3 ms·

Ah, well, about a four percent change and you no longer can produce carbon during regular fusion. You need atoms capable of making at least three bonds to prod

Ah, well, about a four percent change and you no longer can produce carbon during regular fusion. You need atoms capable of making at least three bonds to produce structure more complex than a chain. Carbon can do four, is lovely, otherwise you would have to make do with boron and nitrogen. Crank the value up to .1 and you get no fusion at all. This one is super-interesting, because no fusion means no photonic pressure keeping silly large accumulations of gases up and so you will crank your way to neutron stars and black holes much faster, as well as resulting in a universe whose only light is the remaining cosmic background radiation. No more supernovae creating shockwaves and the like. In the other direction and you have a different problem -- molecules won't molecule and you will just have a bunch of disconnected atoms incapable of covalent bonds.

lordnacho 6y ago
Yes but how do we know what the numbers could have been? It's not like we have a generating theory that says it had to be between a and b, and thus it being x is really unlikely.
- at_a_remove 6y ago
  Ah, okay, that's a different question. Aside from common sense ("this being negative would be self-contradicting") for a given number and sets of inter-relations, that's out of my wheelhouse. I very dimly recollect some work on allowable sets of constants somewhere in the nineties, something to do with superstrings, but that was never a huge interest of mine. I will admit that such a generating theory may exist and I am just unaware of it. In some sense, each constant represents a bit of embarrassment to physics. Having this rather large set of adjustable parameters calls to mind the von Neumann quote "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk." Why this seemingly arbitrary number? Can we take multiple constants and find some smaller set from which they are derived? Can I make a constant emerge from a physical law, devoid of measurement?

lordnacho 6y ago

Yes but how do we know what the numbers could have been? It's not like we have a generating theory that says it had to be between a and b, and thus it being x is really unlikely.

at_a_remove 6y ago
Ah, okay, that's a different question. Aside from common sense ("this being negative would be self-contradicting") for a given number and sets of inter-relations, that's out of my wheelhouse. I very dimly recollect some work on allowable sets of constants somewhere in the nineties, something to do with superstrings, but that was never a huge interest of mine. I will admit that such a generating theory may exist and I am just unaware of it. In some sense, each constant represents a bit of embarrassment to physics. Having this rather large set of adjustable parameters calls to mind the von Neumann quote "With four parameters I can fit an elephant, and with five I can make him wiggle his trunk." Why this seemingly arbitrary number? Can we take multiple constants and find some smaller set from which they are derived? Can I make a constant emerge from a physical law, devoid of measurement?