproducible, and appears to be true.

Then P.A.M. Dirac's field theory of the electron. (Dirac, 1928)

If the electron is viewed as a field (rather than as a particle at the center of a field) then not only is it bigger than a point, but it fills all of space, right?

But an electron is also a "particle".
[YOUTUBE]https://www.youtube.com/watch?v=jvO0P5-SMxk[/YOUTUBE]

This same experiment has been done with "buckyballs" which, while small... are substantially larger than electrons! So it isn't merely electrons that behave in this fucked up bullshit... and completely reproducible way. So at that point, one needs to stop concentrating on if electrons are particles or waves, but what in the heck is going on with verifiable matter? I got up to Class 7 (8?) of the MIT intro to quantum mechanics course on YouTube. The math starts freaking my brain out, way outside my league.

 

[bilby]

Quantum field theory is complete bullshit, that make little sense, is reproducible, and appears to be true.

Then P.A.M. Dirac's field theory of the electron. (Dirac, 1928)

If the electron is viewed as a field (rather than as a particle at the center of a field) then not only is it bigger than a point, but it fills all of space, right?

But an electron is also a "particle".
[YOUTUBE]https://www.youtube.com/watch?v=jvO0P5-SMxk[/YOUTUBE]

This same experiment has been done with "buckyballs" which, while small... are substantially larger than electrons! So it isn't merely electrons that behave in this fucked up bullshit... and completely reproducible way. So at that point, one needs to stop concentrating on if electrons are particles or waves, but what in the heck is going on with verifiable matter? I got up to Class 7 (8?) of the MIT intro to quantum mechanics course on YouTube. The math starts freaking my brain out, way outside my league.

Field theory allows us to understand why we observe both particle-like and wave-like behaviours. A particle is a maximum of amplitude; It need not be the only maximum in the field for a given particle at a given time, but all classical objects exhibit the property of only being in one place at a time, and human brains have evolved to consider that classical approximation to be an inviolable law, when it is in fact a mere statistical result that is almost inevitable when considering aggregates of large numbers of particles.

Lots of "fundamental" laws of nature turn out to be statistical effects, and this isn't only true of quantum weirdness. A Newtonian model of an ideal gas leads to entropy as a statistical effect, and allows us to formulate the Second Law of Thermodynamics, and establish an 'arrow of time', despite the underlying laws of motion being entirely reversable (that is, they work in exactly the same way when you run the model backwards in time as they do when you run it forwards). Hot gases tend to cool and expand, only because that's far more probable than that they will warm and contract - there are simply vastly more possible big cold states than there are hot dense ones.

Physics is weird. To single out quantum physics as particularly weird is just a reflection of the conditions in which humans evolved - quantum effects weren't important, so our brains didn't develop the ability to understand them - but the same can be said of plenty of classical physics. Everyone knows that an object in motion will slow to a stop unless acted upon by a force. Everyone knows that heavy objects fall faster than lighter ones. Everyone knows that things can't be in more than one place at a time. But 'everyone' is wrong on all three counts - except in the special case of pretty much every aspect of human life.

We like to think that human scales and human environments are the norm. But actually, they're very much the exception in our universe.