Astronomers have discovered a huge filament of hot gas bridging four galaxy clusters. At 10 times as massive as our galaxy, the thread could contain some of the universe's 'missing' matter, addressing a decades-long mystery.
It’s not dark matter, it’s normal (baryonic) matter that we hadn’t found a way to see yet. Dark matter doesn’t interact with light at all, so we only detect its gravitational effects.
In astronomy, dark matter is an invisible and hypothetical form of matter that does not interact with light or other electromagnetic radiation. Dark matter is implied by gravitational effects that cannot be explained by general relativity unless more matter is present than can be observed.
Dark matter was posited, in part, because we couldn’t explain how galaxies don’t fling apart due to the rotational forces. Since we observed the effects, but couldn’t see nor detect the cause, we thought something should be there that doesn’t interact with light. However, these findings and that of Caltech show that there isn’t a need for a theoretical matter as normal matter at very low densities will do just fine.
Dark energy is the force believed to drive the expansion of the universe. The distance between galaxies continues to grow and the doesn’t seem to be a good explanation for it yet. It’s the “X” variable acting as a placeholder until that’s answered. Or at least that is my understanding.
After reading the wikipedia article, that basic understanding of it might be correct, but I’m not an astrophysicist.
Dark energy is basically a placeholder name. We have no direct evidence of it, but we indirectly know it has to exist due to other gravitational effects. As soon as we understand what it is the term “dark energy” will probably be replaced with whatever we discover to cause the observables currently attributed to dark energy, as dark energy is basically scientist for “no fucking idea why we observe these effects, but we do observe them”. I’m not currently an astrophysicist but I spent time during undergrad as a research assistant on a LIGO project
It’s not dark matter, it’s normal (baryonic) matter that we hadn’t found a way to see yet. Dark matter doesn’t interact with light at all, so we only detect its gravitational effects.
wikipedia
Dark matter was posited, in part, because we couldn’t explain how galaxies don’t fling apart due to the rotational forces. Since we observed the effects, but couldn’t see nor detect the cause, we thought something should be there that doesn’t interact with light. However, these findings and that of Caltech show that there isn’t a need for a theoretical matter as normal matter at very low densities will do just fine.
So it’s unrelated to this?
Which leads us back to the question, dafuq is dark energy?
Dark energy is the force believed to drive the expansion of the universe. The distance between galaxies continues to grow and the doesn’t seem to be a good explanation for it yet. It’s the “X” variable acting as a placeholder until that’s answered. Or at least that is my understanding.
After reading the wikipedia article, that basic understanding of it might be correct, but I’m not an astrophysicist.
Dark energy is basically a placeholder name. We have no direct evidence of it, but we indirectly know it has to exist due to other gravitational effects. As soon as we understand what it is the term “dark energy” will probably be replaced with whatever we discover to cause the observables currently attributed to dark energy, as dark energy is basically scientist for “no fucking idea why we observe these effects, but we do observe them”. I’m not currently an astrophysicist but I spent time during undergrad as a research assistant on a LIGO project