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angelito
Honorable
Undefeatable Hero
proud father of a princess
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posted May 27, 2009 08:54 AM |
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And here it is again.....
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Better judged by 12 than carried by 6.
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stankelbenet
Adventuring Hero
bringer of nostalgia & darknes
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posted May 27, 2009 09:44 AM |
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Quote:
That doesn't matter. What I meant by "external" is that it is NOT confined in the locality of the Universe. I.e while the universe without that force has a 'preservation of energy', that energy has to COME from SOMEWHERE. If it were part of the Universe itself (local, not external), then it would NOT be a preservation of energy, your only single argument you had for it.
If you stretch a rubber band, you will eventually tire. How come, if the energy isn't wasted and is in an infinite loop, according to you?
Will the Universe eventually tire? Then there's no equillibrum.
It's all diffusion . Since there's no material outside the universe, the material inside our universe is drawn out. The force that stretches isn't coming from the outside but from the inside.
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TheDeath
Responsible
Undefeatable Hero
with serious business
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posted May 27, 2009 08:36 PM |
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It's all diffusion. Since there's no material outside the universe, the material inside our universe is drawn out. The force that stretches isn't coming from the outside but from the inside.
Did you even read my post?
There's no such thing as a ping-pong Universe since it is currently accelerating. Which means this EXTRA energy, EVEN if hypothetically it will magically contract or God decides to contract it later, had to come from somewhere. Which means, the next time, if there's no more such external energy left, it wouldn't be the same.
No matter how you put it, there's simply no equillibrum.
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stankelbenet
Adventuring Hero
bringer of nostalgia & darknes
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posted May 27, 2009 09:11 PM |
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unlimited = x/0
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Did you even read my post?
There's no such thing as a ping-pong Universe since it is currently accelerating. Which means this EXTRA energy, EVEN if hypothetically it will magically contract or God decides to contract it later, had to come from somewhere. Which means, the next time, if there's no more such external energy left, it wouldn't be the same.
No matter how you put it, there's simply no equillibrum.
Physics is abstract when it comes to potential and kinetic energy AKA mechanics. They're mostly used to work with forces and friction so we can understand those(the truth is: We don't understand anything, but we guess we're on the right track). Potential energy is determined by the force, that is affecting it, and how high the object is elevated above the constant term. The problem here is: We can put the constant term where we want. Gravity stops by the core of the planet so potential energy could be determined on our planet. There's just so many types of forces and some of them don't have any ending point. Simultaneously I'm also affected by the forces from the moon and the sun and all mass in the universe.
If we take our world, the size is unlimited. The force of diffusion doesn't have any ending point. The potential energy within our universe is thereby unlimited
Thermodynamics rock! Of course the amount of energy is eternal if it's unlimited
Post Scriptum: My english sucks, so if you can't understand it, blame me .
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TheDeath
Responsible
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with serious business
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posted May 27, 2009 09:40 PM |
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You confuse energy with force. Force is abstract, energy is not.
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Corribus
Hero of Order
The Abyss Staring Back at You
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posted May 27, 2009 09:56 PM |
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@Death
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There's no such thing as a ping-pong Universe since it is currently accelerating.
Just because an acceleration is positive now does not mean it will always be. There's no scientific consensus now about the ultimate fate of the universe. The Big Crunch scenario isn't as popular now as it once was, but nobody has been able to rule it out.
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I'm sick of following my dreams. I'm just going to ask them where they're goin', and hook up with them later. -Mitch Hedberg
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TheDeath
Responsible
Undefeatable Hero
with serious business
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posted May 27, 2009 10:03 PM |
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Just because an acceleration is positive now does not mean it will always be.
You realize it would have to at least stop accelerating first and then decelerate like hell.
Can you please point me what makes the Big Crunch more likely than a creator, since both are based on 0 evidence?
Further if it is accelerating it means it gets energy from somewhere, which would rule out completely the idea that "Big Bangs happen infinitely many times" since that energy would either wear out, or be infinite.
