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1500 questions
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Do mixed type remnant collisions produce anything interesting?
The recent detection of a binary neutron star inspiraling and colliding raises an interesting question in my mind. Type Ia supernovae are believed to be caused by white dwarf/regular star pairs and/or white dwarf pairs. Short gamma ray bursts are…
Sean Lake
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How can the Sun burn without oxygen?
How does the Sun burn without oxygen?
It might not be burning but a big part of the society speaks of it as burning.
So how does it work?
NullReference
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What would it feel like to be orbiting near a merging black hole?
The recent 4th discovery of gravitational waves where the black hole masses were 31 and 25 times the mass of the sun, and they released 3 solar masses of energy as gravitational waves, made me wonder what would it feel like to be orbiting this…
joseph.hainline
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How precise are the observational measurements for the speed of gravity?
General Relativity says that gravity moves at the speed of c. How precise are the measurements?
Zamicol
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Why is Mars considered the outer edge of the "goldilocks zone"?
In both books and documentaries I often see the Goldilocks Zone as described between Venus and Mars with the Earth "just right." This seems sort of ill thought out to me, because it assumes that Venus' atmosphere comes from its distance from the sun…
simontemplar
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Gas giants and seismology
A long time ago I read a very interesting way of studying the sun's internal structure via sound waves. This new field of study, probability already known here, is called helioseismology.
How much can we learn from gas giants by "listening" to sound…
Vyndicu
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Are satellites orbiting around earth visible to the naked eye?
I was just lying under the sky trying to possibly see some meteorites, unfortunately never seeing any I might add, but I saw three objects all moving at about the same speed( all at different times). They were far too faint and small to be aircraft…
TheBluegrassMathematician
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What was the "brilliant new star in Aquila" on June 8, 1918, just after the solar eclipse?
This great answer about the US Naval Observatory's $3,500 expedition to Baker City Oregon to observe the June 8, 1918 total solar eclipse links to the January 1919 Popular Astronomy article about the expedition. The article notes on page 6 the…
uhoh
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How big a dish do I need for radio astronomy?
I've recently become interested in the idea of building my own small-scale radio telescope. A quick online search finds a few instructions on how to build this using a satellite dish. These suggest a dish of radius of around 1 metre, but the only…
Beta Decay
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Could the Earth survive a red giant Sun?
So my question is that, is not a lie that we are flying away from the sun slowly, that is increasing by time because the sun loss mass, so when the scientist usually talk that we will get swallow by Sun when it get red giant, do they count on this?…
Alberto Martínez
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Is there a better explanation of Hawking radiation?
I'm writing a piece on Hawking radiation, and find I have something of a problem. The "given" explanation which I find on Wikipedia and elsewhere is unsatisfactory:
"Physical insight into the process may be gained by imagining that…
John Duffield
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Why black holes have positive energy?
How could Hawking get the conclusion "[...] and black holes have positive energy. That’s why empty space is stable. Bodies such as stars or black holes cannot just appear out of nothing. But a whole universe can."? It would make sense to me, if a…
lu yuan
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How the position of this black hole known?
How do scientists know the positions of black holes?
Observe the highlighted area in the image:
Harsh Kumar
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Can you see the starting and the ending of a light beam passing in the distance?
This question arose to me when I saw a SciFi movie where they shot with laser guns and you clearly could see the dashes of light beams travelling from the shooter to the target. Nonsense of course, reality is much more boring.
But I wondered if you…
Pathfinder
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Is the wind's intensity on Mars similar to Earth?
I've read that in Mars' poles, the winds can be as fast as 400 km/h, when the poles are exposed to sunlight because the frozen $CO_2$ sublimes. I know that the Martian atmosphere is much thinner than Earth's atmosphere.
So, by knowing the wind…
Pablo
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