Introducing "Dark Matter"

[Julian of York]

You may need to go to a "GOOGLE" site to get a description of the phenomenon known as "Dark Matter" to bring you up to speed, but I would like the opinion of the board: "What do you think "Dark Matter" is?"
It will be my privelege to respond as promptly as possible.

Julian of York
Revelation 4:11 "For thou art worthy,O Lord, to receive glory and power and honor: for thou hast created all things, and for thy pleasure they are and were created."

 

[Wiccan_Child]

In the absence of evidence, I can only say, "I don't know". We know a lot about what dark matter isn't, but not that much about what it is.

 

[Julian of York]

Thank you for your reply!
The subject of Dark Matter leads one to do a lot of thinking on one's own.
Here are a few of the items that one considers:
1)Dark Matter is a hypothesis, used to explain 80-85% of the matter in the universe.
a)It is invisible in any known manner of observation,exept in a negative sense. That is, Dark Matter affects other matter (White Matter?) in such a way that it reveals itself.
b)Dark Matter is,by definition, unbelievably huge. A good reference point for this would be to "Google" up the HUBBLE pictures from their deep space surveys. Seeing these light/radiation emitting objects at extreme distances reminds us that we are viewing only the objects that are near enough to be seen, by any method we now have, and yet at most those objects are conjectured to consist of only 15% of matter in the universe.
I feel we might expect one of my favorite authors, Douglas Addams, to say that this "leaves one big whack" of matter unaccounted for.
c)Dark Matter, seen only by what it does to other things, i.e. galaxies ,Quasars, supernovae, etc., must have enourmous power, even if that "power" is only the act of existing and,therefore, impeding other "things" by mass alone.

A short word should be said about dimensions as well...
YIPE!
Perhaps in reply to some of your comments we might mention dimensional theorem.

JoY

 

[Michael]

In the absence of evidence, I can only say, "I don't know". We know a lot about what dark matter isn't, but not that much about what it is.

Oh, we know EXACTLY what it is. It's metaphysical "gap filler" for mainstream astronomers. Nobody else uses the stuff actually.

 

[Nabobalis]

In the absence of evidence, I can only say, "I don't know". We know a lot about what dark matter isn't, but not that much about what it is.

That is the only sensible answer at the moment

 

[Nabobalis]

Oh, we know EXACTLY what it is. It's metaphysical "gap filler" for mainstream astronomers. Nobody else uses the stuff actually.

Well what else would it be at the moment? We don't know what it is, it is therefore a gap filler. When we know what it is, it will cease to be a gap filler.

 

[Michael]

Thank you for your reply!
The subject of Dark Matter leads one to do a lot of thinking on one's own.
Here are a few of the items that one considers:
1)Dark Matter is a hypothesis, used to explain 80-85% of the matter in the universe.
a)It is invisible in any known manner of observation,exept in a negative sense. That is, Dark Matter affects other matter (White Matter?) in such a way that it reveals itself.

FYI, I can easily accept the fact that "dark matter" is invisible to HUMANS on Earth, with our relatively PRIMITIVE technology (compared to say in a 1000 years from now). When I was introduced to the idea 30 years ago, the term was more or less equated with MACHO forms of "dark matter". It was simply *ORDINARY* matter that was located inside of objects that are/were too small for our technology to see yet. Mainstreamers somehow jumped from assuming our technology was "limited" to assuming our technology was "perfect", and now they fixate almost EXCLUSIVELY on claims about "exotic" (never been seen in the lab) forms of "dark matter". Why? When did our technology go from "limited" to "perfect"?

I willing embrace the notion of 'missing mass' just as I embrace the concept of "unidentified flying objects". I won't however ASSUME that all unidentified flying objects come from another planet, nor will I ASSUME that all "missing mass" is NECESSARILY contained in "exotic" forms of matter. How can you demonstrate that our our limited technology has ruled out all MACHO forms of "dark matter"?

The shining - astronomers find our universe is twice as bright (Science Alert)
Galaxies Demand a Stellar Recount - NASA Jet Propulsion Laboratory
A Real Whopper: Black Hole Is Most Massive Known | Space.com

Have *ANY* of these recent findings been incorporated into standard theory and has the mainstream made ANY attempt to use that information to MINIMIZE the need for exotic brands of matter? If they have, it's news to me. I haven't seen the mainstream budge even a single percentage point in terms of their EXOTIC matter claims. It's as though they emotionally CLING to their faith in EXOTIC forms of matter, and they simply refuse to face any facts related to recent findings of NORMAL matter that we knew NOTHING about until just recently. What's up with that behavior?

 

[Wiccan_Child]

Thank you for your reply!
The subject of Dark Matter leads one to do a lot of thinking on one's own.
Here are a few of the items that one considers:
1)Dark Matter is a hypothesis, used to explain 80-85% of the matter in the universe.

While dark matter makes up about 83% of all matter, dark energy overshadows both: the universe is made of 4.6% matter, 23% dark matter, and 72% dark energy.

a)It is invisible in any known manner of observation,exept in a negative sense. That is, Dark Matter affects other matter (White Matter?) in such a way that it reveals itself.

I don't know if it's right to call that 'negative', it's more simply 'indirect'. We see dark matter in the same way we first saw Uranus, Neptune, and Pluto: through gravity. Calling it 'negative' has epistemological implications.

b)Dark Matter is,by definition, unbelievably huge.

Well, not exactly: by definition, it's dark. It just so happens that it's huge.

A good reference point for this would be to "Google" up the HUBBLE pictures from their deep space surveys. Seeing these light/radiation emitting objects at extreme distances reminds us that we are viewing only the objects that are near enough to be seen, by any method we now have, and yet at most those objects are conjectured to consist of only 15% of matter in the universe.
I feel we might expect one of my favorite authors, Douglas Addams, to say that this "leaves one big whack" of matter unaccounted for.