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stankelbenet
Adventuring Hero
bringer of nostalgia & darknes
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posted May 27, 2009 10:12 PM |
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This post will not be edited
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You confuse energy with force. Force is abstract, energy is not.
Tomorrow I will answer with illustrations.
I don't have time right now since I'm doing my physics homework, which should've been handed in yesterday .
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Corribus
Hero of Order
The Abyss Staring Back at You
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posted May 28, 2009 12:14 AM |
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You realize it would have to at least stop accelerating first and then decelerate like hell.
The acceleration can steadily decrease until it becomes a deceleration. It doesn't have to be a rapid change, especially when you're talking about billions and billions of years in which it can happen.
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Can you please point me what makes the Big Crunch more likely than a creator, since both are based on 0 evidence?
You of all people should know that's really a nonquestion. If you're just trying to be funny or rhetorical, then fine. But "creator" isn't scientific and thus is impossible to quantify, so asking whether a scientific hypothesis has more or less likelihood of being true than a "creator" is purposeless.
All models of the fate of the universe are based only on extrapolation of a very incomplete dataset, and we lack a lot of the pertinent information (omega factor, universe density, e.g.). Most of them are speculative at this point, so there's really zero "evidence" that unequivocally "prove" one hypothesis or the other. I'm sure if you are genuinely interested, you can look up some real sources of information about the Big Crunch hypothesis - both factors in support of it as well as factors which support other models (Heat Death, etc.) But to suggest that the Big Crunch hypothesis is some sort of pseudoscience on the level of creationism just demonstrates your ignorance of modern cosmology.
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Further if it is accelerating it means it gets energy from somewhere, which would rule out completely the idea that "Big Bangs happen infinitely many times" since that energy would either wear out, or be infinite.
First, that doesn't make much sense; beyond that, you are assuming the universe is a closed system. Another important point is that applying classical thermodynamics to such exotic physical systems is probably not the best way to go about it. Understanding how the laws of thermodynamics behave in relativistic quantum systems is very much an active area of theoretical physics, so it's rather amusing that amateurs think they can easily disprove current cosmological theories with arguments as simple as "well it's against the law of conservation of energy", as if the world's greatest physicists somehow haven't thought to consider something they learned in high school physics class.
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I'm sick of following my dreams. I'm just going to ask them where they're goin', and hook up with them later. -Mitch Hedberg
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TheDeath
Responsible
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with serious business
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posted May 28, 2009 12:39 AM |
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Edited by TheDeath at 00:41, 28 May 2009.
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You of all people should know that's really a nonquestion. If you're just trying to be funny or rhetorical, then fine. But "creator" isn't scientific and thus is impossible to quantify, so asking whether a scientific hypothesis has more or less likelihood of being true than a "creator" is purposeless.
Creator is definitely, to a certain extent, scientifical. Of course, I said a "creator", not THE creator, or THE God, but ANY creator, maybe machines and we're in a virtual world?
While I agree about the fact that we lack the complete dataset, it seems to me that there is no way that anything supports a contracting Universe -- even if the redshifts are caused by something else, that would render it a stationary Universe at worst, not a contracting one!
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But to suggest that the Big Crunch hypothesis is some sort of pseudoscience on the level of creationism just demonstrates your ignorance of modern cosmology.
Then what is it?
That would be like saying, that you have a hypothesis that objects go upwards because of gravity. Then when you see the evidence that they fall, you mean that "going upwards" is still science?
Or rather, "maybe sometime later they will start to go upwards instead"? I mean of course, such a thing may be weirdly possible I do not dismiss it at all, seeing as how I'm not the most scientifical freak out here, BUT how can that thing be considered science?
Like Planck said, there's no reason to assume that tomorrow the laws of physics will continue to function in the same way. But until then all we have are guesses, what-ifs, and science doesn't deal with that, even if they would be true. (I'm talking about a change in evidence, while I absolutely do NOT say it's impossible at all, I just don't see it as scientific, but I have no problem with it since i'm not, again, an all scientific freak ).
