Jan 4 2013 10:00am

Exploring Carl Sagan’s Cosmos: Episode 8, “Journeys in Space and Time”

Exploring Carl Sagan's Cosmos: Episode 8, "Journeys in Space and Time"

The eighth episode of Cosmos, “Journeys in Space and Time,” returns to the style of earlier episodes with a specific topical focus: space and time (rather obviously). It’s an information-heavy installment that takes place for the most part in Tuscany, where both Leonardo Da Vinci and a young Albert Einstein did their intellectual work. The episode begins by discussing the constellations again and uses that as a springboard to discuss issues of distance, perception, and the speed of light—all considering the stars and our relationship to them. Sagan illustrates the connections between space and time by diving into a discussion of travel to the stars and the problems posed by the general theory of relativity (time dilation, etc); that leads into a set of thought experiments on time travel and speed-of-light travel. It’s also, as might be clear by now, one of the more science-fiction-friendly episodes.

The return to the informative, topic-driven style is a definite shift from the last several episodes, which have focused on big ideas. “Journeys in Space and Time” reminds me much more closely of the opening episodes of the series—its primary purpose is to deliver factual information and offer explanations of contemporary phenomena related to its subject. As such, it’s a more sedate episode than the past two, which dipped their proverbial toes into turbulent waters regarding religion and science among other contentious issues. This time around, the sharpest line is an aside about the only good use for nuclear weapons—though it’s a very good aside.

“We are drifting in a great ocean of space and time. In that ocean, the events that shape the future are working themselves out. […] The roots of the present lie buried in the past.”

Whether we realize it or not, we are always already time and space travelers. That’s the singular idea that sticks out to me in this episode—our tendency to remain unaware of the nature of our motion on the surface of the Earth on a daily basis, or our shifting through time from moment to moment. But, they’re happening regardless. It’s a thought that I find at once sobering and fascinating. The “always already” thing applies to a lot of aspects of postmodern life, but we don’t often apply it to scientific paradigms; in this case, I think it’s something good to keep in mind. Even the most wild speculation—travel to the stars, travel through time—is already happening in mild and innocuous forms in our every-day life.

It’s sort of like looking at a smartphone and actually thinking about the computing power I’m holding in the palm of my hand. Pretty big deal, and yet we notice it hardly at all.

Of course, it’s not only one line from the opener that I find neat in “Journeys in Space and Time.” Sagan, throughout the episode, illustrates the constancy of space/time as well as how we’ve come to understand their functions as natural laws via a series of thought experiments. The thought experiments themselves, and the visual effects the episode uses to work through them, are particularly memorable—and also make the occasionally complex information more easily understandable. Visual effects, thought experiments, and speculation form the core of this episode, fleshing out the theory of general relativity that stands as the main data-point. I find them all memorable and informative.

Exploring Carl Sagan's Cosmos: Episode 8, "Journeys in Space and Time"

One of my favorites is actually early in the episode: the bit where Sagan shows us, using a computer simulation, how the constellations looked far in the past and how they might appear far in the future. It’s a brief throwback to the astrology episode, but digs in much more deeply to the problems of vantage point and perception than that episode did—I love the attention paid to the various different contemporary constellations, and how each will change/has changed in a different way. Comparing the expansion of the “big dipper” into a strange, long line in the past to the future of Orion is thrilling. The birth and death of bright, hot stars within the area of Orion over millions of years is just stunning—and the way it’s represented on screen is effective, though remarkably simple, just dots of color moving on a dark background. Though we all know, now, that the stars move and that we move in relation to the stars, seeing how that change works—something we weren’t alive during and will be dead long before—is something that I won’t forget. It’s the ultimate speculation: what will the sky look like to the beings on earth in a few million years? And it’s accurately computed, too.

Those stars and their movements lead to a discussion of how we receive their light, and a few simple but evocative lines: “We see that space and time are intertwined. We cannot look out into space without looking back into time.” To look at a star, we see that star as it was seventy-five years ago, a hundred years ago, or billions of years ago—before our galaxy even formed. That’s sort of the theme of this episode, really, the way I see it: simple but overwhelming truths. The scope is almost unreal, and that’s no different now than it was in 1980 or a century ago, or further back still.

Exploring Carl Sagan's Cosmos: Episode 8, "Journeys in Space and Time"

And how could we get there, to those stars? Of course science fiction readers are familiar with just about every proposal for travel near the speed of light, or travel to the stars without it—generation ships, nuclear fusion engines, ships with scoops to power their travel, etc. The illustrations of these potential ships, as Sagan discusses them, are nostalgic and a bit dated; all the same, it’s a provocative section of the episode, because of the comparison to Da Vinci. His flying machines may not have worked, but he still started the ball rolling on the process. Which leads us, also, into time travel, and one of the best zingers of the episode: what if we could take out a major figure in the past as a time traveler—like, say, Pythagoras?

Exploring Carl Sagan's Cosmos: Episode 8, "Journeys in Space and Time"

As we noted in the last episode, Sagan is not a fan of Pythagoras. His not-so-subtle suggestion that the world would have been a vastly better place without the suppression of science Pythagoreans enacted is as amusing as it is disheartening. Superstition and greed have, certainly, set us back—with that I don’t disagree. And maybe, if we could time travel, it’d be good to create a timeline without Pythagoras. (But not in the hideous “time machine” from this episode. Good lord.)

