Recent content by Ken G

I think what's interesting about attributing such crucial importance to "empirical adequacy" (meaning that no physics theory should ever try to predict more than we could ever possibly observe, and any that do are by definition being equipped with extraneous features that are of no value and...

Indeed. Neveretheless, it is the fundamental topic of those two videos, and I believe is a valid question to ask. After all, astronomy is a societal issue itself. That's not by itself a valid reason. If all of physics was organized in terms of the number of papers being proportional to the...

I think what is emerging clearly here is we have to wonder why the great majority of people in the wider public prefer MOND type solutions, and the great majority in the astrophysics community favor the dark matter approach (dark energy is a whole different matter, I don't see any connection...

This could be an example of the problem with "theories of everything": those darn "issues at the edge of consciousness for philosophers of physics." Issues that I translate into, "the more you know, the more you know you don't know."

Yeah, I think that's very much the hope of loop quantum gravity. Of course I have no idea if it will succeed, but if it does, I think it will still only be a "theory of everything" in the backward looking sense.

Let's just say that "theories of everything" have a pretty dismal history in our business, so it seems to border on illogical to expect one of those. Unification is a key goal of physics, but any time you push your understanding farther it tends to open up new frontiers, so you kind of unify...

And that really sounds like the ultimate irony. The main impetus to quantize the gravitational field is to unify it with other fields that need to be quantized, resulting in a cleaner theoretical description of all things. Except that now you have split your gravity into a part that makes the...

I've never understood why anyone would view any physics theory as something different from an effective theory, if we define it that way. Surely we can't believe that just because a theory works in all domains where it has been tested, it should therefore work in all other domains (which sounds...

Yes, I thought it was completely clear that in the process of addressing this extremely subtle article that brings up a lot of new ways to think about the meaning of the terms "open" and "closed" in gravitational physics, you were saying that they mean "closed" as in unable to exchange anything...

That's why I agree with her that the really important point to make here is that this is not the time to be arguing over "which is the solution to the dark matter problem", it is to be exploring just what the problem really is, and how do various approaches take a bite out of it. Maybe none of...

I think she makes a good central point, which is that what she is calling the "dark matter problem" is something that is extremely complicated, and cannot be answered by some simple modification to gravity. Full stop, she really could have honed in on just that point and made a very convincing...

I agree that whether it has 2 solar masses or 3 shouldn't matter much, but that's why I'm wondering why those Xray sources in the globulars couldn't be a whole lot of BHs along with even more NSs. If so, the question is not so much where are the BHs, it is where are the BHs and NSs that we see...

Yes, binaries do allow conditions to keep the pulsars shining, making them more visible as with black holes. But I do think it's true that most pulsars are not in binaries (consider for example those two most famous pulsars, Vela and Crab). So there is an advantage for seeing pulsars that...

OK that's a good point, gravitational detectability can last billions of years, so one can ask how many NSs are known by their pulsing, and how many are known gravitationally. Since the Wiki says only 1/20 of known pulsars are in binaries, we see that many more of them are known by their pulses...

Do you still have any unresolved questions?