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First, that doesn't make much sense; beyond that, you are assuming the universe is a closed system. Another important point is that applying classical thermodynamics to such exotic physical systems is probably not the best way to go about it.
But that was mvass' only argument, to which I was replying
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mvassilev
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posted May 28, 2009 12:42 AM |
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It might not be a Big Crunch, though that is the best idea based on what I know of the subject. Nevertheless, even if there was no Big Crunch, that still does not imply a creator.
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Eccentric Opinion
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TheDeath
Responsible
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posted May 28, 2009 12:52 AM |
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It might not be a Big Crunch, though that is the best idea based on what I know of the subject. Nevertheless, even if there was no Big Crunch, that still does not imply a creator.
No, but it renders the "Time is a circle" thing wrong (metaphorically of course)
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Corribus
Hero of Order
The Abyss Staring Back at You
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posted May 28, 2009 01:21 AM |
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Edited by Corribus at 01:21, 28 May 2009.
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@Death
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Creator is definitely, to a certain extent, scientifical.
Actually, it's not scientific to any extent at all.
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While I agree about the fact that we lack the complete dataset, it seems to me that there is no way that anything supports a contracting Universe -- even if the redshifts are caused by something else, that would render it a stationary Universe at worst, not a contracting one!
It seems to me that you aren't even familiar with the idea as a real scientific theory. Rather than just thumbs-downing the idea out of prejudice, I urge you to actually find out some information first. This isn't an idea that was just pulled out of air. There are a number of theoretical models that predict a Big Crunch is possible. You don't have to go to the primary literature to find out about it, either (though certainly there have been papers published). I'm sure you can find a Scientific American article or some other popular literature that gives you lots of pretty pictures and simple explanations describing the theory.
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That would be like saying, that you have a hypothesis that objects go upwards because of gravity. Then when you see the evidence that they fall, you mean that "going upwards" is still science?
Not at all. It's more like if you've lived your whole life in outerspace and someone showed you a movie of a cannon shooting off a ball, and then they stopped the movie while the ball was still ascending and they asked you what the ball would be doing 10 minutes later. Well if you extrapolate from current and past position, you'd reach the conclusion that the ball would keep going up forever. But of course, being an extrapolation and not interpolation, your conclusion would have a large margin of error and in this case would in fact be wrong. We know eventually the ball would reach an apex and then start falling. Common sense. But not to the guy from outerspace - he's making an extrapolative conclusion based on an incomplete set of data.
We don't know what the final fate of the universe is going to be because there are a number of unknown variables that will have an impact on the final result. We have red-shift values which show the universe is expanding, but those data represent the edges of the universe as it was in the past (far in the past), not as it is now. We have evidence that suggest that the expansion may be accelerating. Again, now, not in the future.
Consider if you will a car that is accelerating in the X direction. What conclusions can we make from that fact? Do we know where the car will be 10 minutes from now? Do we know it's rate of speed or acceleration 10 minutes from now? Of course not. The degree to which we can predict the future depends on our ability to define all the forces/conditions involved. However, a single acceleration value doesn't tell you anything about the various forces that sum up to give you that value of acceleration at this one given instant. For instance, let's assume there are only two forces involved: the force of the engine driving the car and a reverse force due to friction of the tires (in truth there are probably countless others). The car's acceleration at time t is due to the counteracting forces of friction and the engine driving it forward. However, there's no assurance that those two forces are constant in magnitude in time. If they were, you could easily predict the car's properties 10 minutes after time t. But let's say that 5 minutes later the conditions of the road change and the friction goes up, which decrease the car's acceleration so much that it begins to decelerate. Or perhaps a rainstorm comes which lessens the friction. Or the air pressure changes, increasing the air resistance force. Or, or, or. Even when you can identify all the forces giving rise to a single acceleration value, you don't know how those forces change in time. And if you don't know what forces drive the object's motion/properties, the uncertainty is exponentially worse.
