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Blazing Speed: The Fastest Stuff In The Universe
Unfallversicherung writes "'If you're light, it's fairly easy to travel at your own speed -- that is to say 186,282 miles per second or 299,800 kilometers per second. But if you are matter, then it's another matter altogether.' Astronomers are now measuring matter that moves at 99.9 percent of light-speed. Jupiter-sized blobs of hot gas embedded in streams of material ejected from hyperactive galaxies known as blazars."
(SPACE.com) -- If you're light, it's fairly easy to travel at your own speed -- that is to say 186,282 miles per second or 299,800 kilometers per second.
... are extremely energetic and are capable of propelling matter very close to the absolute cosmic speed limit," said Glenn Piner of Whittier College in Whittier, California.
But if you are matter, then it's another matter altogether.
Nothing we know of zips along more quickly than light. Einstein, nearly 100 years ago, said it's not possible. For us, the speed limit makes strange sense: Go faster than light, and you could return before you've left, become your own grandpa, or other perform other leaps of cosmic logic.
Fast forward a century. Astronomers are now measuring stuff -- material, matter, things -- that moves at so close to the speed of light you might think it'd make Einstein a bit nervous. His theory of relativity appears not to be endangered by the blazing speeds, though.
Among thee speed demons of the universe are Jupiter-sized blobs of hot gas embedded in streams of material ejected from hyperactive galaxies known as blazars. Last week at a meeting here of the American Astronomical Society, scientists announced they had measured blobs in blazar jets screaming through space at 99.9 percent of light-speed.
"This tells us that the physical processes at the cores of these galaxies
Ponder the power of the fast moving superheated gas, known as plasma:
"To accelerate a bowling ball to the speed newly measured in these blazars would require all the energy produced in the world for an entire week," Piner said. "And the blobs of plasma in these jets are at least as massive as a large planet."
The blazar jets are running around the universe in some fast company. Slightly faster, in fact.
In another study presented at the meeting, ultra high-energy cosmic rays thought to originate in a collision of galaxy clusters are slamming into Earth's atmosphere at more than 99.9 percent of the speed of light. Measurements put the number at 99.9 followed by 19 more nines -- about as close to light-speed as you can get without splitting hairs.
The particles are not light, but actual matter. They are tiny, thought to be mostly protons, but the energy that motivates them is similarly fantastic, and the mechanisms may be intertwined.
Scientists still don't know the exact mechanisms involved in accelerating matter to such high speeds, however. In the case of a blazars, it appears a black hole is involved. Anchoring an active galaxy, a supermassive black hole draws gas inward. Some is swallowed, yet some is simply accelerated and then ejected in high-speed jets along the galaxy's axis of rotation. Intense, twisted magnetic fields may play a role.
Some ultra high-energy cosmic rays might originate in blazar jets, Piner told SPACE.com. But other phenomena may serve as particle accelerators in space, such as merging galaxies or colliding black holes.
Piner and his colleagues observed three blazars, known from previous observations to be super speedy, using the National Science Foundation's Very Long Baseline Array radio observatory.
The results confirm the previous work and pin down the speeds with greater accuracy. The phenomenal pace of the plasma blobs looks to have reached a limit.
"All the results from blazar jet observations are in agreement with Einstein's Theory of Special Relativity," Piner said. "The jets are accelerated right up to the edge of the speed-of-light barrier but not beyond, even though these are some of the most efficient accelerators in the universe."
I'm interested in how we can measure the speed of things that far away at that level of precision. Any measurement would rely on light from those gas balls reaching us at different times -- and as such, how can we tell that nothing is interfering with the light between there and here?
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Maybe its possible to travel faster then light then
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In modern accelerators electrons routinely have energies of a few GeV, meaning that their velocity differs from c by probably less than one part in a billion (I can't be bothered to do the calculation, but the rest mass of the electron is about 0.5 MeV).
What if you just poof go faster, or something exists that's already going faster?
Either my calculations are wrong or I might be a bit rusty in understanding but with that speed on protons they would wigh approx 3 mg each... now that is a heck of a lot and with that speed they should do some damage even if they are small. Anyone care to elaborate on this?
I've always been intrigued by Feynmann's conjecture that there's only one electron, which moves so fast that it appears in all the times/places in the universe that appear to be individual electrons. That accounts for "every" electron having identical properties - it's the same electron. But I suppose that setting different quantum properties, like spin, to different states, without seeing that state "propagated" to "other" electrons, defies that model. Or does it? Maybe we just haven't tested enough electrons, or maybe our technique for setting state actually sets the state of the (moving) space in which we measure that persistent electron state. Or maybe Feynmann had even more clever subtleties in his model. Or maybe it was all just a bad idea.
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You should also read about the Oh My God particle (it's real and not a joke). This proton particle travels almost as fast as light. After traveling one light year, the particle would be only 0.15 femtoseconds--46 nanometres--behind a photon that left at the same time.
