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Cosmos with Cosmos Episode 8: Journeys Through Space and Time

Are we imprisoned in both?

Posted by Casey Dreier

17-12-2013 15:00 CST

Topics: product review, astronomy and astrophysics spacecraft, fun, stars and galaxies

Cosmos with Cosmos is a weekly series that encourages people to get together and watch Cosmos with a cosmo(politan) or drink of your choice. We're posting weekly episode recaps and discussion through February of 2014. This series is made possible by members of the Planetary Society. If you like what you're reading, please consider joining the Society or donating $10 to help support projects like this in the future. To learn more about this series and find out how to watch Cosmos, see our introduction.

« Episode 7: The Backbone
of night

Episode 9: The Lives of
the Stars »

We see only a smattering of stars in our night sky. The few that we see appear to be flattened on a plane, shimmering in two dimensions instead of three. The brevity of our lives ensures that we see these stars frozen in place, not as the swarming bee hive of motion that I imagine plays out over billions of years.

These stars are so far away that we will never visit them. Even fast ships that use exotic technology we haven't invented yet will tax the limits of our endurance. We can increase our speed, but we pay a heavy price: we leave behind our former lives and perhaps even our civilization. The faster we go, the more remote we are in time from our origins. That seems to be an inescapable law of nature. Not that it really matters to us in the here and now–with our technology even the nearest stars are hopelessly distant.

We seem condemned to experience the cosmos through a sliver of space and time. We are severely limited by our own brief lifetimes and the incomprehensible distances between the stars. So how can we truly journey through either?

Cosmos episode 8, Journeys in Space and Time, provides us with a partial answer: science and our intellect allows us this journey. Despite our short lives, we've developed ways to preserve information over thousands of years, building a collective human understanding of the cosmos that hints at the richness of the natural world. We can use advanced instrumentation and clever techniques to visualize distant places and past and future events, but the journey there will be made within.

I've always felt that to be an unsatisfying answer. But we don't have much else. As Sagan says in this episode, the universe rarely accommodates our desires. Despite this somewhat dour idea, the journeys we are able to have with our intellect are reasonably satisfying.

This episode excels at showing how much of our everyday views of the cosmos are like looking upon that flat, two-dimensional sky. The sequence highlighting the stellar motion of stars in our favorite constellations remains one of my all-time favorite scenes in the series. We can't emphasize the arbitrary nature of constellations enough, in my opinion. Likewise, spinning around stars of the constellations themselves reinforces the tempting slip into an Earth-centric view of the cosmos. It's a humbling tour of the impermanence of what was once thought permanent and immutable.

The sequence with poor Vincenzo humming along near the speed of light not hold up well. This is one of the ideas I can't wait to see re-interpreted for the new series of Cosmos, which the assistance of CG providing the tools missing to the creative team in 1979. Einstein's ideas of relativity are difficult and excel at defying our commonsense notions of reality. They are difficult to explain and visualize, though I think Cosmos does a pretty good job of the first part.

And once again we see the great animation of evolution, which I believe is the fourth time we walk through the concept of evolution in this series. In line with Sagan's continuing desire to humble us, this step through of our evolution emphasizes the random nature of our adaptations. We are not an inevitable product of evolution. We are the result of a multitude of forgotten accidents, set in a sequence that would never happen again. For anyone who has read Stephen Jay Gould's great book, Wonderful Life, this concept is a familiar one. Through a process of decimation, death, coincidence, and catastrophe, humans are now able to ponder their own limitations before the immensity that surrounds us.

I'm reminded of something said by the cognitive psychologist Steven Pinker – that it's astonishing that the brains molded by blind evolution in the savannahs of Africa are able to understand even some of the patterns that underlie nature. There's no reason to expect that accidental biological adaptations millions of years ago would allow us to intellectually journey through space and time. We should be grateful for our frustrations.

Loren Eiseley, in his book The Invisible Pyramid, writes about the prisons that cage humanity: our short lifetime is one; the vast distances of space another. The study of astronomy provides us hints to the magnificence further out, but we will never personally explore those ourselves. Maybe, if we can travel close to the speed of light, but the price we pay for that is banishment – gone are the homes, families, and friends we left behind. Gone is the society that sent us. Gone, maybe, is humanity itself. Mortality still imprisons those left behind.

But the caged bird still sings. Our intellect allows us to see beyond our cell walls into the great cosmos that surrounds us. What we've learned humbles and moves us. There is beauty and mystery that calls out to us, and we can make our plans for escape even if we may never see them come to fruition. That's the optimism that drives us and that Sagan understood. The desire to explore and see beyond the horizon is a deep part of being human. That even caged within the great prison of biology and immensity, we still yearn to break free.

Stray observations

  • Cosmos uses the ocean as its visual metaphor for immensity. A nice choice given that most people have stood out on a shore gazing out into an endless sea. Note the similar slow-motion composition used at the beginning of this episode to the opening shot from episode one.

  • I was disappointed not to see the strange, sideways alligators constellation in Ursa Major mentioned this time out.

