Thursday, July 05, 2018

Did 12 astronauts cause global warming by 2 °C on the Moon?

Or does an organized movement of brain-dead liars calling themselves "journalists" spread far-reaching cosmic superstitions about a mundane hot piece of dark surface under the sunlight?

How much a group of 12 men can change the world? Well, if they're apostles, they may have the last supper with Jesus Christ. They didn't have to pay a penny. Assuming that Jesus Christ was more than Warren Buffett, they saved over $39.6 million.

Incidentally, before He arrives again, they have accepted a temporary job. Every hour, they entertain tourists at the 600-year-old Prague Astronomical Clock (The Orloj). I've seen it many times but only now, I watched it carefully enough to notice that six of them only appear in the left window and six of them in the right window. In my life so far, I have never found it important enough to investigate this detail.

However, weeks ago, some media, e.g. How Stuff Works brought an eye-catching story. A group of 12 Unistatians – the astronauts – has caused the global warming... on the Moon! How did they do it?

The claim boils down to some NASA tapes that were lost 40 years ago. If you're the world's only superpower and if you invest 4.4% of your GDP to the space program (the peak year was 1966), don't forget to ask your dog to eat the multi-billion homework. At any rate, some folks have recently performed the autopsy of the dog, found the tapes, and... they show that right after the several years in which the Unistatians were shooting moonwalkers to the air (well, to the approximate vacuum, as I will discuss), the temperature readings went up by a whopping 2 °C.

On Earth, the hysterical global warming psychopaths "blame" the mankind for a "catastrophic" rise of the global mean temperature by 0.7 °C in a century – something that the whole evil capitalist and industrial civilization should be hated for. We're still occasionally told that evil billions of cars etc. have already ruined the planet by warming it by less than a degree Celsius and they will finish it by adding another degree in this century.

Meanwhile, on the Moon, 12 people – starting with Armstrong and Aldrin – were enough to achieve a greater warming – by 2 °C – and they didn't even need a single SUV. It was enough for them to walk. By slowly walking on the Moon for a while, they removed the lighter dust from the surface and they created darker paths in the terrain. Those have increased the absorption of the solar radiation. And that has quasi-permanently warmed the Moon by some 2 °C. Great.

Almost a month ago, Anthony Watts reported this story. Sadly, he didn't include any common sense, let alone physics. He just blindly copied some scientifically sounding comments and arguments designed to impress or intimidate the readers (such as comments about regolith) – while the claim that matters is real bullšit, as some WUWT readers pointed out. As I will disappointingly mention at the bottom, Anthony approached this story in the same way as the "journalists" in the "mainstream" media – whose recipe is to uncritically copy the eye-catching junk.

Maybe he wanted or expected the readers to disbelieve the main claim of the story. However, his text provided no rational reason to disbelieve.

The main problem with the "global warming on the Moon caused by astronauts" claim was nicely summarized by Tom Sheahen – and then Roy Spencer and Thomas Wysmuller – in an e-mail conference of ours. What's the problem with the claim? The problem is that the "warming" wasn't "global" at all. It was heavily or almost completely localized. The temperature sensors were located near the darker paths from the astronauts' shoes, and they got warmer for the same reason why asphalt gets (and nearby thermometers get) hot on a sunny day on Earth (the celestial body underneath most TRF readers).

Can the asphalt cool down quickly?

Well, on Earth, the asphalt could be cooled by the wind. But there's really no wind on the Moon because, you know, there is almost no atmosphere on the Moon. The pressure over there is 14.5 orders of magnitude lower than it is on Earth! The gravitational field of the Moon is so weak that most of the atmosphere that could have been there has escaped. The negligible lunar atmosphere is dominated by argon.

There are no winds, no precipitation, no hurricanes, no meteorological effect on the Moon. The heat is transferred merely by radiation and conduction. The radiation is what guarantees that each place of the surface wants to have a temperature that is a decreasing function of the reflectivity (albedo). The astronauts have lowered the reflectivity of the nearby places which is why they increased the temperature expected from the equilibrium of the incoming solar and outgoing thermal radiation.

