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- Scientists know that dark matter is distinct from ordinary baryonic matter because whatever particles dark matter comprises either don't reflect, absorb or emit electromagnetic radiation or if they do interact with light, they do so incredibly weakly. This means dark matter can't be seen in traditional ways that rely on electromagnetic radiation.
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Dec 24, 2017 · How is dark matter different from ordinary (visible) matter? 1) Does dark matter consists of invisible astronomical objects like white dwarfs, black holes? 2) Has dark matter not been directly observed?
Aug 28, 2006 · By David Biello. Space & Physics. Robert Caldwell, a cosmologist at Dartmouth College, explains. Dark energy and dark matter describe proposed solutions to as yet unresolved gravitational...
May 9, 2018 · Lisa Randall. Illustration by Chris Gash. Physicists and astronomers have determined that most of the material in the universe is “dark matter”—whose existence we infer from its gravitational...
- Lisa Randall
- 2018
- Matter Or Gravity?
- Comparative Testing
- Young and Old Galaxies
- Dark Matter For The Win?
So far, dark matter has never been observed directly—hence the name. What astronomers observe in the night sky are the consequences of matter that is potentially present: bending of starlight, stars that move faster than expected, and even effects on the motion of entire galaxies. Without a doubt all of these effects are caused by gravity, but the ...
Brouwer and her colleagues selected over 259,000 isolated galaxies, for which they were able to measure the so-called 'Radial Acceleration Relation' (RAR). This RAR compares the amount of gravity expected based on the visible matter in the galaxy, to the amount of gravity that is actually present—in other words: the result shows how much 'extra' gr...
Thus it seems that, at least one dark matter model does appear to work. However, the alternative models of gravity also predict the measured RAR. A standoff, it seems—so how do we find out which model is correct? Margot Brouwer, who led the research team, continues: "Based on our tests, our original conclusion was that the two alternative gravity m...
If it turns out that extra gas cannot explain the difference between the two types of galaxies, then the results of the measurements are easier to understand in terms of dark matter particles than in terms of alternative models of gravity. But even then, the matter is not settled yet. While the measured differences are hard to explain using MOND, E...
- Science X
May 4, 2023 · Scientists know that dark matter is distinct from ordinary baryonic matter because whatever particles dark matter comprises either don't reflect, absorb or emit electromagnetic radiation...
View 10 Images. View gallery - 10 images. It sounds like science fiction to say there’s invisible, undetectable stuff all around us, and it doesn’t help that it has the spooky name of dark...
Unlike normal matter, dark matter does not interact with the electromagnetic force. This means it does not absorb, reflect or emit light, making it extremely hard to spot. In fact, researchers have been able to infer the existence of dark matter only from the gravitational effect it seems to have on visible matter.