  • The whole sequence with the theoretical interstellar spacecraft reminds me of how much an optimist Sagan was. Traveling arbitrarily close to the speed of light, we can circumnavigate the universe, we just may have no Earth or Sun left to come home to. This is why I like Cosmos, "hey, let's take a break from the science and talk about cool spaceships for 10 minutes."

  • Note how Sagan always deeply ties the improvement of humanity and the exploration of the cosmos together, as if they are inseparable. The endeavors can (and should) benefit each other.

  • The Cosmos update talks about wormholes as a way to get around the speed of light problem with exploring the universe. I'm no expert in wormholes, but I think I remember reading that even if these could exist in a stable way, introducing any matter into them would cause them to collapse. We still seem bound by our cosmic speed limit.


  • "The number of stars we see is only the tiniest fraction of the number of stars that are. What we see at night is the merest smattering of the nearest stars with a few more distant bright stars thrown in for good measure. Meanwhile, the cosmos is rich beyond measure."

  • "Each creature on every world to the remotest star, owe their existence to the great coursing implacable forces nature, but also to minor happenstance."

  • "Every constellation is a single frame in a cosmic movie. But because our lives are so short, because the star patterns change so slowly, we tend not to notice its a movie."

  • "The roots of the present lie buried in the past."

  • "We see that space and time are intertwined. We cannot look out into space without looking back into time. The speed of light is very fast, but space is very empty, and the stars are very far apart."

  • "Why should we expect our common sense notions to have any reliability on a matter of this sort? Why should our experience at 10km/hr constrain the laws of nature at 300,000 km/s?"

  • "The universe is not required to be in perfect harmony with human ambition."

« Episode 7: The Backbone
of night

Episode 9: The Lives of
the Stars »

See other posts from December 2013


Or read more blog entries about: product review, astronomy and astrophysics spacecraft, fun, stars and galaxies


Jonathan Ursin: 12/18/2013 03:49 CST

I think creating a worm hole from say Earth to some planet in another solar system would require more energy than creating that planet over here. I think it has to do with entropy.

Torbj??rn Larsson: 12/18/2013 04:27 CST

The symmetry between space and time travel makes for a good plot device, and it is analogous to what astronomers, geologists and biologists see when they look back into deep time. But since Sagan did this series, a whole lot of problems have surfaced around time travel. From having time travel computing blow up the computer science Turing machine complexity scale and making all physics equally simple (which isn't observed), over destabilization of the light cone of gauge theories (but they observably work) to censorship mechanics of time travel worm holes (which is a rare no go theorem). "I'm no expert in wormholes, but I think I remember reading that even if these could exist in a stable way, introducing any matter into them would cause them to collapse." Possibly, but there is also the recent observation that quantum histories (which in the form of Feynman integrals and diagrams embodies the most generic quantum mechanics) makes only a subset of worm holes. E.g. the invention of Maldacena and Susskind, recently confirmed in parts by numeric analysis of a special case, that quantum entanglement makes wormholes that enables correlation but not causation when thrown into black holes. I.e. quantum mechanics and spacetime has yet another touchstone. Parts of entangled systems, usually understood in (approximately) flat spacetime, that are accelerated outside causal connection (say, one part thrown into a black hole, never mind that the acceleration at the event horizon of large black holes tends to zero) throws up correlative wormholes between themselves, a veritable swiss cheese. Make of it what you will. On another note I was surprised by the naive view of the protoplanetary disk and planet accretion shown. Ironic, since our own more deliberated models seems as of yet incomplete when studying exoplanets. But I don't know the history of the subject.

Torbj??rn Larsson: 12/18/2013 04:31 CST

Oh, I forgot: Entanglement also seems to be able to work over time, maybe encompassing the past in some recent gedanken models. But again, as wavefunction correlation (with or without wormholes), not time travel matter causation.

Jimi Maze: 12/18/2013 05:13 CST

For the Vancouver Olympics I was super lucky to work at the Vancouver Art Gallery which was publicly displaying notebooks by De Vinci for the first time ever. After hours, I got to really spend time with his genius. I enjoyed Carl saying that Leonardo was born in the wrong century to fly, and then Carl jumped over into the topic of super-spaceships. Center of the Milky-Way in 21 years? Sign me up! I just can't get my brain to accept time slowing down near the speed of light. Whaaat? All the explanations I've read make no sense. Too, I simply can't even accept any posibility of backwards time travel. Moving forward through time like HG Wells, yes, that makes sense, especially if time slows down near the speed of light. Thanks for holding this forum.

Mariusz Gaj: 12/20/2013 08:42 CST

Curiosity but maybe future we find out other ways than : travel near speed of light therefore especialy human body because gravitation cause by speed and Einstein theory wich explain every object gain much more weigh.

Supernaut: 03/07/2014 03:29 CST

"I just can't get my brain to accept time slowing down near the speed of light. Whaaat? All the explanations I've read make no sense. " However, it's how nature works. To see how this works, start with the postulate that the speed of light is a constant, no matter how fast you're moving. All experiments confirm this.

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