A science lesson from The Times

In its editorial 'Conservative Future' The Times informs us today:

"The second law of thermodynamics implies that the energy inside a closed system will always tend towards the lowest level possible. ..."

This is meant to be a metaphor for the complacency of the present Conservative government.

From Wikipedia:

"The first law of thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems. The law of conservation of energy states that the total energy of an isolated system is constant; energy can be transformed from one form to another, but cannot be created or destroyed."

So it seems that in a closed system, the energy is unlikely to always tend to the lowest level possible (which would presumably be zero, ignoring quantum fluctuations).

But wait, The Times mentioned the second law. From Wikipedia again:

"The second law of thermodynamics states that in every real process the sum of the entropies of all participating bodies is increased."

So got that? In a closed system the entropy (not energy) will increase (not decrease).

But entropy is way too hard a concept for Times readers.

I imagine that the unfortunate author might have recalled some folk-memory involving free energy: Wikipedia is again your friend:

"According to the second law of thermodynamics, [...] there is a general natural tendency to achieve a minimum of the Gibbs free energy."

Perhaps Times readers are more familiar with the pioneering work of Willard Gibbs.

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I never fail to be impressed by the sheer entitlement of arts-educated journalists, who would never commit a solecism - but feel free to display their basic ignorance of science as a form of tribal virtue signalling.

In case you think free energy vs energy is a distinction without a difference, consider the money available to spend in your bank account vs. the total money which happens to be in circulation. You would soon notice the difference if your bank account emptied and its contents were dispersed elsewhere in the economy.

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Incidentally, here's a test you can use to gauge the Asperger level of a science lecturer.

If the academic, faced with a gratuitous error such as that committed by The Times', simply points out that it's wrong, then that's a high-score for AS.

If, however, they try to infer the source of the error in the student's misunderstanding (energy confused with free energy) and straighten that out, they score as more on the neurotypical scale.

Just thought I'd mention that.

Gosh, it feels cold!

Lubos Motl posted this extraordinary video on his site - ultra-high-speed cameras show the sub-orbital speed of the detonation wave in "Prince Rupert's Drops". You can skip the ad after a few seconds and also the chat at the end.



It's very cold at the moment, even in a centrally-heated house. Touch the exterior-facing walls or the double-glazed windows. They have a c. 20°C thermal drop across them - naturally they're quite cold even with the insulation. Despite the warm air in the house, you still feel quite chilly.

OK, let's try again, why is that exactly? The second law of thermodynamics tells us that heat flows from hot objects to cold ones. More operationally, your body radiates in the infra-red to its surroundings and your surroundings radiate in the infra-red back at you. But if they're colder than you, there's a net imbalance: you're doing most of the radiating at the walls and windows, they're not returning the favour. So you feel the chill.

How does this work at the level of individual molecules, how does this infra-red radiation actually occur? Only quantum mechanics can tell us. In a typical house at c. 20°C (infra-red radiation) energy transitions correspond to random changes in the vibrations of molecular components: it's like the atoms are connected together by bouncy springs as they thermally bash into one another.

In quantum mechanics this reminds us of harmonic oscillators and their energy eigenstates spaced at the order of ℏω - which at infra-red values of ω are pretty finely spaced. Throw in some Doppler smearing and you've got a continuous black-body spectrum.

So that's why we feel just a tad uncomfortable this week.