Dark matter & dark energy?

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Jim_Baur said:
How are the detected or observed?
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Dark matter is like visible matter in that both have gravitational effects. So, dark matter can (currently) be detected not directly, but by observing its gravitational effects upon visible matter.

Dark energy, as far as I know, is simply an hypothesized energy that is thought to be responsible for the fact that the universe’s expansion is accelerating rather than decelerating or remaining constant. I don’t know if it has been directly detected.
 
Jim_Baur said:
How are the detected or observed?
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Both are observed indirectly.

1 Dark Matter. Look at a galaxy, make an estimate of the number of stars you can see and hence arrive at an estimate of the mass of the galaxy. Do the same with a second galaxy near the first. Observe the paths of two galaxies and calculate the gravitational force between them needed to keep them on their paths. Compare the calculated gravitational force with the gravitational force expected from the visible masses in the two galaxies. The difference comes from invisible matter - dark matter. We can’t see it, because it is dark, but it is there and having a gravitational effect.

2 Dark Energy. Gravity attracts, so we would expect the force of gravity to slow down the expansion of the universe. However, measurements indicate that the expansion of the universe is speeding up, not slowing down. Something must be causing the expansion to speed up. Cosmologists aren’t sure what that something is yet, but for the moment it is called Dark Energy. We can calculate the amount of energy by looking at how big the speed-up is compared to what we expected from gravity alone.

Currently roughly 75% of the universe is dark energy, 20% is dark matter and 5% is visible matter.

rossum
 
Thank!

The vast majority of the universe cannot be sensed by our five external senses, is that correct?

Thanks!
 
Jim_Baur said:
The vast majority of the universe cannot be sensed by our five external senses, is that correct?
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Yep at least according to current theories and observations. It’s always possible that missing mass or acceleration might be due to some other reasons.
 
Thank you, thank you, thank you!

Dark matter and dark energy are known to exist. However, we do not know their properties and functions, at least not clearly. Is this correct?

Is this an accurate statement, we know of their existence, but we do not know their essence?

Could they be animate beings?

Is the following correct, the fundamental parts of the atom cannot be observed directly, even with our most powerful instruments of today?

Thanks!!!
 
Jim_Baur said:
Thank you, thank you, thank you!

Dark matter and dark energy are known to exist. However, we do not know their properties and functions, at least not clearly. Is this correct?

Is this an accurate statement, we know of their existence, but we do not know their essence?

Could they be animate beings?

Is the following correct, the fundamental parts of the atom cannot be observed directly, even with our most powerful instruments of today?

Thanks!!!
Click to expand...
We don’t know what dark matter is made of, as it doesn’t interact easily with normal matter. We have detected it however, there are pictures of it, such as this one home.slac.stanford.edu/pressreleases/2006/20060821.htm .

Dark energy can’t be seen, any more than we can “see” gravity or magnetism. We can see its effects, the way it is accelerating the universe’s expansion.

We don’t know what dark matter is made of, but we know a lot of the properties it must have. For example, it must be cold, otherwise it would radiate electromagnetic radiation (such as infra-red or visible light or radiowaves, depending on the temperature). We know it doesn’t interact with normal matter easily. I think the question about existance and essence is only partly right, because of this. I hope that answers the question about properties and functions, if not could you clarify what you mean by that?

We can’t take a photograph of a proton or a neutron directly, for one thing, they are far too small. They are smaller than the wavelength of light that we could use to take an image of them. It isn’t about building better microscopes, it is simply a limitation of the laws of physics. We can never know with complete accuracy exactly where a particle is and how it is moving. The more exactly you know the position, the less exactly you know the momentum and vice versa. There is no way, other than the existance of these particles, that we can explain all the experimental results we’ve had. For me, that is every bit as good evidence as a photograph would be.

If you wish to feel an electron, put your fingers on your keyboard. What you feel as the surface is actually the outermost electrons in the atoms in your fingers being repelled by the outermost electrons in the atoms in the keyboard.

Your earlier question about us being unable to experience most of the universe with the five senses, is sort of unanswerable, as even the parts made of normal matter can only be experienced with the sense of sight. We can’t go out and touch or smell or taste astronomical objects. The only one we ever have experienced is the Moon, for the record, the rocks outside of sunlight are very cold (one astronaut was lucky not to get frostbite touching a rock he’d left in shadow before loading into the LEM, he had to move it once they’d pressurised the craft and had taken off their gloves. It took the skin off his hand) and the Moon smells like spent fireworks. The astronauts must have eaten some Moon dust on their journey home, as it got everywhere (one houseproud command module pilot made his returning commander and the lunar module pilot strip naked before he would let then into his nice clean command module, in an attempt to avoid the dust). Alas, I’m not aware that any mentioned how it tasted, and as far as we know none of them had a Moon rock as a quick snack.

Could we touch or taste dark matter? No, but there are many things in normal matter that are beyong the reach of our senses too, but we know they exist.

Could dark matter be made of animate beings? No, as we would be able to see the energy they would give off, just like humans radiate in the infra-red, as detected by the “heat-seeking” cameras used to rescue earthquake victims. Also, what could these beings possibly live on? They would need to be on a planet and that would vastly outweigh any number of animate beings on its surface.
 
starsmurf said:
We don’t know what dark matter is made of, as it doesn’t interact easily with normal matter. We have detected it however, there are pictures of it, such as this one home.slac.stanford.edu/pressreleases/2006/20060821.htm .

