Let’s pretend that you have a basket with 100 apples. You know apples are about 100g each, because you weighed 10 of the them and all of the apples seem about the same size. You know that basket weighs 1000g. You put the whole thing on a scale and find it weighs 500,000g. You know something else is in that basket. You aren’t sure what, and frankly it doesn’t make sense, but trying different scales and remeasuring more individual apples gives the same result. So you decide that there must be something you can’t see but must exist. That’s dark matter/energy.
That’s dark matter/energy.
No… it’s dark apples
The worst pie - Dark Apple Pie. QED
The scale probably just can’t measure the apples all together that way. Maybe it’s not calibrated to see all the different ways apples can interact. Maybe time to go back to the scale drawing board.
That’s that funny thing, they’ve tried different scales. They’ve tried radically different ways of measuring it, and always come up with the same discrepancy.
If summing energy works differently on a large scale, why? Since we don’t know what we can do is start measuring the difference between observable energy and the “extra” that appears when we add it up. We could call that “unobservable energy” so we can see if there is a pattern, or if it’s actually something else. You know “unobservable energy” is a mouthful, why not just call it dark energy?
We don’t know what it is. We have tested lots of theories and dark energy doesn’t seem to fit any answer, hence the name. I get thinking that it can’t be that hard to reconcile and scientists must be missing an obvious conclusion, but it’s likely that your theory has already been tested. Maybe you have the solution and can resolve the discrepancy, but right now all data shows that dark energy is a large part of the universe.
I’m not sure what you’re getting at. Dark matter has been proven numerous times, is a predictive model, and is the only explanation that has held up to scrutiny and observations. It’s very clearly the right explanation and we know how dark matter generally behaves, we just don’t know specifically what it is.
See, for example, the behavior of the bullet cluster merger.
Sorry, but…aren’t modified gravity theories gaining some more traction recently? Not enough to say that modified gravity is the most likely explanation for observations, but at least enough to avoid saying that dark matter is “clearly the right explanation”?
edit: I’ve just realised that some people would describe modified gravity as a specific theory to describe the observational effect of dark matter. Is that what you were doing here?
Sorry for not responding earlier, I don’t seem to be getting notifications! My other reply further down in the thread hopefully answers all of your (wonderful) questions, though. Have a great day!
Why isn’t it called “cold matter”?
Don’t we just not see it because it’s not burning?
Couldn’t the unseen mass be clouds, planets and black wholes?
As far as we’re aware, dark matter only interacts with the universe gravitationally. It doesn’t even interact with itself, which is why we don’t see dark planets/stars/galaxies popping into existence. It only follows normal matter around.
As for why it’s not called cold, is for two reasons:
- Cold gases of normal matter can condense to form stars. Dark matter doesn’t interact with itself, which implies it cannot condense into more concentrated forms of itself the way a gas cloud can eventually form a star.
- We just don’t know what the stuff is, it could be clouds, planets, black holes, neutron stars, brown dwarfs, etc. But our best observations of dark matter are from very large distances away where we can measure the distortion of spacetime due to dark matter. We can’t see these smaller objects at these distances. But we should be able to see other clues that would indicate it’s normal matter.
If it happened to be clouds of gas and dust that overall had a net gravitational effect on the background galaxies, we’d be able to detect the spectral lines of these clouds. Same for just about all the other objects in that list. In some cases we do detect intergalactic gas clouds. But in places where there’s very clearly unaccounted for gravitational lensing, there isn’t any sign of this. So far the only things we can match up to the observations is a mathematical model of the stuff.
No, because those would also interact with other things like electromagnetic radiation, light, etc. Dark matter only interacts with normal matter via gravity.
Dark matter is admittedly a bit of a misnomer but that’s what everyone’s been using for years 🤷🏻♂️
1+1=3
Hypothesize there’s an extra 1 out there we don’t know about yet
Relentlessly test hypothesis for decades
Every test lines up with hypothesis
Relentlessly move humanity’s understanding of physics forward
Get made fun of by dumb fucks who struggle with division
This is the most-tested, best-proven scientific theory humanity has known. For some reason, it completely breaks if you remove these Wingdings characters we added to the code.
You forgot to scale by an arbitrary “heuristic” constant to mask the excess of simplification of the models.
Details in the supplementary information
It’s okay since the 1s are dimensionless and so is the 3.
Is this how dark matter works? (That’s the joke, right?)
Although we haven’t observed dark matter on a microscopic scale, we have been measuring the effects of dark matter on a macro level for decades.