Science Follows A Dark Path As It Tries To Explain The Observed Universe

It was a major fail. There I was, a naive undergraduate, waiting in my professor’s office as he spoke with an older student about some theoretical problem that wasn’t working out. After the student left I boldly asked him: “Couldn’t you just redefine everything to make it come out OK?” The withering look that followed told me all I needed to know about how really stupid my suggestion had been. Rewriting X as Y in all the equations wasn’t going to help anything.

But what are the options when a scientist faces a problem with no obvious solution?

That is the dilemma astronomers have faced over the last few decades as they took a census of cosmic matter and motion. Mapping the beautiful pinwheel arcs of spiral galaxies, they found the constituent stars moving far too fast to be explained by the galaxies’ known mass. All matter produces a gravitational force that tugs surrounding material into motion. But summing up all the matter they could see in the pinwheels left astronomers with far too small a reserve to explain how fast the galaxies were spinning. -Adam Frank (Photo credit: M.J. Jee and A. Mahdavi/NASA/ESA/CFHT/CXO)

The human mind is more amazing than the universe,” said my teenage daughter the other day. “How come?” I asked. “Well, it all really starts in our heads, doesn’t it? Like, without our minds there wouldn’t be a universe.

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Is The World An Idea?

It got me thinking. The rift between what is and what is perceived is at least as old as philosophy itself. Yes, it has something to do with the popular “if a tree falls in a forest and no one sees it, did it fall?” or “if you are not looking at the moon is it really there?” But things are a bit more complex than that. (By the way, the answer is unequivocally “yes” to both of those questions, at least to this blogger.) -Marcelo Gleiser

I thought it would be fun to start the year addressing some questions that many people have about the universe. Mind you, some of these are far from simple, true to what Milan Kundera once wrote, “the only truly serious questions are the ones that even a child can formulate.”

—Marcelo Gleiser fills us in on “What Happened Before The Big Bang? And Other Weird Cosmic Questions”

Scientists have discovered a planet not too much bigger than Earth that’s circling a distant star that’s much like our own sun. What’s more, this planet is in the “Goldilocks zone” around that star — a region that’s not too hot and not too cold. That’s the kind of place that could be home to liquid water and maybe even life.

The planet, known as Kepler-22b, is the first near-Earth-sized planet to be found smack dab in the middle of the habitable zone of a twin to our Sun.

The planet is about 2 1/2 times the size of the Earth. It orbits a little closer to its star than our planet does to our sun, and goes around once every 290 days compared with our 365. But its star is a bit cooler than our sun, says William Borucki of NASA Ames Research Center, who heads NASA’s Kepler space telescope mission, which detected this planet.

“That means that that planet, Kepler-22b, has a rather similar temperature to that of the Earth,” Borucki says. “Its surface temperature would be something like 72 Fahrenheit.”

It’s not yet clear what kind of surface the planet might have — researchers don’t know if the planet is made mostly of rock or water or something else. And don’t expect astronauts to climb on a rocket and go there anytime soon.

“The star is some 600 light-years away,” says Borucki, “so it’s not terribly far away, but not terribly close either.”

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Dark energy is here to stay. This year’s Nobel Prize in Physicswas given to a trio of astronomers who made an extraordinary discovery in 1998: that the universe not only is expanding, but it’s doing so at an accelerated rate. Nobel Prize winner physicist Frank Wilczek called this ”the most fundamentally mysterious thing in basic science.” It’s an understatement to say that when the accelerated universe was first announced, the physics and astronomy community were completely baffled. To a large extent, we still are, 13 years later. I’d like to use the blog today to put their discovery into context, exploring why dark energy is so bizarre.

—Marcelo Gleiser in 13.7: Cosmos And Culture

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Life Out There? It Depends

The essential reason why so many scientists are confident that life exists elsewhere is the regularity of the laws of physics and chemistry across the cosmos. The same laws of nature that apply in our solar system apply to galaxies billions of light-years away. They move in similar ways and shine in similar ways to galaxies nearby, allowing us to identify their distance and chemical composition with near certainty. If the same laws apply everywhere and at (mostly) every moment of the universe’s history, and if the same chemical elements are found in distant stellar systems, it’s fair to assume that the same chemical processes that led to life here on Earth some 3.5 billion years ago will reoccur in other planetary platforms. This is what could be called the argument from regularity.

But is it enough?

(13.7: Cosmos And Culture : NPR)

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Space: You Are Here poster series by Mike Gottschalk