"Dark Matter May Not Exist After All But Dark Energy May" Topic

Dutch physicist argues that there is no such thing as "dark matter," but rather that gravity doesn't work quite the way we think it does, plus some really confusing stuff about quantum interactions and the "holographic model" of the Universe that's the cause of it all. link

Just so long as I am not required to believe any of this, under the pain of mortal sin, and have to explain it to a Dominican or Jesuit, I'm ok with whatever Top Scientists believe.
Errrrr…. I don't have to worry about "consensus", do I?

Pity…

With dark matter and dark energy we had science arguing for things that were only detectable by their presumed impact on the physical universe.

Rather metaphysical actually.

I never fully bought into the whole dark matter-dark energy business. It didn't make sense and so far the universe has always made sense (at least to me).

The Universe allows me to exist, and I reciprocate…

I never fully bought into the whole dark matter-dark energy business. It didn't make sense and so far the universe has always made sense (at least to me).

They are very different concepts.

Dark energy is a place holder name for the apparent energy that is accelerating the observed expansion of the universe. It doesn't make sense (so far) to anyone as far as I can tell. It's an anti-gravity force.

Dark matter is a totally different thing and is very understandable (at least in theory). It is any physical matter that doesn't radiate any energy that we can see or measure.

For instance, take the neutrino. It's existence was theoretically postulated by Pauli back in 1930. It was finally discovered in 1956. It has very little mass, no charge and doesn't interact with surrounding matter. So it is "dark". However, since we know about it, neutrinos are not considered dark matter, even if they display similar behavior.

Dark matter's existence is inferred by the movement of galaxies, gravitational lensing, red shift distortions and a host of other astronomical observations. It's easy to look up all this on the internet. The consensus, for what it's worth, is that it exists. What the scientists don't know is what dark particles make up dark matter and in what proportions.

Of course if Verlinde is correct, then the weird observations are due to our misunderstanding on how gravity works under the influence of dark energy, and we don't have to look for these dark particles. Verlinde isn't the first guy to suggest this, but it seems that these ideas don't get a lot of traction. Of course, that doesn't mean he's wrong.

Dark matter makes the math easier…

Based on what we know, "something" must be causing the effect we observe. I just have a hard time with the ratio of Dark Matter that get used.

Just so long as I am not required to believe any of this….

No, your are not required to. Who is?

I'm ok with whatever Top Scientists believe.

Well both dark matter and dark energy are postulated to explain the current observations. Dark matter just seems to have more evidence going for it right now.

If Dark Matter's existence is implied (NOT 'inferred')
by the movement of galaxies and a 'host of other
astronomical observations,' I infer that any other cause
for those phenomena has been ruled out, or am I drawing
an invalid inference ?

At this point they are playing with math, trying to find things that make the equations work and square with the observations. You can't do experiments to test this stuff at the cosmic scale, so it's all math and untestable theory. It was getting that way thirty years ago when I got my astrophysics minor and it's only gotten more esoteric since.

However, since we know about it, neutrinos are not considered dark matter …

Ah, "dark" anything is a euphemism for ignorance. Like the "dark ages"; which are only "dark" because little is known about them compared to less "dark" (better documented) ages.

Ah, "dark" anything is a euphemism for ignorance. Like the "dark ages"; which are only "dark" because little is known about them compared to less "dark" (better documented) ages.

No. More like "not emitting radiation". Therefore, there is nothing to "see". Hence dark. When you look at the next galaxy over you only "see" the mass that is sending some type of radiation towards us.

If Dark Matter's existence is implied (NOT 'inferred')
by the movement of galaxies and a 'host of other
astronomical observations,' I infer that any other cause
for those phenomena has been ruled out, or am I drawing
an invalid inference ?

They haven't been ruled out. According to Wiki:

"Although the existence of dark matter is generally accepted by most of the astronomical community, a minority of astronomers argue for various modifications of the standard laws of general relativity, such as MOND, TeVeS, and conformal gravity that attempt to account for the observations without invoking additional matter."

link

Also what is wrong with inferred?

It is interesting that the latest physicist questioning the existence of dark matter is Dutch, when the first person to infer the existence of dark matter was also a Dutchman. Back in 1922.

Dark Matter's existence is implied by the evidence.

From observation of the evidence, we infer its existence.

Thanks

So Dark Matter and Dark Energy are just a different way for scientists to say: "We don't know what's going on here."

Give me a call when they do.

So Dark Matter and Dark Energy are just a different way for scientists to say: "We don't know what's going on here."

Give me a call when they do.

Well in the middle of the 19th century, Louis Pasteur discovered infectious agents that were so small they wouldn't show up on the most powerful microscopes. At the end of the century Ivanovsky started making smaller and smaller ceramic filters that would filter everything out except for the infectious agents. The scientists didn't understand what they were dealing with, and couldn't see them, but they knew which filtrates caused which diseases. Adding the filtrate solution to susceptible cells always caused the same disease. They began assembling a collection of diseases which followed these patterns.

They gave these entities a placeholder name of "Contagium vivum fluidum", meaning a contagious living fluid. This later became simplified to "virion" and "virus".

It was in 1931 when the electron microscope was invented and a few years later the first image of a virus was made. Later it was discovered that these entities carried DNA and RNA. This was about 80 years after Pasteur's initial discoveries.

Just because they couldn't even see what the infectious agent actually was, didn't mean that the scientists "didn't know what was going on". They actually knew quite a bit and the young field of virology was already a few decades old.

I suppose the situation is the same in astronomy now. The study of Dark Matter is already about 90+ years old. Your characterization is just not quite accurate.

Oh my. I'm still wrestling with the number of angels that can dance on pin heads; when I get this straight in my head, maybe then I can spare some energy for these even MORE esoteric and incoherent concepts from today's masters of bafflegab, the eggheads in white coats. Or so says my inner peasant, more occupied with practical concerns. (Hey, if my hens ain't laying eggs, do I blame Satan or Dark Matter?)