Douglas Adams is one of my favourite authors I wonder just how striated dark matter is? That is, does it come in flavours, like normal matter comes in elements? Are there planets of dark matter? Are there whole 'dark' solar systems, dark stars and planets?

c)Dark Matter, seen only by what it does to other things, i.e. galaxies ,Quasars, supernovae, etc., must have enourmous power, even if that "power" is only the act of existing and,therefore, impeding other "things" by mass alone.

It only interacts with matter through gravity, but I do wonder how it interacts with itself.

It strikes me as humanity's lucky glimpse into some far-flung physics we've not even come close to scratching. The Voyager probes are accelerating, more than we thought they should be. It fills me with the sense that we're walking along a precipice, slowly navigating our way down - but every now and then, we peek into the abyss, and see the enormity of how much there's left to uncover.

 

[Michael]

Douglas Adams is one of my favourite authors I wonder just how striated dark matter is? That is, does it come in flavours, like normal matter comes in elements? Are there planets of dark matter? Are there whole 'dark' solar systems, dark stars and planets?

I'm sure you realize it, but for the benefit of our readers, it should be noted that until just recently in terms of astronomy (last decade or two) *EVERY SINGLE PLANET in the universe outside of our little solar system was "dark" to us. It's only due to RECENT technology that we have actually started to "see" things, and previously "DARK" energies and dark planets have become visible to our improving technologies.

Mysterious Gamma-Rays at Galactic Center Baffle Astronomers - YouTube

There are whole chunks of the EM energy spectrum that only RECENTLY have become "visible" to our technologies. It turns out that some of your so called 'dark energy' is simply LIGHT! It's not DARK, our TECHNOLOGY is simply LIMITED.

 

[Doveaman]

We don't know what it is, it is therefore a gap filler.

When we know what it is, it will cease to be a gap filler.

We don't know what a dark buffalo is, it is therefore a dark buffalo.

When we know what a dark buffalo is, it will cease to be a dark buffalo.

 

[Nabobalis]

We don't know what a dark buffalo is, it is therefore a dark buffalo.

When we know what a dark buffalo is, it will cease to be a dark buffalo.

When we know what dark matter is, we can tell you. Right now, it is a placeholder term.

 

[Doveaman]

When we know what dark matter is, we can tell you. Right now, it is a placeholder term.

Isn't a placeholder used in place of the real thing until we figure out what the real thing is?

Do we not know that the real thing is “matter” because of its gravitational effects, and do we not know that the matter is “dark” because we cannot see its light?

This dark matter doesn’t sound like a placeholder term to me. It sounds like the real thing. It is matter, with real gravitational effects, that is presently too dark for us to see, therefore it is dark matter, not placeholder.

 

[NGC 6712]

Isn't a placeholder used in place of the real thing until we figure out what the real thing is?

Do we not know that the real thing is “matter” because of its gravitational effects, and do we not know that the matter is “dark” because we cannot see its light?

This dark matter doesn’t sound like a placeholder term to me. It sounds like the real thing. It is matter, with real gravitational effects, that is presently too dark for us to see, therefore it is dark matter, not placeholder.

It is a placeholder because it does have mass but it is not baryonic matter. But the exact form of non-baryonic matter is not known.

 

[Doveaman]

It is a placeholder because it does have mass but it is not baryonic matter.

If you know that it is non-baryonic matter that has mass then you know what it is, therefore no placeholder.

According to you, it is non-baryonic matter with mass.

But the exact form of non-baryonic matter is not known.

Not knowing what form of non-baryonic matter it is doesn't change the fact that you know it is non-baryonic matter with mass.

Even if you found out what form on non-baryonic matter it is it will still be non-baryonic matter with mass.

This is not a placeholder term used in place of what is not known. This is an explanation of what is known.

According to you, dark matter is non-baryonic matter with mass.

 

[Nabobalis]

That still doesn't go into in any detail. We don't know what non-baryonic matter it is. We have yet to discover it. Therefore the term dark matter.

 

[dbcsf]

My opinion (fast) is that dark matter is the current theoretical explanation as to why our galaxy (or most other spiral galaxies) spin in an manner which is contrary to what I otherwise would have assumed by looking at a picture of them (specifically, that the stars at the far edges of the spiral arm's are moving at a much greater than expected speed outpacing the speed of the rotation of the stars at the center).

From what I understand, we do not have any other explanations with our current level of scientific understanding which could propose any other substance other than mass (and a whole lot of it) which could explain this phenomenon.

Could be planet sized bodies which are not hot enough to emit light, could be black holes, some mixture of white dwarfs, comets, asteroids, planets,gas, black holes...who knows?

So, from what I understand, we either have to come up with a whole heck of a lot more mass, or we need another scientific breakthrough, a new way of looking at things, to explain the varying speeds of stars in our galaxy.

 

[juvenissun]

What is wrong if we say the dark matter is composed of many small black holes? Would the number of black hole be too many to be possible?

 

[Michael]

It is a placeholder because it does have mass but it is not baryonic matter. But the exact form of non-baryonic matter is not known.

How do you KNOW it's "non-baryonic" matter? I just posted references to three different observations that show we GROSSLY underestimated the amount of "normal" matter in galaxies.

 

[Wiccan_Child]

What is wrong if we say the dark matter is composed of many small black holes? Would the number of black hole be too many to be possible?

Black holes give off and absorb light. Dark matter only affects light through gravity, while black holes have other tell-tale signs.

 

[TemperateSeaIsland]

No one really knows. May be this whole non-baryonic matter hypothesis will go the same way as planet Vulcan when it was used as a placeholder for the effect seen on Mercury's orbit. May be an unknown gravitational effect.