I did read what you wrote. If you had read the Wikipedia article you would know that 1) The evidence that dark matter is actually a new physical thing is overwhelming. 2) The evidence is not only "interactions between galaxies". 3) The theory does not allow for other causes of the interaction. 4) Everyone that works with it does use the name dark matter for the proposed particles (such as WIMPs, axions, or sterile neutrinos).
Spoken with the certainty of someone that knows nothing about the subject. Instead of being proud of your ignorance, you should try to read at least the Wikipedia article about it.
That is an extremely complicated theory. Your "God" concept is not even well-defined. The best attempts to do it involve books with hundreds of pages, that are nevertheless full of contradictions.
Particles evolving under the laws of General Relativity, on the other hand, can be described in a few pages. The universe doesn't care about whether your primate brain understands it. There exists an objective measure of complexity - Kolmogorov complexity - and this is what science cares about.
I have a PhD in theoretical physics. Not in cosmology, but I have some contact with people who do work on it.
So, 2) is astronomically unlikely. The experimental evidence comes from multiple independent sources spanning decades. It consists of simple things such as measuring the rotational speed of galaxies and more sophisticated measurements such as anisotropies in the cosmic microwave background. If you are willing to doubt this kind of evidence you might as well doubt GR itself.
As for 3), everyone and his dog likes to propose modified theories of gravity that would do away with dark matter. The problem is that reconciling them with the mountain of evidence for dark matter is really tough. The most popular candidates, MOND and entropic gravity are far from being able to do it. Until they do, we're stuck with 1).
If we would go with "weird" as a criterion to discard theories, we wouldn't have quantum mechanics. Or relativity. Or electromagnetism. Or almost anything that goes beyond our day-to-day experience.
Of course, one needs a lot of evidence to accept a new kind of matter, as it does require changes to our fundamental theories. We do have such evidence, and we don't have any other theory that can explain it.
Well, that is indeed the gold standard of theory falsification, but I think is not strictly necessary. If I have a theory that is both simple and consistent with all available data that theory is good enough for me.
But this is a bit beside the point, as we have the famous Baryon acoustic oscillations, which were predicted by cosmological models with dark matter, and then observed by WMAP and SDSS.
"fantasy matter"?! Come on, you can do better than that. This is about science, not politics. Or is there a anti-dark matter conspiracy theory I was unaware of?
While I agree with the spirit of your post, I think your description of Dark Energy is inaccurate. It is not simply the accelerated expansion of the universe, but more precisely explaining this accelerated expansion through a nonzero cosmological constant. While alternative explanations are considered implausible by the cosmologists, they are far from being inconceivable.
I don't think there is something wrong with postulating stuff to make our observations match our predictions. This is how science advances. Try explaining the observations of particle accelerators without postulating the existence of quarks, electrons, protons, neutrons, or atoms for that matter.
The real criterion is whether the stuff you postulate has simple properties or it behaves like fairy dust, magically explaining everything by having several arbitrary properties. I think dark matter falls clearly in the former category, as it can interact only through gravity, greatly restricting what it can do.
Why go through these complications? You could just outright forbid this crap.
It amazes me that you would find even remotely acceptable to ask someone to leave a plane they have already boarded. Have your expectations been so dramatically lowered?
Meanwhile, in the civilized world, it is just plain illegal to drag someone out of a plane they have already boarded.
If some European company, in a fit of insanity, tries to call the police to get someone removed from a plane because they want the seat (as opposed to the passenger threatening others and so on) the police would just say no. And probably arrest the airline exec if they make too much of a fuss.
Because 4chan is such a shinning example of interesting arguments made by knowledgeable parties, that does not degenerate into name-calling or trivial logical fallacies.
Building fast trains in Switzerland is highly nontrivial because of all the mountains. Not even the Swiss are rich enough to build all the tunnels and bridges that would be necessary.
Poor pharmaceutical companies, they have to jack up the price! Otherwise they wouldn't have such fabulous profit margins, or be able to spend such an incredible amount of money in marketing! Imagine the horror!
The only thing we need for a simulation is the ability to approximate the solutions as well as we want. And the numerical methods do give us that.
The Wikipedia page about the Church-Turing-Deutsch thesis is garbage, I'm sorry for linking to that. I was in a hurry with a mobile phone and didn't read it, just went with blind trust in Wikipedia. A proper essay about the subject, written by a respected researcher, is here.
