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1500 questions
13
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3 answers
Do parallel universes exist?
Do other universes like ours exist?
If they exist, how do we know that they exist when we have even not seen the ends of our own universe?
ashu
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13
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2 answers
Did a piece of Halley's comet strike the Earth 1,500 years ago?
A friend showed me an article saying that there's evidence that a piece of Halley's comet may have struck the earth about 1,500 years ago. Is anyone here aware of such evidence?
Mitchell Kaplan
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13
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4 answers
How can we avoid needing a leap year/second?
Given the Earth's current speed around the sun and current rate & axis of rotation, what is the best way to keep time to avoid a leap year? How many hours should we have in the day and days in a year would keep things balanced to not need to add or…
TheSmallestOne
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13
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3 answers
Why is the Earthian atmosphere so thin?
Venus is somewhat lighter then Earth, yet has a much thicker atmosphere. One would imagine that the following should be true:
During the formation phase, all inner planets had captured as much gas as they could hold per gravitational/thermodynamic…
oakad
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13
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3 answers
Do magnetic fields affect planetary rings?
Planetary rings seem to generally form on the ecliptic plane because of the rotation of the planet, but I was wondering what kind of effect the magnetic field of the planet might have on the ring system. Would it help keep the ring system together,…
duzzy
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13
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4 answers
Is "Main Sequence" a temporal sequence?
Stars plotted by luminosity and surface temperature fit into patterns in a Hertzsprung–Russell diagram. A rough diagonal subset of this plot is called the main sequence. Is this in any sense a temporal sequence? There's a clue in the stellar…
Bob Stein
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13
votes
6 answers
Why doesn't the sun pull the moon away from earth?
If the suns gravitational pull is strong enough to hold much larger masses in place (all the planets) and at much greater distances (all planets further away from the sun then earth) why does it not pull the moon away from earth?
TheDudeAbides
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2 answers
How do scientists know there are about 300 billion stars in a galaxy and there are about 100 billion galaxies?
Just to think about this is mind boggling. But how do scientist get these numbers? What technology/system/theory do they they use?
cosmic
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13
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3 answers
Life planets orbiting black-holes. Can/Do they really exist?
So, I watched Interstellar and if you watched it too you know that there's a planet orbiting a black-hole, they call it Miller's Planet. According to the movie, every hour on Miller's Planet is equivalent to 7 years on Earth due to time dilation…
kptlronyttcna
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13
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2 answers
How does one determine the effective temperature of a star from its spectrum?
Determining effective temperature of a star is in general a non-trivial task. Simple reason for this is that we can only study the electromagnetic radiation from a star, but not the temperature directly. The complexity is due to the fact that the…
Alexey Bobrick
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13
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2 answers
How to calculate the expected surface temperature of a planet
I'm writing a program to generate solar systems but I'm having trouble calculating the expected temperature of a planet. I have found a formula to calculate this, but I haven't been able to get a remotely correct answer out of it as it doesn't…
Eegxeta
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12
votes
1 answer
How can only 1 magnetic pole of the Sun change at a time?
I read some news stories about the current Solar maximum and the flipping of the magnetic poles. They say that one of the magnetic poles has switched polarity and the other will switch in about a month. I don't really understand magnetism, but I had…
Mitchell Kaplan
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12
votes
1 answer
What are the next planned space telescopes?
We've had hubble for two decades. Its become the most famous space telescope, and lately Kepler seems to be running for the second place. Are there any more powerful, better telescopes planned for launch in the near future?
bogen
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12
votes
2 answers
Does the cosmic microwave background change over time?
Does the cosmic microwave background pattern change over time? I would assume it is getting "cooler" as in more redshifted as time passes, but I am more interested if the pattern on the background, as depicted below changes. I would expect we…
Jonathan
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12
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1 answer
Is it possible to observe if there is traces of life on an exoplanet?
We can observe exoplanets, but is it possible with today's technology to observe if there is life as we know it on an exoplanet? What do you look for when doing this kind of observation?
bogen
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