The only way how other places of the Moon – those unchanged by the astronauts' shoes – could help to cool the darker paths is conduction. I mean heat that is literally going through the solid. But that diffusion of heat is governed by the diffusion equation (\(\phi\sim aT+b\))\[

\frac{\partial\phi}{\partial t} = D\cdot \Delta \phi

\] which is, for TRF readers who are as quantum mechanical as I am ;-), just a Schrödinger's non-relativistic equation (see below) without the \(i\). What a nice way to teach classical physics. :-)\[

i\hbar \frac{\partial\psi}{\partial t} = -\frac{\hbar^2}{2m}\cdot \Delta \psi

\] Now, if you create a localized bump in the initial conditions for the temperature, it's analogous to a localized wave packet in Schrödinger's equation. And regardless of the \(i\), some scalings of the subsequent behaviors will be the same. I remember we were calculating this helpful exercise with Dr Pavel Čihák, our undergraduate instructor teaching complex analysis and differential equations.

First, he offered us some potatoes from his garden. Second, we calculated it and one of the results was that some significant heat only gets 10 meters to the depth after half a year. He wanted us to learn the important lesson: You can see why it's a good idea to bury yourself in the soil.

If you take the Schrödinger's equation with the \(i\), you may easily solve it in the momentum representation. The phase of \(\tilde \psi(p)\) is being multiplied by some \(\exp(iC p^2 t)\). This change of the phase becomes substantial for \(p\sim \sqrt{1/Ct}\) which, by the inverse "uncertainty" relationship, tells you that the width of the wave packet is \(\Delta x \sim \hbar \sqrt{Ct}\). That function grows sublinearly. The more you wait, the slower the propagation of the heat is, and it simply takes years for the heat to escape by dozens of meters (to make a statement like that, you need to know something about \(C\) and analyze the consequences).

Nothing changes about the square root behavior if you replace \(i\) by \(-1\) in the phase \(\exp(iC p^2 t)\) – if you switch from the Schrödinger's to diffusion equation.

The important qualitative lesson is that the conduction is so slow that you may assume that only regions whose size is comparable to ten meters exchange the heat effectively enough. Regions that are much further apart than 10 meters are segregated almost perfectly i.e. hermetically.

So what the thermometers have measured isn't any "global warming on the Moon". It's a completely localized effect around the footprints that is as mundane as the hot asphalt during a hot summer day (we had a hot morning which became a very rainy evening). One of the three men in our e-mail conference estimate that a change of the albedo by 3% was enough to account for the effect.

But most of the media will never tell the people about this punch line – that it's just a silly local effect. They don't really have any competent people (from physical sciences) who can debunk similar nonsense. And because millions of readers have happily devoured similar garbage for many years, the media arguably don't have any motivation to print the truth. Eye-catching garbage is just as good for them – if not better. So they're encouraging millions of people to believe literally medieval superstitions (or worse) about 12 men who can warm a celestial body by 2 °C by walking there.

Not even Jesus Christ could do such a thing in the Bible (walking on the water is trivial relatively to walking on the Moon and heating the whole Moon by two degrees), let alone His 12 down-to-Earth apostles. But 12 down-to-Moon astronauts can do it between 1969 and 1972, according to the faithful believers in 2018 who buy literally anything. Millions of people just believe garbage that would probably be recognized as unscientific nonsense by most folks in the church even in the Middle Ages. And this kind of stuff is being served all the time.

To make the picture even more frustrating, it's not just the "mainstream media" whose "journalists" are already known to be more or less brain-dead – by everybody who is not. The sad detail is that even Anthony Watts, the guy with the world's most visited website dedicated to the climate, basically copied the story without any truly serious effort to figure out whether the basic claim makes any sense and why it doesn't. I like Anthony but this treatment of this bullšit story (like his treatment of Andrea Rossi's cold fusion) shows that the idiocy may have a far higher penetration power than we often assume. Anthony's blind copy-and-paste, MSM-style attitude is particularly surprising given the fact that he has spent thousands of hours by trying to show that global warming may be actually caused by asphalt near the weather stations on Earth. But he sort of overlooked that the same comment applies on the Moon (where the statement is much more true than on Earth).

Physicists are trained and expected to be good at order-of-magnitude and parametric estimates. But to some extent, plus minus five orders of magnitude in related situations, every rational person should be an amateur physicist. Rational people simply can't believe a claim in the media that twelve men making a few steps in the dust warm the Moon by two degrees. There are dozens of relevant comparisons and tests one can make and the claim doesn't pass any of them.

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