Questions tagged [vacuum]
Questions about the properties of vacuums or perfect vacuums
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Are vacuum fluctuations that produce dark matter correlated to fluctuations that produce baryonic matter?
When cosmic inflation began vacuum energy fluctuations created matter . But were the fluctuations that created dark matter dependent on the fluctuations that created matter ? Is the ratio of dark ...
user50918
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Does the existence of hydrogen in the universe create an obscuration effect similar to the way air does at great distances?
I've had this question for a while. I understand the universe is full of "dust". I am also aware of the fact that there is an average measure of particle density in the universe.
I am ...
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If a false-vacuum event occurred, would we be able to detect it?
Ever since I read about false vacuum decay a few years ago, I've always been having thoughts about whether or not it would be detectable (the end is near!). As the vacuum bubble propagates at the ...
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Cosmic inflation was faster than light. Why would a false vacuum decay bubble only expand at the speed of light?
I have been reading about cosmic inflation: the initial step in the formation of our universe when space/time inflated to fill whatever preceded it. I understand that this inflation happened faster ...
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is there any excuse or reason why our bubble in Hawking's space-time foam theory is retained? [closed]
Hawking said that universes are like bubbles that pop into existence and pop back into the vacuum some form then immediately pop, he calls this space-time foam, our bubble doesn't seem to pop ...
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What would happen if you jumped out of a moving spacecraft? [closed]
I've watched a film where one of the characters claimed to have rapidly disembarked a moving spacecraft during a 5g burn (?!) and immediately wondered how he survived.
For example, you're on a ...
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Why does radiation not need a medium to travel?
I wanted to know how radiation moves in vacuum of space and why it doesn't need any medium ?
( Like sunlight reaching a planet )
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How do we know that vacuum is devoid of matter?
According to Wikipedia:-
Vacuum is a state with no matter particles (hence the name), and no photons.
I don't understand how can we find a part of space where there is no matter present?How is it ...
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How Essential is the Vacuum Energy to Our Present Model of the Expanding Universe? [closed]
How essential to modern cosmology is the vacuum energy concept, and what would happen to our model of the expanding universe if it were proved to be non-existent?
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Water vapour in space
This question is inspired by, but different from, What happens if an ice cube is left in space?
Mark's accepted answer says "…if you stick your ice cube out in the Oort Cloud, it'll grow: the mean ...
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How does the Earth not lose its atmosphere to space? [closed]
First, I’m genuinely interested in a working explanation for this question. It is for this reason that I am editing the question to fine-tune it. In essence, the question has remained the same.
In ...
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Does space not make sound, or can we just not hear it? [duplicate]
This is a question regarding sound waves and space.
I know that sound waves must travel through a medium "air", enter our brains, and then we can decipher what exactly the sound is.
But in space, ...
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Could vacuum energy dim standard candles?
It is assumed that particles and anti-particles pop out in vacuum (vacuum energy). Could this have an effect on the paths of photons when they interact with these particles? The amount of photons ...
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How can we hear the sound of the Sun?
Recently NASA has revealed that they have recorded the sound of Sun. They say that it produces a sound like "Om". I can't understand how they can hear it.
To the best of my knowledge, sound can't ...
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