Exploring Carl Sagan's Cosmos: Episode 8, "Journeys in Space and Time"

The one last thing I found intrigued by this episode is Sagan’s explanation of why we do thought experiments at all—because, “The universe is not required to be in perfect harmony with human ambition.” So, we can’t actually travel at light speed. But we can think about what it would mean, and what the effects would be, those familiar problems like aging slowly and coming home to dead friends and relatives, or if you’ve gone far enough, a dead planet. It’s a subtle thumbs-up for speculation, one that the “Update” about Sagan’s own novel seems to support, and it’s worth remembering.


Come back next week for episode 9, “The Lives of the Stars.”

Brit Mandelo is a writer, critic, and editor whose primary fields of interest are speculative fiction and queer literature, especially when the two coincide. She can be found on Twitter or her website.

Paul Weimer
1. PrinceJvstin
I loved the scooter relativity bits when I was young. I felt I understood time dilation in a real way, afterwards
Jeff Patterson
2. Jeff Patterson
The George Pal time machine is many things, but hideous is not one of them.
Christopher Bennett
3. ChristopherLBennett
@2: Agreed. That's the actual time machine from the 1960 motion picture, a genuine sci-fi classic, designed by MGM art director William Ferrari and production illustrator Mentor Huebner with input from George Pal. So it's literally a Ferrari time machine! That beats a DeLorean!

And it's perfect for this show. Throughout, Sagan uses the conceptual language and techniques of science fiction to teach about science -- starships, time travel, aliens, alternate histories, it's all in there. He had to invent his own starship, but here he actually managed to get a classic, iconic piece of SF cinema and use it in the show. And it was the original Time Machine, the same prop that had appeared in the movie, as restored by noted SF-memorabilia collector Bob Burns, who'd come into possession of it in the mid-'70s.

Speaking of iconic SF designers, that blueprint in the middle of the Daedalus fusion-drive starship was almost certainly drawn by future Star Trek stalwart Rick Sternbach. At least, the different blueprint and painting of it that appear in the book are his work, and the painting shows the ship at the same angle as the blueprint shown here.

It's weird that the episode is called "Journeys in Space and Time" when the corresponding chapter of the book is called "Travels in Space and Time." Maybe they changed it in the show to avoid the similarity to "Travelers' Tales."
Brit Mandelo
4. BritMandelo
@Jeff Patterson @ChristopherLBennett

Ah, I wasn't aware of the origin of the time machine. That's a nice visual shout-out, then. (Without the background knowledge, it looks remarkably gaudy and odd compared to the rest of the show's aesthetic.)
Jeff Patterson
5. Eugene R.
Rather steampunk-y, isn't that classic Time Machine? Everything old is retro again!

The intertwining of space and time, so that looking across space is looking through time, is one aspect of Relativity that never fails to drop a little awe into my soul. Simultaneity shatters just because we move about the cosmos. The fact that we cannot travel at the speed of light, yet we can think ourselves through What Would Happen If? is another aspect of existence that humbles and empowers.

As for time travelers taking out Pythagoras, well, I think that Sagan is sufficiently cautious to keep it on the level of a thought experiment, even if the capability were available, given his speculations on the ways in which History could be derailed by the actions of something so tiny as a virus (polio killing FDR being the example).

Plus, looking back at the last chapter, I do note that even Sagan finds a few nice things to mention about Pythagorean musical theory (based on observation) and anatomy studies (first recorded dissection of a human corpse). Heck, he even includes a footnote about all the fascinating thinkers alive around 600 BCE along with Pythagoras ( like Thales, Anaximander, the Pharaoh Necho, Zoroaster, Confuscius, Lao-tse, Gautama Buddha) and the resultant intellectual and spiritual ferment. It was a period so interesting that Gore Vidal wrote his novel Creation to explore the same (dare I say?) simultaneous outbursts of creativity.
Michael Burke
6. Ludon
Sagan speaks of absolutes and certainties regarding the speed of light and relativity - just as our current understanding of the subject concludes - but watching this episode always takes me back to thinking about Johannes Kepler's story in the third episode. What if the theories of relativity someday turn out to be our misinformed attempts at nesting the heavens in the perfect five regular solids. I'm not saying that I think Relativity is wrong, but this episode always leads me to a thought experiment wondering what if it is wrong. There was one line that suggests, to me, that he was aware of the remote possibility that what we know as correct today may someday be known to be wrong. He mentioned that the ships we may eventually use to go to the stars might be more different from the designs he showed us than the machines we use to fly in today are different from Da Vinci's designs.

You are right that this is a science fiction friendly episode but you missed the key reason why it is so. He asks "What if..." as he leads us to the demonstrations or thought experiments. "What if..." is the very heart of what separates science fiction from general fiction. If you break the first few chapters of a general fiction novel down into the core components you'd find that the writer is telling you that "There were these people who..." In science fiction, while the writer may not actually use the words "What if" in his setup, the reader is presented with information that leads to the questions of what if we had starships, or what if aliens made contact with us, or something simpler, but still fantastic, like what if some people have developed the ability to...