So, we have an acceleration value for the universe at time t (say, now), which might, if you extrapolate out, suggest that the universe will continue to expand at faster and faster velocities until the velocity is infinite. But I'm sure you don't know all the forces involved, do you? If you don't, your ability to extrapolate with accuracy is poor. So, different models of the universe's fate are based on different hypotheses of what forces are involved, and their respective magnitudes. Of course, one of those forces is gravity, and how well do we really understand gravity?
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Like Planck said, there's no reason to assume that tomorrow the laws of physics will continue to function in the same way. But until then all we have are guesses, what-ifs, and science doesn't deal with that, even if they would be true.
I'm not even talking about the "laws of physics" changing (in actuality or just our understanding of them). You don't have to be that exotic. Just the simple fact that we don't understand the conditions of the system means we can't predict the future with any degree of certainty. Yet. That's why we study the heavens.
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I'm sick of following my dreams. I'm just going to ask them where they're goin', and hook up with them later. -Mitch Hedberg
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TheDeath
Responsible
Undefeatable Hero
with serious business
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posted May 28, 2009 01:41 AM |
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Actually, it's not scientific to any extent at all.
Do you think artificial intelligence isn't science as well? Just wondering though (no I don't know what you'll answer).
If we have it, we have done it to a limited extent in our virtual worlds.
What would be interesting is if they would also make a virtual world inside our virtual world -- and so on. That would be really something don't you think?
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It seems to me that you aren't even familiar with the idea as a real scientific theory. Rather than just thumbs-downing the idea out of prejudice, I urge you to actually find out some information first. This isn't an idea that was just pulled out of air. There are a number of theoretical models that predict a Big Crunch is possible. You don't have to go to the primary literature to find out about it, either (though certainly there have been papers published). I'm sure you can find a Scientific American article or some other popular literature that gives you lots of pretty pictures and simple explanations describing the theory.
I'm pretty aware of the Big Crunch. But no matter how nice it sounds, it doesn't make it more plausible, especially if the current interpretation of the evidence suggests the opposite. (yes, interpretation).
Einstein had debates with Bohr around quantum mechanics because "it didn't make any sense" or that it doesn't sound nice to be based on probabilities (Einstein said God, or the Universe, doesn't play dice; you can expect why he was against it). You can't argue with evidence tho, as Einstein learned later
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Not at all. It's more like if you've lived your whole life in outerspace and someone showed you a movie of a cannon shooting off a ball, and then they stopped the movie while the ball was still ascending and they asked you what the ball would be doing 10 minutes later. Well if you extrapolate from current and past position, you'd reach the conclusion that the ball would keep going up forever. But of course, being an extrapolation and not interpolation, your conclusion would have a large margin of error and in this case would in fact be wrong. We know eventually the ball would reach an apex and then start falling. Common sense. But not to the guy from outerspace - he's making an extrapolative conclusion based on an incomplete set of data.
Please tell me how is that different than "an Earth being was gazing at the heavens and said that there's no God cause it doesn't see any, but then some aliens came and take it on a trip to the 'edge' of the Universe and showing it something else." (whatever, that sounded bad but you get the idea).
It is POSSIBLE. But there's no reason, based on current evidence, to suggest it. This is mvass favorite argument too
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Again, now, not in the future.
I agree but we can take ANY guess at what will happen, but none have any basis at the moment.
