4 ms·

Not very long ago, people couldn't explain why things fell to the ground at 9.8m/s^2 instead of some other acceleration factor. The answer now seems straightfor

by chroma 16y ago

Not very long ago, people couldn't explain why things fell to the ground at 9.8m/s^2 instead of some other acceleration factor. The answer now seems straightforward to us. You can't tell the difference between an irreducible fact of nature and a reducible one until you've reduced it.

Confusion 16y ago
That they couldn't explain it did not mean they thought or claimed it was irreducible. The reason for claiming the exact numeric value of the speed of light is irreducible is not because we can't currently explain it: it is because it is part of the definition of the universe. The universe consists of space and time components and they are related by a ratio of c. Would the ratio have been 1, then nobody would have posed the question in the first place. You don't go around asking why pi has the value it has either. It may turn out it is possible to relate these values to other properties and values, but they can never be reduced to them. That would just be choosing a different basis for your description, while that basis is arbitrary.
- lurker19 16y ago
  I agree with your main point, I think, but c and pi are different. c has a unit and so can take any numerical value under a compensating choice of units. Pi is unitless, however, and cannot be defined as any other value. C and pi are similar also: c would be different, if the universe's geometry where scaled differently, even if meters and seconds were unchanged in transition to the alternate universe (assuming one can formalize what I am saying in a sensible way). Likewise, pi (circumference divided by diameter) would take a different value (or not even be a constant) in an alternate (non-Euclidean) geometry (assuming that a circle could still be defined there, which is more obviously possible than the c/spacetime hypothetical)

4 ms·

Not very long ago, people couldn't explain why things fell to the ground at 9.8m/s^2 instead of some other acceleration factor. The answer now seems straightfor

by chroma 16y ago

Confusion 16y ago
That they couldn't explain it did not mean they thought or claimed it was irreducible. The reason for claiming the exact numeric value of the speed of light is irreducible is not because we can't currently explain it: it is because it is part of the definition of the universe. The universe consists of space and time components and they are related by a ratio of c. Would the ratio have been 1, then nobody would have posed the question in the first place. You don't go around asking why pi has the value it has either. It may turn out it is possible to relate these values to other properties and values, but they can never be reduced to them. That would just be choosing a different basis for your description, while that basis is arbitrary.
- lurker19 16y ago
  I agree with your main point, I think, but c and pi are different. c has a unit and so can take any numerical value under a compensating choice of units. Pi is unitless, however, and cannot be defined as any other value. C and pi are similar also: c would be different, if the universe's geometry where scaled differently, even if meters and seconds were unchanged in transition to the alternate universe (assuming one can formalize what I am saying in a sensible way). Likewise, pi (circumference divided by diameter) would take a different value (or not even be a constant) in an alternate (non-Euclidean) geometry (assuming that a circle could still be defined there, which is more obviously possible than the c/spacetime hypothetical)