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> what would it take to convince them that dark matter may not exist? Just a better alternative that fits all the evidence. The problem is not scientists stubb

> what would it take to convince them that dark matter may not exist? Just a better alternative that fits all the evidence. The problem is not scientists stubbornly hanging on to their pet theories and refusing to accept alternatives (though obviously they do have their pet theories), it's just a downright weird area of science. Dark Matter is preposterous and unintuitive. It affects gravity just like a lot of mass, but it's totally invisible. We have no idea what it is or how it formed, but the majority of mass in the universe is somehow dark matter! Obviously there must be a simpler, more elegant explanation. And yet, through numerous experiments, other theories get ruled out while dark matter survives.

qikInNdOutReply 4y ago
Does its distribution show an corelation with visible objects?
- teamonkey 4y ago
  No, as mentioned in another reply there are galaxies that appear to be free of dark matter.
throwawaymaths 4y ago
> Just a better alternative that fits all the evidence. This is the problem. There is a real possibility that what is "really" going on only fits some of the evidence and there are other phenomena at play. The explanatory power of "unseeable distribution of arbitrary matter" is dangerously high.
- teamonkey 4y ago
  There's no danger it will be left at a vague "unseeable distribution of arbitrary matter", if that's what you mean. Every astrophysicist studying in the field of dark matter wants to know exactly what it is, even if it's an artefact caused by multiple different unknowns.
  - throwawaymaths 4y ago
    This is a highly idealistic and naive caricature of scientists (I used to be one)
Hayvok 4y ago
> but the majority of mass in the universe is somehow dark matter! Forgive me, but shouldn’t it be, “the majority of gravity” we observe? > through numerous experiments, other theories get ruled out while dark matter survives We keep experimentally ruling out exotic modifications to gravity and relativity that don’t require extra mass, and dark matter theory continues because it makes the math work while it continues to fail experiment after experiment. We’re like a kid in school being asked to show their work on a math problem, knowing the answer, and tacking “+3” at the end because it came up short. The gravity we get at the end is correct (we can see it) but we have no idea where that “3” actually comes from.
- teamonkey 4y ago
  > Forgive me, but shouldn’t it be, “the majority of gravity” we observe? Yes you're right, or maybe more precisely, "if we assume dark matter is a form of matter that behaves like normal mass in all ways except that it doesn't interact with light, then it must form the majority of mass in the universe." > and dark matter theory continues because it makes the math work while it continues to fail experiment after experiment. The point is that it doesn't fail experiment after experiment. If it had, it would no longer be a valid theory. It's annoyingly robust. > We’re like a kid in school being asked to show their work on a math problem, knowing the answer, and tacking “+3” at the end because it came up short. Sort of, but you make it sound like scientists are making things up rather than just doing experimental science. We can explain dark matter if we modify the laws of gravity by some factor. What is that factor? OK, so how would modification of those fundamental laws affect other things in the universe? Can we see evidence of this happening anywhere, or not happening where we think it should? OK, we observed something that disproves that factor within a certain range of values. Does that give us more information, how can we test it more, does it give us insight into how the theory can be tweaked? Etc.
  - Hayvok 4y ago
    > more precisely, "if we assume dark matter is a form of matter that behaves like normal mass in all ways except that it doesn't interact with light > you make it sound like scientists are making things up rather than just doing experimental science No, I have a ton of respect for the process and experiments done so far. I’m reminded of early attempts to understand Mercury’s orbit - there must be some massive body in the glare of the sun perturbing its orbit! (Is the extra body orbiting inside the sun, what is going on??) The possible explanations became increasingly out-there, until Einstein extended our theory of gravity and introduced spacetime. I appreciate that we’ve tried and failed every which-way to modify gravity on large scales to make this work, but how close are we to saying we’ve tried every which-way to detect this supposedly normal mass? There may be a deeper insight to the universe we’re missing, and it’ll take another general-relativity-spacetime-style revolution crashing into astrophysics before we figure it out.
nickersonm 4y ago
Exactly - often people forget the 'dark' in 'dark matter' just means 'we have no idea what it is'! All dark matter researchers would love for it to become '<x> matter'. It's not like dark matter is an ideal explanation, as another comment says it's more like a remainder term in an equation that we don't know the origin of.

