Questions tagged [space]
The near-vacuum extending between the planets and stars, containing small amounts of gas and dust. Also called outer space to refer to the physical universe beyond the Earth's atmosphere.
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Does the SailBeam concept violate conservation of etendue?
SailBeam is a proposed method of spacecraft propulsion based on laser-driven sails. The SailBeam laser pushes on a series of "microsails," each sail having around 0.1m radius. Each microsail ...
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Are there closed simply connected 2D manifolds that do not require a third dimension?
In the context of cosmology, space is commonly described as potentially having a global curvature that can be positive, zero, or negative. A common way that textbooks describe positive curvature is by ...
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Turbulence in flow of spacetime
Why is there no turbulence in the flow of spacetime around black holes? How does this flow differ from typical physical flows described by the Navier-Stokes equations with friction, or even the ...
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What will happen to the Milky Ways nucleus when Andromeda collides with the Milky Way?
Andromeda will collide with the Milky Way in about 4.5 billion years. What I want to know is, will the Milky Ways nucleus reactivate when we collide with Andromeda, will it combine with Andromeda's ...
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How can a triangle have a sum exceeding 180 degrees in a curved space?
I was reading a book to understand the limits of the euclidean space I understand that lines that are parallel in 2d can meet in 3d space like on a sphere but it is hard to imagine or fathom why the ...
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Is there a galactic "goldilocks" region in the galaxy
I'm wondering if there's a region where the star density in the galaxy create the conditions in outer space where the galactic temperature is between 0 and 200°F. This may cause a ring shaped where ...
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Efficiency Loss of Rocket Engine in a Vacuum Due to Underexpansion
A rocket engine in the vacuum will experience efficiency loss due to under-expansion in which the pressure of the exhaust is greater than the ambient pressure, which in a vacuum is near zero.
How ...
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Is spatial distance objective?
While reading some papers on Einstein's theory of relativity, seeing how the flow of time is not the same for everyone, a doubt occurred to me:
Let us imagine a photon moving in a well-defined space ...
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Could a fish swim out of a sphere of water in a zero-gravity environment?
Can a fish swim out of a sphere of water in a zero-gravity environment?
I am going to state some assumptions.
We assume the sphere of water is not affected by any thermal properties of its zero-...
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How smooth must a surface be to produce specular reflection, and do Lunar boot prints meet this standard?
Question: How smooth must a surface be to produce specular reflection, and do Lunar boot prints meet this standard?
A recent post on Space Exploration asked why footprints on the moon displayed ...
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"Space is a medium of gravity but not of electromagnetism"...how does this work?
It is undeniable that spacetime is medium for gravitational waves propagation as first confirmed by LIGO experiment having elasticity and compressability.
However, for electromagnetism space has the ...
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Questions about CCD sensors and low temperatures?
The dynamic range of a CCD sensor increases at low temp, they say. What does this mean, and why does it happen?
Near saturation a CCD sensor begins to exhibit non-linear characteristics. Is this in ...
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What happens when you bump into a black hole while space traveling (not at/through event horizon)? [closed]
Let's assume a galaxy has super massive black hole in it's center. We can't see what's inside the black hole because light cannot escape from it.
In simple terms, black hole is a hole in the space and ...
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Is matter in space, or independent from it, but interracts?
Considering the "hierarchy" of the Universe, or the world in a broad sense, as I understand it consists of matter, matter consists of "substance" (fermions), and fields and so on.
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What could a year long journey look like, while traveling near the speed of light, through the lens of that telescope?
Hypothetically speaking if you had a satellite going near the speed of light in a straight line towards an exoplanet light years away and that satellite had a telescope pointed at the surface of an ...
