(January 17, 2015 at 8:26 am)Alex K Wrote: P.s. I think your confusion about my talk about friction maybe came from the fact that when you hear matter, you first think of a solid, not a dilute gas. By friction I just meant a shorthand for losing energy during movement because of inelastic processes. Maybe that's not such a great word choice, but I used it for lack.of a better one.
No, I understood what you meant by friction, it's just difficult to wrap my head around. But then that seems to be the case for almost everything about particle physics - classical physics makes perfect sense, we can play with matter and energy and directly observe the relation between energy, mass, friction, inertia, and so on. Particle physics regularly produces results which seem (to me at least) to be counter-intuitive.
So I simply have to accept that whatever it is that is distorting the images of visible bodies in the background must, by dint of its ability to distort space-time, have mass. Yet it does not interact with "normal" matter in any other discernible way, thus being "frictionless."
My brain doesn't like the idea of something that has mass (and therefore gravity) yet doesn't interact with the visible Universe other than via gravity. Question: Dark matter creates a gravity well, but isn't "pulled" by other gravity wells? Do I have that right?
Just for the record, my brain doesn't like quantum entanglement either. I find that the only way I can learn about particle physics is to tell my common sense to shut up and accept that reality is far weirder than I can fully grasp.
As has been said by others, I am extremely grateful that you see fit to spend some of your time answering these (presumably simplistic) laymans' questions. Your above lengthy post in answer to my questions provided a number of "aha!" moments, which are always fun.
Now I need to return to something I actually do understand: fermenting tempeh culture in black beans. Thank the FSM for the macro level of reality!
I look forward to further brain-picking sessions.
