Measurements Confirm Universe Is Expanding Faster Than Expected (sciencedaily.com) 186
Slashdot reader The Snazster shares a report from ScienceDaily, reporting on materials provided by Johns Hopkins University: New measurements from NASA's Hubble Space Telescope confirm that the Universe is expanding about 9% faster than expected based on its trajectory seen shortly after the big bang, astronomers say. The new measurements, published April 25 in the Astrophysical Journal Letters, reduce the chances that the disparity is an accident from 1 in 3,000 to only 1 in 100,000 and suggest that new physics may be needed to better understand the cosmos.
In this study, [Adam Riess, Bloomberg Distinguished Professor of Physics and Astronomy at The Johns Hopkins University, Nobel Laureate and the project's leader] and his SH0ES (Supernovae, H0, for the Equation of State) Team analyzed light from 70 stars in our neighboring galaxy, the Large Magellanic Cloud, with a new method that allowed for capturing quick images of these stars. The stars, called Cepheid variables, brighten and dim at predictable rates that are used to measure nearby intergalactic distances. The usual method for measuring the stars is incredibly time-consuming; the Hubble can only observe one star for every 90-minute orbit around Earth. Using their new method called DASH (Drift And Shift), the researchers using Hubble as a "point-and-shoot" camera to look at groups of Cepheids, thereby allowing the team to observe a dozen Cepheids in the same amount of time it would normally take to observe just one. [...] As the team's measurements have become more precise, their calculation of the Hubble constant has remained at odds with the expected value derived from observations of the early universe's expansion by the European Space Agency's Planck satellite based on conditions Planck observed 380,000 years after the Big Bang. "This is not just two experiments disagreeing," Riess explained. "We are measuring something fundamentally different. One is a measurement of how fast the universe is expanding today, as we see it. The other is a prediction based on the physics of the early universe and on measurements of how fast it ought to be expanding. If these values don't agree, there becomes a very strong likelihood that we're missing something in the cosmological model that connects the two eras."
In this study, [Adam Riess, Bloomberg Distinguished Professor of Physics and Astronomy at The Johns Hopkins University, Nobel Laureate and the project's leader] and his SH0ES (Supernovae, H0, for the Equation of State) Team analyzed light from 70 stars in our neighboring galaxy, the Large Magellanic Cloud, with a new method that allowed for capturing quick images of these stars. The stars, called Cepheid variables, brighten and dim at predictable rates that are used to measure nearby intergalactic distances. The usual method for measuring the stars is incredibly time-consuming; the Hubble can only observe one star for every 90-minute orbit around Earth. Using their new method called DASH (Drift And Shift), the researchers using Hubble as a "point-and-shoot" camera to look at groups of Cepheids, thereby allowing the team to observe a dozen Cepheids in the same amount of time it would normally take to observe just one. [...] As the team's measurements have become more precise, their calculation of the Hubble constant has remained at odds with the expected value derived from observations of the early universe's expansion by the European Space Agency's Planck satellite based on conditions Planck observed 380,000 years after the Big Bang. "This is not just two experiments disagreeing," Riess explained. "We are measuring something fundamentally different. One is a measurement of how fast the universe is expanding today, as we see it. The other is a prediction based on the physics of the early universe and on measurements of how fast it ought to be expanding. If these values don't agree, there becomes a very strong likelihood that we're missing something in the cosmological model that connects the two eras."
Someone (Score:4, Funny)
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There appears to be something to [phys.org]
Re:Someone made dark matter disappear? (Score:5, Insightful)
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It decreases the expected amount of "dark matter". Dark Matter fills in the missing matter in equations to describe gravitational reduction of the Hubble Constant over cosmic distances. There remains no compelling physical reason to describe it as strings, "Dark Energy", "non-baryonic matter", or anything other than experimental error or, possibly, a much higher amount than expected of intra-galictic congealed matter such as rogue planets.
Buzzword bingo fail. (Score:2)
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I'm no expert here, but you appear to not know what you're talking about. And although I haven't done anything crazy like RTFA yet, the implications of this discovery are probably not known or agreed on.
Re:Someone made dark matter disappear? (Score:5, Informative)
We also know that Dark Matter is not just an error in General Relativity as Modified Newtonian Dynamics suggests. We know for instance, that the Bullet Cluster, where two galaxies have nearly collided, can't be explained by MOND. Here, the nearly-collission has separated baryonic, electromagnetically-interacting matter from Dark Matter (we can tell the distribution of Dark Matter via the gravitational lensing). We know galaxies, which apparently don't have Dark Matter. Thus Dark Matter has its own existance and is not just a property of galaxies and thus cannot be described solely by modifications of General Relativity. It can be part of a galaxy, but it does not necessarily do so. The same problem arises from NGC 604, where you have a very hot cloud of interstellar gas, as we can tell from their X-radiation. But hot gas contains many particles at high speed, and the gas cloud should long have been spread out in the neighbouring space except for a force that keeps the particles at their place despite their high speed.
