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Fastest Waves Ever Photographed
starfoot writes, "Pictures of the fastest waves ever photographed, traveling at 99.997% of the speed of light, were presented today at the APS Division of Plasma Physics meeting in Philadelphia. The waves were formed in the wake of an intense laser pulse passing through a plasma of electrons and ionized atoms. The waves create enormous electric fields (over 100 billion electron volts/meter), which can be used to rapidly accelerate charged particles to high energies in the span of a few meters. The pictures will help scientists better understand wakefield interactions — an important factor in their quest to replace machines that accelerate particles over the course of miles with compact, tabletop versions. High energy particle accelerators are vital for cutting edge physics and many types of medical therapy, and miniaturizing them would be a boon for both basic physics research and medicine."
I bet it was just photoshopped. Gimme ten minutes, and I can give you a wave doing 99.999% of the speed of light.
Apology to Ubuntu forum.
Thats hot.
"I use a Mac because I'm just better than you are."
They run from all operating systems.
My Sysadmin Blog
Dead serious, I know there's a difference here between my family photo album and the pretty graph thing FTFA, could someone explain to me why photographing LIGHT doesn't count here?
The heavens do not fall for such a trifle.
The electric field is merely the negative gradient of the scalar potential (ie, voltage)*. So in SI it will have units of Volts/Meter.
* (Just in case any E&M sticklers want to point that my electric field definition here ignores the contribution from vector potential, just assume a time-independent gauge).
make world, not war
If you made instant coffee in the microwave, would you go back in time?
let me guess, you refresh slashdot at relativistic speeds.
There's currently no way to take a snapshot of a single photon in motion and produce an image out of it. An ordinary photograph captures the effect of many millions of them impacting a chemical, so that's not really the same
The reason this is so awesome is that scientists can apply this to nanotechnology -- actually, the prefix "nano" is not small enough. After all, everything moves in waves, but these waves are only noticeable on a small enough scale. On this scale, electric energy is so much more important than gravity. The fact that this energy is electric and not physical means that, instead of bumping atoms around continuous for a month, something might happen sooner. The fact that it's been proven done might help with something, like (for example) supplying a power source. The question is, "How easy is it to synthesize this phenomenon, and is it worth it?"
What excites me most is the fact that Are we still afraid of put explosives into our chemistry kits for fear that kids might get hurt? Just like how, around Sputnik time, the US gov't tried to make all of the children in its public education system little scientists of future, it is (seriously) important to get kids interested in science, math, and academic pursuit at a young age. Can a little kid read the KJ version of the Bible at 4 years old, as was done in days of yore?
It would be a good thing that, with this increased technology, scientists would try to give nuclear chemistry to the public and make atomic physics more tangible. There was an ambitious project some time ago that wanted to create a huge electromagnetic field somewhere in Texas. It was shut down because the US gov't saw no use of it. If this technology can do something as simple as power a light bulb, the public will notice. No one cares if Element 118 is created in a matter of seconds instead of across the span of a week, but if people can actually see something, this is better for science in general. (So long as John Galt doesn't get angry.)
And in the realm of plasma physics, the eV is a common surrogate for temperature, in which Boltzmann's constant k is omitted. It's always fun when you have multiple definitions for the same abbreviation in exciting, but overlapping, branches of physics! Since I was at this talk early this morning, it certainly was exciting to see the progress in this field.
o/
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This is me waving so fast my arm looks stationary
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
Which is 100% (not approximately, but exactly 100% :)). A lot of people are unaware and the concept seems a bit strange but .9(repeating 9) is equal to 1.
:).
Just thought I'd take the time to throw in a piece of trivia. Carry on gentlemen
"People who think they know everything are very annoying to those of us who do."-Mark Twain
many types of medical therapy
Hey, so I understand the applications in Physics of desktop particle accelerators, but what kinds of medical therapy use particle accelerators? Wikipedia suggests creating rare "proton-heavy" isotopes, but I'm having trouble finding more about what kinds of "killer apps" (pun intended) would be enabled if there were cheap desktop particle accelerators. Someone in med school?
Electron Volts per Meter (eV/m) is actually a perfectly valid measure of electric field. It's how much energy an electron going through the field would gain per meter. To get the actual electric field, you would just divide by the elementary charge e = 1.6*10^-19 C. In relativity and particle physics, one often sees masses expressed in eV/c^2 and momenta in eV/c. It's just a convenient notation to absorb unweildy constants such as e and c, and show the numbers that really matter.
These laser pulses are on order 100 femtoseconds. That's 100 * 10^-15 seconds. That works out to only about 3 Watts assuming the 30 TW and 1 shot per second (which is reasonable).
This is nothing compared to the petawatt laser that is being built in the same building here at UT in the same building that this published research was done (one door down from my office in fact). They can only take a shot every 45 minutes after charging a huge bank of capacitors.
----------------- Oink. Moo. rarr! -----------------
+-----------+
| _ 5MPH__ |
| No Wake_|
+----+-----+
|
|
~~~~~~~~~~~~
The harbor master isn't going to like this one.
--
BMO
Here is a neat little proof of this: http://en.wikipedia.org/wiki/.999
I want me one of those tabletop accelerators for my shop, oh and a tabletop nuclear fusion reactor would be nice too.