Comments on: Why does my coffee cup not just fall through the coffee table?

By: IBY

IBY — Tue, 28 Sep 2010 01:19:40 +0000

@Laden
Then I am so sorry. There is no explanation in existence that will satisfy you because the fundamental explanation for this has to do with wavefunctions, energy, and uncertainty principle. 🙁 In fact, without quantumy explanations, there is no way to explain a vast array of things in our universe, like magnets, neutron stars and white dwarfs, the rate of proton-proton fusion in our sun, etc. In a way, satisfying explanations don’t exist for many of these phenomena.

By: Greg Laden

Greg Laden — Sun, 26 Sep 2010 15:49:51 +0000

IBY: Yeah, but, saying it’s all quantumy is not a very satisfying answer, and the original question was now about how two things can’t be in the same place. The question is how come a tiny itty bitty thing can’t pass through the hugemongous vast expanse of nothingness between two other tiny itty bitty things.

By: IBY

IBY — Sun, 26 Sep 2010 08:30:02 +0000

@Greg Laden
Pauli exclusion principle states that two particles can’t be in the same quantum state, whether it is energy level, angular momentum, or spin. And yes, part of it has something to do with the electrostatic force, but it just turns out that the answer is more complicated than that because it has to take account of quantum mechanical interaction. It is only due to the exclusion principle that a white dwarf and neutron star doesn’t collapse into a black hole. So, in the quantum mechanical version of the normal force, it is not that some fundamental force does the pushing, a quantum mechanical interaction prevents two particles from being in the same quantum state. And yes, since the standard model is built on quantum mechanics, pauli’s exclusion principle still applies.

By: Pierce R. Butler

Pierce R. Butler — Sat, 25 Sep 2010 18:16:51 +0000

One fine morning your coffee cup, like Wile E. Coyote, will make the mistake of looking down.

By: Greg Laden

Greg Laden — Sat, 25 Sep 2010 18:09:14 +0000

Tristram, I don’t buy that. The “normal force” is not one of the fundemental forces. Or at least, I don’t think it is. Mathematically the exclusion principle may work, but doesn’t that predate the current version of the standard model? Or, if not, how not?

By: Sinan

Sinan — Sat, 25 Sep 2010 10:20:43 +0000

Very good, this like page.

By: Tristram Brelstaff

Tristram Brelstaff — Sat, 25 Sep 2010 09:45:30 +0000

The Pauli Exclusion Principle is the ultimate source of the solidity of matter. From the Wikipedia page on Freeman Dyson:

A seminal work by Dyson came in 1966 when, together with Andrew Lenard and independently of Elliott H. Lieb and Walter Thirring, he proved rigorously that the exclusion principle plays the main role in the stability of bulk matter.[13] Hence, it is not the electromagnetic repulsion between electrons and nuclei that is responsible for two wood blocks that are left on top of each other not coalescing into a single piece, but rather it is the exclusion principle applied to electrons and protons that generates the classical macroscopic normal force. ...

By: Dave v.

Dave v. — Sat, 25 Sep 2010 06:44:57 +0000

Well that’s no fun…

Look at the distance from Sun to Earth: the first parenthesized value appears copied from the Sun-Mercury distance of 60M km, while all the other listed values are variations of 150M km.

I only spotted it because it’s one of the few distances in the chart I know offhand — although I think “8 light minutes” is a more thought provoking variation than any of those listed.

It’s still there, I doubt anyone’ll even look at it ’til next week.

By: Greg Laden

Greg Laden — Sat, 25 Sep 2010 05:29:05 +0000

What is it?

By: Dave v.

Dave v. — Sat, 25 Sep 2010 02:04:58 +0000

Cool animation. There’s at least one error, looks like a cut ‘n paste typo. Finding it could be assigned as an extra credit problem to make students really look at the values — maybe it’s intentional.

And yeah, I sent Primax Studio a message…