Hubble Law
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Cosmology Demystified
That has got to be the single strangest post title I’ve ever written. Of all the whacky branches of science out there, cosmology almost takes the cake — second only, I think, to the downright trippy world of quantum mechanics.…
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Cosmology: How Do We Know?
Have you ever wondered how the heck astronomers think we know anything about cosmology? It’s a truly mind-blowing field of study, full of whacky concepts like the shape of empty space, the expansion of the universe, and dark energy. More…
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Should Expanding Space be Slowing Down?
Einstein’s theory of general relativity holds that matter curves the fabric of space-time. That’s how gravity works. In turn, that gravity shapes the fabric of the universe. Depending on how much mass is in the universe, gravitation can curve the…
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Could the Universe be Curved?
I know…that seems like a strange question to ask, doesn’t it? Out of context, it makes no sense at all. What are we even talking about? The curvature of what? Cosmology is full of questions like this — questions that…
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Cosmological Redshift Demystified
If you’ve been following my recent posts, cosmological redshift will likely be a familiar idea. I introduced it in my post on the Hubble Law. We revisited it again in our discussion of the size and brightness of galaxies. When…
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What is Cosmology?
Cosmology is the study of the universe itself: how it came to be, how it has behaved since, and why the laws of physics operate the way they do. It’s one of the strangest branches of science — second only,…
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What the Heck is a Quasar?
I’ll give you a hint: this is not an image of a quasar. This image is from a first-season Star Trek: The Original Series episode, “The Galileo Seven” — the original footage, before it was remastered (and before astronomers had…
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Galaxies Demystified
From the smallest of irregular and dwarf galaxies, to the most spectacular of spirals, to the most massive of ellipticals, there’s no denying that galaxies are incredible objects. On this blog, we’ve covered a great deal of information about galaxies.…
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How Big and Bright are Galaxies?
The brightest galaxy in our night sky is the Andromeda Galaxy, our nearest intergalactic neighbor. Hey…notice we’re talking about intergalactic neighbors now? 😀 In most of the posts on this blog, we’ve talked about interstellar neighbors, interstellar space, etc. But…
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What is the Hubble Law?
Last week, I teased you with the idea that it’s actually easy to estimate distances to galaxies. I do mean estimate — and distance indicators are still important. The Hubble Law is named for Edwin Hubble, the astronomer who was…
