A question about dark matter
Discussion
Dark matter is a phrase rather than something real. It has been invented to try and explain why the universe behaves the way it does. It may not even exist, because we may not really understand why the universe behaves the way it does.
If it DOES exist and it really is a form of "matter", then all matter has mass and therefore it would be affected by gravity, including the gravity generated by black holes.
If it DOES exist and it really is a form of "matter", then all matter has mass and therefore it would be affected by gravity, including the gravity generated by black holes.
Dark matter exists as a phenomenon. We can see effects so there must be something that causes such things. Giving it a name makes it look like scientists know what it is.
The fact they can't explain what it is does not mean it does not exist. It seems, from reading popular science publications, that there are many arguments about what gravity is. It must exist of course, because I fell down the stairs once, but it seems our understanding (I say our, I mean their) understanding is based, to a certain extent, on, if not faith, then hope.
I read a lot about Einstein, including both Hawking's books on the subject, yet now I have no valid opinions.
This sciency stuff can get very confusing.
During the programme on TV I wondered if dark matter might be in black holes and, if so, did the 'amount' of DM make a difference.
The fact they can't explain what it is does not mean it does not exist. It seems, from reading popular science publications, that there are many arguments about what gravity is. It must exist of course, because I fell down the stairs once, but it seems our understanding (I say our, I mean their) understanding is based, to a certain extent, on, if not faith, then hope.
I read a lot about Einstein, including both Hawking's books on the subject, yet now I have no valid opinions.
This sciency stuff can get very confusing.
During the programme on TV I wondered if dark matter might be in black holes and, if so, did the 'amount' of DM make a difference.
Put simply
Its matter we cant see.
We think its there, because calculations using current theories need it to be their to match the theory to the observable universe, but we cant find it.
As a lot of space is fairly dark, there could easily be lots of things out there not reflecting a great deal of light, hence 'Dark matter'
However Douglas Adams thought all the missing mass of the universe was actually hidden in the little foam squiggles used as packing in boxes.
Its matter we cant see.
We think its there, because calculations using current theories need it to be their to match the theory to the observable universe, but we cant find it.
As a lot of space is fairly dark, there could easily be lots of things out there not reflecting a great deal of light, hence 'Dark matter'
However Douglas Adams thought all the missing mass of the universe was actually hidden in the little foam squiggles used as packing in boxes.
Eric Mc said:
SOMETHING is causing the effects seen. However, it may not be matter. There is also something they refer to as "Dark Energy" - which is another made up phenomenon used to explain currently unexplained characteristics regarding the expansion of the universe.
What might be causing the effects that have been found is a poor understanding of gravity. Perhaps, whisper it, Einstein, like that other genius Newton, might be wrong. Or at least, his theory is not spot on. If history tells us anything - and it tells us a lot - Einstein's theory will be modified at least in the future.
One TV programme said something along the lines of; The proof of Einstein's genius was in challenging Newton. Principia was accepted as invioalble in the same way as relativity is now. Therefore, what's causing the effects could be a misunderstanding of what the effects are. That seems to cover all the objections.
The cosmological constant was mentioned in the TV programme, and in a number of articles in New Scientist. That appears to me as desperation. But, like Einstein, I've been wrong before.
It might be better if the terms matter and energy were replaced by something with less of an assumption implicit in them. How about dark teddy for the former and dark lollipop for the second?
Derek Smith said:
Eric Mc said:
SOMETHING is causing the effects seen. However, it may not be matter. There is also something they refer to as "Dark Energy" - which is another made up phenomenon used to explain currently unexplained characteristics regarding the expansion of the universe.
What might be causing the effects that have been found is a poor understanding of gravity. Perhaps, whisper it, Einstein, like that other genius Newton, might be wrong. Or at least, his theory is not spot on. If history tells us anything - and it tells us a lot - Einstein's theory will be modified at least in the future.
One TV programme said something along the lines of; The proof of Einstein's genius was in challenging Newton. Principia was accepted as invioalble in the same way as relativity is now. Therefore, what's causing the effects could be a misunderstanding of what the effects are. That seems to cover all the objections.
The cosmological constant was mentioned in the TV programme, and in a number of articles in New Scientist. That appears to me as desperation. But, like Einstein, I've been wrong before.
It might be better if the terms matter and energy were replaced by something with less of an assumption implicit in them. How about dark teddy for the former and dark lollipop for the second?
Unsurprisingly there are many theories on why galaxies behave in the way they do and why the universe is expanding quicker than it should ['DE'] and for myself DM/DE is an unsatisfying explanation but it seems to be the most consistent with observations so far. I think with the improved LHC coming back online with a mission to look for non-baryons, the new space telescopes in a few years which will refine immensely observation and the next generation LIGO upgrades we'll be able to examine this profound question with far better tools and perhaps begin to understand which theories are most likely and perhaps increase our knowledge of the universe, literally, by 95%.
And yes, DM/DE is a bit of a misnomer, but they are of themselves extremely odd in the first place!
and of course, black holes are nothing special. They are a local mass so big the gravity field is so massive not even light can escape its pull and they emit nothing but hawking radiation from the event horizon so while they are easyish to find if you know where they are, they are very difficult to spot when you dont and have to rely on their effect on light from stars being bent as they move infront of them.
As such, a huge amount of matter maybe held in black holes.
What I dont get, is why the universal expansion rate is increasing ? is the observable universe surrounded by super massive black holes
As such, a huge amount of matter maybe held in black holes.
What I dont get, is why the universal expansion rate is increasing ? is the observable universe surrounded by super massive black holes
Dark matter is deduced to exist because visible matter can't explain the mass distribution that must exist in galaxies to explain the speed at which stars are orbiting their galactic centres. So whatever DM is, it generates a gravitational field and therefore feels gravitational forces including those from black holes. No reason to think the stuff isn't falling into black holes along with everything else.
ATG said:
Dark matter is deduced to exist because visible matter can't explain the mass distribution that must exist in galaxies to explain the speed at which stars are orbiting their galactic centres. So whatever DM is, it generates a gravitational field and therefore feels gravitational forces including those from black holes. No reason to think the stuff isn't falling into black holes along with everything else.
that is my understanding of it too.at the galaxy level where we are in our milky way and the speed of rotation of the galaxy we should have spun off out into the universe - something is holding the spinning galaxy more stable than spinning forces suggest it should be.
that we can't see it is the perplexing issue, but it does form part of the fact we know what less than 20% of the universe actually is by observation.
if dark matter is matter, should it not have a charge and therefore by its volume be detectable? or is it antimatter or neutral? i have literally no idea.
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