MRI scan time

Today I had my MRI scan appointment, for the nerve issues I mentioned last week. They did a scan of my lower spine, looking for pinched nerves or something. The neurologist will tell me what they found in our follow-up appointment.

I’ve done a few MRIs before, but all cerebral ones. The machine is very noisy, and they give you earplugs and headphones, but it still makes a racket. But I have to say that scanning your lower spine is a bit easier and less claustrophobic than a cerebral scan where they lock your head in a face clamp.

Apart form that I did 4 ethics classes, finishing off the “Success and Failure” topic for the week, and worked on comics for a bit. I’m rushing to get enough comics buffered for our trip to Europe in two weeks. I’m concentrating on Darths & Droids, and don’t have any Irregular Webcomic! buffered, so this week I’m doing the hiatus thing and running reruns on IWC.

For dinner my wife made pizza dough and I topped it with cheese, pumpkin, asparagus, and walnuts. I was thinking what other nuts would make sense, and I think some time I’ll make another satay sauce pizza with broccoli and cashews. (Neapolitans are spinning in their graves, but I reckon you can put whatever you like on a pizza and it’s valid.)

New content today:

5 thoughts on “MRI scan time”

  1. This is random: I have an astrophysics question. I’m writing here specifically to give you a chance to say, “No, I don’t feel like answering random science question.” I mean that–I will not be offended if you just ignore this, or say “No.”

  2. So, please be aware that I only understand advanced physics in the someone-explained-it-in-words level. I don’t have the maths to follow non-classical field theory, for example.

    So, as I understand cosmological consensus, if there is a Big Rip, the Cosmological Constant (“Dark Energy”) will increase to the point where first, all macroscopic objects will be torn apart by the increasing expansionary forces, leaving matter only in the form of molecules and smaller. Then, the molecules would be reduced to atoms as the expansionary force continues to increase. Finally, atoms would be reduced to leptons and nucleons, after which the unbound neutrons would decay to protons and some leptons, and all remaining matter in the universe would be a mixture of leptons, and of quarks in the form of protons. (Of course, photons would also still exist.)

    There being no reason for the expansionary force to stop increasing, though, presumably it would eventually be enough to tear the three quarks that make up a proton apart. However, I’ve read popular articles by physicists that say we can never observe a free quark (not bound to another quark or quarks) because the Strong Force holding them together is so great that you’d need to add so much energy to overcome it, it would be sufficient to spontaneously generate more particles (quarks) that would bind to the “original” quark.

    So, assuming the expansionary force continues to increase without bound, it would start rapidly generating quarks (and the reactions here would presumably be generating enormous numbers of photons and I think leptons). You end up with an extremely energetic quark-gluon plasma expanding with tremendous speed.

    Isn’t that a lot like the Big Bang followed by the inflationary period?

    Pardon the extreme length.

    1. Oh… I thought you were going to ask about stars or galaxies or something! These details of cosmology aren’t really my area of expertise, though I know a bit about it.

      I’m following you and think everything sounds right, up until your final question. It sure sounds a lot “like” the Big Bang, but I’m not sure if there are other conditions that are significantly different. For example, we know the Big Bang era was extremely dense, but it’s not clear to me what sort of densities we get under the Big Rip conditions – it may be extremely low density, which then doesn’t match the Big Bang at all. There’s also the ratio of energy versus matter, which may be completely different.

      So while I can see your similarities, I don’t think that’s enough to say it’s close enough to potentially be the same sort of environment.

      1. You most certainly know more than a former high school teacher does!

        I can argue (again, not knowing the math) that the matter and energy density could be any arbitrary value, because dark energy would be producing arbitrarily large pseudo-repulsive forces and thus potential energies, which once they interact with quarks would be converted into mass … but I’m just playing around with the concepts now.

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