Cosmos Recap: The Speed of Light Is Very Unfair To Creationists

einstein speed limitWe’re at week 4 of Cosmos: The Rebootening, and since last week was all about how Isaac Newton revolutionized physics, then for this week’s episode, it’s time (and space and gravity) for Einstein. As an English major, Yr. Dok Zoom has what you’d call a “lay understanding” of relativity and some of the crazier stuff in modern physics, which is to say that I understand it up to a point, and then I have to go lay down.

Still, Neil deGrasse Tyson is going to try his damnedest (which is very damned indeed) to pull us science ninnies along with him as we explore how time, space, gravity, and the speed of light are all connected, even if it does make our heads feel a little wibbly-wobbly. To start off with, we get a little family scene, an animation of the astronomer William Herschel (voiced by Patrick Stewart) explaining to his son John on a nighttime beach that he doesn’t believe in ghosts, but that the light we see from the stars is ghostly, in a sense — depending on the star, we may see light that began its trip to our eyes centuries ago, from stars that may be dead now, but whose death we won’t see for more centuries.

There’s a lot of awestuck cartooniform gazing. And there’s your metaphor — a telescope is a time machine, and everything we see in space is actually at a light-speed remove in the past. To illustrate, Tyson patiently explains the differences in scale — the closest star to our own sun, Proxima Centauri, is just 4 light years away… but the fastest human-made object, Voyager 1, traveling at 56,000 KM/hr, would take 80,000 years to get there. And so on, out to the Crab Nebula, some 6,500 light years away. And here it’s time for another finger-wag at Creationists: if the universe were created 6,000 to 10, 000 years ago, as they say, then we shouldn’t be able to see anything of even our own galaxy beyond the radius of that little circle below, let alone other galaxies.

Cosmos Recap: The Speed of Light Is Very Unfair To Creationists

Obviously, Dr. Tyson is simply unfamiliar with the important creation science explanation of “apparent age,” which means God created the universe 6,000 years ago, but with light from the most distant places — 13 billion light years away — already on its way to Earth so we could see it. Because God is just funny that way. Or maybe light was faster back then, shut up. And that’s the last nod Tyson gives to pseudoscience this week.

Next we’re off to the center of our own galaxy, 30,000 light years away (Tyson shows us cave paintings to add a human scale). Then ever farther out: Light from 30 million light years away left the “Sombrero Galaxy” when our ancestors lived in the trees, weighed about five kg, and had tails. And so on, out to the farthest detectable galaxy, some 13.4 billion light years distant, photographed by the Hubble Space Telescope. And if we try to look much farther, “we come to what appears to be the end of space — but actually, is the beginning of time.” I’d go to commercial there, too.

Next, gravity, and a terrifyingly cute baby trying to get herself to stay off the floor. And then we’re back at the ol’ Cosmic Calendar, with some thoughts about the age of the universe, Big Bang, the birth of galaxies, and so on — and the loopy idea that space, time, and gravity all came into being with the Big Bang. To walk us through this gravity stuff, we go back to the beach with William Herschel, and then to Newton, and Michael Faraday and later James Clark Maxwell and their discoveries about gravity and the electromagnetic force… and this is where my own lack of familiarity with the history of science left me wondering what the show was getting at, because damned if it doesn’t sound like they’re saying electromagnetic force and gravity work the same way, which doesn’t seem right to this English major. SPLAIN MORE PLEZE. Or maybe we don’t need much of an explanation, because now we get to Einstein, who’s just going to upset the whole thing anyway.

