4 ms·

Your understanding of what naturalness is seems odd. If you get rid of naturalness, you just have fine tuning. Fine tuning is not beautiful but it is not a lo

by platz 9y ago

Your understanding of what naturalness is seems odd. If you get rid of naturalness, you just have fine tuning. Fine tuning is not beautiful but it is not a logical disaster as you describe.

stareatgoats 9y ago
ok thanks, on further investigation I realize my interpretation of "naturalness" was a laymans uninitiated one: "In physics, naturalness is the property that the dimensionless ratios between free parameters or physical constants appearing in a physical theory"[0] I have no idea what that means atm [0] https://en.wikipedia.org/wiki/Naturalness_(physics) https://en.wikipedia.org/wiki/Naturalness_(physics)
- auntienomen 9y ago
  Incomplete quote: '...dimensionless ratios between free parameters or physical constants appearing in a physical theory should take values "of order 1" and that free parameters are not fine-tuned.' It just means that theorists are suspicious of theories where the parameters have to be adjusted to high precision to match reality. That's reasonable grounds for suspicion, but it's not natural law.
- mikekchar 9y ago
  I'll take a stab (I Am Not A Physicist (in fact I couldn't handle the math and moved to CS ;-) ). Parameters or constants in a theory generally have units (i.e. speeds, density, whatever). But lots of things (usually ratios) have no units because they all cancel out. Those are called "dimensionless". Pi is dimensionless, as is e. What the naturalness property seems to be saying is that these dimensionless parameters (which you have to stick into the equations to make the math work out) should all be around the same order of magnitude and not require too much precision. If there is such a parameter that is super huge or super small (in relation to the others) or requires a lot of precision, it's an indication that the theory is incomplete. There should be an observable reason for that difference/precision. If I've gotten that right, then I can see why people would be sceptical of naturalness. If naturalness was correct, I would actually be curious of why it was correct.
  - manyoso 9y ago
    Moreover, "naturalness" is not mathematically well-defined even though many of its most passionate proponents claim that it is. This is one of the primary objections that Sabine has of "naturalness", not only might it be wrong, but when you plumb the motivations for it and actually try to make it mathematically well-defined, the motivations turn out to all disintegrate.

by platz 9y ago

Your understanding of what naturalness is seems odd. If you get rid of naturalness, you just have fine tuning. Fine tuning is not beautiful but it is not a logical disaster as you describe.

stareatgoats 9y ago

ok thanks, on further investigation I realize my interpretation of "naturalness" was a laymans uninitiated one: "In physics, naturalness is the property that the dimensionless ratios between free parameters or physical constants appearing in a physical theory"[0] I have no idea what that means atm [0] https://en.wikipedia.org/wiki/Naturalness_(physics) https://en.wikipedia.org/wiki/Naturalness_(physics)

auntienomen 9y ago
Incomplete quote: '...dimensionless ratios between free parameters or physical constants appearing in a physical theory should take values "of order 1" and that free parameters are not fine-tuned.' It just means that theorists are suspicious of theories where the parameters have to be adjusted to high precision to match reality. That's reasonable grounds for suspicion, but it's not natural law.
mikekchar 9y ago
I'll take a stab (I Am Not A Physicist (in fact I couldn't handle the math and moved to CS ;-) ). Parameters or constants in a theory generally have units (i.e. speeds, density, whatever). But lots of things (usually ratios) have no units because they all cancel out. Those are called "dimensionless". Pi is dimensionless, as is e. What the naturalness property seems to be saying is that these dimensionless parameters (which you have to stick into the equations to make the math work out) should all be around the same order of magnitude and not require too much precision. If there is such a parameter that is super huge or super small (in relation to the others) or requires a lot of precision, it's an indication that the theory is incomplete. There should be an observable reason for that difference/precision. If I've gotten that right, then I can see why people would be sceptical of naturalness. If naturalness was correct, I would actually be curious of why it was correct.
- manyoso 9y ago
  Moreover, "naturalness" is not mathematically well-defined even though many of its most passionate proponents claim that it is. This is one of the primary objections that Sabine has of "naturalness", not only might it be wrong, but when you plumb the motivations for it and actually try to make it mathematically well-defined, the motivations turn out to all disintegrate.