# What is your favourite physical constant?

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#1
So what is it?

I'm mainly asking those people who know it from memory.

Although its a pretty obvious one I'd say mine has to be Plank's 6.626x10^-34. Useful for so many things.

WHATS YOURS?
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6 years ago
#2
Planck's does come up quite a lot, but more often than not h bar. I always like the Stefan-Boltzmann constant it just flows nicely 5678, although I didn't use it very often.
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#3
(Original post by Fizzel)
Planck's does come up quite a lot, but more often than not h bar. I always like the Stefan-Boltzmann constant it just flows nicely 5678, although I didn't use it very often.

that's true although (even though I do remember 1.055x10^-34) you only need to know plank rather than hbar.

Stephan-Boltzmann does flow nicely I always think the same about the age of the Earth (going by meteorites) 4.567 Ba.
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6 years ago
#4
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6 years ago
#5
epsilon nought without a doubt
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6 years ago
#6
G - the gravitational constant, if you asked the average person what the gravitational constant was they'd probably say g = 9.81ms^-2 but it's not really constant, it changes depending on where you are in the world and it's only a very specific example, G, 6.67x10^-11 m^3 kg-1 s-2 is ultimately the gravitational constant and gravity is one of the most important physical properties of the universe so that is my answer
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6 years ago
#7
The speed of light as I don't think anything can travel faster than it and go beyond it.
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6 years ago
#8
I always liked e. I just think the symmetry behind it is beautiful
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6 years ago
#9
(Original post by cant_think_of_name)
I always liked e. I just think the symmetry behind it is beautiful
Explain!
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6 years ago
#10
I don't really like universal physical constants because there isn't a reason why they're that number; they just are. They're arbitrary constants that you just have to deal with and use.
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#11
(Original post by CJG21)
Haven't come across that before, looks like it might be more of a chemistry thing?

(Original post by AreebWithaHat)
epsilon nought without a doubt
Ahh the permittivity of free space, can you quote it from memory though?

(Original post by cant_think_of_name)
I always liked e. I just think the symmetry behind it is beautiful
I'm guessing you mean 'e' in the mathematical sense because e is also used as the charge on an electron...
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#12
(Original post by Chlorophile)
I don't really like universal physical constants because there isn't a reason why they're that number; they just are. They're arbitrary constants that you just have to deal with and use.
Isn't that a bit like saying you don't like the laws of physics because you just have to use them?

Physical constants come form those laws. Most are found empirically.
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6 years ago
#13
Haven't come across that before, looks like it might be more of a chemistry thing?<br />
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Ahh the permittivity of free space, can you quote it from memory though?<br />
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I'm guessing you mean 'e' in the mathematical sense because e is also used as the charge on an electron...
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no i wish, i'm not even a physicist I'm a medic lol. it has the best sounding name tbh
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#14
(Original post by AreebWithaHat)
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no i wish, i'm not even a physicist I'm a medic lol. it has the best sounding name tbh
lol fair enough, there really isn't much use to being able to know it from memory, it's just funny cus when you talk to physicists they'll probably know quite a few off the top of their head from using them so much.
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6 years ago
#15
Pi.

But if it has to be more Physics-based, either the Avogadro constant or the gravitational constant.
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6 years ago
#16
Haven't come across that before, looks like it might be more of a chemistry thing?
It is, but that doesn't make it not physical? Physical doesn't mean physics. And it's part of physical chemistry which in itself is basically physics anyway.
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6 years ago
#17
I'm quite fond of the Rydberg constant. Maybe it's because he was Swedish.
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6 years ago
#18
The Boltzmann constant 1.3806488 × 10^-23 m2 kg s-2 K-1 is so useful as is Planks constant(OP stated it). Also Avogadro's constant is 1 of the most important constants in chemistry 6.022 x 10^23.
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#19
(Original post by CJG21)
It is, but that doesn't make it not physical? Physical doesn't mean physics. And it's part of physical chemistry which in itself is basically physics anyway.

I didn't say that it wasn't a physical constant. I haven't done too much chemistry I was simply saying that that might be why I hadn't heard of it.

S'all, no stress.
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6 years ago
#20
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