3 ms·
"So I'd treat this veeeeery carefully until confirmed by independent groups and measurements." So would I, and most would especially with the LK-99 incident fr
by hilbert42 3y ago
"So I'd treat this veeeeery carefully until confirmed by independent groups and measurements."
So would I, and most would especially with the LK-99 incident fresh in our minds.
I'm not an astrophysicist, so it would be stupid of me to discuss the specifics of MOND, so I'll just make a few observations from the perspective of a lay observer. First, I have no fixed position on the matter except to say that if MOND were determined as fact then it would only be so after possibly the most extensive verification process yet undertaken in science—and it would upend everything, and science would be in turmoil for years.
That said, being an outsider, I have the luxury of having an opinion that if wrong won't wreck my career—no one would care, not even I. That preface was necessary because I come at physics from a slightly different perspective to many. Decades ago I spent much of my professional life trying to make electronic circuits, amplifiers etc., as linear and distortion free as possible and it's not an easy task. When one gets distortion figures down to -120dB and below even capacitor dialectics conspire against one by exhibiting nonlinear responses that contribute distortion. That experience instilled a distrust in me that made me question even the intrinsic nature of the physical constants, their stability over time, variation with energy levels etc.
Sure, the transfer characteristics of the electronic circuits I was working with were way, way up the chain from any physics that could be responsible for variations in the physical constants—so far as to be irrelevant—and their properties were emergent anyway. What mattered was my perception of the physical world changed. Let me give you an example: take a large volume of space somewhere in the universe that's free of physical matter, over time dust and matter drifts in and a star forms and eventually dies and forms a black hole and after 10^xyz eons it evaporates and we are left with empty space again (all else being equal of course). Can we say for certain that that volume of space is absolutely identical to that before the dust drifted in? Specifically, is spacetime perfectly elastic and that the black hole left no distortion in its fabric—not even the most infinitesimal amount?
Same goes for physical constants, are we certain the electric constant (vacuum permittivity), ε0, is immutable and has never changed (since the end of inflation anyway), if it has then so has c changed. Same goes for the cosmological constant and we still have the problem of the 'vacuum catastrophe' to contend with. Then there's alpha, α, the fine structure constant, we have its precision to nine or more digits, but there are still questions whether it varies over time and or by location, and its liable to vary with energy levels. If α changes so does the electric charge, e, and also does c. (Simply, it's unlikely every constant is immutable and perfectly linear/predictable over almost 'infinite' time and scale.)
Now to the gravitational constant, we have its accuracy to only about five digits, some four orders of magnitude less than, say, c and α, which is a bit of a worry. Thus it seems to me there's potential wiggle room in those constants, and whilst it's unlikely MOND has substance, we shouldn't rule it out without further research.