Where do you get your information? The only thing that matters is what's published in scientific journals.
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There is mounting evidence that filaments of dark matter connect galaxies and galactic clusters together like a vast, cosmic web.
It is conjectured that hydrogen flows along these strands, feeding into the galaxies.
In 2021, astronomers directly imaged the faint emission from diffuse hydrogen in intergalactic space.
They concluded that the Lyman-alpha (Ly-α) hydrogen emission line overdense regions are expected to be populated by dark matter halos with masses around 10^11.3 solar masses.
https://www.aanda.org/articles/aa/full_html/2021/03/aa39887-20/aa39887-20.html
It is conjectured that hydrogen flows along these strands, feeding into the galaxies.
In 2021, astronomers directly imaged the faint emission from diffuse hydrogen in intergalactic space.
They concluded that the Lyman-alpha (Ly-α) hydrogen emission line overdense regions are expected to be populated by dark matter halos with masses around 10^11.3 solar masses.
https://www.aanda.org/articles/aa/full_html/2021/03/aa39887-20/aa39887-20.html
It would appear that 95 percent of the universe is 'missing'.
As long as the mysteries of dark matter and dark energy remain, the work of physics will not be complete.
However, understanding 5% of a subject as vast as the Universe is, in itself, a wonderful achievement.
As Isacc Newton put it: “What we know is a drop, what we don't know is an ocean.”
As long as the mysteries of dark matter and dark energy remain, the work of physics will not be complete.
However, understanding 5% of a subject as vast as the Universe is, in itself, a wonderful achievement.
As Isacc Newton put it: “What we know is a drop, what we don't know is an ocean.”
Observations of galaxy cluster 1E0657-56, aka the 'bullet cluster', suggest that the separation of normal matter from dark matter is taking place. The bullet cluster was formed after the collision of two large clusters of galaxies.
In the Chandra X-ray telescope image attached, hot gas is seen as two pink clumps and contains most of the "normal" matter in the colliding clusters. The bullet shape of the hot gas on the right gives the galactic cluster its name. The blue areas in this image show where astronomers detect most of the mass in the clusters, which they suggest comprises of dark matter.
The research team postulate that the hot gas in this collision was slowed by a drag force, similar to air resistance. In contrast, the dark matter was not slowed by the impact, because it does not interact directly with itself or the gas except through gravity. This produced the separation of the dark and normal matter.
In the Chandra X-ray telescope image attached, hot gas is seen as two pink clumps and contains most of the "normal" matter in the colliding clusters. The bullet shape of the hot gas on the right gives the galactic cluster its name. The blue areas in this image show where astronomers detect most of the mass in the clusters, which they suggest comprises of dark matter.
The research team postulate that the hot gas in this collision was slowed by a drag force, similar to air resistance. In contrast, the dark matter was not slowed by the impact, because it does not interact directly with itself or the gas except through gravity. This produced the separation of the dark and normal matter.
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I took a look at this and it does remind me of relativity. Relativity explains the nonlinear increase of momentum at relativistic velocities, does it not? Momentum is a property of mass. Gravitational force is a property of mass as well. This MOND describes an increase of gravitational force with increasing accelerations, does it not? I hope I'm understanding it.
Cracking this case of observed vs predicted rotation curves would sure answer a few questions.
We tend to think of dark matter as some kind of modern invention, but evidence for its existence extends back as far as 1933 when Swiss astronomer Fritz Zwicky noticed something odd about the Coma cluster of galaxies. The stars on the edges of the cluster were revolving much faster than could be explained by his estimate of the mass of visible matter in the cluster. He calculated that there was about four hundred times more mass in the Corona cluster than could be accounted for.
I haven't fully looked into MOND because, as I have said, dark matter is the more promising candidate.
However, I believe your brief summarisation is correct.
These are the kinds of observations that lead to breakthroughs.
The crackpot isn't intended for you. We've entered dingbat territory, again, with moon landing denial, vaccine paranoia, etc.
The irony kills me that this stuff is posted on a site frequented by engineers that actually use some of the technology being denied.
Fritz Zwicky's 1933 observations were followed in 1939 by those of Dutch astronomer Jan Oort who showed that the distribution of mass in a certain elliptical galaxy differed from the distribution of the light emited by the visible matter within the galaxy.
Neither of these observations was taken seriously till 1970 when American astronomer Vera Rubin mapped out the rotational velocities of the stars in the Andromeda galaxy and found that the outer stars were moving so fast that they should be flying off into intergalactic space. The only explanation was that the stars were being held in place by the gravitational influence of invisible matter.
Yes, MOND is a modification of standard Newtonian dynamics and general relativity.
I agree.
Both MOND and dark matter may sound like science fiction, but only by exploring such hypotheses do scientists hope to come closer to understanding the nature of the Universe.
Any hypothesis is merely a starting point for further investigation.