Recent content by jbergman

Greg, when I click formus in the left nav. I see the Active Discussions section at the top with a list of posts. The third or fourth line has the forum name with slightly larger text. I thought it would stand out more of bolded. But it looks a bit clearer today.

I am getting more used to it. One minor request would be to have to forum name bolded so it stands out a bit more on the active posts that proceed the forum name.

Something about the new style makes it much less readable. I don't know if it's the font? Do we have any control over these things? So far I don't like the change.

I think the whole discussion about how gravity fits in here at least suggests that they aren't necessarily all compatible. Penrose's interpretation is radically different. At this point we don't have any experiment to decide but I personally think it is worth thinking about the implications of...

Ballentine has a rebuttal which argues that the previous paper is incorrect on that point. The TLDR for me is that combining QM and gravity is subtle. https://ui.adsabs.harvard.edu/abs/1982PhRvL..48..522B/abstract

I don't agree with this point completely. If Gravity was semi-classical you still could postulate a MWI theory but it just wouldn't make sense. Editing to restate my opinion more clearly. I think this is a fundamental difference between other QM interpretations and MWI, the requirement that...

That assumes a working model of quantum gravity that we don't have today. You can easily do an experiment with say a boulder that can go left or right based on some quantum coin flip. It's not clear at all why the gravitation effects wouldn't be impacted by both versions of the boulder which you...

I would say, "their claims go beyond what we can test by experiment now". For instance with MWI, one could conceivably devise an experiment to measure the gravitational effect of the different worlds which would prove or it. But of course. We don't believe we have a complete theory of gravity...

Isn't that the entire point of what he says, i.e., you can have an s-wave state that is a superposition of straight line states?

Paper is more relaxing. Something about screens annoys me. The only exception are Kindle Paperwhites.

Yes. In Lee's book, he defines a smooth functor with which you can lift constructions on vector spaces to vector bundles. https://en.wikipedia.org/wiki/Smooth_functor

The second doesn't look correct. It should be a multilinear function of sections of the tangent space, not the cotangent space. It's helpful to just look at a vector space since fields over a bundle don't really add that much. But for a vector space ##V## over the field ##\mathbb R##, ##V^*...

Not following all the arguments that closely but I think I agree with Martin. Once you learn some category theory, products are defined as something satisfying a specific universal property and are unique up to isomorphism. It's fairly easy to construct "different" products that satisfy the dame...

I think the context is that the book is from a mathematician who usually proves things. So, it's mostly just making the distinctions between QM, a physical theory, and say a mathematical theory.

I have said similarly before. Barandes' formulation appears to not guarantee properties like continuity and localism.