Battle of the "Cosmos," Round 3

The new Cosmos show is doing an inspirational job bringing the wonders of science to a mass audience. There was one segment of the first episode where I thought the writers went off-track, however. In an earlier post I described my concern about how that episode  depicts philosopher Giordano Bruno and his role in the discovery of the infinite universe. My column prompted a reply from Cosmos co-writer Steven Soter, along with my further thoughts.

The Spaceship of the Imagination voyages out to distant galaxies and into the mysteries of DNA in the new Cosmos. (Credit: Fox)

Now, the third and final round: Soter offers some closing commentary on the matter, which appear below.

Inevitably, this dialogue has grown increasingly detailed, focused on the thoughts and actions of men who lived more than 400 years ago. To some readers the whole discussion may seem like nitpicking (a few have said as much in the comments), but I think it is greatly important. It offers a rare opportunity to debate the evolving relationship between science and religion. It is a window into the dramatic ways our conception of the universe has changed in modern times. And I must say, it is a tribute to Soter–and the whole Cosmos project–that he is taking the time to respond and share these ideas with the whole world.

The Case for Bruno, by Steven Soter

Your suggestion that Giordano Bruno was not the first to realize that the stars are suns is mistaken. You cited his predecessor Nicolas of Cusa, who referred in one passage to “the earth, the sun, or another star.” But Cusa did not mean that the sun is another star as we understand the term. Throughout his book, he used the word “star” indifferently to refer to the earth, the moon, the sun and the planets, as was common in his time. He also distinguished them from the “fixed stars” on the surface of the eighth celestial sphere. His pre-Copernican conception of the solar system was antithetical to any notion of the stars as other suns.

You claimed that “Cosmos confusingly presents Bruno’s infinite cosmology as a physical theory of the universe”, because Bruno believed the planets and stars had souls. It is true that Bruno’s worldview was vitalistic and magical. He imagined that the Earth had a soul like the other planets. But he passionately believed in the physical reality of the planets and suns, all made of the same material elements as understood in his time. He wrote:

“. . . every one of those bodies, stars, worlds and eternal lights is composed of that which is named earth, water, air and fire . . . Those in whose composition fire predominates will be called sun, bright in itself. If water predominates, we give the name telluric body, moon or such like which shines by borrowed light . . .” Bruno was the first to recognize this fundamental distinction between stars and planets.

Bruno described a universe of  “innumerable globes like this one on which we live and grow . . . In it are an infinity of worlds similar to our own, and of the same kind.” He urged his readers to “dissolve the notion that our earth is unique . . . we may perceive the likeness of our own and of all other stars . . . the substance of the other worlds throughout the ether is even as that of our own world.” Bruno made it as clear as he could, using the rudimentary understanding of matter available in his time, that this was a physical theory of the universe.

You said that Bruno took “a big step backward by interpreting the universe more in theological than mathematical terms.” Bruno was neither a mathematician nor a scientist, and his mind was not modern by any means. But he was without doubt the first to imagine a universe resembling the one we know today.

Again, you claimed that Bruno’s cosmology “was not a correct scientific idea, nor was it even a guess as Cosmos asserts. It was a religious and philosophical statement.” However you characterize Bruno’s cosmology has no bearing on its essential correctness. Can we expect a philosopher living in a world steeped in mysticism, groping in the dark at the dawn of modern science, to see things in modern terms? Scattered among his many pages of metaphysical nonsense are nuggets of pure gold. We should be grateful for them and not expect more.

Finally you claimed that Thomas Digges, “far more than Bruno, built on the tradition of Copernicus and sought to bring more of the universe into the grasp of math and geometry.” Digges made a major contribution by extending the realm of the stars into infinite space, but he then veered back from reality by describing the stars as “the palace of felicity . . . the very court of celestial angels, devoid of grief and replenished with perfect endless joy.” He is talking about the traditional theological heaven, not the material universe.

It was Bruno who used the opening made by Copernicus to give us the first glimpse of the modern astrophysical cosmos. And that was no incremental step. It was a giant leap.

Some Closing Reflections, by Corey S. Powell

It is crucial to remember that neither Bruno nor Digges was thinking about the universe in modern terms. This is, I think, one of the most meaningful upshots of this whole conversation. There is a natural tendency to project our current conceptions onto people who lived long ago. That leads to two kinds of errors.

First, we sometimes regard ourselves as inherently smarter than those in the past, simply because we start from a place of greater understanding. Such casual arrogance overlooks the incredible efforts required by people like Bruno, Digges, and thousands–no, millions–of others who have contributed to science and to the great march of human knowledge.

Second, there is a tempting inclination to view the past as a prelude toward an inevitable present. This attitude, which has been known to afflict academics as well, is known as Whig history. I still think Cosmos fell prey to this error, in trying to make Bruno’s universe look too much like our own. Seen in clear-eyed historical context, Bruno’s views still strongly resembled the spiritually ordered Church universe of the time–not to mention the philosophies of his ancient Greek influences, Lucretius and Anaxagoras.