For relativity, we get a nice travelogue, with Neil riding a bike (without a helmet? Not cool, dude — remember gravity?) to illustrate the notion that everything in the universe is in motion, relative to each other — there’s no fixed place to compare speeds from. Ah, but then there’s the speed of light, which happily enough is a constant. And then things get weird, and then there’s a young woman on a motorcycle, who conveniently begins traveling near the speed of light — and then turns on her headlight. And to answer the old Steven Wright but, the light doesn’t go any faster — it’s still the speed of light. And so on. The one big rule is that the speed of light is a constant, and so weird stuff happens when you get close to it. It feels a bit rushed, but that may also be a bit of viewer fatigue — I think I had the same trouble following Theresa Russell as Marilyn Monroe character explaining relativity to Albert Einstein (Michael Emil) in the movie Insignificance:

Next, black holes. Wait, what was all that stuff about the weird stuff at light speed? Now we’re doing gravity, we’re in New York and Neil has imagined turning off the gravity and then turning it up to a whole lot, and I need to pee. This is where cutting things into commercial-TV-sized chunks gets frustrating — Cosmos jumps around enough here that I found myself just enjoying the visuals until we got back to something a little more familiar, like the collapse of a star into a superdense black hole with the mass of 400 million suns. And again, this “journey into a black hole” feels like it’s all over the place — a sampler of cool ideas, but there’s just not enough time to develop them in any systematic way. This is probably just what you get when you try to explain complex physics in the last ten minutes of a teevee show. Again, that’s probably OK — nobody’s pretending that Cosmos is a substitute for a class; it’s more of a teaser trailer, to give viewers the SensaWonder that might spur further reading. And for that, it will do, probably.

And then we get a wrapup via a return to the animated William Herschel and son John, with a note that John Herschel became an astronomer in his own right, and an early dabbler in making pictures with light — and shares credit for coining the term “photography,” which Tyson calls another form of time travel. He speculates that we may be able to somehow “capture the past in three dimensions” and see it again… And that bit of fancy gives Cosmos a moment to reimagine Tyson’s 1975 meeting with Carl Sagan. “It reminds me of those ghost stars” that Herschel saw. “You know, the ones that still shine their light upon us, long after they’re gone.” And maybe that isn’t science, exactly, but it’s pretty damn sweet.

Correction: I originally had the wrong title for the movie with that “Marilyn explains Relativity” clip. It’s Insignificance (1985). Apologies for the error! I feel no shame getting science inadvertently wrong, but IMDB is not hard.

Cosmos: A Spacetime Odyssey airs on Fox 9:00 Sundays Eastern/Pacific, 8:00 Central/Mountain. Reruns Monday on National Geographic Channel 10:00 Eastern. Episode 4 online at

TV Show: Cosmos

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  • elvigy

    Pretty spot on, imho. I thought this was the weakest episode so far though I did still enjoy it. It seemed to be kind of “all over the place” in whatever story it was trying to tell.There were at least two occasions where Tyson basically said “We’ll come back to that in a minute.” That doesn’t help keep the thread of your story going when you’re trying to explain something as non-intuitive as relativity.Plus, you’re right about the EM waves and gravity. He didn’t come right out and say it, but the implication was definitely that there are gravity waves that hold stuff together. That’s not correct as I understand it. There are gravity waves, but they are basically ripples in spacetime, not some kind of beams that hold stuff together. Someone correct me if I’ve got that wrong.Still, looking forward to next week for more stick-poking in the eyes of creationism.

    • $73376667

      There are gravity waves, but they are basically ripples in spacetime, not some kind of beams that hold stuff together. Someone correct me if I’ve got that wrong.

      Long story short: you’re getting into “gravity according to general relativity” versus “gravity according to quantum mechanics” territory. It’s an ongoing struggle.

      • Caelan Aegana

        Ah, but String Theory! Tiny vibrating loops of….somethingorother… provide the means by which quantum mechanics and relativity exist together. And there is even some small amount of data now that supports the theory. The consensus seems to converge best around a universe in which there are 13 dimensions.Math!

  • le_renard_de_velours

    Let me see if I can help. There are four fundamental forces in the Universe as far as we know: Electro-magnetism, the Weak Nuclear Force, the Strong Nuclear Force, and Gravity (Valveeta is not one of them). Don’t get hung up on the middle two. Up until now, we’ve been able to show that the further back in time we go—the closer to the big bang, and the more energy everything has—these first three forces are in fact all just aspects of something greater (something that we perceive to be separate and distinct at the lower energy universe we live in today). The trick has been trying to find evidence that gravity is also just an aspect of this single greater force (which is what theory predicts). The very recent experimental evidence that gravitational waves exist (revealed in the different way—or polarization— the radiation left over from the big bang propagated) is a step closer to uniting gravity with the other forces. I think.

