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Comment by eequah9L | Hacker News Reader

> quasicrystal materialized in temperatures above 2700 degrees Fahrenheit and pressures of 5000 to 8000 pascals. To you and me, it would feel similar to [...] someone carrying thousands of elephants [...] stands on your back.

Hmm, from my mechanical engineering times, 8 kP does not sound like a big deal at all.

Say it's 5 tons per elephant, which would be about 50kN. A human foot is about 25 cm long, and I guess two of them might be about as wide, so 0.0625 m^2. Pressure is force over area, so 800 kN/m^2, or 800 kP. That's per elephant.

I'm going to assume the article is missing a "mega" somewhere in there.

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Given that atmospheric pressure is around 100,000 pascals, yeah they're probably missing some SI prefix.

Edit: The original article talks about pressures of 5 to 8 GPa. [1]

[1]: https://paulsteinhardt.org/wp-content/uploads/2021/05/BindiE...

Reading those Fahrenheits and pascals in one sentence really hurts.

For anyone not in USA (or the tiny handful of other countries still using it), Fahrenheit hurts to read full stop.

I don't think Celsius can be considered less arbitrary, and the anthropocentricity of Fahrenheit has its advantages. I would honestly be happy to give up Celsius if in exchange the US et.al. moved over to metric distances.

That then would be the foot in the door for eventual full metric conversion!

I agree Celcius is also entirely arbitrary, any scale would be really, but when 95% of the world's population uses Celcius (and the metric system has similar worldwide usage) perhaps it's time for them to go with the consensus.

boiling water is 100•F. freezing water is 0.

what’s not to like about this human-perspective?

Why yes. Running a fever is dangerous because that's exactly the point where the blood starts to boil. Let it simmer too long and smoke comes out of your ears.

centigrade surely?

Not if you're a human describing their environment: zero is F.cold and 100 is about as hot as you can stand.

That's not much of an advantage if you haven't grown up with it. It's also very arbitrary in that it doesn't account for preference or acclimatisation.

EDIT: or humidity, which is also going to be a major factor in how much you can stand.

37°C is fine in my opinion, just drink enough water and don't stand in the sun.

The official Fahrenheit scale is something that only USA can love.

Hmm, 100 for human body temperature is good, but 0 for the lowest temperature achievable in a lab 300 years ago is not so good.

The Aspden scale has its zero at water-freezing and 100 at this-will-kill-you-if-you-can't-sweat. 50A is "nice". It's really intuitive and perfect for weather reports. For science, use Kelvin of course.

>but 0 for the lowest temperature achievable in a lab 300 years ago is not so good.

It's approx the temp that sea water freezes at. That's not useless.

212-32= 180 degrees between fresh water freezing and boiling.

The metric system has its merits, but US units aren't as arbitrary or pointless as people think. It may not be made for decimalization, but it does feature units that are easily divisible by even numbers and 1/8ths.

It's a balance between useful approx characteristic points and convenient divisors.

And based on how many people struggle with knowing where to put the decimal (or use the correct prefix) in metric, I'd argue decimalization isn't the great "simplification" it's made out to be.

And the fact that people think the decimalization of time would be crazy is proof that it's more about familiarization than simplicity.

Yeah, I can't stand freezing nor boiling either! Let's go ahead and embrace a better unit of measurement now!

What if some humans have different temperature preferences? Do they get a different temperature scale to suit them?

Temperature doesn't really exist. It is a concept for describing the kinetic energy of molecules. So we could go with some combination of meters/seconds/mass/atomic mass. We could call it the ped-kelvin, the temperature scale only used by the most pedantic of scientists.

This sounds like you're trying to reinvent the Boltzmann constant without quite knowing what it is.

(and without quite knowing what temperature is, but that's besides the point)

As I said, a scale for the most pedantic of scientists. I and everyone else who took physics in highschool is well aware of Boltzmann's work.

Surely m*s as the average speed of molecules you are measuring would be the sanest.

Temperature is a measurement of kinetic energy, speed x mass. Two substances with the same temperature can have different m/s atomic speeds. Moving at the same speed, Uranium atoms will be 'hotter' than hydrogen atoms because the uranium atom is heavier.

(This distinction is important in rocketry. At a given exhaust temperature, the lighter substance will be moving faster, resulting in greater efficiencies.)

Oh right. I completely forgot about the mass of the individual atoms.

So basically:

(Sum of the speed * mass of (from atom[1] to atom[total number])) divided by the total number of atoms?

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