An excellent conversation with the mathematical physicist Freeman Dyson from Quanta Magazine, touching on everything from quantum electrodynamics to why getting kids into science might change the world.
Dyson is often contrarian, but always sharp and intelligent. From founding quantum electrodynamics alongside one of my heroes, Richard Feynman, to such science future fictions as the Dyson sphere, he has a particular way of approaching the known and unknown world that we’d all be well-served to consider.
On the value of math:
I was trained as a mathematician, and I remain a mathematician. That’s really my skill, just doing calculations and applying mathematics to all kinds of problems, and that led me into physics first and also other fields, such as engineering and even a bit of biology, sometimes a little bit of chemistry. Mathematics applies to all kinds of things. That’s one of the joys of being a mathematician.
I love that. No matter your field, you’ll do well to remember that you’re a problem-solver first and an applier-of-specific-skills second.
On the value (or not?) of the Ph.D.:
I’m very proud of not having a Ph.D. I think the Ph.D. system is an abomination. It was invented as a system for educating German professors in the 19th century, and it works well under those conditions. It’s good for a very small number of people who are going to spend their lives being professors. But it has become now a kind of union card that you have to have in order to have a job, whether it’s being a professor or other things, and it’s quite inappropriate for that. It forces people to waste years and years of their lives sort of pretending to do research for which they’re not at all well-suited. In the end, they have this piece of paper which says they’re qualified, but it really doesn’t mean anything. The Ph.D. takes far too long and discourages women from becoming scientists, which I consider a great tragedy.
I think he’s spot-on about many of the Ph.D.’s failings, but I think he simplifies the value of the “title” here, rather than the work one does to get the Ph.D. Therein lies the value, or lack thereof. The Ph.D. process (quite effectively) teaches a manner of thought and problem-solving that is tough (but not impossible) to replicate elsewhere. But a Ph.D. is most certainly not the only way (or even the best way?) to become a scientist, at least with respect to a scientist being not a vocation but being “someone with a generally scientific mindset”.
Finally, on why we need to get every child interested in science:
We should try to introduce our children to science today as a rebellion against poverty and ugliness and militarism and economic injustice.
Baffling Balloon Behavior
Not only does Destin have one of the best YouTube channels on this fair planet, but he is also a wizard.
Just kidding, he just has an eye for science in everyday life. In the latest Smarter Every Day, Destin and his two adorable assistants make a helium-filled balloon do something very, very strange inside their accelerating minivan. So strange, in fact, that you might feel like his family car is a secret portal to a land where physics is broken.
Here’s an idea: After Destin shows you the trick, pause the video for a few minutes and see if you can figure out what’s going on. Then, if you don’t understand or agree with his explanation, head on over to Reddit to continue the discussion!
Prepare to be mesmerized by the video above. The folks from Firefight Films piloted a GoPro-equipped quadcopter drone through massive glacial ice caves in Alaska, and the result is stunning. It’s “cool” in both senses of the word, eh?
After I broke free from the slack-jawed catatonia (videos like this do that to me), one thought stuck with me: Why is the ice so blue?
Water is almost entirely transparent to visible light. Like, amazingly so. That’s the reason that life exists in the first place, because photosynthesis could occur near the surface of prehistoric (and modern) oceans. But it’s not totally transparent to visible light. It selectively filters out red stuff, leaving just the blues behind. B.B. King would like that.
So what gives? It’s not because of the reason that the sky is blue. That’s due to a phenomenon called Rayleigh scattering, where air molecules scatter short wavelength (blue) visible light into our eyes (it’s also why sunsets are red, but I made a whole YouTube video about that if you want to know more).
Nope, ice and water are blue thanks to a completely different, and more complex, bit of cerulean science.
Water, even when frozen solid, isn’t rigid. Like any molecule, it vibrates. The hydrogens are ever-so-slightly oscillating around the central oxygen, stretching those covalent bonds to and fro. Since a water molecule has three atoms (N=3), that means it has 3N-6 primary dimensions of vibration (3 total). Check ‘em out below:
Just at ‘em, wavin’ their hydrogens in the air like they just don’t care! You can easily mimic these aquatic dance moves in front of your bedroom mirror, or at the club, just be sure to credit me next time you bust out the “water shuffle”.
And just like a vibrating string, a vibrating molecule can emit overtones. Overtones in molecules are kind of how a guitar (or violin, or banjo, or any stringed instrument) can make harmonics, only with a hefty spoonful of Fourier transforms added. “Fourier transform” may bring back nightmares of sweaty-palmed calculus exams, but in truth they are one of the most elegant principles in math, underlying everything from mp3’s to Homer Simpson’s face.
These vibrating water molecules can absorb energy at very particular wavelengths. The physics behind this absorption gets complicated real quick (you can drink deeper here if you’re so inclined), but you can observe a similar phenomenon right in your kitchen. You know how your microwave heats up food thanks to the molecular shaking induced by long-wavelength radiation? You didn’t know that? Well, that’s how it works. Except when it comes to blue water, instead of long-wavelength microwaves vibrating entire water molecules, we have shorter wavelength radiation sending just the arms of water molecules into harmonic vibrations.
It just so happens that, thanks to all those combined overtones and disco-dancing hydrogens, water absorbs a tiny bit of electromagnetic radiation around 698 nanometers in wavelength. That just so happens to be red light! (Water also slurps up plenty of other wavelengths across the spectrum, but very little of that happens in the visible range):
Liquid or solid, water shines azure, stripping visible light of its reds, and leaving only the blue hues behind to be reflected back to our landlubbers’ eyes thanks to microscopic particulates.
There’s always something to learn, even when it comes to water, a chemical we think know so well. Goes to show, even the clearest of views can unlock curiosities when we look deep enough…
(Bluest of blue image of Crater Lake, via Wikipedia)
When light travels through areas of different air density, it bends. You’ve probably noticed the way distant pavement seems to shimmer on a hot day, or the way stars appear to twinkle. You’re seeing light that has been distorted as it passes through varying air densities, which are in turn created by varying temperatures and pressures.
Schlieren Flow Visualization can be used to visually capture these changes in density: the rising heat from a candle, the turbulence around an airplane wing, the plume of a sneeze … even sound. Special thanks to Mike Hargather, a professor of mechanical engineering at New Mexico Tech, who kindly provided a lot of these videos.
I’m totally Schlieren right now. Amazing sights of sounds.
FORCES OF NATURE
Here’s what keeps it all together (and breaks it all apart)
Gravitational Wave Discovery! Evidence of Cosmic Inflation
Join Derek from Veritasium and take a look at the universe’s adorable baby photos! Aww, who’s a cute widdle universe? YOU ARE! You’re growin up sooooo fast with your inflation, yes you are!!
Smoooshybooshybooboo look how homogenous that made your cosmic background radiation! And those cute little gravity wave lumps, d’awwww, I hope you never lose those.
(I’m baby talking the Big Bang. I think I should get some fresh air.)