General relativity is successful in virtually every application. There is no dissent on the existence of dark energy or dark matter.
Our equations may be incomplete, but they are not incorrect.
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Researchers detect possible signal from Dark Matter
- Thread starter Amir0x
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General relativity is successful in virtually every application. There is no dissent on the existence of dark energy or dark matter.
Our equations may be incomplete, but they are not incorrect.
That's what science said about the heliocentric model. Just keep adding circles, they said. Our equations aren't wrong, just incomplete. I mean look, they accurately predict the progression of the other planets through the sky so they might be right.
Personally? I'm going to stick with good old occum's razor on this one. "Our theories must be right so if they don't work lets insert some extra matter we can't detect and don't know exists so that they work right" just doesn't sit well with me. I find it far more likely we've come up with a working model that mostly makes accurate predictions, that we can accurately describe what happens, but that our theories for what causes what we see are fundamentally flawed. It wouldn't be the first time that's happened. It won't be the last.
Big eye roll at that analogy.
General relativity has successfully answered any question put to it. It would be quite awkward if it was just completely wrong about something as rundementary as measuring the known gravity in the universe.
Again I say, there is no dissent about the existence of dark matter and dark energy. An entire community comprised of smarter people than you, with more knowledge on this subject than you, are at a consensus.
It's so bizarre. It's easy for me to grasp physics at microscopic levels, but when people on this tiny planet start making such certain assumptions about something as large as our universe it's really hard for me to grasp or accept that. Like the idea of "counting all the planets/starts/etc." in the universe and getting a rough number. It boggles my mind that a species only a few feet tall can make such certain assumptions about a universe that is so very large. I have trouble believing it, but I'm also no astrophysicist, so of course I don't know enough to grasp it with full faith.
Its funny cause such an assumption can't really be ruled out, since we don't really know shit about dark matter and dark energy.
Anyhow, fascinating stuff. Hoping to hear something come of this.
Dark energy acts as a form of "negative pressure" or repulsion. The most plausible idea at the moment is that dark energy is a consequence of the vacuum of space itself having an intrinsic energy called the cosmological constant.
Dark matter evidence:
- Galactic rotation curves (the velocities of stars on the edge of galaxies are consistent with a spherical "halo" of near-uniformly distributed dark matter. Similarly, applying the virial theorem to galaxy clusters reveals that the amount of unseen matter vastly outweighs optical matter and hot, X-ray emitting gas)
- Fluctuations in the cosmic microwave background radiation (including baryon acoustic oscillations). Most consistent with what we observe is the Lambda Cold Dark Matter model (ΛCDM), in which baryonic matter comprises roughly 5% of the universe, dark matter 26%, and dark energy 69%. Slow-moving, or "cold" dark matter is consistent with galaxy-building scenarios, since relativistically moving dark matter results in the "smoothing out" of small scale structures that would later become larger-scale variations in density as the universe expands.
- Gravitational lensing (including the image of the bullet cluster I posted earlier) - light 'bends' around massive pockets of matter, allowing us to detect the presence of invisible matter.
MACHOs (Massive Astronomical Compact Halo Objects) such as black holes, dwarf stars, planets, etc. are pretty much ruled out. MOND (Modified Newtonian Dynamics) isn't entirely ruled out, but seems rather unfavourable since it cannot entirely account for these missing matter observations.
It is very, very, very likely that the standard model is incomplete, since it does not account for these cosmological discrepancies (in addition to other problems that I listed earlier, such as the very big problem that gravity is not yet unified with the strong force, the weak force and the electromagnetic force - we have yet to find that coveted "Grand Unified Theory"). This is how science works - we are always seeking to find new physics beyond what it is currently known. Dark matter is not a "fudge factor" to try and make theories work, but a very real observed discrepancy between "observed mass" and "actual mass" that needs an explanation, which we currently do not definitively have.
Dark matter evidence:
- Galactic rotation curves (the velocities of stars on the edge of galaxies are consistent with a spherical "halo" of near-uniformly distributed dark matter. Similarly, applying the virial theorem to galaxy clusters reveals that the amount of unseen matter vastly outweighs optical matter and hot, X-ray emitting gas)
- Fluctuations in the cosmic microwave background radiation (including baryon acoustic oscillations). Most consistent with what we observe is the Lambda Cold Dark Matter model (ΛCDM), in which baryonic matter comprises roughly 5% of the universe, dark matter 26%, and dark energy 69%. Slow-moving, or "cold" dark matter is consistent with galaxy-building scenarios, since relativistically moving dark matter results in the "smoothing out" of small scale structures that would later become larger-scale variations in density as the universe expands.
- Gravitational lensing (including the image of the bullet cluster I posted earlier) - light 'bends' around massive pockets of matter, allowing us to detect the presence of invisible matter.
MACHOs (Massive Astronomical Compact Halo Objects) such as black holes, dwarf stars, planets, etc. are pretty much ruled out. MOND (Modified Newtonian Dynamics) isn't entirely ruled out, but seems rather unfavourable since it cannot entirely account for these missing matter observations.
It is very, very, very likely that the standard model is incomplete, since it does not account for these cosmological discrepancies (in addition to other problems that I listed earlier, such as the very big problem that gravity is not yet unified with the strong force, the weak force and the electromagnetic force - we have yet to find that coveted "Grand Unified Theory"). This is how science works - we are always seeking to find new physics beyond what it is currently known. Dark matter is not a "fudge factor" to try and make theories work, but a very real observed discrepancy between "observed mass" and "actual mass" that needs an explanation, which we currently do not definitively have.
Cameron122
Member
this made me laugh
EndlessSky
Member
Things like this really excite me. I can't help but think of the possibility of instead of small particles jumping in and out of our universe (hawking radiation) a hole to another universe appears and life as we know it is completely different. I know I watch too much anime and play too many games, but it's exciting to think about lol.
Heh, I once armchair theorized that maybe it was matter existing in a different dimension, since I read different dimensions are what might make gravity as weak a force as it appears in our dimensions... To my surprise I later read a not too old article precisely on that idea. It's probably a laughable theory in real science though. ¯\_(ツ
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