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Consider if you will a car that is accelerating in the X direction. What conclusions can we make from that fact? Do we know where the car will be 10 minutes from now? Do we know it's rate of speed or acceleration 10 minutes from now? Of course not. The degree to which we can predict the future depends on our ability to define all the forces/conditions involved. However, a single acceleration value doesn't tell you anything about the various forces that sum up to give you that value of acceleration at this one given instant. For instance, let's assume there are only two forces involved: the force of the engine driving the car and a reverse force due to friction of the tires (in truth there are probably countless others). The car's acceleration at time t is due to the counteracting forces of friction and the engine driving it forward. However, there's no assurance that those two forces are constant in magnitude in time. If they were, you could easily predict the car's properties 10 minutes after time t. But let's say that 5 minutes later the conditions of the road change and the friction goes up, which decrease the car's acceleration so much that it begins to decelerate. Or perhaps a rainstorm comes which lessens the friction. Or the air pressure changes, increasing the air resistance force. Or, or, or. Even when you can identify all the forces giving rise to a single acceleration value, you don't know how those forces change in time. And if you don't know what forces drive the object's motion/properties, the uncertainty is exponentially worse.
What about a lightning strike hitting the car?
I understand what you mean, I just am saying, that those are just guesses AT THE MOMENT, obviously not later on.
I'm not saying you're saying something false, I'm saying that it's just a guess for now -- I myself claim that I don't know. But why would I take your guess and not some other, or that the lightning will hit the car, or that God will come and move the car or take it away??
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Corribus
Hero of Order
The Abyss Staring Back at You
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posted May 28, 2009 05:28 AM |
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Edited by Corribus at 04:01, 29 May 2009.
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@Death
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Do you think artificial intelligence isn't science as well? Just wondering though (no I don't know what you'll answer).
See, that's a trick question. If you mean something like the Matrix (Yeah I know, your favorite movie of all time), where an AI which is unperceivable to us (without purposely revealing itself) created our world, then that's really no different from the great philosophical deceiver or god or whatever you want to call it. If you can't test it, it's not scientific. Could a sophisticated AI have built this elaborate world, something like Plato's Cave? Ok, sure. Is it a scientific theory? No.
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I'm pretty aware of the Big Crunch. But no matter how nice it sounds, it doesn't make it more plausible, especially if the current interpretation of the evidence suggests the opposite. (yes, interpretation).
There is certainly no consensus of interpretation of what little evidence exists.
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Einstein had debates with Bohr around quantum mechanics because "it didn't make any sense" or that it doesn't sound nice to be based on probabilities (Einstein said God, or the Universe, doesn't play dice; you can expect why he was against it). You can't argue with evidence tho, as Einstein learned later
That's a bit of a misrepresentation of the debate between Bohr and Einstein. The argument was really over the philosophical interpretations of quantum theory (determinism, etc.), not over whether the theory was right. Nobody really knows if the Copernican Interpretation is right - and that's more of a metaphysical discussion than a scientific one in any case.
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It is POSSIBLE. But there's no reason, based on current evidence, to suggest it. This is mvass favorite argument too
Well, I at least see now why you're taking this line of argument, but I think you are confusing the typical Occam's Razor principle with a complex prediction of the future.
Certainly, you don't add extra widgets to a theory without a compelling reason to do so. If current data led to the unequivocal conclusion that the universe was destined to go on expanding forever, then I agree that you don't go making up new alternate models unless you have new data that warrants it.
But cosmologists aren't anywhere near that point yet. There isn't enough data to suggest an extrapolation to infinite expansion. If you look at any of the popular literature, you'll find that a lot of the fate of the universe is dependent on the density of the universe, a value that nobody has been able to estimate properly. There's the whole dark matter issue that's not solved. And so on.
So I'll go back to my car analogy. If I were to say to you that the car is accelerating at X m/s2 at time t, and then asked you to predict what its velocity/position/whatever was 10 minutes from now, you might theorize based on the available information that the car would have a velocity of X m/s, calculated assuming that the acceleration does not change. However, that theory is only as good as your assumptions, which in this case are horrible. Just because the data might indicate that your theory is correct, it would be equally valid to make other theories based on alternate models the system at hand. What you'd probably have is a theory that gives several possible alternatives based on criteria A, B, and C, and then you, as a good scientist, would go about trying to better define the system (what's the air density, surface friction, weather conditions, etc.) so to make the theory better.
