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- Thread starter a.a
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May be the amount of overal lenergy in the universe would increase....

because of E= hf??

because of E= hf??

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As to your E=hf conjecture, I'm inclined to think we would just see fewer photons with frequency f, since for the same E we would require a smaller f. Again, the subtle implications I'm not sure of.

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Surely there must me some other largerscaled implucations of a change in the constant?...

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It can be seen as the difference between Little-League and Pro. Same game, same rules, just cranked up a notch (or down depending on what you do)

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I mean, the peak of the blackbody curve would shift... what could that do?

I would imagine that the Planck time, distance, etc. would also change, and that could have effects....

I would imagine that the Planck time, distance, etc. would also change, and that could have effects....

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I think I can answer your question. The basic answer to is if we were to increase Planck's constant to say 6.62 x 10 ^2 (for example)....then a lot of principles we see at the quantum level would be experienced by us in our everyday lives.

For instance - "Wave - Particle duality" would be seen everyday when you hit a tennis ball for instance. Hitting this tennis ball you would see the ball as it hit your racket but as soon as it goes flying back into the air, the ball would become a "wave" and you would no longer be able to see this ball as a solid object again until it made contact with something else. (Similar to how electrons and photons now behave on a quantum level).

Also, similar to the Heisenberg uncertainty principle in quantum physics, if you were to go speeding in a car or a plane at say 100 mph, you wouldn't be able to measure your speed and your exact location at the same time with precision. Basically any movement at any speed (when multiplied together) its error would have to be greater than Planck's constant. Thus your navigation systems and measurement abilities would be severely impaired if you increased Planck's constant to a really high number.

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so a.a, it's sorta a meaningless question. asking what would happen if a

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c connects space and time. h connects spacetime and energy. etc.

If you changed all of the dimensionful constants proportionally, nothing would happen. But if you changed one without changing the other, we'd live in a very different world.

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c connects space and time. h connects spacetime and energy. etc.

If you changed all of the dimensionful constants proportionally, nothing would happen. But if you changed one without changing the other, we'd live in a very different world.

ya gotta worry a little bit about "proportionally". some of these dimensionful constants team up and others don't. consider the fine-structure constant

[tex] \alpha = \frac{e^2}{\hbar c (4 \pi \epsilon_0 )} [/tex]

if

i might word it as: "if some god-like being changed any dimensionful constant yet constraining all 26+ of the dimensionless constants to be the same, nothing would be noticed by mortals. if any of these 26 dimensionless constants were changed,

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I'm not so sure that changing a constant would be essentially meaningless just because it has units that are chosen by humans. I mean, *how many* of those units describe something is not chosen by humans, and neither is how many of those units are relevant to other physical situations.

The argument seems to rest on something like this (excerpted from that link, which looks interesting, by the way): "...in the grand scheme of things, units are not very important. They are arbitrary human conventions." True, but as in NYSportsguy's argument, the number of those units that go into processes comparable in size, time, and whatever other dimension/scale of interest to those we experience relative to some fundamental building-block such as "h" is not a convention! In other words, it is not a convention that there is a difference between the "macroscopic" world we inhabit and the "quantum" world where the discrete nature of "h" (as opposed to continuous) becomes important. That was never a choice we had to make! It was simply where we found ourselves. The very fact we can talk about a "macroscopic" and "quantum" world is due to the vast multiples of "h" that are relevant to ordinary human affairs. However if h increases then (for instance) the de Broglie wavelength increases, too, so assuming we all stay the same size then the macroscopic world would go wonky.

A femtomenter isn't small because it's 10^-15 meters; it's "small" because WE are about 2 meters!

Or am I totally off base? :)

The argument seems to rest on something like this (excerpted from that link, which looks interesting, by the way): "...in the grand scheme of things, units are not very important. They are arbitrary human conventions." True, but as in NYSportsguy's argument, the number of those units that go into processes comparable in size, time, and whatever other dimension/scale of interest to those we experience relative to some fundamental building-block such as "h" is not a convention! In other words, it is not a convention that there is a difference between the "macroscopic" world we inhabit and the "quantum" world where the discrete nature of "h" (as opposed to continuous) becomes important. That was never a choice we had to make! It was simply where we found ourselves. The very fact we can talk about a "macroscopic" and "quantum" world is due to the vast multiples of "h" that are relevant to ordinary human affairs. However if h increases then (for instance) the de Broglie wavelength increases, too, so assuming we all stay the same size then the macroscopic world would go wonky.

A femtomenter isn't small because it's 10^-15 meters; it's "small" because WE are about 2 meters!

Or am I totally off base? :)

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From the same link: "The masses of these quarks, divided by the Planck mass, give 6 dimensionless constants."

