Marcelo Gleiser

Marcelo Gleiser is a contributor to the NPR blog 13.7: Cosmos & Culture. He is the Appleton Professor of Natural Philosophy and a professor of physics and astronomy at Dartmouth College.

Gleiser is the author of the books The Prophet and the Astronomer (Norton & Company, 2003); The Dancing Universe: From Creation Myths to the Big Bang (Dartmouth, 2005); A Tear at the Edge of Creation (Free Press, 2010); and The Island of Knowledge (Basic Books, 2014). He is a frequent presence in TV documentaries and writes often for magazines, blogs and newspapers on various aspects of science and culture.

He has authored over 100 refereed articles, is a Fellow and General Councilor of the American Physical Society and a recipient of the Presidential Faculty Fellows Award from the White House and the National Science Foundation.

It was the Roman poet Lucretius, writing around 50 B.C., who famously proclaimed reason as a tool to achieve individual freedom, as a means of breaking free from superstitions that enslave the human mind:

"This dread and darkness of the mind cannot be dispelled by the sunbeams, the shining shafts of the day, but only by an understanding of the outward form and inner workings of nature."

Given that science is believed to be about certainty, betting on a scientific idea sounds like an oxymoron.

Yet scientists bet on ideas all the time, even if mostly for jest. Of course, this only makes sense before we have any data pointing toward the correctness of the disputed hypothesis.

Well into the 21st century, it is indisputable that we know more about the universe than ever before.

So that we don't get lulled into a false sense of confidence, today I provide a short list of open questions about the cosmos, focusing only on its composition. These are some of the mysteries that keep many fundamental physicists and astronomers busy and hopeful.

Mortality is humanity's blessing and its curse.

Because we are aware of the passage of time, because we know that one day we won't be here — and neither will everyone we love (and everybody else) — we have always searched for an answer to this most painful of mysteries: Why do we die?

However painful death is, to many people immortality is not any better. Why would someone immortal want to live? Where would his or her drive come from?

The origin of life remains one of the most challenging open questions in science.

We don't know (yet) how lifeless molecules self-organized to become a living entity. We do know it happened at least here on Earth some 3.5 billion years ago, possibly earlier. Perhaps "self-organized" is the wrong word, as it gives the impression that there was some kind of intention, that life is a cosmic goal and not an accident.

Last week, I came across George Johnson's piece for The New York Times, "Beyond Energy, Matter, Time and Space," where he writes, in his usually engaging style, about two recent books with opposite viewpoints concerning what we can and cannot know of the world.