Here with the universe you have the same scenario. What you have is a value of acceleration and the fact that things are moving away from each other. Based on that very simplistic viewpoint, then the obvious first generation theory would be that the universe is going to expand forever. Well, that would be true assuming X, Y, and Z. However, if NOT X, Y, and Z, then this other thing might happen.
So, what you really get is a complex picture of the future with very different alternatives (continual acceleration, heat death, big crunch, all kinds of fancy names) based on the attributes of the system (one of which, as I said, is average density). Now scientists study those attributes, get better data, and refine the model to try to eliminate possibilities. That's the way it works, as I'm sure you understand.
Big Crunch, Heat Death, etc. - they're all testable theories, but they're really all facets of the same thing. But, I think you'll find, that scientists haven't really been able to get close to ruling anything out yet. There are just too many variables at this point, too much information we don't have.
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I'm not saying you're saying something false, I'm saying that it's just a guess for now -- I myself claim that I don't know. But why would I take your guess and not some other, or that the lightning will hit the car, or that God will come and move the car or take it away??
But you see, assuming that things will be in the future as they are now is just as much a guess as the alternative. You can't plan for eventualities - but you can try to model the factors which will change the forces involved in a predictable way. You can't easily predict a lightning bolt that's going to slam your car to a halt (and I certainly wouldn't try to incorporate something like that into a scientific theory, because it's an isolated, statistically insignificant incident); but you can easily predict the forces of friction on the road, the air resistance, etc., given enough information on the system.
____________
I'm sick of following my dreams. I'm just going to ask them where they're goin', and hook up with them later. -Mitch Hedberg
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stankelbenet
Adventuring Hero
bringer of nostalgia & darknes
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posted May 28, 2009 04:50 PM |
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Now you will all convert to the only true belief, which is SCIENCE!
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Creator is definitely, to a certain extent, scientifical.
Actually, it's not scientific to any extent at all.
The best argument EVAR! A creator is just as scientifically possible as the idea about conservation of energy: Since we can't make an isolated system, we have no idea of what would happen in it.
Theology is in fact just as scientific as biology. Theology is seeking understanding in our world; how it was created, how it all works, how it all will end.
@TheDeath
sorry no images. Seems like I have to find them on the internet. There was none, which I could use.
I will first write about some general mechanics, which you probably know all about. I just need these as proof:
E(potential) = F(force) * H(Height above the constant term)
the constant term is placed where we want it
F = m(mass) * a(acceleration)
Example:
I have a stone(1 kg(that should give just about 10 N)) which I have elevated 2 metres above the ground. The energy I have used and thereby stored in the stone is:
10 N * 2 m = 20 J
As I drop this stone the potential energy will be converted into kinetic energy. Just before it hits the ground, the potential energy is 0 Joule and the kinetic energy is 20 Joule. The laws of conservation haven't been violated. Now I pick up the stone again and bring it to a hole, which is 1 meter deep. I lift the stone 2 metres above the ground and let go of it. As it passes the constant term, which is ground level, the potential energy is 0 J and the kinetic is 20 J. But the stone continues another meter. just before it hits the bottom the potential energy is:
10 N * (-1) m = (-10) J
and the kinetic energy is 30 J. These two put together are still 20 J
Now instead of thinking our gravity as the force, it's diffusion. Instead of a stone it's the border of our universe. The vacuum around our universe sucks it apart.
I won't be writing values, since I have no idea of how much it is.
6386456341886652495488153885412354668462148846842344.968984554789668743688433216518 MN
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You confuse energy with force. Force is abstract, energy is not.
What I meant when I said abstract was unmeasurable. I don't why you see force as abstract .
Potential and kinetic energy aren't very measureable. Potential because of the constant term. Kinetics because it's based on speed. Speed is different when you measure it from different angles and speeds. If you're accelerating in a car towards west, you're actually decelerating compared to the core of the earth . Perfect joke to use when you've driven too fast towards west.