We also can tell the existance of Dark Matter from the Big Bang. Calculations reveal that there were not enough protons and neutrons in the early universe to form atoms and larger structures, as the amount of radiation was much to high and would have destroyed any structures immediately. On the other hand, we know from the cosmic background radiation, when the electrons have started to orbit protones and neutrones and allowed electromagnetic radiation to actually travel some distances without interacting with (baryonic) matter. Thus we can calculate how much additional mass we need in the early universe which doesn't interact with radiation (a.k.a. electromagnetic fields) to allow for the first structures to exist. And those calculations give the same ratio between baryonic and Dark matter of about five to one as we also get from the rotational observation in galaxies.
What we know and what we don't (Score:5, Informative)
Physicists know that Dark Matter acts like a mass. For instance, it bends Spacetime and contributes heavily to the gravitational lensing of galaxies.
This is apparently true. But acting like a mass and actually being matter (exotic or not) are not necessarily the same thing. It's a subtle point I'll admit but an important one.
We also know that Dark Matter is not just an error in General Relativity as Modified Newtonian Dynamics suggests.
No we do not "know" that. A lot of parameters have been established for what dark matter is have been determined. Quite a few possibilities have been ruled out but we have not (yet) conclusively determined that the observations cannot be explained with a better model rather than some new form of matter. The evidence certainly seems to be pointing in the direction of dark matter being some physical thing but the simple fact is that we still have no really good idea what it actually is. All we know is some of the things it isn't. Just because MOND and various other models haven't worked out does not imply that we have exhausted all possibilities regarding model error.
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Incomplete evidence (Score:4, Interesting)
The variation between galaxies seems to strongly argue against it being just an error in the model, barring the discovery of some relevant common factors which the model could use to explain the variation.
I don't disagree that the preponderance of evidence seems to be pointing in the direction of dark matter actually being some physical thing. But until we have some actual direct observation pinpointing what it actually must be, we cannot actually be certain of that. A better model is still an option on the table at present even if it seems increasingly unlikely. All we know for certain right now is a lot of things which dark matter is NOT. We have not exhausted all possibilities and should not pretend we have.
We know for a fact that our current models work very well for a lot of things but we also know for a fact they are incomplete and incompatible with each other. We have not fit gravity into the Standard Model. Until we do or until we have some direct observation that pins down what dark matter must be, the option of a better model (rather than some physical phenomena) will remain on the table even if it isn't the most likely solution to the problem.
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The more I hear about Dark Matter, the more I realize that "Gravity" is far more subtle than we suspect. We have taken our current understanding of the Universe as far as we can and what we need to do is elevate our understanding of the Universe to progress towards a deeper understanding. Instead, we are twisting as hard as we can on the current models, which are CLEARLY insufficient... but nobody wants to recommend new models.
Here is an example of a radical new model that does not invalidate anything that
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Physicist can for instance pretty much rule out that Dark Matter contains any baryons (e.g. protons, neutrons, hyperons)
They can? Have they?
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No. It just increases the Dark Energy or at least the effect it has on the universe.
That doesn't make much sense assuming that the amount Dark Energy has remained constant since the Big Bang. I think a increase in the speed of expansion implies some weird properties of Dark Energy like increased repulsion strength with distance
Quite an age (Score:5, Insightful)
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That's why I always think I'm the center of the Universe. I am actually the center!
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He'll need a lot of SD cards.
Can space itself be energy? (Score:5, Interesting)
What if space itself is energy? An energy which we perceive as space rather than matter. Do not confuse this idea with the vacuum energy.
If space is energy that means everything in the Universe is energy. Basically, the Universe can be thought of as a giant ball of energy. There is no need to separate the Universe into space and energy.
In this context dark energy can be considered a kind of energy which has not turned into space, yet. As the Universe expands I think dark energy decreases. At least that's my idea.
Re:Can space itself be energy? (Score:5, Insightful)
And here we have a good example of what happens when you legalize marijuana.
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And more to the point, whats effect does this have on how much "dark matter" are we looking for? as I believe the rate of expansion was related to the gravitational effects of DM
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It's a fun idea, sweetie. You should do an experiment to see if it's true or not.
