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Isn’t “dark matter” just a way to account for an unexplained behavior? It bothers me that its existence is treated as a given, when it could be a case of mistak

Isn’t “dark matter” just a way to account for an unexplained behavior? It bothers me that its existence is treated as a given, when it could be a case of mistaken assumptions. If calculations say the universe is acting as if it contained much more mass than we observe, we should also consider the possibility that our method of calculation may be flawed. I’m not claiming dark matter doesn’t exist, only that I fear the human tendency to run with a hypothesis too eagerly and discard alternate options. Similar to how everyone seems to speak as if Hawking radiation is a given fact, when it is thus far completely unproven and nothing more than a suggested idea.

empath75 8y ago
Dark matter is an observed phenomenon that can be explain by the existence of an additional, unknown kind of matter. I don't think scientists are unduly hung up on that explanation, though. It's merely the most likely. Plenty of scientists are looking for alternative explanations and I'm sure the rest will get on board if they find something convincing.
- posterboy 8y ago
  So far, dark matter is just the label for an incongruence in the calculation that needs to be falsified. With regard to the article, it could still be that there are many young smaller black holes, too small or even too short lived for the methods employed here.
mattydoincode 8y ago
I think that from the optic of someone who is not a physicist (like myself!) it's natural to think "hey... we can't actually know that it's dark matter vs some other unexplained way that gravity works". And in fact there are many physicists working on trying to figure that out, but there is actually a ton of evidence that what we're seeing is in fact particles, and most physicists consider it to be the most likely current theory. I don't think anyone in the physics community treats anything about dark matter as a given either (or hawking radation for that matter). In fact part of being a true scientist is keeping an open mind.
cdumler 8y ago
Yes, Dark Matter is a statement about the premise that something appears to be operating gravitationally while have no (or perhaps so little that we don't recognize it) interaction with other matter; however, it is not without reason. The primary focus on matter as the candidate is that if you don't believe that some form of matter is responsible, you begin having to explain how a lot of our Laws are incorrect. Dark Matter is really a problem that we have a notion how our Laws should work at the cosmic scale, yet they don't. And yet, we don't see any obvious reason why they shouldn't give how thoroughly we've tests these Laws. For instance, if you say that our equations for gravity is off, why is it completely consistent for everything in our solar system? Why is consistent down to the most precise test for gravitational frame pulling? It seems to be only different when you talk about very large masses creating gravity on objects tugged at very long distances. Why does it just cut over to different behavior? If you say that gravity is emergent, then how do you explain the standard model's place for the graviton? Granted, it's not testable (gravity is so weak it's beyond direct testing), but it seems to be fit right in to a spin-2 tensor where we would expect a gravity-like particle to be. Why would you expect that to not be true? That said, Dark Matter matter candidates are getting weeded out pretty quickly, these days. No new types of particles are being discovered, and Dark Matter observatories are largely coming up empty. But, that's science: got an idea? Test it and let the results speak. As an aside, I think one thing to remember is: just because science doesn't know the answer to something, it often knows what can't be the right answer. Look into the theory's and their criticisms.
- ziftface 8y ago
  Is it possible that it's something other than gravity? A force we don't know about because of how weak it is but has an effect on a large scale? I'm completely ignorant of the subject so I don't know how crazy that might sound.
  - cdumler 8y ago
    No, that is a perfectly valid question. The answer is: science has no idea what gravity _is_. What we do know is: The Newton/Einstein definition is that it is an effect by mass on space/time. Mass always travels in a straight line (unless acted on), but mass causes space/time to curve. So, what we see as gravitation attraction is a fake force. No different than being "pushed" into the back of your seat when a car accelerates. You are staying still, the car is moving forwards. The Newton/Einstein definition does not specify any mechanism. The description, however, is highly specific, and so far every test for the most subtle effects have been validated. Well, except for cosmic structures. Quantum mechanics says that particles emit/receive interactions via the graviton carrier, and that it can be quantized and transmitted via waves. In the last few years, we have detected gravitational waves. It fits perfectly and exactly as we would expect over cosmic distances. Unfortunately, the amount of energy necessary to detect an actual graviton is beyond anything we can expect to be able to produce for the forceable future and likely will never have the resources. So that is out. Also, it makes no claim on how it can affect space/time. So, just like we original argued over whether or not it was particles or waves, I think this paradox strongly suggests that we're just not looking at gravity correctly. I suspect that the real problem is "What is time?" Why do things experience different rates of time? It seems obvious to me that gravity, time, and entanglement are related. Gravity is very likely to be Dark Matter: a stand-in name until we can grasp the fundamentals.