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TheDeath
Responsible
Undefeatable Hero
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posted May 29, 2009 01:04 AM |
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See, that's a trick question. If you mean something like the Matrix (Yeah I know, you're favorite movie of all time), where an AI which is unperceivable to us (without purposely revealing itself) created our world, then that's really no different from the great philosophical deceiver or god or whatever you want to call it. If you can't test it, it's not scientific. Could a sophisticated AI have built this elaborate world, something like Plato's Cave? Ok, sure. Is it a scientific theory? No.
What about the likelihood?
Suppose we create a virtual world, and the "humans" inside of it also create a virtual world, which in turn create a virtual world.
Wouldn't it be somewhat naive to think that 'we are special' since every one of them feels the same? In my opinion, the likelihood would go to almost 100%.
And Matrix isn't my favorite movie, it's just philosophical about this point -- I never actually implied anything about the Matrix movie itself, just the concept.
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That's a bit of a misrepresentation of the debate between Bohr and Einstein. The argument was really over the philosophical interpretations of quantum theory (determinism, etc.), not over whether the theory was right. Nobody really knows if the Copernican Interpretation is right - and that's more of a metaphysical discussion than a scientific one in any case.
Obviously in fact, it's very similar. My point was that Einstein did not say it's 'wrong theory' because it did predict the data in experiments. Notice that Einstein thought that "there had to be a different way to explain it", just like here: There 'has' to be a different way to explain the expansion and acceleration, so as to result in a Big Crunch somehow.
That is what I was talking about.
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Certainly, you don't add extra widgets to a theory without a compelling reason to do so. If current data led to the unequivocal conclusion that the universe was destined to go on expanding forever, then I agree that you don't go making up new alternate models unless you have new data that warrants it.
But cosmologists aren't anywhere near that point yet. There isn't enough data to suggest an extrapolation to infinite expansion. If you look at any of the popular literature, you'll find that a lot of the fate of the universe is dependent on the density of the universe, a value that nobody has been able to estimate properly. There's the whole dark matter issue that's not solved. And so on.
So I'll go back to my car analogy. If I were to say to you that the car is accelerating at X m/s2 at time t, and then asked you to predict what its velocity/position/whatever was 10 minutes from now, you might theorize based on the available information that the car would have a velocity of X m/s, calculated assuming that the acceleration does not change. However, that theory is only as good as your assumptions, which in this case are horrible. Just because the data might indicate that your theory is correct, it would be equally valid to make other theories based on alternate models the system at hand. What you'd probably have is a theory that gives several possible alternatives based on criteria A, B, and C, and then you, as a good scientist, would go about trying to better define the system (what's the air density, surface friction, weather conditions, etc.) so to make the theory better.
Here with the universe you have the same scenario. What you have is a value of acceleration and the fact that things are moving away from each other. Based on that very simplistic viewpoint, then the obvious first generation theory would be that the universe is going to expand forever. Well, that would be true assuming X, Y, and Z. However, if NOT X, Y, and Z, then this other thing might happen.
So, what you really get is a complex picture of the future with very different alternatives (continual acceleration, heat death, big crunch, all kinds of fancy names) based on the attributes of the system (one of which, as I said, is average density). Now scientists study those attributes, get better data, and refine the model to try to eliminate possibilities. That's the way it works, as I'm sure you understand.
Big Crunch, Heat Death, etc. - they're all testable theories, but they're really all facets of the same thing. But, I think you'll find, that scientists haven't really been able to get close to ruling anything out yet. There are just too many variables at this point, too much information we don't have.
Yes but with the current data, the only theories that at least predict the CURRENT data (and variables) are those that assume the Universe is going to expand forever.