qikInNdOutReply 4y ago

Does its distribution show an corelation with visible objects?

teamonkey 4y ago
No, as mentioned in another reply there are galaxies that appear to be free of dark matter.

throwawaymaths 4y ago

> Just a better alternative that fits all the evidence. This is the problem. There is a real possibility that what is "really" going on only fits some of the evidence and there are other phenomena at play. The explanatory power of "unseeable distribution of arbitrary matter" is dangerously high.

teamonkey 4y ago
There's no danger it will be left at a vague "unseeable distribution of arbitrary matter", if that's what you mean. Every astrophysicist studying in the field of dark matter wants to know exactly what it is, even if it's an artefact caused by multiple different unknowns.
- throwawaymaths 4y ago
  This is a highly idealistic and naive caricature of scientists (I used to be one)

Hayvok 4y ago

> but the majority of mass in the universe is somehow dark matter! Forgive me, but shouldn’t it be, “the majority of gravity” we observe? > through numerous experiments, other theories get ruled out while dark matter survives We keep experimentally ruling out exotic modifications to gravity and relativity that don’t require extra mass, and dark matter theory continues because it makes the math work while it continues to fail experiment after experiment. We’re like a kid in school being asked to show their work on a math problem, knowing the answer, and tacking “+3” at the end because it came up short. The gravity we get at the end is correct (we can see it) but we have no idea where that “3” actually comes from.

teamonkey 4y ago
> Forgive me, but shouldn’t it be, “the majority of gravity” we observe? Yes you're right, or maybe more precisely, "if we assume dark matter is a form of matter that behaves like normal mass in all ways except that it doesn't interact with light, then it must form the majority of mass in the universe." > and dark matter theory continues because it makes the math work while it continues to fail experiment after experiment. The point is that it doesn't fail experiment after experiment. If it had, it would no longer be a valid theory. It's annoyingly robust. > We’re like a kid in school being asked to show their work on a math problem, knowing the answer, and tacking “+3” at the end because it came up short. Sort of, but you make it sound like scientists are making things up rather than just doing experimental science. We can explain dark matter if we modify the laws of gravity by some factor. What is that factor? OK, so how would modification of those fundamental laws affect other things in the universe? Can we see evidence of this happening anywhere, or not happening where we think it should? OK, we observed something that disproves that factor within a certain range of values. Does that give us more information, how can we test it more, does it give us insight into how the theory can be tweaked? Etc.
- Hayvok 4y ago
  > more precisely, "if we assume dark matter is a form of matter that behaves like normal mass in all ways except that it doesn't interact with light > you make it sound like scientists are making things up rather than just doing experimental science No, I have a ton of respect for the process and experiments done so far. I’m reminded of early attempts to understand Mercury’s orbit - there must be some massive body in the glare of the sun perturbing its orbit! (Is the extra body orbiting inside the sun, what is going on??) The possible explanations became increasingly out-there, until Einstein extended our theory of gravity and introduced spacetime. I appreciate that we’ve tried and failed every which-way to modify gravity on large scales to make this work, but how close are we to saying we’ve tried every which-way to detect this supposedly normal mass? There may be a deeper insight to the universe we’re missing, and it’ll take another general-relativity-spacetime-style revolution crashing into astrophysics before we figure it out.

nickersonm 4y ago

Exactly - often people forget the 'dark' in 'dark matter' just means 'we have no idea what it is'! All dark matter researchers would love for it to become '<x> matter'. It's not like dark matter is an ideal explanation, as another comment says it's more like a remainder term in an equation that we don't know the origin of.