#the science of star trek

The lovely people at Astronomy on Tap Santa Barbara have uploaded this talk I gave on the science of Star Trek at their event last July (from 1:08:46 in this video - you can also check out my former colleague Dr. Jeffrey Silverman talking about exploding stars in the first half).

A full hour-long version of my talk on the science of Star Trek, as livestreamed (over shaky hotel wifi, sorry!) from the @kiscon-blog convention in Los Angeles.

2017 is the 35th anniversary of Star Trek II: The Wrath of Khan, and to celebrate I held a screening of the movie at the Alamo Drafthouse in Austin, Texas. Here’s the post-movie talk I gave analysing the science (yes, science!) in this movie.

Spock has a tendency sometimes to make wild leaps of logic unjustified by the available information, and it’s even worse when Kirk eggs him on.

The flying pizza monsters of Operation Annihilate are pretty different to any other known lifeform. But they’re not even as different as, say, the Horta, and no one suggested that might have come from a whole other galaxy. It’s not weird to find life on other planets that evolved along a completely different pathway to humans; in fact, it’s far weirder that there are so many humanoids in the galaxy. So weird that the Preservers will be invented in season 3 to explain them.

But ok, let’s say the flying pizza monsters did originate from another galaxy. Imagine they infected a super-advanced species capable of traveling the 2.5 million light years from Andromeda, our closest galaxy. This wouldn’t really help this argument, because the same physical laws that apply here also apply in Andromeda. And even further afield than that; as far as we know, in the entire observable universe.

To get to somewhere with a whole other set of physical laws, you would have to go to a whole other universe. At least, according to some multiverse theories which explain that the reason the physical constants in our universe are so perfectly tuned to allow life is that this is just one of a multitude of universes all with different values of the key fundamental constants. Of course, if the flying pizza monsters are advanced enough to travel between universes, it’s weird that they can’t build their own ships in this one, but what do I know, I’m just a single-universe dweller.

I am by no means an expert on parasites (I had nightmares after a so-called “friend” compelled me to google the emerald wasp - don’t do this if you’re remotely squeamish). However, it seems like a parasite that drives its host so mad that it drives itself directly into the sun is kind of counter-productive. If you’re using your host for transport, you want it to retain sufficient mental faculties to take you to your desired destination. Which, in the case of the flying pizza monsters of Operation Annihilate, is definitely not the center of a burning sun.

That aside, the Enterprise makes a noble but futile attempt to rescue the infected Denevan, which proves difficult because the proximity to the sun considerably heats up the ship’s hull. Which is an excuse to talk about something really neat about stars: the corona.

The visible “surface” of the Sun (the quotes are because it’s not a solid surface, but you know what I mean) is about 5800 Kelvin (at these high temperatures Kelvin is about the same as degrees Celsius, but if you’re wedded to Fahrenheit we’re talking about 10,000 degrees F). You might think it would get hotter the closer you get to that surface, but it turns out that’s not true! Due to the weirdness of magnetic waves, there’s a region known as the corona that extends millions of miles out into space where the temperatures are around a million Kelvin/ degrees C (1.8 million degrees F).

How far from the star the Enterprise would have to be to experience hull temperatures of 1000 degrees depends on too many things to be able to calculate (what kind of star it is, the heat capacity of the ship’s hull, etc.) but suffice it to say, you probably don’t want to hang out right next to a star.

And since we’re talking about how awesome the corona is, you can see the corona of our Sun with the naked eye* during a solar eclipse. If you’re in the US, there’s one coming up this year on August 21st, and here’s a cool interactive map of where you can see it.

*Note that when I say “naked eye” I obviously mean through suitable protective eyewear such as eclipse glasses. Unless you are a Vulcan and have magical protective inner eyelids. Even then, it’s worth splurging a dollar to be safe.

The far-left star in Orion’s belt, which Kirk cites as the home of a future author, is Alnitak, also known as Zeta Orionis.

There’s some disagreement about how far away from us this star is, but it’s somewhere in the region 1000 light years. That’s a year away at warp 10, although as we’ve already learned, distance is pretty flexible in Star Trek.

