At the Late Night Double Feature Picture Show

No, this is not a fuzzy image of the screen of The Rocky Horror Picture Show or Mick Jagger’s (or anyone’s) lip-print, for that matter. It’s a profile of a laser beam. A not particularly friendly laser beam. A nice beam would be round, and its profile would be a zeroeth order Gaussian, but semiconductor lasers don’t always play nice when it comes to beam profiles. The plan was to send this into a single-mode fiber, and single-mode fibers want that nice round beam, and higher-order modes don’t couple very well.

And it was doing it on purpose, just to make my life difficult.

Those Evil Things

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I think the analogous topic for physics is radiation: that all radiation is a bad, evil, dangerous thing, when radiation is all around us. Visible light is radiation, as are radio waves, and all objects emit radiation in the context of blackbody radiation — the most common experience being that moderately hot things radiate noticeably in the infrared and sometimes in the visible part of the spectrum.

There are other basic, common misconceptions, like things needing an impetus to keep moving, and some more targeted ones, like insulation heats things up. But I think the connection here is in the “it’s evil” misunderstanding.

The Wise Gyroscope

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Abstract: Owls have a curious variability in the postrotatory head nystagmus following abrupt angular deceleration. Owls can exhibit a remarkable head stability during angular movement of the body about any axis passing through the skull. The vestibular apparatus in the owl is bigger than in man, and a prominent crista neglecta is present. The tectorial membrane, the cupula, and the otolithic membranes of the utricle, saccule and lagena are all “attached” to surfaces in addition to the surfaces bearing hair cells; these attachments are very substantial in the utricular otolithic membrane and in the cupula.

I want to say side-fumbling is almost completely eliminated, but I will link to the story instead.

Previously we have seen chicken-head stability.

Bonus: slo-mo landing

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The Problem with Not Physics

The problem with physics

Even something as fundamental as Newton’s law of gravity is ultimately an approximation. Textbook authors dutifully write down the famous law without remarking that it results in infinite forces when the two attracting objects get infinitely close together. Never mind that infinite forces are a sure sign that your theory has gone up in smoke: in the current crop of textbooks sitting on my desk, not one mentions the obvious pathology.

To quote the fake president from Dave: Okay, let’s get right to the guts of it: every one of these accusations is absolutely true.

I can’t find fault with them, at least.

Sure, Edison (and perhaps as or more importantly, his staff) knew Ohm’s law and that hot things glowed (which is blackbody radiation). The details of why were far less important than those two models. It’s true that probing the question of Mach’s principle (at what does a gyroscope point?) led to general relativity, but we have that model without the answer to the question.

Physics, like all of science, tries to make models to explain how the universe behaves. It’s not a quest for the true nature of things — that’s metaphysics (and in case this gets translated into hipster, no, that’s not ironic). It may be a shortcoming that this isn;t driven home more forcefully, but it’s not an inherent flaw of science.

So I contend that it doesn’t matter. What he’s complaining about isn’t inherently a problem with physics or with physics education. But the author then acknowledges this, which leaves one to scratch their head and wonder what the point of the article is.

After decades — indeed, centuries — of employing such tricks, physicists have forgotten that they are modelling phenomena, not necessarily uncovering Divine Truth.

Flex those Fields

Electric Field from a Built-In Flex

The flexoelectric effect is the trendy younger cousin of the better-known piezoelectric effect, in which certain solids develop an internal electric field when squeezed or stretched. The phenomenon has proven useful in devices from scanning tunneling microscopes to cigarette lighters, but it can only exist in 20 of the 32 crystal symmetry classes that materials scientists use to categorize solids.

That's Easy for You to Say, Astro Boy

Uncertain Principles: How Much Outreach Do We Need? Depends on What You Mean by “We”

If you want to argue that we have plenty of outreach going on in astronomy and particle physics, that’s fine, but to say that astronomy and physics outreach is sufficient for science as a whole (or even just physics, which I’ve heard people say) is just insulting.

Astronomy and particle physics aren’t the whole of the physical sciences. Astronomers and particle physicists are significantly outnumbered by people doing other types of physics– condensed matter, atomic and molecular, materials science. Those topics don’t get anywhere near as much attention as things you can illustrate with a picture from the Hubble telescope.

“Yeah, but astronomy and particle physics touch on really big questions, that inspire people,” you say. “Oh, bite me,” I reply.

(If anyone is tempted to take this to the next level, I’ll remind you that we have lasers. Just sayin’)

If you give the narrow glimpse of physics as accelerators and telescopes, you make the same mistake as painting grad school as only a pathway to academia: you sin by omission.

Feeling Jumpy

The Virtuosi – Physics in Sports: The Fosbury Flop

The Fosbury Flop came into the High Jumping scene in the 1968 Olympics, where Dick Fosbury used the technique to win the gold medal. The biggest difference between the Flop and previous methods is that the jumper goes over the bar upside down (facing the sky). This allows the jumper to bend their back so that their arms and legs drape below the bar

It is significant that Fosbury is not modeled as a sphere.

 

Dot Physics: World Record Blob Jump

I guess the best explanation for how it works is that it is like a giant see-saw. When people jump down on one side of the huge airbag, the other side goes up. If you consider small energy losses, then the work done by the bag in slowing the falling people down is the same work done on the launched person.