gravity
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Why do Galaxies Exist?
When we look out into the sky, we see a universe filled with galaxies. Galaxies are the second-largest “structure” we’ve covered in depth on this blog. The largest so far have been galaxy clusters, which are just what the name…
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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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How Supermassive Black Holes Work
We first took a peek at supermassive black holes back in our discussion of galaxies. But now that we’ve covered a few types of active galaxies, it’s time to take a deeper dive. Okay, I guess we won’t really be…
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Is Dark Matter Real?
Here we are, people — it’s finally time to talk about dark matter! I’ve teased this subject in my last few posts. We’ve discussed how the idea originated — with observations of the rotation of galaxies. We’ve touched on the…
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How Massive is the Milky Way?
Over centuries of philosophy and research, through the times of the classical astronomers to Galileo’s observations of the Milky Way, humanity’s understanding of our universe has evolved from a simple model of the sun and planets to a vast wheel…
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How to Find a Black Hole
Okay, good question. How the heck do you find an object that emits no radiation? Astronomers find — and study — just about everything in the universe using the radiation it emits or reflects. So…what happens when the object we’re…
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Binary Stars
We know how big stars are; they range from the size of the Earth to over a thousand times the size of the sun (which is in itself over one hundred times the size of the Earth). We know they’re…
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What is Gravity, Anyway?
Q: What is gravity? (asked by Simon) Wow…great question. This is a question the greatest scientific minds have asked and tried to answer for centuries. It’s a question not even Stephen Hawking, the scientific genius of the century, has fully…
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The Battery of the Sun
Does this image look familiar? It should — these are soap bubbles. Okay, now you’re probably going to ask me how soap bubbles have anything to do with the battery of the sun. Well…you might be surprised to know that…
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Einstein: Space-Time Curvature
When you hear about “space-time,” it’s just a way to say that space is related to time. And the curvature of space-time, as Albert Einstein predicted, is the way space and time alike literally bend around a mass such as the…