empath75 8y ago

Dark matter is an observed phenomenon that can be explain by the existence of an additional, unknown kind of matter. I don't think scientists are unduly hung up on that explanation, though. It's merely the most likely. Plenty of scientists are looking for alternative explanations and I'm sure the rest will get on board if they find something convincing.

posterboy 8y ago
So far, dark matter is just the label for an incongruence in the calculation that needs to be falsified. With regard to the article, it could still be that there are many young smaller black holes, too small or even too short lived for the methods employed here.

mattydoincode 8y ago

I think that from the optic of someone who is not a physicist (like myself!) it's natural to think "hey... we can't actually know that it's dark matter vs some other unexplained way that gravity works". And in fact there are many physicists working on trying to figure that out, but there is actually a ton of evidence that what we're seeing is in fact particles, and most physicists consider it to be the most likely current theory. I don't think anyone in the physics community treats anything about dark matter as a given either (or hawking radation for that matter). In fact part of being a true scientist is keeping an open mind.

cdumler 8y ago

Yes, Dark Matter is a statement about the premise that something appears to be operating gravitationally while have no (or perhaps so little that we don't recognize it) interaction with other matter; however, it is not without reason. The primary focus on matter as the candidate is that if you don't believe that some form of matter is responsible, you begin having to explain how a lot of our Laws are incorrect. Dark Matter is really a problem that we have a notion how our Laws should work at the cosmic scale, yet they don't. And yet, we don't see any obvious reason why they shouldn't give how thoroughly we've tests these Laws. For instance, if you say that our equations for gravity is off, why is it completely consistent for everything in our solar system? Why is consistent down to the most precise test for gravitational frame pulling? It seems to be only different when you talk about very large masses creating gravity on objects tugged at very long distances. Why does it just cut over to different behavior? If you say that gravity is emergent, then how do you explain the standard model's place for the graviton? Granted, it's not testable (gravity is so weak it's beyond direct testing), but it seems to be fit right in to a spin-2 tensor where we would expect a gravity-like particle to be. Why would you expect that to not be true? That said, Dark Matter matter candidates are getting weeded out pretty quickly, these days. No new types of particles are being discovered, and Dark Matter observatories are largely coming up empty. But, that's science: got an idea? Test it and let the results speak. As an aside, I think one thing to remember is: just because science doesn't know the answer to something, it often knows what can't be the right answer. Look into the theory's and their criticisms.

ziftface 8y ago
Is it possible that it's something other than gravity? A force we don't know about because of how weak it is but has an effect on a large scale? I'm completely ignorant of the subject so I don't know how crazy that might sound.
- cdumler 8y ago
  No, that is a perfectly valid question. The answer is: science has no idea what gravity _is_. What we do know is: The Newton/Einstein definition is that it is an effect by mass on space/time. Mass always travels in a straight line (unless acted on), but mass causes space/time to curve. So, what we see as gravitation attraction is a fake force. No different than being "pushed" into the back of your seat when a car accelerates. You are staying still, the car is moving forwards. The Newton/Einstein definition does not specify any mechanism. The description, however, is highly specific, and so far every test for the most subtle effects have been validated. Well, except for cosmic structures. Quantum mechanics says that particles emit/receive interactions via the graviton carrier, and that it can be quantized and transmitted via waves. In the last few years, we have detected gravitational waves. It fits perfectly and exactly as we would expect over cosmic distances. Unfortunately, the amount of energy necessary to detect an actual graviton is beyond anything we can expect to be able to produce for the forceable future and likely will never have the resources. So that is out. Also, it makes no claim on how it can affect space/time. So, just like we original argued over whether or not it was particles or waves, I think this paradox strongly suggests that we're just not looking at gravity correctly. I suspect that the real problem is "What is time?" Why do things experience different rates of time? It seems obvious to me that gravity, time, and entanglement are related. Gravity is very likely to be Dark Matter: a stand-in name until we can grasp the fundamentals.