News tagged with black holes

Black hole activity deduced from reflected X-rays

The supermassive black hole in the center of our galaxy, known as Sagittarius A*, is pretty quiet for a black hole. It does however flare up from time to time, when material is captured, as can be seen in ...

Oct 03, 2014
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The entropy of black holes

Yesterday I talked about black hole thermodynamics, specifically how you can write the laws of thermodynamics as laws about black holes. Central to the idea of thermodynamics is the property of entropy, which c ...

Sep 12, 2014
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Black hole thermodynamics

In the 1800s scientists studying things like heat and the behavior of low density gases developed a theory known as thermodynamics. As the name suggests, this theory describes the dynamic behavior of heat ...

Sep 10, 2014
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DRAGNs in the sky

A radio galaxy is a galaxy that emits large amounts of radio waves. They were first discovered in the 1950s, but it wasn't until the 1960s when a technique known as aperture synthesis was developed that we ...

Sep 09, 2014
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Seeking proof for the no-hair theorem

According to general relativity, a black hole has three measurable properties: mass, rotation (angular momentum), and charge. That's it. If you know those three things, you know all there is to know about ...

Sep 09, 2014
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What would it be like to fall into a black hole?

Let's say you decided to ignore some of my previous advice. You've just purchased yourself a space dragon from the Market on the Centauri Ringworld, strapped on your favorite chainmail codpiece and sonic ...

Sep 08, 2014
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Hoisting a telescope with helium

Many a child has forgotten to hold tight to the string of a helium balloon only to have it escape and rise until it disappeared in the glare of the sun. Helium balloons want to rise, but launching a balloon ...

Sep 01, 2014
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How much of the universe is black holes?

We all fear black holes, but how many of them are there out there, really? Between the stellar mass black holes and the supermassive ones, just how much of our Universe is black holes?

Jun 17, 2014
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Image: Grand swirls from Hubble

(Phys.org) —This new Hubble image shows NGC 1566, a beautiful galaxy located approximately 40 million light-years away in the constellation of Dorado (The Dolphinfish). NGC 1566 is an intermediate spiral ...

Jun 12, 2014
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