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Dark Energy Confirmed
bill_mcgonigle writes "By correlating the results of the Sloan Digital Sky Survey and the Wilkinson Microwave Anisotropy Probe, astronomers have confirmed the existence of dark energy.
While gravity attracts, dark energy repels, so by comparing the positions of millions of galaxies and their red-shifts with the temperature map of the early universe, evidence was found for dark energy on the scale of 100 million light years.
"Dark energy, whatever it is, is something that is not attracted by gravity" said David Spergel, a Princeton University cosmologist and a member of the WMAP science team.
"We are finding that most of the stuff in our universe is abnormal in that it is gravitationally repulsive rather than gravitationally attractive," said Albert Stebbins of the Fermi National Accelerator Laboratory. The universe is expanding at an accelerating rate, a switch that happened about 6.3 billion years ago, before which the expansion was decelerating."
The earth stops some of them passing through, and thus the ones from above us push us down. All the standard laws of physics still work on the local level, and nobody has to get a migrane trying to wrap their heads around weird concepts.
This is much simpler than "dark energy"... the farther you are from the source (or field) of gravitons (?? I have no idea where they come from), the less the "gravitational constant" appears to be.
--Mike--
Damn, now I'm thinking of Karen... talk about repulsive being normal.
When I first studied cosmology, I wanted the theories to work out so our universe would be a series of Big Bangs that would go on infinitely. This would mean we were all part of a never ending series of events that can lead to sentient life. Now that Dark Matter is gaining acceptence, it changes things.
If the Big Bang was a one time event, and the Universe will expand forever then the question is how did this first and only Big Bang happen. What forces were at work prior to the Big Bang?
While this knowledge won't have a meterial effect on me, as I age, it's nice to know things of such a grand scale especially if the knowledge is confirmed to be true.
I hope physicists continue to make progress on Dark Matter and that Slashdot keeps posting such articles. Although I would prefer it to be on the main page.
I misread this at first, I thought it was some sort of reference to the Slashdot motto "news for nerds, stuff that matters". My mistake.
Don't blame Durga. I voted for Centauri.
If you're interested in understanding this stuff, I highly recommend QED by Richard Feynman. It's cheap, a quick read, and accessible to anyone who's interested and has a high school education. It's accurate enough to be used in graduate-level physics courses, but is completely qualitative. I.e., there are no numbers or formulas but only conceptual calculations.
... I'd say that I'm the MASTER OF DARK ENERGY! Buaahaha
"Derp de derp."
Rather than assuming some bizarre physics of gravitons where they pull something they ram into, why not take a simpler approach and assume that they push things along, just like a baseball and the milk bottle at the faire?
You appear to be using an overly-simplistic model of what force-carrying particles are.
The classical model of force involves "fields" - continuous distributions of force about their sources (e.g. an electric field that varies as the inverse square of distance from an object with charge, or a gravitational field that varies as the inverse square of distance from an object with mass).
When quantum mechanics came along, it was realized that these fields weren't continuous in all senses - disturbances in the field could only come in discrete packets. These are the force-carrying particles.
A graviton doesn't "ram into" anything. It's a moving ripple in the gravitational field of an object. The net effect of all gravitons (real and virtual) about an object with mass is to produce an attractive force on other massive objects nearby.
Similarly, a photon is a moving ripple in the electromagnetic field, with the net effect of all of the virtual photons in the vicinity of a charged object being to attract or repel other charged objects in the area.
The properties of gravitons are less certain, because it's hard to build a quantized version of Einsteinian gravity, but this is the general idea behind force-carrying particles (in force-carrying contexts, they can be thought of as the minimum (quantized) disturbance of a classical-looking field of force).
Your suggestion amounts to either "there is no such thing as pull forces, objects can only push" or "the only forces that exist are those transferred by physical contact, ie things bumping into one another".
Lets assume (incorrectly) that your suggestion is true. What are some of the consequenses of this assumption? First, let the source be distributed at the center of the solar system. Then, according to your suggestion, the earth should move away from the sun (since the earth needs a center seeking force to continue orbiting the sun, which cannot exist if your suggestion is true). The source must then be outside of orbit of the earth (and obviously all the planets).
Where could it go outside of the solar system? It would have to be distrubuted in a circle around the solar system so that it could push in on the earth at all points of orbit. This brings up many difficulties. If the source is distributed symmetrically around the solar system, why does it push more on one side of the earth than the other? Your argument I would guess is that one side of the earth is farther from the source of the particles than the other (since the other is facing the opposite side of the source). However, according to newton's laws, the particles would lose no momentum on their way to earth unless a force is acting on them, thus the force on both sides of the earth are exactly balanced. Another problem is what happens to the particles that are coming in from both sides when they meet? We would expect some net buildup of particles (in this case, it would be at the sun). This in turn would mean the sun is becoming more massive all the time when in fact it is actually losing mass.
