7 ms·

Are the Constants of Physics Constant?

60 points by Hooke 11y ago

deleted 11y ago
[deleted]
whatshisface 11y ago
M(n) = floor[A^3^n] The above will give you primes, so long as A is filled in with the right constant. So, in a strange way, you might imagine A as number that has information about primes written inside of it. The formula could be thought of as a decompressor to get that information out. In a similar way, could some of our physical constants be "hiding" structure inside of them? If we got all of the structure out and into math, could we end up with a constant-less physics?
- gizmo686 11y ago
  This is essentially what you get in String Theory. The problem is that String Theory requires you to define the "shape" of the extra dimensions. Once you do this, all of the fundamental constants naturally follow. However, there are so many potential shapes that are mathematically valid that this essentially moves the problem from out universe having arbitrary constants to our universe being an arbitrary shape. Unfortunately, it is possible that there is literally to elegant solution to this. For example, consider our solar system. At one point, people tried to explain the distance of the planets from the sun without invoking arbitrary constants. We now know that the distance between the planets and the sun are in largly arbitrary, because we are but one of many solar systems and other solar systems have different distances. Similarly, it is possible (although potentially non-provable and non-falsifiable). That we live in but one of many universes, and that other universes have different constants. If this is true then there is no way to avoid the fact that our universe has some arbitrary constant (even if we obscure it by calling it an arbitrary shape).
  - andrewflnr 11y ago
    Is there a finite or countable number of these "shapes"? That would still be better than a handful of arbitrary-precision numbers. :)
    - Intermernet 11y ago
      Currently thought to be finite, but very large. Some info at https://en.wikipedia.org/wiki/String_theory_landscape https://en.wikipedia.org/wiki/String_theory_landscape and http://physics.stackexchange.com/questions/2873/where-does-the-10500-estimate-for-the-number-of-stringy-vacua-come-from http://physics.stackexchange.com/questions/2873/where-does-t...
- positr0n 11y ago
  Does that equation have a name? A naive google search doesn't return anything. Edit: Found it. A is known as Mill's constant https://en.wikipedia.org/wiki/Mills%27_constant https://en.wikipedia.org/wiki/Mills%27_constant
- Houshalter 11y ago
  There's a numberphile video on that I just watched: https://www.youtube.com/watch?v=6ltrPVPEwfo https://www.youtube.com/watch?v=6ltrPVPEwfo I really don't like this formula. The numbers grow absurdly huge really quickly, and the only way of finding A is brute force search (and there are multiple possible values, they just pick the smallest that works.) It's like saying the number 0.235711131517... contains information about all the prime numbers. Well it does, but once you see how it's constructed it's not terribly interesting. Anyway I think you are saying that the constants might have low kolmogorov complexity. That is, the constant could be compressed to many fewer bits of information. That seems unlikely. There's no reason why constants can't be arbitrary or random. Perhaps there are many universes and each has a different constant. And trying to fit an expression to them is impossible, because we only know them to a few digits. That's not anywhere near enough information, and any expression like that will almost certainly be overfit. But if you insist you could try RIES: http://mrob.com/pub/ries/ries.php?target=1836.15267389&rst= http://mrob.com/pub/ries/ries.php?target=1836.15267389&rst= None of the formulas get out more characters than they put in, or even get more than a handful of digits. It's indistinguishable from a purely random number.
- unabst 11y ago
  > "hiding" structure inside of them Physical constants all "hide" structure inside of them. They are abstractions of some physical virtue of nature; whatever physical in nature that gives rise to the constant. All constants in physics, ideally, emerge from experiment and from evidence. Behind the constant which is the speed of light "hides" light. No?
  - restalis 11y ago
    That's what the researchers are after. It's hard to accept things as singular in themselves so they continuously challenge this "constant" status. The speed of light is given by the nature of the light, which is (presumably) ultimately based on other constants, so in this case the light speed is constant only thanks to being a relation of other constants. If one of the relying constants proves to be at its turn only mostly constant that changes the status of all the upstream constants. That's why that rabbit hole of universe's constants' study is so important! That being said, there are constants out there (e.g. π, which is a constant relation instead of relation of constants) for which "challenge" would probably mean assuming another kind universe entirely.
- lazyant 11y ago
  Carl Sagan's "Cosmos" comes to mind
ankurdhama 11y ago
These constants are invented by humans so that we can make sense of the data collected through measurement.
daxfohl 11y ago
They may alter by, oh, .0000000001 or way less than that, say, when a galaxy cluster explodes or something. Which even if true may be essentially impossible to notice given Planck. So how do we know what's going on at that level? We can't explode galaxy clusters. And maybe there are thousands of layers even below that; you'd need gajillions of universes exploding / collapsing to notice the trend of some sub-Planckian thing happening statistically per universe. And maybe even thousands of layers below that. Or maybe not.
