The Weirdest Substance Known to Science

Science can be pretty weird sometimes, and the temperature and environment you give certain substances can vastly change their properties, sometimes in absolutely bizarre ways. Which bring us to the subject of today's video, looking at one of the most criminally underrated natural resources we have on earth, that also gets super weird when liquefied and cooled to a low enough temperature.

[ninehundreddollarluxuryyac]

I spent a minute and a half thinking that AG-1 food supplement was the most amazing substance. Then we got onto helium.

[aanchaallllllll]

1:22: 🔬 Helium is a unique and difficult to liquefy element with fascinating properties, including behaving like no other liquid on Earth when cooled to low temperatures.
4:26: 🧊 Liquid Helium II exhibits mind-bending properties, including a million-fold increase in thermal conductivity and the ability to flow through small pores without viscosity.
7:03: 🧊 Helium II exhibits contradictory behavior, defying the laws of thermodynamics and displaying both zero and finite viscosity.
9:41: 🧪 Helium II, also known as superfluid helium, behaves differently from regular matter due to quantum mechanics.
12:48: 🧪 Helium II, a superfluid, has the potential to revolutionize electrical engineering and other technologies.
Recap by Tammy AI

[Qenton]

At JPL's open house once I was able to "see" Liquid Helium... the same year they also had the Electron Tunneling microscope open and was able to "See" actual atoms! That day I felt like I'd seen the rock stars of science.

[katherinek]

Whoever did proof-reading for this episode in regards to condensed matter physics did a great job. A lot of things are simplified for the audience, obviously, but without being wrong or misleading. That's, sadly, not something you get very often with pop-sci explanations of anything involving quantum mechanics. I'm sure keeping this episode brief, factual, and easy to follow took a lot of editing work. Kudos!

[mumblbeebee]

The serious side of Simon continues to impress and inspire. Well done, team, for producing such a great condensate of the matter and to Simon for reading it at that speed and still making sense!

[Scott-wdcq]

Awesome video! Superfluidity is a super complicated subject with a lot of quantum nuance. However, there are some people asking about inaccuracies so I've tried to explain a few below:


2:44 Discusses the Van Der Waals force but uses a stock image of H2O, which is covalently bonded

3:00 The video discusses liquid helium and then immediately mentions 'solidifying helium' at 25 atmospheres of pressure. This is correct for solid helium, but liquid helium and helium-2 (including the images shown in the video not least of which include a scientist standing next to an open beaker of it) is completely feasible at room pressure (1 atmosphere)

4:36 The units of specific heat given are incorrect, they should be kilocalorie per gram degree (though, colloquially, calorie and kilocalorie are interchangeable).

8:27 The Second Law of Thermodynamics. This is used in reference to the 'fountain effect' which is still an area of debate and thus is complicated and ill-understood. But the main inaccuracy here is that there must always be a NET change in energy/entropy from the more energetic to less energetic state (therefore some energy can flow the 'wrong way' so long as the NET change in the system follows the Second Law). Quantum physics (and the fountain effect) requires this distinction for many reasons e.g. Casimir Effect.

12:22 "A spin 1-2 particle" doesn't make sense in physics, he means to say "A spin 1/2 (half) particle" i.e. a particle with a spin of 1 over 2 such as helium-3.

[DeirdreSM]

I had a science book when I was a kid that talked about helium's superfluidity. I have no idea how many hundreds of times I read that section, but it was so counterintuitive and I wanted to see it. That book was from the early 1960s, and we've learned a lot since then, so it's really great to have this update.

[KGTiberius]

VERY well written. One of the most concise explanations — yet expansively detailed in permutations. Some errors, yet still conveys understanding, increases awareness, and encourages exploration.

[johnmassey]

As a physical chemist I can say that was a very good video. Great work Simon and team. Keep it up 👍

[the-chillian]

One way you can tell that Simon didn't understand a single word of this script is that he read the quantum spin numbers of 1/2 (which should be "one half") as "one two".

[ElroyMcDuff]

Man, if content like this was available when I was an undergrad I would have chosen a different major. Thanks Simon and team!

[aLexKcss]

Ah, nothing beats a fresh fact boy video

[MrNikolidas]

I was watching a video earlier this month on the LK-99 room-temperature "superconductor" (spoiler: it isn't one), and was thoroughly perplexed as to what Cooper pairs were in the explanation. You single-handedly explained it better in less than a minute what a ten minute video could not.

[Sallyth_]

Psst, the name of the Dewar flask is usually pronounced "joo-wer", emphasis on the first syllable (Americans may call it a "doo-wer" tho'). I worked with cryogens for 10 years as a lab tech and Helium was endlessly fascinating :)

[k.c.sunshine]

Well, if you think helium is weird, then you should cover neutron star material. There are many "weird" things out there. Boise-Einstein condensate is interesting too.

[AllisonAgans]

Thank you Simon and your team for helping me develop a Big Brain

[granatmof]

Helium isn't necessarily dwindling. It's created all the time due to alpha decay.

The weird part about Helium is that it operates as both a boson and fermion. It's the only particle to do so.

[HVM_fi]

I read The Worst Substance Known to Science and AG1 would fit perfectly.

[MindinViolet]

This was a fantastic video and one of your most fascinating ever.

[ONEYEDPiRAT]

Back in the '80s "micro machines" had a spokesman who talked really fast about their little cars, busta rhymes too! I love your enunciation also very clear crisp and defined Thank you sir!