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Gravity is real you dumb fuckers
Posts
Like a sphere.
That's getting into "God exists because by definition He exists" territory. All we detected was gravity. We don't know for certain that something has to "cause" gravity.
Hypersphere.
Well... something has to be responsible for it. Dark matter (which apparently is the mainstream accepted idea right now) or some other thing.
Origin: aiwatt
I am saying that it is silly to assume gravity must be caused by something. Considering how little we actually know about gravity.
Sure.
I mean, assuming that God was detectable by a certain phenomenon, and the only definition of God was that it was the source of that phenomenon...
Waitaminit.
Relevance being?
The fact that we are not able to incorperate quantum mechanics and general relativity into one seemless theory does not mean that one of them is incorrect. Both of them are as succesful as a scientific theory can be: 100% accurate prediction rate for any observed phenomenon they deal with. The fact that they don't mesh is painful and awkward, but hardly a reason to throw either of them out of the window. Quantum Mechanics is also way "weirder" and counterintuitive then Relativity, or even Dark Matter, in my opinion. Who says that QM isn't wrong then, if we absolutely can only have one? (Which i wouldn't say at all).
Relevance being?[/QUOTE]
no real relevance. The talk about models and fitting reminded me of all my 400394209348 physics labs from college where we did such things that I thought was funny
B.net: Kusanku
You're exaggerating the rigidity of the community's attachment to dark matter/energy patches. They're being investigated as possibilities; they are not the only possibilities being investigated. There may come a time when relativity and quantum theory have to be discarded Newton-style, but we're not at that point yet.
Also, folks, observation need not be direct.
Uh, and what are you basing this on? From observation and theory, we know that gravity is "caused by" mass (that is, a massive body will exert a gravitational pull on other bodies). So far as we know, gravity, nor any other force is caused by "nothing", which would seem to imply that it occurs randomly or unpredictably. Gravity is (partly) predictable, and indeed, the entire basis of science is that the universe is a predictable place (which has so far turned out to be true, because science is so successful).
So, yeah, its pretty damn safe to say that gravity is caused by something. If it isn't then we wont really know anyway.
So where is it? From what I can tell, it looks like it's somehow "attached" to regular matter. The observations of those two galaxies made it seem as if the dark matter existed more or less within the confines of the observable matter, as if the latter was swimming in a soup comprised of the former. Is it assumed, then, that dark matter exists as a semi-uniform blob that hangs out across the entirety of galaxies? Would, for example, our solar system be steeped in a big ol' sea of dark matter? If that's the case, could that account for our inability to really see its effects from here on Earth? If we were surrounded by a uniform soup of dark matter, much of its effect would pretty much cancel out.
I make tweet.
I think that's how it's supposed to work. It wouldn't necessarily be a 'uniform blob', since it would have to orbit the center of the galaxy like everything else.
I know this is way late, but there is a "disorder" where a person associates a smell with a color, so whenever they see that color they smell whatever they associate it with. Therefore, people do smell colors.
The term for this is Synesthesia.
Origin: aiwatt
I was being a smartass, but yeah, it happens with all sorts of sensations. It's called synesthesia. Some people claim to see music, and those people are generally musically gifted. It's usually not such a blessing, instead a weirdo fucking curse.
But I now realise that that's where super-massive black holes live. So I don't really have any good idea.
Es-annon NEVA 4GET
I know someone who tastes a sweet taste when she hears a major chord, bitter for minor, and its crazy. She is an amazing musician.
The super-massive black holes could be mostly dark matter anyway.
Anyway, physics is at that point where mathematical and theoretical inference is driving experiment rather than the other way around, which is weird for science and makes everyone uncomfortable. But as I recall, black holes were predicted by the math of general relativity decades before we actually discovered one, and likewise with the neutrino.
My feeling is that this can go on infinitely, that there are an infinite number of sets of rules; one for every magnitude, of which there is no limit.
Its kind of ridiculous. Then again, I'm not a physicist.
The experiment you guys are talking about that "proves" dark matter exists is this one: http://arxiv.org/abs/astro-ph/0608407.
Like most experiments it is not conclusive proof in and of itself; modified theories of gravity could still explain the observations presented in that paper. However, it seems odd that the modified theories of gravity would behave exactly like clusters of mass hanging around in galaxies. This is much like saying "epicycles could explain the retrograde motion of the planets, but it seems odd that the planets behave exactly like we are all in elliptical orbits around the sun".
Also, in response to salvation122's post:
Physicists do admit that the model is incredibly fucking broken because shit is expanding way too fast. The model is broken in other ways too! But the whole point of physics is that you look at how your model is broken and you say "what could explain this?" You seem to have this picture of scientists desperately throwing ridiculous shit in to save their explanation of the universe. That's not what's happening- scientists are trying hard to come up with something, anything, to explain what they see. In this case the "tons of conveniently invisible matter in just the right spot" theory really does explain the observations better than anything else we've come up with.
