Bad Astronomy Newsletter #8

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Pic o’ the Letter

A cool or lovely or mind-bending astronomical image/video with a short description so you can grok it 

I love images of the Earth from space. I look at a lot of them, and while I’m an amateur at IDing various features, I can usually figure out what I’m seeing after a moment.

But this one threw me! It’s an image from the Sentinel-2B satellite taken on February 2, 2018:

[Credit: Copernicus Sentinel data (2018), processed by ESA, CC BY-SA 3.0 IGO]

That’s the northwest part of the Eleuthera archipelago in the Bahamas (the images is about 100 km across). The bright teal is where the water is shallow and clear; you can actually see sand billowing as currents move it around.

But the dark region surrounding it threw me. My brain was trying to tell me it was land, but that doesn’t make sense. And that’s correct: It’s not land, it’s water: very deep water.

On the inside of the archipelago the water is only a few meters deep. But just off the edge it plummets thousands of meters rapidly. The change in color is real — after all, this delineates the Caribbean Sea from the Atlantic Ocean. Still, when I first saw it I really had a hard time interpreting it. I’m not used to seeing such contrast and such a steep change in slope underwater.

I got this image from the wonderful European Space Agency Space In Images site.

Personal Stuff

Yeah, but not too personal

So a little while ago there was a hashtag going around on social media called #FirstHeadshot, where actors and such would post their very first “headshot”, a photo of them basically from the shoulders up. I actually have a few of those I use for bios and such for when I give talks. 

I don’t really have an early headshot that fit the hashtag, so I never posted one. But hey, y’all are throwing filthy lucre my way, so I have decided to post a picture of me my sister put up on Facebook; it’s from 1979 when I was in marching band in high school.

[Credit: Unknown]

So if you’ve ever wondered to yourself, “Hey, has Phil always been as cool as he is now?”

The answer is “Yes”. Exactly as much.

Astro Tidbit

A brief synopsis of some interesting astronomy/science news that may be too short for the blog, too long for Twitter, but just right (and cool enough to talk about) for here.

In 2017 the Lawrence Livermore National Lab released a pile of declassified footage of nuclear weapons tests from the 50s and 60s. I wrote about them then; they are as terrifying as they are mesmerizing.

LLNL released a second batch of these videos, and it’s more of the same, but you should go there and read the article anyway; it’s very informative about the tests.

I’m glad they’re doing this. The science of these explosions is actually useful for many reasons, including studying how stars explode (seriously, a lot of the physics is the same). But they also serve as a reminder to just how screwed up we humans are — we are willing, and at times even eager, to not only kill each other wantonly but to also pollute the entire planet and make it unlivable for our species and most others at the same time.

And it should make you ask yourself: What the hell were we thinking?

Life Hacks

Not what you might expect from an astronomer, but in my defense I am alive 

Colorado is ridiculously dusty, especially in the summer when it hasn’t rained in a while and the wind is howling. Our windows get covered in fine-grained dirt pretty rapidly, and that messes up our view of the great outdoors.

We used Windex and other ammonia-based spray cleaners for a long time, but then my wife found a neat little trick. Mix distilled water 50/50 with isopropyl alcohol (we keep both around the house; the first for various appliances like steam cleaners, and the second for first aid), loaded it into a spray bottle, and boom. Glass cleaner.

It works great: It doesn’t leave streaks, it cuts through grease (as I understand it the long grease molecules like to clump together, but the short alcohol molecule can get in between them and break them up), it sterilizes, it dries rapidly, it doesn’t make you want to die quite so much if you get a snoot of it in the wind, and it costs less than most commercial cleaners. So it’s a win-win-win-win-win-win. I use it to clean my monitor, TV, and touch-screens, too. It takes finger grease right off (NOTE: make sure you use a microfiber towel or one approved for screens; don’t use a paper towel which can scratch). Works for eyeglasses, too.

You’re welcome.

I learned a thing!

Wherein I learn a thing

I don’t remember how I came across this — probably looking for something I once wrote so I included my last name in the search — but by coincidence I stumbled on a mathematical term called a plait point. How about that? The reference I found was pretty complicated, but I was curious, so I kept searching. And every definition I found was pretty much like this one:

Um. OK. The best one I found is here, and, talking about ternary phase diagrams, it says,

I think this is similar to when you plot a phase diagram for water, and at some points it can be both a liquid and a solid (remember that from chem class?). It’s more complicated than that, and involves ternary plots, but in my mind this will always sum things up:

So there you go! I think. Either way, I’m naming my next pets Spinodal and Flecnodal.

Colorado

Because my home state is pretty

For some reason this reminds me of Twitter.

[Credit: Phil Plait]

Et alia

You can email me at [email protected] (I cannot promise to reply before Pluto makes a complete orbit around the Sun, however), and all my social media outlets are gathered together at about.me. Also, if you don’t already, please subscribe to this newsletter! And feel free to tell a friend or ten, too. Thanks!