Banu
You are right, unless you have particles like tachyons, which have imaginary rest mass. Such particles could travel only faster than light and will never slow down under the light speed.
Wikipedia has something about that: http://en.wikipedia.org/wiki/Tachyon
IT doens't work that way. The speed of that laser will appear the same to any observer anywhere. The only thing that will changes is the observed wavelength.
Speed does exist, just not absolutely, it will always be percieved differently by different observers (except for the speed of light.)
The universe is stranger than you think.
I remember a SciAm article about cosmic matter (protons) actually going FASTER than light. The trick was that nothing goes faster than light in a vaccuum, but what about in air? When cosmic rays going .99c hit the interface of the upper atmosphere there are conditions where the refracted speed of light is less than the speed of those particles.
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First off, IAAAP (and I don't even play one on TV).
I understand this is true if the energy or gravity providing the acceleration is in a different frame of reference than the mass being accelerated (think particle accelerator or plasma blob).
But my layman's question is .. what about a rocket?
In a rocket, the energy to accelerate the rocket is in the same frame of reference as the rocket itself. The rocket converts mass into energy which accelerates mass and sends it out the nozzle to provide thrust. As the rocket approaches the speed of light (from Earth's reference, for instance) it becomes heavier and harder to accelerate, but so does the mass upon which it relies to convert into energy to provide thrust. The propellent is also heavier. My guess is that this would all cancel out in such a way that an astronaut travelling inside the rocket would have no way of knowing how close to c he is travelling at without looking out the window.
Now my understanding is that from Earth's perspective the rocket could only reach c at the end of time, but my question is this: given a sufficiently efficient rocket engine, is this the case for the rocket and the astronaut? If the rocket were capable of constant acceleration (for the comfort of the astronaut, lets say an acceleration of G) how long, from the astronauts perspective, would it take for him to reach c?
And once he got there (and he could only know if he looked out the window or kept track of time) what's to stop him from going further? It may be the end of time on earth, but how old is the astronaut?
Error:
excuse my ignorance in physics, but i always wondered: if light has no mass then it has no speed or energy because E=MC^2, right ? if you insert a 0 in M, then 0 times C^2 is 0, thus E = 0
assuming that photons have mass ( or we would live in a very strange universe ) than at least is possible for some kind of mass to travel at the speed of light ( because light have mass and is mass because has energy and velocity )
so why would be impossible for other kinds of mass to travel at the speed of light ?
no, relativity teaches us there are no rigid objects. Consider a 12 inch ruler sliding along a long table with a 10 inch hole in it. If the ruler moves fast enough it will shrink (in the table's frame) enough to fall through the hole. But now consider the ruler's frame of reference. It is still 12 inches long and the diameter of the hole has shrunk. So how does it go through. By bending as it goes over the lip of the hole. (this can be worked out precisely and it *all works*)
So if I'm zipping through space at this speed, and you're passing by me traveling at the same speed but in the opposite direction, will I perceive your speed as nearly twice the speed of light?
bort.
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Interesting theory, but whouldn't its transferance from atom to atom create some sort of electric 'jetstream' as it takes the path of least resitance over and over again in order to be everythings electron? Still, nice to learn a new theory on /. that doesnt have anything to do with computers.
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I think you are missing the point. It is entirely possible that we dont know WTF we are talking about, and while that equation jives with our idea of reality, that idea is flawed.
An excellent question.
Dirac's theory of the electron shows that an electron travelling backwards through time is mathematically indistinguishable from a positively-charged "hole" into which an electron can fall (releasing energy, since the "hole" is a lower-energy state). Alternatively, it's also indistinguishable from an opposite-charged particle, with the same mass, which is destroyed on meeting an electron (along with the electron!), releasing energy.
The last point gives rise to the theory of anti-matter (or, at least, anti-electrons). An electron-positron pair being created and subsequently destroyed is indistinguishable (and the Feynmann diagram notation makes it explicit) from an electron "chasing its own tail" through a loop in time.
So you might as well ask how exactly you decide what is matter and what is anti-matter? Which one is which? Answer that question, and a Nobel Prize is yours.
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Ok, I'm game. Here's some bullshit which I do not believe is at all likely to be true but argues by analogy with another system where an "impossible" barrier is broken.
An old exercise in quantum mechanics is to show that a particle can pass a barrier which is too high for its (classical) energy to get over. The process is called tunelling, and relies critically on Heisenberg's uncertainty principle. In particular, a particle's energy is uncertain if it is measured for a short time. There is a probability that the energy may be sufficiently greater than the barrier's height ...
The analogy should now be obvious. A better understanding of physics may enable us to work out how something can tunnel through the speed of light barrier without actually going over the top of it.
As I said, the above argument has no physical justification, AFAIK.
Paul
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The naive use of redshift as a universal yardstick of distance, predicated on uniform expansion, must end before it does more damage to our understanding of the universe. There are quasars with redshifts on the order of 0.2 obscuring more distant galaxies with redshift on the order of 0.1. It's just not a reliable measure of distance.
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