I've done a good amount of research on them, and it's pretty much the prime example of something we absolutely can't explain. Physics as we know it on Earth does not apply to Black Holes, they defy pretty much everything we know to be true here.
I don't see how you can base gravity among the universe based on your understanding of gravity on earth. How do we know science was correct about the universe? We've been on the Moon and Earth, that's it. I just don't think it's fair to assume the ENTIRE rest of the universe is predictable in those ways. There's no way to know.
Er...we have telescopes. We can observe other parts of the universe. Do math and stuff.
I tend to find that to be an irrelevant question - if the laws change then surely something drives there to be a difference, so let's go find the sub theory.
Anyway, if they did, you would expect to be able to see where they did because the interaction of two separate rules governing interactions would require a transition region of some sort that would look different to both yet again.
I had always understood that the physical laws we use seem to break down, or at least change, under extreme conditions.
The more they look into the concept of a unifying theory to simply explain everything, the more they realize that it's going to be the most complicated nonsensical shit you can ever imagine. It will make you question who you are and where you belong.
It seems to me laws are just a human creation, labels we put on the phenomena of the universe, and if something fails to work as we expect, it is not because the law has broken down, but that ultimately our definition of the law was completely and utterly wrong. Truth?
Dude, seriously? You're going to try and pull this shit?
Let's assume you've discovered something which is indeed profound (rather than simply a profound misunderstanding of science) with your statement that our limited experience with gravity (earth and the moon) means that "there's no way to know" about gravity in the universe at large.
We can state this as a more general principle - we cannot know the appropriateness of a general principle outside the domains and situations in which we arrived at this principle.
So, we can't know about gravity outside of the moon and earth.
Let's consider a far simpler principle which is also less controversial and better understood than gravity - "A metal expands when heated".
So, we've tested that all over Earth and the Moon, and we know why it happens thanks to electron microscopes and physical chemistry and the like. Now, what can we conclude about a metal expanding when heated under a different situation? What about on Mercury? Or Hades Gamma? Or Betegeuse IV? and so on and so forth. Under your maxim, we just cannot know. Which, were the ramifcations of your maxim to stop there would be somewhat workable (but a radically unorthodox view of the role of science).
The question is, how are we restricting domains? We have concepts such as "Earth" and "The Moon" but we certainly do not believe that the universe operates upon these macro-level and cognitive concepts - so, there's no rational reason to believe that the universe would differentiate its behaviour between domains such as "Earth" and "The Moon" and consequently no mechanism by which we can restrict your maxim in a similar fashion.
So, now we're dealing with arbitrarily precise positions - we've tested the expansion of metals in some particular position, and another particular position, and so on and so forth. But under your maxim we just cannot know whether metals will behave the same way under temperature in some other place which we haven't tested. So, even on the surface of the Earth, it turns out we can't really conclude anything interesting about metals, except for in areas in which we've already tested their behaviour.
But wait a minute - why are we assuming that the universe differentiates behaviour solely on position? What if time sensitivity is a factor? What if every 14th minute of every 1400th day metals will actually contract when heated? There's a whole range of time-related factors as well. So, it seems that we can't even predict how any given piece of metal will behave at any given time regardless of metal-related experiences we've had in the past, because we've only had experience with metals at particualr locations at particular times - who knows what will happen next week?
Then there are countless other variables which might be involved - temperatures used, atmospheric pressure, amount of light in the room, atmospheric composition, the shape of the metal, the size of the metal, the colour of the light in the room, the relative position of Jupiter, the abolute position of Jupiter, the quantum state of nearby cats and so on and so forth.
So, it seems like your maxim would render science impossible, and yet you're posting with the fruits of science's labour. Oops.
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TL;DR
Science and rationality assumes the basic regularity of natural law. As science is by defnition a mechanism by which to make predictions about the future using limited datasets, this assumption is necessary for science and rationality to work*. As such, you can't seriously entertain your objection without invoking radical scepticism, which is bad.
* Which isn't to say that science cannot deal with irregularity, only that it must assume a basic state of uniformity.
Es-annon NEVA 4GET
I don't know how you'd describe it in terms of experience of what it would be like to physical laws break down around you.
What it does mean is that when you do the maths for the equations which describe the physical laws at extreme conditions the answers you get are crazy/impossible/incoherent or there are no solutions. For example, in some cases you end up dividing by zero, which tends not to make a lot of sense.
Es-annon NEVA 4GET
What does dividing by zero mean in math?
It's the same thing, sometimes exactly the same thing, that we talk about when we say the laws of physics "break down".
How do you even hope to understand or model something that happens before time exists?
By "break down" we mean that you get non-sense results within the model - i.e. X / infinity, X / 0 etc. It's essentially a term we use to say "this is the limit of this model, we need a more detailed thing to properly explain the phenomenon".
EDIT: A simpler explanation of physical laws breaking down would come from the various approximations used in solid state physics - superconductors for example at first glance appear to be a "break down" of the rules governing conductivity.
Unclear. Rephrase.
Es-annon NEVA 4GET