Quizzes & Puzzles3 mins ago
95 % Of The Universe
I keep reading on scientific websites that we don't know what 95% of the universe is made from?
Its all atoms isn't it?
What is this thing about anti-matter?
Can you explain it to me in laymens terms?
I just don't get that we don't know about what the universe is made of.
Its all atoms isn't it?
What is this thing about anti-matter?
Can you explain it to me in laymens terms?
I just don't get that we don't know about what the universe is made of.
Answers
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Most current theories suggest that (roughly) 68% of the universe is made up of dark energy, with a further 27% being dark matter and only 5% being normal matter.
The explanations on sites such as Wikipedia tend to be incredibly complex but the NASA website is a little easier to understand (if it's actually possible to understand an article about something which simply isn't understood at all anyway!):
https:/
The explanations on sites such as Wikipedia tend to be incredibly complex but the NASA website is a little easier to understand (if it's actually possible to understand an article about something which simply isn't understood at all anyway!):
https:/
I think you will find Nails that the vast portion of the "unexplained" is in fact dark energy.. some 68%, with a further 27% dubbed dark matter. There is a lot to understand. Perhaps I should leave it to Jim. But this site tries to help. I think that the vast portion of that dark matter is comprised by some of my ex girlfriends mind.
https:/
https:/
Not really of any help with the OP, but interesting nonetheless.
We are still discovering thing closer to home.
https:/
We are still discovering thing closer to home.
https:/
Was reading that earlier Talbot very interesting. Sorry to divert Nails.
https:/
https:/
Antimatter. A mirror of normal matter but with opposite charges to the fundamental parts.
Matter and antimatter tends to come into existence together, so there's been many discussions as to where all the antimatter has gone, at least in our local area.
If matter and antimatter meet they tend to annihilate each other.
Wikipedia probably has details.
Matter and antimatter tends to come into existence together, so there's been many discussions as to where all the antimatter has gone, at least in our local area.
If matter and antimatter meet they tend to annihilate each other.
Wikipedia probably has details.
Not Anti-matter
“Dark matter” and “dark energy”
In the question you ask, “It’s all atoms isn't it?”
Well, no.
It’s not even protons and electrons. Nor muons, pions, positrons or any other sub-atomic particle or anti-particle (the stuff of which anti-matter is made). That stuff (both matter and anti-matter) makes up only 5% of the total mass of the universe (probably).
The rest is “Dark matter” and “dark energy”
But don’t ask me what that is. I can tell you something about what it is not. But I can’t tell you what it is.
Actually, I can. It’s a fudge. A frig. A subterfuge. But one that stands up to some heavy mathematical rigour.
Back in the day (the 1990s), physicists made estimates of the total amount of matter in the universe. Once you have that number, it’s possible to work out how fast the universe should be expanding, or how that rate of expansion should be changing with time.
When you do the sums, things don’t add up. There’s not enough matter in the visible universe to make the expansion and rate of change of the expansion behave according to the observations.
It’s even more problematic than that. The universe appears to be expanding at an ever-faster rate. Gravity ought to slow the acceleration down, at the very least. However, careful observations show that there appears to be something at work that reverses the effects of gravity. Something that appears to break the known laws of physics.
This being quite a big deal, people thought long and hard about it, checked the data; did more independent experiments using different datasets and so on.
All that effort did nothing except confirm the observations of accelerating expansion.
The observationists were a bit shocked at this, so handed it over to the theoreticians to see if they could come up with an explanation that could be tested by observation.
There’s a few ways the theoreticians can explain the apparent accelerating expansion. You can propose that free space has some kind of energy through the ‘quantum foam’ of constant creation and destruction of particles and anti-particles. But when you do those sums very accurately, you end up with way too much energy.
You can invoke the controversial ‘Cosmological Constant’ in Einstein’s General Relativity, but that is so offensive (“inelegant”) to many physicists, that they came up with the idea that there is a lot of energy and matter in the universe that we can’t see or understand or explain.
This is Nobel prize-winning stuff (Physics 2011). The reason it is Nobel Prize-winning thinking is that this ‘Dark Energy” solves some other problems around the origins and development of the universe, such as the distribution of galaxies and galaxy-clusters along filaments of matter in a universe that appears to be made up mostly of huge volumes of nothingness called supervoids.
But this dark matter still doesn’t account for all the gravity-reversing weirdness.
So they came up with dark energy. Mass and energy being sort of equivalent, a large amount of energy distorts space-time in the same way that a large amount of mass does.
So it is a bit of a fudge, but a quite brilliant, Nobel-prize winning fudge.
Nails, you can ask more questions, but this is science that is still being developed; still being tested by a combination of theory and observation. Still undergoing fierce debate.
Further reading (in addition to the links above):
https:/
https:/
https:/
“Dark matter” and “dark energy”
In the question you ask, “It’s all atoms isn't it?”
Well, no.
It’s not even protons and electrons. Nor muons, pions, positrons or any other sub-atomic particle or anti-particle (the stuff of which anti-matter is made). That stuff (both matter and anti-matter) makes up only 5% of the total mass of the universe (probably).
The rest is “Dark matter” and “dark energy”
But don’t ask me what that is. I can tell you something about what it is not. But I can’t tell you what it is.
Actually, I can. It’s a fudge. A frig. A subterfuge. But one that stands up to some heavy mathematical rigour.
Back in the day (the 1990s), physicists made estimates of the total amount of matter in the universe. Once you have that number, it’s possible to work out how fast the universe should be expanding, or how that rate of expansion should be changing with time.
When you do the sums, things don’t add up. There’s not enough matter in the visible universe to make the expansion and rate of change of the expansion behave according to the observations.
It’s even more problematic than that. The universe appears to be expanding at an ever-faster rate. Gravity ought to slow the acceleration down, at the very least. However, careful observations show that there appears to be something at work that reverses the effects of gravity. Something that appears to break the known laws of physics.
This being quite a big deal, people thought long and hard about it, checked the data; did more independent experiments using different datasets and so on.
All that effort did nothing except confirm the observations of accelerating expansion.
The observationists were a bit shocked at this, so handed it over to the theoreticians to see if they could come up with an explanation that could be tested by observation.
There’s a few ways the theoreticians can explain the apparent accelerating expansion. You can propose that free space has some kind of energy through the ‘quantum foam’ of constant creation and destruction of particles and anti-particles. But when you do those sums very accurately, you end up with way too much energy.
You can invoke the controversial ‘Cosmological Constant’ in Einstein’s General Relativity, but that is so offensive (“inelegant”) to many physicists, that they came up with the idea that there is a lot of energy and matter in the universe that we can’t see or understand or explain.
This is Nobel prize-winning stuff (Physics 2011). The reason it is Nobel Prize-winning thinking is that this ‘Dark Energy” solves some other problems around the origins and development of the universe, such as the distribution of galaxies and galaxy-clusters along filaments of matter in a universe that appears to be made up mostly of huge volumes of nothingness called supervoids.
But this dark matter still doesn’t account for all the gravity-reversing weirdness.
So they came up with dark energy. Mass and energy being sort of equivalent, a large amount of energy distorts space-time in the same way that a large amount of mass does.
So it is a bit of a fudge, but a quite brilliant, Nobel-prize winning fudge.
Nails, you can ask more questions, but this is science that is still being developed; still being tested by a combination of theory and observation. Still undergoing fierce debate.
Further reading (in addition to the links above):
https:/
https:/
https:/
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