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Sir! Put down the crack pipe, keep your hands where we can see them, and slowly back away from the keyboard
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If space is energy, and we are not to confuse it with vacuum energy, then it must be some mighty special energy. When physicists speak of dark energy, they aren't saying it is some mysterious form of energy. It is simply the "stuff" they need for their math to make sense.
Now go try the little pink pills, the little yellow ones are not strong enough for you.
Re: Can space itself be energy? (Score:1)
Matter can neither be created nor destroyed.
Dark matter is normal matter that the math shows is unaccounted for.
Dark energy is normal energy that the math shows is unaccounted for.
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Except that "dark energy" is repeatedly analyzed as some extraordinary form of matter, undetectable by ordinary means, such as "sstrings".
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1) Science comes up with math that doesn't describe what is observed
2) Rather than say "shit, what we came up with doesn't work," scientists make up some shit to add to their math to force it to work
3) Then, scientists set out to prove that $shit exists rather than discover the math that DOES describe what is observed
This is not science.
Yeh. why 3 dimensions (Score:1)
Yeh, why 3 dimensions, why do they act like they're independent.... I see you attracted a bunch of trolls for asking a simple question, just ignore them. Whiney little dung beetles defending their pile of dung.
"An energy which we perceive as space"
Let me walk you through a rejected thought experiment.
1. Consider time, if you observe an electron moving from X1 to X2, you do it by for example electrons in your brain moving from X1A to X2A....
2. If your brain required the electron in the brain to move 1000x fu
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If I had to make a wild-ass guess, I would guess that spacetime is a field created by "compressing/fusing" energy into matter. Matter is an artifact of energy so to speak. This seems to align nicely with your idea.
If space is energy that means everything in the Universe is energy. Basically, the Universe can be thought of as a giant ball of energy. There is no need to separate the Universe into space and energy.
Well... there kind of is a need. I could call the Earth and everything that exists on/around it to be nothing more than the condensation of variations on the Hydrogen atom.... but that ignores all the interesting shit like lagoons with shoals of fish schooling about or amber waves of grain and pre
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I just had an idea, too: Energy = Force + Information
I would make my equation more complex, but all the other thousands of variables cancel each other out so they're not important.
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What is wrong with having gravity act on empty space, just as it acts on time? Or if it is not ok to have gravity act on space itself, then do we also need to introduce chronons to explain the effect of gravity on spacetime?
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I'm far from an expert here but from my understanding basically all of QM is founded on particle exchange--all of the three forces (all but gravity) work via mediating force-carrier particle
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A chemist will say it's empty. A physicist might say it isn't.
They're both right, in a way.
Handwave goodbye to dark matter? (Score:2)
Like luminiferous aether a century ago, dark matter was invented as a handwave to explain the observation that the visible amount of mass in the universe was too small to explain the expansion rate. Would a faster expansion rate mean no further need for this particular handwave?
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At first analysis, it means a lot less dark matter than expected. The cosmological measurements of the "edge of the universe" have always been prone to various forms of systemic measurement bias, and I'm afraid that a great deal of grad student thesis authorship and computational analysis has been spent on what is really very vague data, "counting the angels that can dance on the head of a pin". Improved satellite instruments have opened up fascinating fields of science and analysis, and it should not be su
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Improved satellite instruments have opened up fascinating fields of science and analysis,
Really? What new things have we been measuring?
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It's mainly a matter of precision. Most people don't realize the kinds of space based telescopes [wikipedia.org] that are not only orbiting this planet, but also the sun for the last few years. Combine that with new technologies that allow us to coordinate multiple ground based observatories with amazing precision, and machine learning algorithms to help us process the results of those surveys, well, lets just say life has gotten exciting for astronomers and astrophysicists. In my lifetime, suggesting that identifying a
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What we don't know, is what the fuck it is, or how much of it there really is.
Dark matter was invented to explain where the missing mass in observed gravitation effects was hiding.
I blame George Bush (Score:1)
I blame George Bush and his subsidies of Maize.
If he didn't start mass subsidies for the world's most unhealthy "vegetable" (it's actually a grain) - America wouldn't be so fat- and now we're all so fat we're making the universe fat too!
