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Wouldn't a galaxy without dark matter be less strange than one with dark matter, considering "dark matter" is literally something we know nothing about?
by hypertele-Xii 5y ago
Wouldn't a galaxy without dark matter be less strange than one with dark matter, considering "dark matter" is literally something we know nothing about?
- ryandvm 5y agoA person without consciousness would be more strange than a person with consciousness, despite consciousness being something we don't understand.
- hypertele-Xii 5y agoA person awake and conscious is, in my opinion, generally much stranger in its behavior than one who is unconscious. Unconscious persons generally just... lie there. Not all that strange, considering most stuff on Earth does that.
- denton-scratch 5y agoWell, a person without consciousness might behave exactly the same as one who was self-aware; all the same processes might occur, but the individual just wouldn't have self-awareness. As it is, it seems that conscious "acts of volition" really follow the initiation of action, rather than preceding it. It's as if we are automata or robots, with something weird called consciousness layered on top. I have no idea whether this is a true representation of how things are, or some kind of artifact.
- grimgrin 5y agoisn’t otherworldly generally strange tho?
- joe_the_user 5y agoIf we knew nothing about dark matter, we wouldn't postulate dark matter. Astronomers define/describe dark matter as matter that seems to interact with normal matter gravitationally but in no other way. But we can "see" this gravitational interaction in a number of ways and so we know a reasonable amount about dark matter, especially, through the motion of normal matter we know approximately where it is and isn't.
- Enginerrrd 5y agoSince it appears most galaxies have a substantial amount of dark matter, it appears that that is the more normal condition.
- gerdesj 5y agoDark Matter is a working title for about 85% of the stuff in the entire universe. What it is is the question posed by its name but its existence is generally agreed upon. Many apologies to any "English is my second language, please have mercy on my internal parser" for that last sentence. Certain properties of galaxies implies that there is more matter in them than is observed directly. The extra stuff could be clotted cream but then I would personally be able to detect it from billions of light years away. We can only really say that gravity is a thing that we think works like ... this (cue pretty piccies from some Holywood films and Hubble etc). Gravity is an emergent property of matter according to Mr Einstein. Take a large collection of matter, say of the order of 100,000 light years across, like our Milky Way or Andromeda, which is spinning and has a measurable distribution of matter. You can predict how it ought to behave. For example it ought to spin at x or be distributed as y etc. However, measurements show that it doesn't. So you take the observed parameters and run your models and equations backwards to get the actual matter that would be involved. It turns out that over four fifths of stuff is currently unobservable, which is a bit embarrassing. A galaxy without Dark Matter is one that doesn't have stuff that we don't even know what it is that it lacks or something. Assuming that stuff is reasonably homogeneously distributed across the universe, this is a very odd ratio of observable to non observable stuff indeed. Hope that clears that up 8)
- foobarian 5y agoDo you know of any sources that rule out regular matter in between celestial bodies that would be sparse enough to be unobservable but massive enough when put together? Like a bunch of cold electrons?
- xenophonf 5y agoWe would see something like that against the cosmic microwave background. Instead, we see that about 5/6ths of the total matter of the universe interacts with the CMB only through gravity. Also, more hidden (somehow) baryonic matter would change our current theories surrounding Big Bang nucleosynthesis in ways that aren't supported by other observations, like the percentages of (visible) matter like helium and lithium.