spacejoe 11y ago
The Gravitational Constant could conceivably not be a constant. Experimental measurements are over the map - most only agree on 3 - 5 significant digits of accuracy.
- greglindahl 11y ago
  Note this text from Wikipedia: "Under the assumption that the physics of type Ia supernovae are universal, analysis of observations of 580 type Ia supernovae has shown that the gravitational constant has varied by less than one part in ten billion per year over the last nine billion years.[13]" The ref is: J. Mould; S. A. Uddin (2014-04-10), "Constraining a Possible Variation of G with Type Ia Supernovae", Publications of the Astronomical Society of Australia 31: e015, arXiv:1402.1534, Bibcode:2014PASA...31...15M, doi:10.1017/pasa.2014.9 It's not the first paper to look into that issue, either! Always fun to remind people that physics involves more than what happens inside the lab.
  - spacejoe 11y ago
    Yet we don't have a high precision value for it. From the same Wikipedia article: "Published values of G have varied rather broadly, and some recent measurements of high precision are, in fact, mutually exclusive.[4][6]"
  - AnimalMuppet 11y ago
    > the gravitational constant has varied by less than one part in ten billion per year over the last nine billion years. Um, that adds up to 9/10, doesn't it? That means that in ten billion years, it could vary by nearly a factor of 2.
- unabst 11y ago
  This. Constants don't come first. Experimental measurement does. It's not like constants are backed by anything. They are what they are because they're always the same no matter how many times we measure them. If they changed, they wouldn't be constants. They are free to change. The one's that haven't just haven't.
acqq 11y ago
Note, now we know, the measured mass ratio is 1836.15267389 which is not 6 times pi to 5 = 1836.1181087116884. And the measured fine structure constant alpha^{-1} also isn't just 137 but 137.035,999,139(31) https://en.wikipedia.org/wiki/Fine-structure_constant https://en.wikipedia.org/wiki/Fine-structure_constant
dschiptsov 11y ago
A constant is mathematical abstraction. There is no mathematics outside people's minds. There are no numbers outside mind of an observer, no time, no space. Which abstractions are good enough approximations of laws of the Universe, and which are mere creations of the mind is an open question since the first human language has been established.) Upanishads and the Buddha have tried to clarify the mess a bit, but... According to the finest human philosophy, nothing is permanent, hence, nothing is constant. Atoms - the basic building blocks, are "stable" as long as they has been made inside a star, but they are not permanent or constant (they might end up in another star). Their weights, electrical properties are stable ("constant" is not applicable here, being from another domain of pure abstractions which we call mathematics). Mathematical ratios could be computed, of course, given that measurements are accurate enough, but they does not exist either. These are rarest concepts of the mind which reflect some aspects of reality as it is.
- tremon 11y ago
  I think the article is talking about physical properties, like c, h, or G, that we measure to be the same every time. You seem to be talking about numerical representations.
  - hansen 11y ago
    c and ℏ don’t encode any physics, they just fix measuring units. Actually it’s common to choose units s.t. ℏ = c = 1.
    - simonh 11y ago
      So the same constants can have different numerical representations. Isn't that what tremon just said?
      - hansen 11y ago
        Maybe I haven’t understood him right, but he said: > […] physical properties, like c, h […] which is false, c and ℏ aren’t “physical properties”. The numerical values we attach to them are merely a convention. In SI units c isn’t even something that is measured. The second is defined via a measurement, c has a fixed defined value (no measurement involved), and the meter is defined via the second and c. In natural units this is even simpler: ℏ = c = 1. The fine structure constant is another thing. It caries no dimension and encodes the strength of EM coupling. But as an interesting site note: These coupling constant are pretty complicated things, they actually depend on the energy/length scale of your experiment. The numbers you find in text books are just the low energy limits.
lfowles 11y ago
Tangential, but I found one of my favorite books on a thread related to this topic, so I thought I would pass on the favor. Vernor Vinge's _A Fire Upon The Deep_ is based on the premise that physics changes throughout the galaxy. The inner "slow" sections have physics that is normal to us, but the outer sections allow faster than light travel and incredible AI.
castratikron 11y ago
Didn't even read the article, but there's at least one "constant" that has been increasing over time. It's called Hubble's Constant, and it's used to determine how quickly a galaxy is moving away from us. The farther away a galaxy is from us, the faster it moves away (Hubble's Law). Since the universe is expanding, the speed at which galaxies move is actually increasing, which is why the value of Hubble's constant isn't actually constant, but also increasing. http://hyperphysics.phy-astr.gsu.edu/hbase/astro/hubble.html http://hyperphysics.phy-astr.gsu.edu/hbase/astro/hubble.html

