It’s Not Kinetic #sciku #haiku #physics

Patterns repeating
Crystals exist in space-time
Through four dimensions

Thanks to for their article on time crystals. What a great term, but when you consider… what else could you call them? Crystals repeating patterns of atoms in the XYZ planes should be called space crystals. Add the fourth dimension we all live with every day (even if we can only ride time’s arrow forward) and what would you expect?

Makes me think of a song: You know Dancer and Prancer and Comet and Blitzen… you know Gases and Liquids and Solids and Plasma…

A standard crystal with atoms arranged in 3D space. Suppose one type of atom flips repeatedly between quantum states? Without absorbing any energy! Perpetually in motion without kinetic energy.

Nothing Travels Faster Than Light, But… #physics #science

I like to think I can have an amateur’s understanding of physics. For things like projectile motion, I feel pretty good. But when it comes to space-time waves:

CF researchers have developed a way to control the speed of pulses of light. Not only can they speed up a pulse of light and slow it down, they can also make it travel backward. UFC

What? I found this analogy from Brian Dunning, who puts out the excellent podcast Skeptoid (listen or read transcripts.)

Event A precedes B in the red frame, is simultaneous with B in the green frame, and follows B in the blue frame… which isn’t the same thing at all, but also weird.

Phase velocities are free to go faster than the speed of light, c, because they are conceptual, like a moire pattern from parallel fences you pass by.

Imagine you have a laser pointer that can paint a dot on the Moon from your back yard. (Caution: Do not look into that laser with your remaining eye.) If you sweep it quickly across the lunar surface the dot can appear to move across the regolith at greater than the speed of light, but the dot isn’t a thing so much as a concept, our name for what the light looks like. The actual photons that are flung to the Moon are moving at good old-fashioned c. Brian Dunning

Huh. If you have the chops for physics, check out “Optical space-time wave packets having arbitrary group velocities in free space” by Ayman F. Abouraddy in Nature Communications 10, Article number: 929 (2019). Open access (yay!) Yes, it’s taken me over a year to trip over the study. When you’ve absorbed the article, come back and explain it to me.

Fusion Power is Always 30 Years Away – Could That Be 5 years? #fusion #energy

Sun viewed in X-rays

The Sun: our only reliable source of fusion power

The joke is older than I am! Fusion power is 30 years away and always will be.

The joke works because, after almost a century and billions spent on government-backed megaprojects, we’ve failed. Huge, doughnut-shaped magnetic tokamaks or enormously powerful lasers suck up vast amounts of electricity to produce… no net gain.

Fusion needs a new approach, and today there’s more than one. At MIT, Oxford, and in southern California, researchers promise big things. Neutral hydrogen fuel, superconductors, and inertial-confinement, along with the latest artificial intelligence, could make a difference.

I’m jaded enough to ignore the latest claims if it weren’t for one thing:

If just one succeeds in building a reactor capable of producing electricity economically, it could fundamentally transform the course of human civilization. In a fusion reaction, a single gram of the hydrogen isotopes that are most commonly used could theoretically yield the same energy as 11 metric tons of coal, with helium as the only lasting by-product.

That would be a mighty significant outcome, so even a small chance of success is hard to ignore.

Private investors are getting involved and that means innovative ideas are being heard. The trouble with a government project (and I was a contractor for the US Federal government for many years) is there’s no exit strategy, and no sense of how to cut loses or remove powerful individuals who have become drones. Of course, in the private world, returns often need to come swiftly, and basic research takes time. Maybe a mix of funding is best.

The world needs abundant, CO2-free energy, so this blossoming of ideas grabs my attention. What truly seems weird is, even with fusion, we’re still boiling water to drive turbines to generate electricity. But if we can do it cheaply, safely, and without frying the planet – that would transform civilization.

Thanks for their article.

But really, thorium sounds like a better idea.


On This Day in History, Remembering a Genuine Genius #physics #poetry #poem #RichardFeynman #Feynman #quantum

Fifty-three years ago today, Richard Feynman gave his Nobel lecture on Quantum Electrodynamics. Even if you don’t remember him for his Nobel Prize or for Feynman Diagrams, you may recall how, during a televised hearing, he demonstrated what caused the shuttle Challenger’s disaster with a simple experiment using a glass of ice water.

Feynman was also a fascinating human being and you should read about his life.

But on this blog, I celebrate Feynman for his challenge to poets.

Poets say science takes away from the beauty of the stars – mere globs of gas atoms. I too can see the stars on a desert night, and feel them…

Far more marvelous is the truth than any artists of the past imagined it. Why do the poets of the present not speak of it? Who are poets who can speak of Jupiter if he were a man, but if he is an immense spinning sphere of methane and ammonia must be silent?

In honor of Feynman, I’m re-posting my poem inspired by his Lecture 1: Atoms in Motion, from the book Six Easy Pieces.

Your cup of tea sits quietly, its surface still and calm.
A tiny wisp of steam is all that’s going on.
Now magnify your vision, expand the scale up.
A cup as big as planet Earth with atoms big as cups.

Tea is a glob of atoms, each jiggling in the heap.
Atoms that are water and jiggling that is heat.
Cup-atoms block tea-atoms, despite how fast they seem.
But if tea-atoms hit the air they pop right out as steam.

Hot tea-atoms jiggle fast – move randomly in air.
If jiggling down, back to the tea, they’re stuck again in there.
Now blow away the steam – atoms don’t return to tea.
Hot atoms still keep popping out; removing heat, you see.

And so atomic theory
Allows your mind to see:
If tea’s too hot for you to sip
Then blow to cool your tea.

Kate Rauner