    • Elaine Kurpiel

      Show off! I think.

    • Caelan Aegana

      That’s some good smartsplaining.

  • Annie Towne

    You have to go LIE down, Dok!!! By the way, thanks for including the best explanation of relativity out there! Love that movie.

    • doktorzoom

      Don’t be silly. If I wanted a lie understanding of science, I’d go to Answers in Genesis :)

      • Annie Towne

        Clever boy. Also, have you noticed that no one seems to remember the existence of the word “as”? As in, for use where “like” is not appropriate? It’s driving me crazy.

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  • $73376667

    First off, IMDB says the title of the flick is Insignifigance.Second, I’m a horrible person who didn’t watch this, but I do know that the math for the classical models of gravity and electromagnetism are very similar. Two masses (say, the earth and the moon) pull on each other, and that force between them increases with (the product of) their individual masses, and decreases with (the square of) the distance between them. The same can be said about two opposite charges: they attract each other based on (the product of) their magnitudes, and the force drops off with an increase in (the square of) the distance between them.The main differences in our day-to-day experiences of the two comes from the fact that some charges repel each other while we’ve yet to see the same behavior between two masses (or even seen proof that it shouldn’t be possible). Really big masses can be built up (like the one we’re sitting on), which cause big influences at great distances, but really big charges will attract their opposite, canceling each other out before they get anywhere near the “billions and billions” range.As for special relativity, I’ve long found it helpful to think of the speed of light (in a vacuum) to be less “speed” and more “fixed ratio.” In the model, meters aren’t fixed and seconds aren’t fixed, but the ratio between the two is. As something moves faster (relative to you), meters will squish themselves and seconds will stretch themselves in order to keep that fixed ratio of 299,792,458/1.If you really want a headache, go search for “barn pole paradox.”

    • Annie Towne

      My IMDb says “Insignificance.” What IMDb are you using? Oh wait–I see. You made a typo and Dok got *that* wrong, too! It is called Insignificance and was directed by Nicolas Roeg.

    • Swampgas_Man

      Wouldn’t that Repulsion thing be where Dark Matter comes in? And thank Odin Tyson hasn’t brought THAT up yet.

      • James Donnaught

        Dark energy. But, yeah, it’s exactly that, and I’d be shocked if it didn’t follow the inverse sqare rule.

  • bellaganj

    good to know my head wasn’t the only one wibblin and wobblin

  • gullywompr

    Some more perspective for ya, put together by Neil’s employer, the American Museum of Natural History. It’s scary how infinitesimally small we are in the vastness of the known universe, a mere dust mote lost among the [ahem] billions and billions of stars. And yet, we humans have each other, so that’s kind of comforting.

  • Elaine Kurpiel

    From going from a sweet little girl in the 50’s who imagined the sky was a great big dome that protected earth from everything to hearing the truth about that blue sky….I am very dizzy. And from trying to imagine what was around BEFORE time, I am now ready for a lie-down myself. Along with lots and lots of adult beverages. COSMOS is fantastic; I have a major crush on Neil and can’t wait to go on a spaceship with him to explore all the mysteries. Plus I totally understand a little of it.

  • Swampgas_Man

    I never understood (among other things) why the Xtianists take a metaphorical approach to the Revelation of St. John the Divine — it’s not a REAL seven-headed serpent, it’s secular-humanism or the European Common Market or something — but a LITERAL take on Genesis, even if that means that God is willing to screw w/ us. One of the defining traits of an All-Beneficent embodiment of Truth is that he CAN’T screw w/ us; even Descartes thought that. But no, God is faking fossils and even messing w/ the Speed of Light, just to punk us humans.

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  • Warpde

    Always time for learn’in Dok. learn’in at that.

  • dsmith

    You might think this would be irrefutable evidence that clearly shows the universe cannot be 6000 years old but you would be wrong. I’m sure Ken Ham has a ready explanation that insist God is not bound by the speed of light…end of argument. Next.

  • joe mac

    Riding a bike is an homage to Mr. Tompkins.