60 points by Hooke 11y ago

deleted 11y ago

[deleted]

M(n) = floor[A^3^n] The above will give you primes, so long as A is filled in with the right constant. So, in a strange way, you might imagine A as number that has information about primes written inside of it. The formula could be thought of as a decompressor to get that information out. In a similar way, could some of our physical constants be "hiding" structure inside of them? If we got all of the structure out and into math, could we end up with a constant-less physics?

gizmo686 11y ago
This is essentially what you get in String Theory. The problem is that String Theory requires you to define the "shape" of the extra dimensions. Once you do this, all of the fundamental constants naturally follow. However, there are so many potential shapes that are mathematically valid that this essentially moves the problem from out universe having arbitrary constants to our universe being an arbitrary shape. Unfortunately, it is possible that there is literally to elegant solution to this. For example, consider our solar system. At one point, people tried to explain the distance of the planets from the sun without invoking arbitrary constants. We now know that the distance between the planets and the sun are in largly arbitrary, because we are but one of many solar systems and other solar systems have different distances. Similarly, it is possible (although potentially non-provable and non-falsifiable). That we live in but one of many universes, and that other universes have different constants. If this is true then there is no way to avoid the fact that our universe has some arbitrary constant (even if we obscure it by calling it an arbitrary shape).
- andrewflnr 11y ago
  Is there a finite or countable number of these "shapes"? That would still be better than a handful of arbitrary-precision numbers. :)
  - Intermernet 11y ago
    Currently thought to be finite, but very large. Some info at https://en.wikipedia.org/wiki/String_theory_landscape https://en.wikipedia.org/wiki/String_theory_landscape and http://physics.stackexchange.com/questions/2873/where-does-the-10500-estimate-for-the-number-of-stringy-vacua-come-from http://physics.stackexchange.com/questions/2873/where-does-t...
positr0n 11y ago
Does that equation have a name? A naive google search doesn't return anything. Edit: Found it. A is known as Mill's constant https://en.wikipedia.org/wiki/Mills%27_constant https://en.wikipedia.org/wiki/Mills%27_constant
Houshalter 11y ago
There's a numberphile video on that I just watched: https://www.youtube.com/watch?v=6ltrPVPEwfo https://www.youtube.com/watch?v=6ltrPVPEwfo I really don't like this formula. The numbers grow absurdly huge really quickly, and the only way of finding A is brute force search (and there are multiple possible values, they just pick the smallest that works.) It's like saying the number 0.235711131517... contains information about all the prime numbers. Well it does, but once you see how it's constructed it's not terribly interesting. Anyway I think you are saying that the constants might have low kolmogorov complexity. That is, the constant could be compressed to many fewer bits of information. That seems unlikely. There's no reason why constants can't be arbitrary or random. Perhaps there are many universes and each has a different constant. And trying to fit an expression to them is impossible, because we only know them to a few digits. That's not anywhere near enough information, and any expression like that will almost certainly be overfit. But if you insist you could try RIES: http://mrob.com/pub/ries/ries.php?target=1836.15267389&rst= http://mrob.com/pub/ries/ries.php?target=1836.15267389&rst= None of the formulas get out more characters than they put in, or even get more than a handful of digits. It's indistinguishable from a purely random number.
unabst 11y ago
> "hiding" structure inside of them Physical constants all "hide" structure inside of them. They are abstractions of some physical virtue of nature; whatever physical in nature that gives rise to the constant. All constants in physics, ideally, emerge from experiment and from evidence. Behind the constant which is the speed of light "hides" light. No?
- restalis 11y ago
  That's what the researchers are after. It's hard to accept things as singular in themselves so they continuously challenge this "constant" status. The speed of light is given by the nature of the light, which is (presumably) ultimately based on other constants, so in this case the light speed is constant only thanks to being a relation of other constants. If one of the relying constants proves to be at its turn only mostly constant that changes the status of all the upstream constants. That's why that rabbit hole of universe's constants' study is so important! That being said, there are constants out there (e.g. π, which is a constant relation instead of relation of constants) for which "challenge" would probably mean assuming another kind universe entirely.
lazyant 11y ago
Carl Sagan's "Cosmos" comes to mind

ankurdhama 11y ago

These constants are invented by humans so that we can make sense of the data collected through measurement.

daxfohl 11y ago

They may alter by, oh, .0000000001 or way less than that, say, when a galaxy cluster explodes or something. Which even if true may be essentially impossible to notice given Planck. So how do we know what's going on at that level? We can't explode galaxy clusters. And maybe there are thousands of layers even below that; you'd need gajillions of universes exploding / collapsing to notice the trend of some sub-Planckian thing happening statistically per universe. And maybe even thousands of layers below that. Or maybe not.