I can think of two objections to the idea that if post-humans come to exist they will be simulating us all the time:
1 - Post-humans will be themselves simulations (in the sense of running on a computer instead of brains, not in the sense of they themselves being simulated by post-post-humans). Therefore they will have strong ethical concerns about simulated people being created and destroyed at will. 2 - Since a huge chunk of their society will exist as a simulation, computing power will be valuable real state, unlikely to be wasted simulating boring people like us. If they would be interested in their history they would simulate the world once, store the interesting part of the results, and be done with it.
Go to higher order perturbation theory, the error goes to zero. Come on, I can't believe I'm being asked to provide evidence that one can solve differential equations numerically. You can, and that is why scientists look for differential equations to describe phenomena. This is a matter of scientific consensus.
The only objection against solving differential equations numerically is complexity, as one needs exponetial time to solve the ones for quantum systems. It is widely believed, however, that quantum computers will solve this problem. See the Church-Turing-Deutsch thesis.
The approximation I used was to consider the nucleus to be a point with infinite mass and charge +1, so the problem reduced to finding the ground state for two electrons in a 1/r potential, for which I used perturbation theory. I'm mystified about why do you think the simulation would fall apart as soon as I try to evolve it out of the ground state, or why quantum computers would fare any better at this: they would be solving the same equation.
Spoken like someone who has never actually tried to simulate those differential equations for something more complex than a hydrogen atom. I have actually solved Schrödinger's equation for a Helium atom numerically, it works fine. But you are right that one needs exponential time in general to simulate quantum mechanics in a classical computer.
This is not relevant, however, for either Hossenfelder's or Bostrom's arguments, as they don't hinge on the complexity of the simulation, but only on the possibility.
Your argument is even worse than hers. Just because we don't know what is the correct theory for quantum gravity it doesn't mean that we have no idea how complex it is going to be. For the universe to be non-simulatable we would need quantum gravity to be not merely very difficult to compute, but actually uncomputable. And there is zero evidence for that (no physical theory we have is uncomputable). In fact, the evidence we have points in the opposite direction, that the dimension of the Hilbert space of any bounded area is finite, because of things like the Bekenstein bound.
Slashdot Mirror
I did read what you wrote. If you had read the Wikipedia article you would know that
1) The evidence that dark matter is actually a new physical thing is overwhelming.
2) The evidence is not only "interactions between galaxies".
3) The theory does not allow for other causes of the interaction.
4) Everyone that works with it does use the name dark matter for the proposed particles (such as WIMPs, axions, or sterile neutrinos).
Spoken with the certainty of someone that knows nothing about the subject. Instead of being proud of your ignorance, you should try to read at least the Wikipedia article about it.
"electromagnetic chauvinists" made me laugh. One internet for you, sir.
Good luck doing science with this conspiracy-theoretical mindset.
That is an extremely complicated theory. Your "God" concept is not even well-defined. The best attempts to do it involve books with hundreds of pages, that are nevertheless full of contradictions.
Particles evolving under the laws of General Relativity, on the other hand, can be described in a few pages. The universe doesn't care about whether your primate brain understands it. There exists an objective measure of complexity - Kolmogorov complexity - and this is what science cares about.
I have a PhD in theoretical physics. Not in cosmology, but I have some contact with people who do work on it.
So, 2) is astronomically unlikely. The experimental evidence comes from multiple independent sources spanning decades. It consists of simple things such as measuring the rotational speed of galaxies and more sophisticated measurements such as anisotropies in the cosmic microwave background. If you are willing to doubt this kind of evidence you might as well doubt GR itself.
As for 3), everyone and his dog likes to propose modified theories of gravity that would do away with dark matter. The problem is that reconciling them with the mountain of evidence for dark matter is really tough. The most popular candidates, MOND and entropic gravity are far from being able to do it. Until they do, we're stuck with 1).
If we would go with "weird" as a criterion to discard theories, we wouldn't have quantum mechanics. Or relativity. Or electromagnetism. Or almost anything that goes beyond our day-to-day experience.
Of course, one needs a lot of evidence to accept a new kind of matter, as it does require changes to our fundamental theories. We do have such evidence, and we don't have any other theory that can explain it.
Well, that is indeed the gold standard of theory falsification, but I think is not strictly necessary. If I have a theory that is both simple and consistent with all available data that theory is good enough for me.
But this is a bit beside the point, as we have the famous Baryon acoustic oscillations, which were predicted by cosmological models with dark matter, and then observed by WMAP and SDSS.
"fantasy matter"?! Come on, you can do better than that. This is about science, not politics. Or is there a anti-dark matter conspiracy theory I was unaware of?