The star we call Alnitak is really a system of at least three stars. The main one is a blue supergiant somewhere between 14 and 30 times the mass of our Sun (depending on how far away it really is), and it has a companion of about half that mass orbiting pretty closely, at about the orbit of Saturn. There’s then a third star - around the same size as the smaller one in the main double system - orbiting about 75 times further away.

Because these stars are so hot (more massive stars = hotter), the habitable zone is pretty far away - around 300 times further from the main star than Earth is from the Sun, or 10 times further out than Neptune. We don’t currently know of any planets in this system, but if one exists it hasn’t had much time to cool down, let alone evolve life: the larger and hotter a star is, the shorter its life, and these stars are only around 7 million years old. For comparison, we think it took around a billion years for life to arise on Earth, so we wouldn’t expect to see anything in this system. So this author wouldn’t be a species that originated on that planet, but maybe there’s a colony there on a still-cooling planet, for… reasons? Maybe his parents study planet formation and he grew up in a scientific research outpost? I’m going with that.

(ETA: Thanks anon for pointing out my typo)

Edith Keeler drops a massive hint early in City on the Edge of Forever that she’s going to turn out to be important to the future by being able to predict it.

She starts by saying that “soon, man is going to be able to harness incredible energies, maybe even the atom.” This is pretty prescient for 1930, considering the neutron would not be discovered until 1932 and the first nuclear fission reaction (splitting the atom) would not occur until 1934.

The basic theory behind extracting energy from the atom was already in existence, though; it comes from Einstein’s famous equation E = mc², published in 1905, which states that mass and energy are equivalent. The mass, m, in an atom is tiny, but the speed of light, c, is large, so you get a lot of energy from a small amount of mass.

Keeler goes on to say that this nuclear power will one day be used in spaceships. There have indeed been nuclear powered space missions, including Voyager andNew Horizons, which were heading too far from the Sun to get sufficient power from solar panels. And if we’re ever to manage interstellar travel, nuclear fusion is one of the suggestions of how that might be done.

Her further predictions that nuclear power will be used to find ways to feed the hungry and cure diseases have also, alas, not come to pass. 

Incidentally, the world’s first nuclear powered aircraft carrier was launched in 1960, just a few years before this episode was written. It was called the USS Enterprise.

Like the Guardian of Forever, I’ve been questioning Spock’s science knowledge for a while.

Mostly, though, I just wanted an excuse to gif this scene for everyday use.

City on the Edge of Forever opens with the Enterprise in orbit around something that’s setting off the fireworks in the navigation console in front of poor Sulu. Spock is unperturbed, though, because he’s chasing Science: specifically, something he calls “ripples in time.”

Now, obviously, we know these time ripples are caused by the Guardian of Forever. But it’s pretty cool that we’ve actually observed an effect like this recently from Earth: we call them ‘gravitational waves’.

Gravitational waves are a consequence of Einstein’s theory of General Relativity, which says that massive objects (by which I mean anything that has mass) distort the space around them. When dense objects like neutron stars or black holes orbit each other, these distortions radiate outwards as gravitational waves, which are essentially ripples in spacetime. Although Einstein suggested this around a hundred years ago, they were only detected for the first time by LIGO in September 2015.

When the gravitational field changes, so does the speed of time. So technically, your head - which is further from the Earth’s center of gravity - is aging faster than your feet (although the difference is tiny - something like a few billionths of a second over an average lifespan). Hence, those gravitational waves also contained “ripples in time,” albeit very, very tiny ones, because they came from far away.

So ripples in time are real! Does that mean the LIGO detection was not a pair of merging black holes as has been assumed, but actually the Guardian of Forever? I vote yes.

I’m sure every parent wishes they had the superpower of making all instruments of violence suddenly 350 degrees to make their kids drop them, right?

The answer to that is obviously no, because 350 degrees is seriously hot (even assuming the Organians work in the illogical Fahrenheit for some reason). We’re talking oven or curling iron burns. You can get an instant 1st degree burn from water at a mere 150F, so this seems excessive. Of course, like all good superadvanced aliens, the Organians have evolved beyond the inconvenience of bodies, so I guess they’ve forgotten about skin and nerves and stuff.