Dark energy can’t be seen, any more than we can “see” gravity or magnetism. We can see its effects, the way it is accelerating the universe’s expansion.

We don’t know what dark matter is made of, but we know a lot of the properties it must have. For example, it must be cold, otherwise it would radiate electromagnetic radiation (such as infra-red or visible light or radiowaves, depending on the temperature). We know it doesn’t interact with normal matter easily. I think the question about existance and essence is only partly right, because of this. I hope that answers the question about properties and functions, if not could you clarify what you mean by that?

We can’t take a photograph of a proton or a neutron directly, for one thing, they are far too small. They are smaller than the wavelength of light that we could use to take an image of them. It isn’t about building better microscopes, it is simply a limitation of the laws of physics. We can never know with complete accuracy exactly where a particle is and how it is moving. The more exactly you know the position, the less exactly you know the momentum and vice versa. There is no way, other than the existance of these particles, that we can explain all the experimental results we’ve had. For me, that is every bit as good evidence as a photograph would be.

If you wish to feel an electron, put your fingers on your keyboard. What you feel as the surface is actually the outermost electrons in the atoms in your fingers being repelled by the outermost electrons in the atoms in the keyboard.

Your earlier question about us being unable to experience most of the universe with the five senses, is sort of unanswerable, as even the parts made of normal matter can only be experienced with the sense of sight. We can’t go out and touch or smell or taste astronomical objects. The only one we ever have experienced is the Moon, for the record, the rocks outside of sunlight are very cold (one astronaut was lucky not to get frostbite touching a rock he’d left in shadow before loading into the LEM, he had to move it once they’d pressurised the craft and had taken off their gloves. It took the skin off his hand) and the Moon smells like spent fireworks. The astronauts must have eaten some Moon dust on their journey home, as it got everywhere (one houseproud command module pilot made his returning commander and the lunar module pilot strip naked before he would let then into his nice clean command module, in an attempt to avoid the dust). Alas, I’m not aware that any mentioned how it tasted, and as far as we know none of them had a Moon rock as a quick snack.

Could we touch or taste dark matter? No, but there are many things in normal matter that are beyong the reach of our senses too, but we know they exist.

Could dark matter be made of animate beings? No, as we would be able to see the energy they would give off, just like humans radiate in the infra-red, as detected by the “heat-seeking” cameras used to rescue earthquake victims. Also, what could these beings possibly live on? They would need to be on a planet and that would vastly outweigh any number of animate beings on its surface.
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Thats a nice link and I watched the animated video on it of the colliding galaxy clusters. Which reminded me of those old executive toys, you know the one with the row of steel balls where the first hits the second and knocks the last one off the row. Couldn’t the same thing be happening here; the clusters collide and ‘matteresque’ matter flies off the end at the same speed, more or less, as the clusters had been traveling.
 
Thank you, thank you, thank you!

To many this could sound really, really, really silly. However, I am going to ask it anyway.

Could dark matter and energy be animated immaterial being or beings?

Again, thanks!!!
 
You said:
Thats a nice link and I watched the animated video on it of the colliding galaxy clusters. Which reminded me of those old executive toys, you know the one with the row of steel balls where the first hits the second and knocks the last one off the row. Couldn’t the same thing be happening here; the clusters collide and ‘matteresque’ matter flies off the end at the same speed, more or less, as the clusters had been traveling.
Click to expand...
It isn’t quite like the desk toy (it is called Newton’s cradle), that works by the principle of conservation of momentum. The momentum of the first ball is passed along the other four balls, resulting in the final ball swinging out to the same height as the first ball came from.

In the colliding galactic clusters, it is the first of Newton’s three laws of motion that is the reason. This states that any moving object that is not experiencing any forces acting upon it (either a “push” or a “pull”), will move at a constant speed and in the same direction. The dark matter is not experiencing any forces acting on it, so it keeps moving at the same speed and in the same direction. The normal, visible matter is interacting and experiencing forces, this changes its speed, slowing it down. So the normal and dark matter are seperated.
 
Jim_Baur said:
Thank you, thank you, thank you!

To many this could sound really, really, really silly. However, I am going to ask it anyway.

Could dark matter and energy be animated immaterial being or beings?

Again, thanks!!!
Click to expand...
There is no such thing as a silly question.

Dark matter could not be animated, immaterial beings, as it is matter, it can’t be immaterial.

Dark energy could not be the same type of being as it is a force, it is a bit like a mirror version of gravity, in that instead of attracting masses together, it pushes them apart.

I assume from your questions on this subject that you have been wondering if the explanation of dark matter or dark energy could be the existence of God, a god or several gods. For the reasons given above, that is not the explanation.

By the way, dark matter and dark energy are two different things, simply because they are both labeled “dark” does not mean that they are somehow connected. It was dark matter that was the first to be detected, through observing the behaviour of stars in galaxies. It was called dark matter because it does not radiate any energy, unlike normal matter. When the force that is speeding up the expansion of the universe was discovered, it was nicknamed “dark energy” (even though it is nothing to do with dark matter), simply because, like dark matter, it is only felt at galactic scales.
 
Starsmurf:

I did not even consider the possibility that dark matter and energy were God, god, or gods.

That never crossed my mind.

Thanks!
 
Jim_Baur said:
Starsmurf:

I did not even consider the possibility that dark matter and energy were God, god, or gods.

That never crossed my mind.

Thanks!
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Sorry, couldn’t think what else an immaterial being would be… 😊
 
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