While I agree with the spirit of your post, I think your description of Dark Energy is inaccurate. It is not simply the accelerated expansion of the universe, but more precisely explaining this accelerated expansion through a nonzero cosmological constant. While alternative explanations are considered implausible by the cosmologists, they are far from being inconceivable.
I don't think there is something wrong with postulating stuff to make our observations match our predictions. This is how science advances. Try explaining the observations of particle accelerators without postulating the existence of quarks, electrons, protons, neutrons, or atoms for that matter.
The real criterion is whether the stuff you postulate has simple properties or it behaves like fairy dust, magically explaining everything by having several arbitrary properties. I think dark matter falls clearly in the former category, as it can interact only through gravity, greatly restricting what it can do.
Also, obligatory XKCD.
Why go through these complications? You could just outright forbid this crap.
It amazes me that you would find even remotely acceptable to ask someone to leave a plane they have already boarded. Have your expectations been so dramatically lowered?
Meanwhile, in the civilized world, it is just plain illegal to drag someone out of a plane they have already boarded.
If some European company, in a fit of insanity, tries to call the police to get someone removed from a plane because they want the seat (as opposed to the passenger threatening others and so on) the police would just say no. And probably arrest the airline exec if they make too much of a fuss.
Because 4chan is such a shinning example of interesting arguments made by knowledgeable parties, that does not degenerate into name-calling or trivial logical fallacies.
Building fast trains in Switzerland is highly nontrivial because of all the mountains. Not even the Swiss are rich enough to build all the tunnels and bridges that would be necessary.
I feel your pain. If there is something that I dislike more than a bad user interface, it is when it is changed to a different bad user interface.
Poor pharmaceutical companies, they have to jack up the price! Otherwise they wouldn't have such fabulous profit margins, or be able to spend such an incredible amount of money in marketing! Imagine the horror!
Or maybe people who are actually murdering innocents are terrorists?
As these videos led to a terrorist attack, I think charging those idiots with a felony is entirely appropriate.
That the felony in question is only related to the recording of the video is irrelevant to me. Al Capone was, after all, arrested for tax evasion.
The only thing we need for a simulation is the ability to approximate the solutions as well as we want. And the numerical methods do give us that.
The Wikipedia page about the Church-Turing-Deutsch thesis is garbage, I'm sorry for linking to that. I was in a hurry with a mobile phone and didn't read it, just went with blind trust in Wikipedia. A proper essay about the subject, written by a respected researcher, is here.
I can think of two objections to the idea that if post-humans come to exist they will be simulating us all the time:
1 - Post-humans will be themselves simulations (in the sense of running on a computer instead of brains, not in the sense of they themselves being simulated by post-post-humans). Therefore they will have strong ethical concerns about simulated people being created and destroyed at will.
2 - Since a huge chunk of their society will exist as a simulation, computing power will be valuable real state, unlikely to be wasted simulating boring people like us. If they would be interested in their history they would simulate the world once, store the interesting part of the results, and be done with it.
Go to higher order perturbation theory, the error goes to zero. Come on, I can't believe I'm being asked to provide evidence that one can solve differential equations numerically. You can, and that is why scientists look for differential equations to describe phenomena. This is a matter of scientific consensus.
The only objection against solving differential equations numerically is complexity, as one needs exponetial time to solve the ones for quantum systems. It is widely believed, however, that quantum computers will solve this problem. See the Church-Turing-Deutsch thesis.
The approximation I used was to consider the nucleus to be a point with infinite mass and charge +1, so the problem reduced to finding the ground state for two electrons in a 1/r potential, for which I used perturbation theory. I'm mystified about why do you think the simulation would fall apart as soon as I try to evolve it out of the ground state, or why quantum computers would fare any better at this: they would be solving the same equation.
Spoken like someone who has never actually tried to simulate those differential equations for something more complex than a hydrogen atom. I have actually solved Schrödinger's equation for a Helium atom numerically, it works fine. But you are right that one needs exponential time in general to simulate quantum mechanics in a classical computer.
This is not relevant, however, for either Hossenfelder's or Bostrom's arguments, as they don't hinge on the complexity of the simulation, but only on the possibility.
This is not her argument. Read her post again.
Your argument is even worse than hers. Just because we don't know what is the correct theory for quantum gravity it doesn't mean that we have no idea how complex it is going to be. For the universe to be non-simulatable we would need quantum gravity to be not merely very difficult to compute, but actually uncomputable. And there is zero evidence for that (no physical theory we have is uncomputable). In fact, the evidence we have points in the opposite direction, that the dimension of the Hilbert space of any bounded area is finite, because of things like the Bekenstein bound.