Sure they are missing something (Score:2)
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The universe expanded considerably at first, slowin
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Mostly when we talk about the effects of dark energy, we are talking about effects that are significant only on the scale of galaxies and clusters. The laws of gravitation still apply, most of the things we identify "galactic death" will remain the same, since dark energy doesn't interact on a local scale strongly enough to overwhelm the local effects of gravity. Imagine it like a gentle breeze that blows around your boat, but doesn't blow it apart. Dark Energy, however, is increasing. That fact has led
It makes me wonder (Score:2)
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This makes me wonder if these patches of "dark matter" are really just touch points between our universe and something outside and that the only thing that can cross the "barrier" is gravity. The actual mass the gravity is attached to exists in the other "thing," maybe another universe.
Further: Are these "touch points" moving? Is the "touch point" "other universe" moving relative to our own? That would mean the "other universe" is moving relative to our own. Thus we (humanity) could learn something about another universe.
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Questions from idle thoughts (Score:1)
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the uiverse is expanding faster in all directions, how do galaxies collide?
Eddies caused by rotation of galaxies around localized centers of mass.
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Eddies caused by rotation of galaxies around localized centers of mass.
So, wouldn't "eddies" imply an action of fluid dynamics in space which does not comprise a "fluid"? What then do these "eddies" consist of?
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Parallel concepts - not actual fluids. Are you not aware of clusters of galaxies rotating? If their centers of gravity are expanding with the universe, the outer edges are expanding relative to that center. Two galaxies definitely have a way of crossing paths of they are in separate clusters.
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The universe expanding is separate from objects moving away from each other. Not every single object is moving away from every single other object, so the ones that aren't moving away from each other can collide.
Dark energy is a fudge factor, yes. Probably best to ignore it unless you're applying for funding.
I don't know what they did or didn't account for, but the center of the Milky Way is estimated at around 4.1 million solar masses, which is small compared to the 100-400 billion stars in the Milky Way.
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If the uiverse is expanding faster in all directions, how do galaxies collide?
Because at this juncture, gravity is a far stronger accelerator than dark energy.
The metric expansion of space doesn't stop local gravitational interactions.
This is why (Score:2, Funny)
Aging (Score:2)
Well, look, this is not unexpected. Universe is getting kind of old, now. It's just a natural progression of things. Universe cannot just continue with the way it has done everything in the past and expect to remain the same, of course faster expansion will occur.
It's time to start laying off the heavy breakfast baked goods, eat some more balanced meals, and most importantly, take time to exercise and move around a bit more. Start a daily routine of walking, taking the stairs, try running or lifting (weight
My crackpot theory (Score:2)
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Rubbish - its turtles all the way down! (Score:3)
Though I feel sorry for the elephants, they must be seriously bored after 10 billion years.
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Re:What else? (Score:5, Insightful)
I suspect universes come and go, but reality and some core version of physics that gives rise to universes is eternal. Its always existed and always will exist. The question of why anything exists will probably remain unanswerable for some smart monkeys on a planet.
Re: What else? (Score:2)
That is the big head fuck for me. How can it be infinite? But at the same time, how can 'everything' be finite? If the metaverse is finite it must have a boundary, which surely implies 'something' on the other side of the boundary. But that then means it's not finite, but rather we've just not included everything. So we're back to infinity which is just impossible to conceive. Infinite what? It seems literally unknowable.
God doesn't even answer the question, because who created God, etc, etc, turtles all
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Re: What else? (Score:4, Informative)
The universe can likely be described as a closed manifold. It does not imply something beyond. In a closed or compact manifold geometry, there need not be an "outside", The concept of an "outside" probably doesn't even make sense.
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It's turtles all the way down
Re: What else? (Score:2)
But logically speaking, doesn't even a closed manifold have to exist inside some kind of context? I'll admit I'm a complete layman, but that sounds just like the mathematical equivalent of God - in that it ignores the context that God exists within.
Where did the closed manifold come from?
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Re: What else? (Score:2)
And to me, a limit implies a bigger context that the limited thing exists within. It sounds like they've just changed the definition of 'everything'.
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Well, "some core version of physics that gives rise to universes" would necessarily HAVE to be eternal, possibly in the strong meaning of "existing outside of time".
Actually, that's true even if the current universe is the one and only. Existence requires a basis for existence...though how much basis is quite dubious. I think the basis would need to be enough to construct a finitely-bounded Turing Machine, but I'm not sure.
So there needs to be an underlying layer that everything else is based on which exi
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Anything that changes state in some sort of time framework. Therefor time must exist at all times. Outside of time makes no sense - if there's no time then by definition no state changes can occur so no universe can come into existence.
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You're assuming time when you say "change". So if you postulate change rather than just a specified potential transition, you are postulating time. And it seems to simplify things, but it doesn't seem to be necessary. I quote "The transient and the eternal are the same.".... Well, OK, the author probably didn't mean that seriously. But it's a valid model. And it can predict the exact same results as the "time is a stream" model.
