# What is the most important constant in physics?

## What is the most important constant in physics?

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22
So, what is it?

Let's make it "what is your favorite constant?" All of these constants are important for different reasons.

Need more options

I wanted to vote for 0. Or maybe 1.

What about the universal gravitation constant?

Voted c.

Pi is great because it comes up everywhere. Pi is especially great on Thanksgiving... mmmm...
I have to agree with Ambitwistor. 0 and 1 are pretty important too, but they're not as natural as pi. By that I mean, pi is a constant of nature (if you consider geometry a part of nature). 0 and 1 we made up. If either were an option, I would have hesitated.

turin
Homework Helper
e and pi are not physical constants, they are mathematical constants. I suppose you could say that that makes them physical constants by default, but my point is that c, for instance, is NOT a mathematical constant. In that regard, I would have to say that e and pi are more important than any other physical constant, but that they are equally important to each other.

e is the most significant (e is the charge of an electron right?)

If there was not speed limit of nature it wouldnt really affect our lives as much if there was no charge then we would sink through the floor since the molecules wouldnt have a intermolecular relationship keeping them rigid, there would be no elements, no chemestry.

g isnt really a constant is it. as soon as we blast a spaceship off the planet, then the g of the planet is going to change ever so slightly since its mass has changed. Without g im going to assume that by u mean g being important means that if it werent existant there wud b no gravity.

We cud live without gravity quite happily, life wud be a bit more consvative.

Wow im tired and off 2 bed

alpha, of course

fine structure constant.

JMD

If we're talking about actual, experimentally measured physical constants, and not just mathematical constants like &pi; and e, then I don't really take dimensional constants to be truly fundamental. Of the dimensionless constants, I'd also vote for the fine structure constant &alpha;. See:

http://math.ucr.edu/home/baez/constants.html

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Originally posted by FZ+

I agree, what about planck's constant? Seems like an important constant to me.

P.S. h-bar is important but it is h/2pi(I think). So you would have to have that important constant pi to have h-bar. For this reason I would put pi above h-bar as a more important constant.

Originally posted by bdkeenan00
P.S. h-bar is important but it is h/2pi(I think). So you would have to have that important constant pi to have h-bar.

No, you don't need &pi; to define hbar. You could take hbar as fundamental, and define h = hbar * 2&pi;, and then it would be h which requires &pi;. In fact, hbar is really more fundamental than h; it's what appears in the canonical commutation relations which are the foundation of quantum theory.

Originally posted by Ambitwistor
In fact, hbar is really more fundamental than h; it's what appears in the canonical commutation relations which are the foundation of quantum theory. [/B]

Oh really? I didn't know that. I guess you learn something new everyday.

QuantumNet
due to the length contraction etc. you might think it's c

but length contraction seldom appears in real life

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QuantumNet
I think it's e (as I wrote before)

Look.
c can be changed, pi is used for circles and similar figures,
g variates and G is not included.

The right answer is e, cause e^ix = cos(x) + isin(x), D(e^x)= e^x etc.
e^i2(pi)= 1

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Originally posted by QuantumNet
c can be changed

How exactly do you change c? Sounds fishy to me.

QuantumNet

Originally posted by bdkeenan00
How exactly do you change c? Sounds fishy to me.

you put c to 1 and E = m and x^2 + y^2 + z^2 = t^2 etc.