Sagan used the phrase "if we don't destroy ourselves" again. That phrase is part of why some people I know hate the show and everything Carl Sagan stood for. But, I see that phrase as being at the heart of the series. What if we don't destroy ourselves? What wonders await us out there on the cosmos?
Christopher Bennett
7. ChristopherLBennett
@6: The difference between relativity and Kepler's perfect solids is experimentation. Kepler had to abandon his ideas of cosmic perfection when the evidence proved inconsistent with them; he realized the only legitimate interpretation of observed planetary motions was that they followed "imperfect" elliptical courses. But relativity is not merely an untested idea; its predictions have been consistently verified by every experiment and observation we've used to test it for over a century. Relativity is something we make practical use of every day; the GPS software in our cars and phones works by comparing the subtle differences in the GPS satellites' clock rates resulting from their different relative motions, using the equations of relativity to compute their positions from those time discrepancies and thereby compute where the car or the phone is relative to the satellites. If relativity were wrong, GPS wouldn't work.

Of course, it's always possible that relativity is incomplete -- that there could be extraordinary circumstances where it doesn't apply. After all, relativity itself was about exposing the incompleteness of Newton's laws of motion -- laws that work fine in a certain set of conditions, but break down in other conditions. Newton's laws are now understood to be a special case of Einstein's laws, or rather an approximation that works well enough in a narrow set of conditions but doesn't apply, or at least isn't accurate enough, in other conditions. So it could be that there are extreme conditions where the equations of relativity break down -- as we know they do in something like the singularity of a black hole. The search for a unified field theory and quantum gravity is about trying to do exactly that -- find the broader, more universal laws of which relativity is an incomplete approximation.

But Newton's laws didn't stop working in everyday conditions once Einstein's laws came along. They weren't "wrong," just incomplete. Relativity is undeniably right as far as it goes. And the circumstances where it breaks down might be too extreme for humans ever to exploit.

As for "if we don't destroy ourselves," I wonder, how old are your friends who hate that line? I think people today often don't realize just how inevitable nuclear war seemed back in the '80s. It was a Sword of Damocles hovering constantly over our heads. The idea that long-term species survival was a low-probability event was hardly unique to Sagan at the time.
Jeff Patterson
8. Eugene R.
Ludon (@6): Not long after Cosmos, Dr. Sagan was involved with the publication and publicizing of the "TTAPS" (Turco, Toon, Ackerman, Pollack, Sagan) study (1983), which described the likelihood of a "nuclear winter" (decades-long cooling and disruption of weather patterns and agriculture) that would follow even a limited nuclear exchange (such as a "surgical" first strike), making even the short-term "winners" of a nuclear war into long-term losers.

So, his cautionary statements about not destroying ourselves were not just random expressions of pessimism. As ChristopherLBennett (@7) notes, a lot of us in the Eighties were troubled by the ways in which humanity might cut ourselves off from that amazing adventure, the Future. As you so rightly observe, that adventure is what lies at the heart of the series and is what Dr. Sagan was offering.
Christopher Bennett
9. ChristopherLBennett
@8: Agreed. Heck, by '80s standards, Sagan was an optimist, because he at least acknowledged the possibility that we might not destroy ourselves, and saw great potential for our future if we didn't.
Michael Burke
10. Ludon
@ ChristopherLBennett and Eugene R

As I said, I don't think relativity is wrong. Incomplete fits what I'm thinking of. After all. We are a society living at the bottom of a well that is dug into a much bigger well. We have limited experience of being outside that first well and, as of yet, no direct experience of being outside the second well. I'm talking about gravity wells, not real wells, but I think the analogy works. All the experiments that prove relativity have been conducted within those wells and all the observations have been made from within those wells. We judge the data against our knowledge and experiences. Could it be possible that we, like ground well dewlling people, will learn a lot more about our world/universe after we get out onto flat land? A society living in a ground well would be able to figure out the wind and storms, but could they determine the nature of a huricane based on their limited observations?

As I said, though, I get to thinking about this after watching this episode. The rest of the time, relativity works good enough for me.

I'm in my fifties so I know what the moods and fears were in the 60s, 70s and 80s. (As a kid, I once walked into a room and saw on the TV that cowboy riding that bomb. That and the following explosions had me too afraid to sleep for a few days. I was too young, then, to understand what Dr. Strangelove was really about.) The people I mentioned who do not like that line have a wide range of ages but they all have a strong right-wing pro-military point of view. They are people I know through my job or through art and/or aviation history orginizations, not people I call close friends. They tend to label this series and whatever else Sagan said as left-wing propaganda.
Jeff Patterson
11. Eugene R.
Ludon (@10): I suspect that Dr. Sagan would take your comments about how Cosmos gets you to thinking and speculating to be the highest of compliments.

As for the folks who dislike and dismiss his cautionary statements in Cosmos as "left-wing propaganda", well, as noted TV pundit Stephen Colbert points out, Reality has a well-known liberal bias, no?

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