Now again this does attribute some significance to the Planck mass; if we keep the units the same and take 100 times the number we'd get a drastically different quotient! The very act of making such a comparison implies that we are getting a number that tells us how many units of the Planks mass go into each quark.

Also "...the "fine structure constant", e2/ hbar c..." if hbar were 20 orders of magnitude greater, would be 1.37*10^-18 instead of 137! But of course if things adjusted proportionally then we wouldn't notice.

It is a very interesting topic. I like that fellow John Baez's stuff, too.

Now again this does attribute some significance to the Planck mass; if we keep the units the same and take 100 times the number we'd get a drastically different quotient! The very act of making such a comparison implies that we are getting a number that tells us how many units of the Planks mass go into each quark.

Also "...the "fine structure constant", e2/ hbar c..." if hbar were 20 orders of magnitude greater, would be 1.37*10^-18 instead of 137! But of course if things adjusted proportionally then we wouldn't notice.

It is a very interesting topic. I like that fellow John Baez's stuff, too.

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The argument seems to rest on something like this (excerpted from that link, which looks interesting, by the way): "...in the grand scheme of things, units are not very important. They are arbitrary human conventions." True, but as in NYSportsguy's argument, the number of those units that go into processes comparable in size, time, and whatever other dimension/scale of interest to those we experience relative to some fundamental building-block such as "h" is not a convention! In other words, it is not a convention that there is a difference between the "macroscopic" world we inhabit and the "quantum" world where the discrete nature of "h" (as opposed to continuous) becomes important. That was never a choice we had to make! It was simply where we found ourselves. The very fact we can talk about a "macroscopic" and "quantum" world is due to the vast multiples of "h" that are relevant to ordinary human affairs. However if h increases then (for instance) the de Broglie wavelength increases, too, so assuming we all stay the same size then the macroscopic world would go wonky.

A femtomenter isn't small because it's 10^-15 meters; it's "small" because WE are about 2 meters!

Or am I totally off base? :)

assuming we all stay the same size in the macroscoping world

i don't necessarily want to get in a tiff about this, but i have in the past (but it was about either

in my opinion, the salient questions are not

Now, I don't know why an atom's size is approximately 10

This same argument can be made for

so moral of the story is this, when asking "what would be different if some universal quantity changed?" ask that if we measured everything in terms of Planck Units and remember that Nature doesn't give a rat's ass which units we use to measure things.

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Tiff averted (?).

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The most fundamental definition of Planck constant:

[tex]\boxed{\hbar = E_p \cdot t_p}[/tex]

[tex]E_p[/tex] - Planck energy

[tex]t_p[/tex] - Planck time

The Planck constant is a measurement of the magnitude in which Planck energy is conserved in a Planck time dimension as a harmonic oscillator and is used to describe the sizes of quanta.

Increasing or decreasing the Planck constant changes the Planck energy magnitude conservation in a Planck time dimension as a harmonic oscillator.

[tex]\boxed{\alpha = \frac{dE \cdot dt}{\hbar c}}[/tex]

Increasing the Planck constant magnitude decreases the interaction strength.

Decreasing the Planck constant magnitude increases the interaction strength.

The Planck constant is an immutable fundamental physical constant in the Universe.

Reference:

"[URL [Broken] constant - Wikipedia[/URL]

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My brain hurts and it's 2:32 am.

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I think that is all this guy is asking...most of the rest of you are getting to philosophical with this question right now.

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The bottom line is if we all stayed the same but Planck's constant was bigger ( ie the size of light quanta and energy were bigger by nature) all the things I said would happen.

call it philosophyzing, but when you speak of changing Planck's constant (or

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LowlyPion

Homework Helper

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If you are not changing the fundamental nature of matter, (if you are preserving the 26 dimensionless variables discussed by the John Baez piece referenced earlier) and you are expecting that a constant that falls out of observation can just be arbitrarily changed, you've got to ask yourself what you are going to do with that tail when you finally catch it? Complain that something is biting it?

Intuitively I'd say that if Planck's constant changed, then one should expect that the dimensions of time, mass, distance would also need to change, in lock step, preserving the same relationship expressed now in the current Planck's constant. Net sum zero gain. Reprint the table of fundamental physical constants and move on.

Similarly if you changed the speed of light to be an arbitrary value of meters per second the practical effect seems to me to be that you would need to change road markers throughout the world. And good luck with that.

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Is the dog chasing the tail or the tail the dog?

If you are not changing the fundamental nature of matter, (if you are preserving the 26 dimensionless variables discussed by the John Baez piece referenced earlier) and you are expecting that a constant that falls out of observation can just be arbitrarily changed, you've got to ask yourself what you are going to do with that tail when you finally catch it?

welcome to PF, Lowly. i like your PF name.

i think that we "catch it" right away. because in any observation, any physical experiment with quantitative results, the net raw results are dimensionless numbers. if either

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