Now that know planets exist around other stars in our galaxy, we have to find a way for these planets to stay in orbit. Cleary we need a source of particles around each of these stars as well. In fact, since there is no reason to think any one star is more special than any other, we need a source around every star in the galaxy. Furthermore, since all the stars in our galaxy orbit our galaxy, we need a source in a circle outside of our galaxy. But wait, how do all these sources affect earth's orbit. Surely we cannot expect all the forces from the particles to magically balance out at earth. It is safe to assume, the force on the earth would no longer be in the correct direction to orbit the sun.
I have mentioned nothing about galxies orbiting in clusters (which they do). However, it is clear that you would have to make some pretty heavy modifications to your theory and add a ton of exceptions. Your theory would be about as far as you can get from an Okham's razor explanation.
There are numerous other problems to your theory (so many in fact that I don't have time to cover even a small percentage). However, I will highlight the most important aspect. Your theory makes numerous predictions that directly contradict experimental and observational results.
Please leave the theorizing to physicists and astronomers. You are not the next Einstein. Einstein may have been "just" a patent clerk, but he was a patent clerk fresh off degrees in physics and mathematics. If you continue to say things like this, you will quickly and justifiably labeled as a crackpot.
Actually, to be fair, particle theorists have been saying for quite a while that there should be a cosmological constant, (This is what Dark Energy essentially is). Unfortunately, particle physics currently has this constant many, many orders of magnitude too high. Really the major thing about Dark Energy is it is a reversal of the previously widely held contention in cosmology that the universe was decelerating, but this is not the first time that cosmology has been reversed like this however with the new precision of measurements like WMAP it might be the last time such a reversal occurs.
This sounds a lot more like a re-statement of the reason that people started theorizing that "dark energy" might exist. Confirmation? pfft.
Mr. Hawk "We dont know why this is happening."
Mr. Beard "Hmm,, maybe it's 'Dark Energy', that acts in reverse."
Mr. Hawk "Hey look, the same thing is happening over here.. I wonder why.."
Mr. Beard "This conclusively proves my earlier hypothesis!!"
-- 'The' Lord and Master Bitman On High, Master Of All
Now we've been decelerating...then accelerating?
This is the thing that has been driving me absolutely crazy vis-a-vis the Big Bang theory, is that the practitioners seem to operate under the maxim:
"Keep adding terms until the data fits"
That's not the way science is supposed to work.
We've had a fair share of juggling of terms, including:
- "Big Crunch" - gravity will let the universe collapse again
- "Flat Universe" - universe will expand forever, but keep slowing down
- "Inflationary Universe" - universe expanded faster than the speed of light for a tiny moment (addressing the age and isotropy problems)
- Not sure what to call this... "Second wind universe" - universe slows its acceleration before dark energy becomes the reigning cause of repulsion
I sincerely doubt it will end there - the Missing Mass problem and the Age of the Universe problem will push the equations incrementally.The Hubble telescope observations are getting awfully close to the predicted age of the universe. I wonder what age-of-the-universe estimate this new theory will predict; something more than 13.7 billion years?
The missing mass in the form of dark matter is, by all accounts, supposed to be mass that attracts; the inflationary universe theory depends on it for flatness. This might be another move 'around' the problem.
The Big Bang theory fell from grace for me over a period of fifteen years. While I don't subscribe to the notions of Velan, I'm curious, yet ambivalent about Alfven's plasma cosmology, there are a number of viable cosmological theories that don't have age, mass or exotic physics problems. It seems we closed the book on alternatives too soon, and are constantly interpreting data so it fits with theory, instead of breaking the back of theory on data.
Proving mathematically that you can never hit a wall must be tempered with observations of a hole in the wall and drunk in front of said wall on his back at a frat party :)
Binary geeks can count to 1,023 on their fingers
Actually, Mike, such a mechanism was proposed by George Lewis LeSage in 1784. The theory keeps on getting shot down, then revitalised in periodic cycles. There are those who have derived Newton's equations from this sort of paradigm, and there are those who have indicated that if gravitons (assuming such a particle is involved) go at the speed of light, there might be problems with orbits.
I prefer to wait and see on the subject. I'm just waiting for the book Pushing Gravity: New Perspectives on Le Sage's Theory of Gravitation to arrive for yet more "light reading" :)
Side thought: I think I got my don't-close-the-door-on-them attitude to these various theories from being a good debugger. If reality is anything close to the way debugging operates, the same symptom can have multiple causes, but any instance really has one cause...
...and it's hardly ever what any of your initial guesses were, regardless of how sensible they seemed. ;)
Binary geeks can count to 1,023 on their fingers