Thursday, November 12, 2020

Some science (for relief from politics)

*  Nature has an interesting article updating us on the research into the question of whether infections cause Alzheimers:

Are infections seeding some cases of Alzheimer’s disease?

A fringe theory links microbes in the brain with the onset of dementia. Now, researchers are taking it seriously.

*   I've been watching many Youtube videos on physics lately, mainly regarding quantum theory and relativity, and one of them talked about how most of the mass of the proton comes not from the Higgs Boson, but via the interactions between the quarks which make up the proton.  Individually, those quarks only have a small percent of the total mass of a proton:

Protons are made up of even smaller particles known as quarks. It might seem reasonable that simply adding up the quarks’ masses would give you a proton’s mass. Yet it doesn’t. That sum is far too small to explain the proton’s bulk. New, detailed calculations show that only 9 percent of a proton’s heft comes from the mass of its quarks. The rest comes from complicated effects occurring inside the particle.

I had probably read that before, but sometimes just being told via video sticks more in the mind than reading it quickly.

This fairly recent article in Quanta gives a pretty good idea of how complicated the physics of quarks inside protons really is.   Mind you, it's pretty incredible, when you think about it, that we have the technology to be able to conduct experiments at this level of tininess at all.

*  While watching the videos on physics, I have also thought again about how it seems that Einstein's complicated theories have sort of made us loose appreciation for the innovation and complexity of Maxwell's electromagnetism equations.   I seem to recall that when doing senior high school physics, I didn't like how there was no attempt to put how Maxwell came up with his formulae in proper context, so you got the impression that they sprang out of no where.   Interestingly, when I Google the topic now, I see that Freeman Dyson  wrote an article (or gave a talk?) entitled "Why is Maxwell's Theory so Hard to Understand" - which makes me feel better about my life long gut feeling about it!   I didn't know this:

For more than twenty years, his theory of electromagnetism was largely ignored. Physicists found it hard to understand because the equations were complicated. Mathematicians found it hard to understand because Maxwell used physical language to explain it. It was regarded as an obscure speculation without much experimental evidence to support it. The physicist Michael Pupin in his autobiography “From Immigrant to Inventor” describes how he travelled from America to Europe in 1883 in search of somebody who understood Maxwell. He set out to learn the Maxwell theory like a knight in quest of the Holy Grail. 

Pupin went first to Cambridge and enrolled as a student, hoping to learn the theory from Maxwell himself. He did not know that Maxwell had died four years earlier. After learning that Maxwell was dead, he stayed on in Cambridge and was assigned to a college tutor. But his tutor knew less about the Maxwell theory than he did, and was only interested in training him to solve mathematical tripos problems. He was amazed to discover, as he says, “how few were the physicists who had caught the meaning of the theory, even twenty years after it was stated by Maxwell in 1865”.

So, the electrification of cities, which seems to have only got going in the 1880's, was proceeding before Maxwell's ideas were thoroughly or widely understood by scientists?  Huh.

3 comments:

GMB said...

Quark theory is total gibber. They don't have the data.

John said...

The Alzheimer's-infections link has been around for a long time. There probably is something to it because amyloid protein is a stress related protein and infections cause cellular stress. However it isn't infection alone that creates the problem, there are a range of other factors to think about including the phagocytic state of microglia, whether astrocytes are under stress, and the general bioenergetic state of various cells in the CNS. Just last night I received an abstract that highlighted another mystery about Alzheimer's: some people can have very high amyloid loading and have no symptoms of cognitive impairment, the authors argue the root cause is loss of energy supply. The bioenergetic argument is interesting but confuses symptoms and causes. It is interesting to note though that creatine, a body building supplement, is sometimes used in neuropathology and creatine is precisely about bioenergetics.

GMB said...

It was Oliver Heaviside who made Maxwell's maths comprehensible. The kids used to throw stones at him.