Obviously I am not saying that this theory is going to be the universal truth. In fact, doing so would render it into a religion. But UNTIL any data is pointed out to make the assumption of Big Crunch at least to predict some data (which currently it doesn't), then there's no reason to say it. Of course this doesn't mean we have to stop "looking" at alternative variables/data, it only means that those are at this point, based on nothing other than, well, assumptions.
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But you see, assuming that things will be in the future as they are now is just as much a guess as the alternative.
Exactly but at least the accelerating model predicts the data, so it passes a few tests CURRENTLY, contrary to a contraction theory, which currently passes none.
Anyway your post was really insightful for me
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TheDeath
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posted May 29, 2009 01:11 AM |
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Edited by TheDeath at 01:12, 29 May 2009.
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@stankelbenet: Quote:
What I meant when I said abstract was unmeasurable. I don't why you see force as abstract.
Because force is only a measure of the effects we perceive.
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Potential and kinetic energy aren't very measureable.
Because they aren't energies in the real sense. When I say energy I mean relativistic energy -- photons or mass particles (which is also energy, E=mc^2). Well kinetic is less abstract.
And yes they are measurable.
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Now instead of thinking our gravity as the force, it's diffusion. Instead of a stone it's the border of our universe. The vacuum around our universe sucks it apart.
I won't be writing values, since I have no idea of how much it is.
You mean the Universe is pulled out by gravity? I don't really get it though -- that would be one possible theory but can it predict more than current theories? (not that it would be more complicated, if you ask me "dark matter" is also 'complicated' or more complicated than necessary -- Occam's Razor and all that).
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If you're accelerating in a car towards west, you're actually decelerating compared to the core of the earth. Perfect joke to use when you've driven too fast towards west.
Deceleration happens in a certain direction, in this case, you would reduce your angular momentum (which is mostly given by the Earth).
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Corribus
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posted May 29, 2009 04:07 AM |
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@Death
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What about the likelihood?
What about it?
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Yes but with the current data, the only theories that at least predict the CURRENT data (and variables) are those that assume the Universe is going to expand forever.
The point of science is to explain the past/present so you can predict the future.
I guess you and I are just having a disconnect - I think we're sort of arguing about different things.
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Exactly but at least the accelerating model predicts the data, so it passes a few tests CURRENTLY, contrary to a contraction theory, which currently passes none.
It does? We don't really have enough data yet to apply a model to! You can't say a theory that a car goes on accelerating forever fits a single data point better than a theory that predicts it will decelerate in the future. You only have one data point, so there's not enough data to make ANY reasonable prediction....
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I'm sick of following my dreams. I'm just going to ask them where they're goin', and hook up with them later. -Mitch Hedberg
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TheDeath
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posted May 29, 2009 06:45 PM |
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What about it?
Well I just mentioned it in my post (it was meant to be a question that I answered "my way", not posed to you ).
This would fall, at least slightly into science, because we could use data from our virtual worlds (in which we are gods) to predict things in there -- extrapolating it to "a higher level" (i.e from which we are seen as virtual entities) is based, at least, on something.
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The point of science is to explain the past/present so you can predict the future.
I guess you and I are just having a disconnect - I think we're sort of arguing about different things.
I thought it was the opposite: predicting the future with theories. If they fail (compared to data), it means it's wrong or has to be adjusted. But until then, if they have passed tests since, they are pretty valid, no?
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It does? We don't really have enough data yet to apply a model to! You can't say a theory that a car goes on accelerating forever fits a single data point better than a theory that predicts it will decelerate in the future. You only have one data point, so there's not enough data to make ANY reasonable prediction....
I mean we don't see this acceleration changing. If it did, we would have to use a different model/approximation, but currently it seems constant. Assuming it is going to be constant in the next 5 seconds isn't unreasonable. You can do that for more than just 5 seconds too (and at least, compared to contraction, it is based on something even though limited -- i.e our current constant acceleration (I think?) observations). But once the model fails to predict it is either adjusted or changed. I thought that was the whole point of science?
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