The part I’m really concerned about is even their bodies are suddenly 350 degrees? I assume this is some sort of magic that radiates outwards without affecting their skin, because otherwise Bones is going to be dealing with some very messy all-over 3rd degree burns.

I’m also very curious about the definition of “instruments of violence” and the necessity of making this affect the entire planet. It’s even shown to affect the Enterprise in orbit around the planet. So somewhere, was someone idly chopping vegetables for dinner when they suddenly received serious burns from their kitchen knife?

The Organians may be super-advanced, but they’re also assholes.

As Kirk and Spock visit the Galactic Ren Faire, Spock gets really into his innocent-Vulcan-trader character by saying something no scientist ever would: estimating a number to five significant figures with no stated uncertainties, and adding “approximately.”

In the middle of their slightly embarrassing pissing contest, Kirk unwittingly (I’m fairly sure it’s unwitting) makes a very good point that really underlines my biggest problem with militarised science fiction: the universe is big.

I guesstimated back in Balance of Terror that there are probably somewhere in the region of 4 billion Earth-like, habitable planets in our galaxy alone. I find it hard to believe that with such a vast number of options to choose from, planets and resources are at such a premium that it’s necessary to fight over specific ones.

That said, there’s plenty of room on Earth for all the humans, and that hasn’t stopped us fighting over little bits of it, so perhaps I’ve just answered my own question: humanoids suck in every century.

Kudos to MC SuperDuperNova (aka Jeff) for spotting that the planet in This Side of Paradise is orbiting Mira (aka Omicron Ceti). This is a really neat star, and also very weird.

Mira is about the same mass as the Sun and so would once have looked very similar, but it’s approaching the end of its life and has swollen up into a red giant. It’s not impossible for a red giant to host habitable planets, but it’s complicated. Back when it was a regular (what we call ‘main sequence’) star like the Sun, its habitable planet(s) would have been at around the same distance the Earth is from the Sun; this is where the temperature is exactly right to have liquid water. As the star swelled up, though, a planet at that distance would become far too hot (in fact, it might even be swallowed by the star), and you would need to be at about twice the distance of Pluto in order to be habitable.

As it happens, there was no life on Omicron Ceti III before the colonists in this episode arrived a few years ago, so it is entirely possible that this was once a frozen planet on the edge of a solar system that has only recently (in astronomical terms) become habitable. It’s juuuuust plausible for the star to have been at this stage for long enough for life to evolve, so the fact that there’s abundant plant life when the colonists show up just scrapes a pass.

So far, so good… but there’s more. Mira isn’t just a red giant, it pulsates. This means it grows brighter and dimmer with time, and it’s brightness changes by a factor of about 1,000. Each cycle is just under a year, so the colonists will have experienced several. That’s one hell of a seasonal variation!

Another complicating factor with Mira is that it has a companion star. Its companion is a white dwarf, the hot core left over after the outer layers of a red giant evaporate into space. That white dwarf companion (known as Mira B) is a little closer to the star than the planet needs to be, which raises questions about how stable the orbit of the planet can be. Mira B is also stealing material from the red giant: you can see this in the top left image, which was taken with the x-ray telescope Chandra (the artist’s illustration on the top right shows what we think is going on).

And it gets even weirder! Mira is zooming through space at almost 300,000 miles per hour. That’s not a problem (the planets would be moving at the same rate), but as it zooms along it’s leaving a tail of its outer atmosphere that’s visible in ultraviolet light and stretches for around 13,000 light years. The lower image shows this tail as seen by GALEX, a space telescope that observes ultraviolet light, in 2007.

Overall, I’m unconvinced this star would host a habitable planet, let alone one that could be described as “paradise.” But if you’re looking for somewhere to put a super-weird planet that suffers from mysterious “Berthold rays”? Sure, why not.

My life has been derailed by health issues over the last few months, but I’m pleased to finally be able to share this talk I gave at the Alamo Drafthouse screening of Star Trek (2009) for Trek’s 50th anniversary.

Surprisingly, I have some good things to say about the science in this movie! And maybe one or two minor quibbles…

I’ve given four public talks on the science of Star Trek over the last month for the 50th anniversary. One of them, from Astronomy on Tap ATX, is now available on YouTube, so here is a quick 20-minute summary of 50 years of science in Star Trek.