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Cascade Effect

In Earth by Brian KoberleinLeave a Comment

In the movie Gravity the driving force of the plot is a catastrophic cascade of space debris. An exploding satellite sends high speed debris into the path of other satellites, and the resulting collisions create more space debris until everything from a space shuttle to the International Space Station faces an eminent threat of destruction. Not unexpectedly, the movie portrayal of such a situation is not particularly accurate, but the risk of a debris cascade is very real. Read More

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Looking For Higher Dimensions In Gravity

In Physics by Brian Koberlein3 Comments

In the effort to unify the gravitational theory of general relativity with the quantum theory of the very small theoretical physicists explore a lot of wild ideas. One of these is the idea of higher dimensions. While we may live our lives in the three-dimensional volume of space and the temporal dimension of time, that may just be a fraction of the total number of dimensions the Universe has. Some models of string theory, for example, propose an eleven dimensional universe. These extra dimensions give string theory the mathematical space necessary to combine aspects of gravity and quantum mechanics. But if we’re trapped in the subspace of four dimensions, how could we possibly detect these higher dimensions? It turns out that gravity could provide evidence of these higher dimensions (if they exist) because gravity wouldn’t be bound to our regular space. Read More

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Manx Comet

In Solar System by Brian Koberlein1 Comment

Traditionally the difference between comets and asteroids is that comets have tails and asteroids don’t. As we’ve studied comets and asteroids, however, we’ve found the aren’t so clearly divided. It is not simply a matter of comets being icy snowballs and asteroids being dry rocks. Nor is it simply a matter of having a tail. As we’ve seen, asteroids can form tails as they enter the inner solar system. Recently we’ve seen a comet that doesn’t have a tail, and it may hold important clues to the origin of our solar system. Read More

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The Incredible Shrinking Universe

In Cosmology by Brian Koberlein8 Comments

The Universe is getting smaller. Not the observable universe, which is currently a sphere about 93 billion light years across and increasing all the time, but the much smaller portion that we could ever hope to reach. Since the Universe is expanding, our cosmic playground is shrinking all the time. Read More

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Dark Matter Is Still Not Axions

In Dark Matter by Brian Koberlein3 Comments

Dark matter is one of the big mysteries of modern cosmology. We have lots of evidence to support its existence, but the enigmatic, invisible stuff has been notoriously resistant to direct detection. Because of this, there have been lots of ideas about just what dark matter might be made of, and just how such particles might be detected. One of these ideas focuses on particles known as axions, but recent work has eliminated at least some versions of axions as a dark matter candidate. Read More

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Looking For Narnia

In Science by Brian Koberlein3 Comments

Recently I wrote a post rather critical of the EmDrive, which supposedly defies the laws of physics. As a result I’ve gotten a flurry of emails criticizing me for being closed minded, or claiming that defending the status quo for financial gain. After all, Einstein overturned Newton, so perhaps I should show some humility and be open to new ideas. It’s a common accusation when I’m critical of the electric universe model and other fringe science. There is this view that scientists are like dogmatic clergyman who refuse to look into Galileo’s telescope. In reality, the reason we’re so critical of radical scientific ideas is that we’re actually looking for Narnia. Read More