It's not clear that time is a part of the basic minimal physics that allow
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Time is simply a convenient shorthand for a sequence of 1 or more states changing. If a universe comes into existence then by definition a state change has occured ergo time (or whatever you want to call it) must exist for it to happen.
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Re:What else? (Score:4, Informative)
No, I read Lawrence Krauss' book, he does think nothing is unstable. I don't think he understand what truly nothing is. He seems to think that the "outside" of the Universe is some sort of time-space continuum which spawns particle-antiparticle pairs spontaneously. But the space-time continuum is a product of this Universe, there is no outside. So he's still wrong but not in the way you said.
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> nothing must have some properties
**Facepalm**
Nothing is no thing by definition.
IF it has properties THEN it is no longer nothing, it is something
Quite trying to hijack definitions.
Only a fucking moron thinks something can come from nothing. This like saying 0+0=1.
> There aren't any. It's unknowable BY Science.
FTFY.
Science is a Subtractive Knowledge System. It finds truth by removing error.
There is also an Additive Knowledge System but man has not evolved enough yet to understand it.
There is no such
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The grammar is fine.
You obviously lack the intelligence to understand basic concepts. Try actually using a fucking dictionary for once instead of whining about non-issues.
I'll even give you a clue stick to get the ball rolling:
What is the definition of nothing?
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Re:What else? (Score:5, Interesting)
The surface of the earth is a 2-sphere (two dimensional surface of a 3-ball)
The universe is (probably) a 3-sphere (three dimensional surface of a 4-ball)
Due to relativity, though, if the universe is a 3-sphere, the radius of the 4-ball is always c*t with respect to any frame of reference (where t is the age of the universe) because objects approaching the distance of c*t away from the observer are increasingly flat due to relativistic contraction from their relative velocity from the observer.
See also Minkowski space.
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If the spatial slice (comoving coordinates) of the universe were a 3-sphere its curvature would be positive. We know the universe is close to flat and could also have slight negative or positive curvature. So this is not clear. Minkowski space would be flat space time. You could embed a spatial slice with negative curvatore into Minkowksi space, but we know this is not the case.
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> what existed before that universe?
The universe has always existed.
Proof:
1. According to the 1st Law of Thermodynamics: Energy can neither be created nor destroyed.
2. Einstein showed us Energy and Mass are equivalent.
3. Therefore the universe has ALWAYS existed (or either the laws aren't static, or our understanding about them is incomplete.)
Only a fucking moron thinks something can come from nothing.
The bigger question is What is CAUSING the acceleration? IMO.
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You should check out quantum physics. And yes our understanding is incomplete as we have 2 seeming correct theories that only work in their domains.Relativity breaks down at really small scales and quantum works at really small scales, where something can come from nothing.
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While this is an argument made quite often, I don't really think this is true. General relativity by itself works just fine at small scales (but there it usually does not matter) and quantum theory work just fine at large scales (but there it usually does not matter). It is believed that for high energies and small scales quantum gravity effects play a role and this would imply that both theories need to be modified at very small scales. But each theory on its own seems consistent at all scales. (ok, for th
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See: Singularities.
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At small scales, particles may still move at or close to the speed of light and therefore their behavior can only be fully explained by taking at least special relativity into account.
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The first law of thermodynamics describes a closed system. If the system is not closed, energy can be introduced from or transferred to elsewhere. It raises a whole set of other questions.
It's very important when making deductions from scientific principles to include the whole principle.
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**Facepalm**
Try READING the fucking question:
WHERE did the energy in the universe come from?
* Has it ALWAYS existed? OR
* Did it just magically decide to spring into existence one day??? i.e. This is retarded argument that "something came from Nothing." Space-Time just "magically" came into being without a cause.
Likewise, WHERE did the Laws of Physics come from?
* Have they always existed?
* If not then WHAT (or who) caused them?
Infinity. It's a simple concept for everyone but you.
> first law of thermodynam
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Right, which why I said:
Re:Dark Energy was Always a FRAUD (Score:4, Insightful)
Nothing at all has yet indicated that dark energy doesn't exist. The observation it's based on is acceleration of expansion instead of deceleration. That acceleration represents an energy of some sort (energy is required for it to happen.) We call it dark because we don't understand what it is or why it's happening. If you think it's disproved, present your evidence and competing theory. Also interested to know whom you think has been massively profiting from the propagation of the dark energy "fraud".
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Universal Warming
But Khan [wikipedia.org] said, "It is very cold in Space." He is going to be really upset.