Soter beautifully describes Bruno as “steeped in mysticism, groping in the dark.” In that context, his conception of an infinite universe full of stars and planets was an astonishing leap of insight–but it was still a theological one more than a conceptual one. Conversely, Digges made brave moves to create a cosmological model that blended the idea of a sun-centered solar system with infinite space–but he still regarded the expanse beyond our solar system as the realm of the angels.

In truth, it took both Bruno and Digges (and their many successors) to build–slowly, incrementally, with many stumbles along the way–toward our modern understanding of the universe. My biggest concern is that, in presenting Bruno as a lone hero and a lone martyr, Cosmos missed a fabulous opportunity to convey this communal and cumulative aspect of science.

In taking time to share his thoughts here, though, Soter has filled in many of those missing details. He has also shown a generous commitment to participating in the grand process of exploring the world through science. That is one of the happiest results of this whole exchange.

For more, watch the next episode of Cosmos and then join our Cosmos Rewind Google Hangout on Tuesday, March 18, at 8PM EDT. And follow me on Twitter: @coreyspowell

CATEGORIZED UNDER: astronomy, cosmology, dark energy, dark matter, exoplanets, moons, select, solar system, space, space flight, stars, sun, Top Posts, Uncategorized

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Ripples in Space Are Evidence of Universe's Early Growth Spurt

When the universe expanded tremendously after the Big Bang, the resulting gravity waves interacted with the cosmic microwave background to produce this characteristic “B-mode” pattern. Credit: BICEP2 Collaboration

Big news in the cosmos today! Researchers from the BICEP2 south pole telescope have found ancient proof that the universe expanded tremendously after the Big Bang, a theory known as inflation. The discovery tells us (albeit indirectly) about an even earlier stage of the universe than we’ve ever before observed, and it provides crucial evidence that inflation did indeed occur. In so doing, it extends our model of the early universe from about one second after the Big Bang right back to less than 10-37 seconds after the event — a stunning leap forward (or backward, as the case may be).

To understand this, let’s back up 13.8 billion years or so, to the Big Bang. Also known as the birth of the cosmos and the origins of time and space, this burst of everything set the universe in motion. But a few niggling issues cast some doubts on the Big Bang theory — one of which was the mystery of how the universe came to be so uniformly spread out.

Enter the idea of inflation, in 1980, which suggested that just a few instants after the big moment, the universe suddenly grew enormously. This addition to the cosmic timeline explained why the universe was relatively uniform and it fit nicely with what we already knew about the universe’s earliest moments. However, cosmologists had no direct proof of inflation.

One way to prove inflation occurred, physicists thought, would be to look for gravitational waves created in its wake. These are basically ripples in the “fabric” of space-time — what the universe is made out of. Gravity is a relatively weak force, though, so we could only hope to detect the largest waves out there, caused by huge interactions like black holes colliding. Even though inflation was a relatively huge thing — it literally shaped the whole universe — the gravity waves it produced are now too weak to measure directly.

So instead, researchers were looking for the effect of inflation’s gravity waves on light. And not just any light, but the cosmic microwave background, “echoes” of light leftover from the Big Bang’s energy, created when the universe was just 380,000 years old. When this light interacted with the gravity waves, the theories said, it would have produced a distinctive pattern, called the B mode, in the light’s polarization. Such a pattern would be direct evidence that the gravity waves caused by inflation were real, and thus a key proof of inflation. And today, scientists announced they’d found it.

Assuming the finding is confirmed (and that looks likely — the team apparently spent 3 years going over their own data to make sure it was sound before coming forward with it), that’s huge news for cosmology. Direct evidence for inflation has been sought after for decades. Nature quotes Alan Guth, the main “inventor” of inflation, as saying, “This is a totally new, independent piece of cosmological evidence that the inflationary picture fits together,” and adding that the findings are “definitely” Nobel prize-worthy.

But it’s also big news for a couple of other reasons. First, in addition to being the first evidence for inflation, it’s also the first direct evidence for gravitational waves. Even though some observatories have been (and will continue!) looking for these gravitational waves, they’re still incredibly hard to find. The more data we have on these weird, space-time warping ripples, the more we’ll be able to understand the universe itself, and this is a great step in that direction. 

And the other bit of significance to this has to do with understanding gravity in the first place. It’s currently the only one of the four fundamental forces not to play nice with quantum mechanics, which explains how things work on the tiniest scales. At high temperatures (like those found shortly after the Big Bang), the other three even begin to unify into a single super-force. One of the biggest issues in physics today is figuring out how (or if) gravity fits into this picture, and the findings that gravitational waves can result from inflation, a fundamentally quantum phenomenon, suggests that quantum gravity might indeed be possible.

A glimpse into the very first milliseconds of our universe, plus bigger questions ahead — all in all, it’s a pretty good day for science.

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