spacejoe 11y ago

The Gravitational Constant could conceivably not be a constant. Experimental measurements are over the map - most only agree on 3 - 5 significant digits of accuracy.

greglindahl 11y ago
Note this text from Wikipedia: "Under the assumption that the physics of type Ia supernovae are universal, analysis of observations of 580 type Ia supernovae has shown that the gravitational constant has varied by less than one part in ten billion per year over the last nine billion years.[13]" The ref is: J. Mould; S. A. Uddin (2014-04-10), "Constraining a Possible Variation of G with Type Ia Supernovae", Publications of the Astronomical Society of Australia 31: e015, arXiv:1402.1534, Bibcode:2014PASA...31...15M, doi:10.1017/pasa.2014.9 It's not the first paper to look into that issue, either! Always fun to remind people that physics involves more than what happens inside the lab.
- spacejoe 11y ago
  Yet we don't have a high precision value for it. From the same Wikipedia article: "Published values of G have varied rather broadly, and some recent measurements of high precision are, in fact, mutually exclusive.[4][6]"
- AnimalMuppet 11y ago
  > the gravitational constant has varied by less than one part in ten billion per year over the last nine billion years. Um, that adds up to 9/10, doesn't it? That means that in ten billion years, it could vary by nearly a factor of 2.
unabst 11y ago
This. Constants don't come first. Experimental measurement does. It's not like constants are backed by anything. They are what they are because they're always the same no matter how many times we measure them. If they changed, they wouldn't be constants. They are free to change. The one's that haven't just haven't.

acqq 11y ago

Note, now we know, the measured mass ratio is 1836.15267389 which is not 6 times pi to 5 = 1836.1181087116884. And the measured fine structure constant alpha^{-1} also isn't just 137 but 137.035,999,139(31) https://en.wikipedia.org/wiki/Fine-structure_constant https://en.wikipedia.org/wiki/Fine-structure_constant

dschiptsov 11y ago

A constant is mathematical abstraction. There is no mathematics outside people's minds. There are no numbers outside mind of an observer, no time, no space. Which abstractions are good enough approximations of laws of the Universe, and which are mere creations of the mind is an open question since the first human language has been established.) Upanishads and the Buddha have tried to clarify the mess a bit, but... According to the finest human philosophy, nothing is permanent, hence, nothing is constant. Atoms - the basic building blocks, are "stable" as long as they has been made inside a star, but they are not permanent or constant (they might end up in another star). Their weights, electrical properties are stable ("constant" is not applicable here, being from another domain of pure abstractions which we call mathematics). Mathematical ratios could be computed, of course, given that measurements are accurate enough, but they does not exist either. These are rarest concepts of the mind which reflect some aspects of reality as it is.

tremon 11y ago
I think the article is talking about physical properties, like c, h, or G, that we measure to be the same every time. You seem to be talking about numerical representations.
- hansen 11y ago
  c and ℏ don’t encode any physics, they just fix measuring units. Actually it’s common to choose units s.t. ℏ = c = 1.
  - simonh 11y ago
    So the same constants can have different numerical representations. Isn't that what tremon just said?
    - hansen 11y ago
      Maybe I haven’t understood him right, but he said: > […] physical properties, like c, h […] which is false, c and ℏ aren’t “physical properties”. The numerical values we attach to them are merely a convention. In SI units c isn’t even something that is measured. The second is defined via a measurement, c has a fixed defined value (no measurement involved), and the meter is defined via the second and c. In natural units this is even simpler: ℏ = c = 1. The fine structure constant is another thing. It caries no dimension and encodes the strength of EM coupling. But as an interesting site note: These coupling constant are pretty complicated things, they actually depend on the energy/length scale of your experiment. The numbers you find in text books are just the low energy limits.

lfowles 11y ago

Tangential, but I found one of my favorite books on a thread related to this topic, so I thought I would pass on the favor. Vernor Vinge's _A Fire Upon The Deep_ is based on the premise that physics changes throughout the galaxy. The inner "slow" sections have physics that is normal to us, but the outer sections allow faster than light travel and incredible AI.

castratikron 11y ago

Didn't even read the article, but there's at least one "constant" that has been increasing over time. It's called Hubble's Constant, and it's used to determine how quickly a galaxy is moving away from us. The farther away a galaxy is from us, the faster it moves away (Hubble's Law). Since the universe is expanding, the speed at which galaxies move is actually increasing, which is why the value of Hubble's constant isn't actually constant, but also increasing. http://hyperphysics.phy-astr.gsu.edu/hbase/astro/hubble.html http://hyperphysics.phy-astr.gsu.edu/hbase/astro/hubble.html