Einstein predictions confirmed by NASA probe - Technology & Science. According to Einstein's theories of relativity, the mass of Earth dimples space-time like a heavy person sitting in the middle of a trampoline. ((NASA)) A NASA probe circling the Earth has found evidence that confirms two key predictions based on Albert Einstein's theory of general relativity. The results from the Gravity Probe B mission show that the Earth's mass does warp space and time, which are interlinked, NASA announced Wednesday. They also confirm that the Earth does drag space-time with it as it rotates, as predicted.
"Imagine the Earth as if it were immersed in honey. As the planet rotates, the honey around it would swirl, and it's the same with space and time," Francis Everitt, the Stanford University physicist who led the mission, said in a statement. The results are published in the journal Physical Review Letters. Space-time and relativity Gravity Probe B was designed to test the predictions by taking measurements from four ultra-precise gyroscopes. The Everett Interpretation. Q0 Why this FAQ? This FAQ shows how quantum paradoxes are resolved by the "many-worlds" interpretation or metatheory of quantum mechanics. This FAQ does not seek to that the many-worlds interpretation is the "correct" quantum metatheory, merely to correct some of the common errors and misinformation on the subject floating around.
As a physics undergraduate I was struck by the misconceptions of my tutors about many-worlds, despite that it seemed to resolve all the paradoxes of quantum theory . The objections raised to many-worlds were either patently misguided or beyond my ability to assess at the time , which made me suspect (confirmed during my graduate QFT studies) that the more sophisticated rebuttals were also invalid.
I hope this FAQ will save other investigators from being lead astray by authoritative statements from mentors. See "Does the EPR experiment prohibit locality? " Sample objection: "Creation of parallel universes violates energy conservation/Ockham's razor". 4) [M]. Size Of A Proton? Really Small. There are three possibilities: Either physicists have made a mistake in their calculations, protons are playing a terrible practical joke on physicists, or — a really long shot — the quantum theory describing charged particles is wrong.
This month scientists in Germany reported measuring the size of the proton by scattering electrons off it, an experiment they’ve done before. But the diameter they found is decidedly different from other recent measurements using energy shifts in hydrogen, they report in the Dec. 10 Physical Review Letters. Measuring a consistent size for the proton was supposed to be yet another check on the theory that marries the quantum world with electromagnetic fields, called quantum electrodynamics or QED. But now, that discrepancy stands even firmer. “In a way, it’s reinforced the problem rather than solved it,” says Jeff Flowers, a physicist at the National Physical Laboratory in Middlesex, England. “A huge disagreement requires some explanation,” says Flowers. Documaga: The Scale Of The Universe. Physics Is Beauty (Video) Spiffy new laser is powerful enough to rip a hole in space. When you want to try and generate particles of something from nothing, you’re going to need a hell of a lot of energy.
The European Commission has already approved the construction of three giant lasers with a fourth that for a split second would be more powerful than all of the energy ever produced by mankind. At peak power, the fourth laser in Europe’s Extreme Light Infrastructure project (or ELI) will combine ten beams into a single pulse measuring 200 petawatts. 200 petawatts is significantly more power that our entire race generates at any given moment, and in fact more total power than Earth receives from the sun.
The point of all this is to try to explore some of the weirdness of quantum mechanics, which suggests that space is actually a giant party of random particles that are popping in and out of existence too fast for us to see. Via. Antihydrogen Trapped For 1000 Seconds Antihydrogen is rare in our part of the Universe. Indeed, it was only last year that scientists at CERN’s Antihydrogen Laser Physics Apparatus (ALPHA) managed to trap a significant amount of the stuff for the first time, albeit only 38 antiatoms for just 172 milliseconds.
Today, they announce a significant improvement. These guys now say they’ve trapped 309 antihydrogen atoms for up to 1000 seconds. That’s an increase in trapping time of four orders of magnitude, comparable to what’s possible with good old ordinary matter. The news is significant because it makes possible a new set of experiments that should answer some important questions. Most important of these is whether ordinary gravity attracts or repels antimatter. Although there have been many attempts to do this experiment, all have been inconclusive because nobody has been able to trap a good lump of antimatter for long enough to try. All that should soon change. CERN Physicists Trap Antimatter for a Record-Breaking Quarter Hour, Observe It. Scientists working on the Antihydrogen Laser Physics Apparatus (ALPHA) at Cern's particle physics laboratory had very exciting quarter hour recently.
The team conjured and contained atoms of antihydrogen for a full 1,000 seconds--that's nearly 17 minutes and 10,000 times longer than they were previously able to keep antimatter around before it disappeared in burst of particle-on-particle annihilations. Antihydrogen is the antiparticle to hydrogen (but you might have guessed that), and is of interest to researchers because, basically, we don't know a whole lot about antihydrogen specifically and antimatter generally. That's because it's notoriously difficult to study. Put antihydrogen and hydrogen in contact and you end up with nothing. To keep antimatter and matter separate, the ALPHA team has been experimenting with magnetic antimatter traps that allow them to keep a cloud of anti-particles in existence for very short periods of time. [New Scientist, Technology Review]
Lectures. Physics Challenge 2011. Welcome to The Virtuosi's Physics Challenge Problem website! The only [1] website that offers prizes for answering fun physics problems. Anyone can enter, just send an email with your response to the contact link above. RECENT CHALLENGE PROBLEM: The current problem ("Time Machine") can be found here. It was posted on 5 Sept. 2011 and will be open until Friday November 4th. update Award Show. Solutions. There are two main classes of problems for you to solve. The first is The Physics Challenge Problem.
The second class of problem we have is the always-ongoing set of Kapitsa Problems (see the Problems link above for a listing). One of our main goals here is to encourage discussion of fun problems, so we have set up a forum in which you can discuss the problems or your solutions with others. . [1] I have no idea if this is actually true. [2] This "deadline" is contingent upon us receiving enough valid entries and our own laziness. Questions or comments? Brought to you by The Virtuosi. Relativity of Electric and Magnetic Fields. Previous home next Michael Fowler, University of Virginia A Magnetic Puzzle… Suppose we have an infinitely long straight wire, having a charge density of electrons of coulombs per meter, all moving at speed to the right (recall typical speeds are centimeters per minute) and a neutralizing fixed background of positive charge, also of course coulombs per meter.
The current in the wire has magnitude (and actually is flowing to the left, since the moving electrons carry negative charge). Suppose also that a positive charge is outside the wire, a distance from the axis, and this outside charge is moving at the same exact velocity as the electrons in the wire. What force does the positive charge feel? The wire is electrically neutral, since it contains equal densities of positive and negative charges, both uniformly distributed throughout the wire (the illustration above is of course schematic). However, since is moving, it will feel a magnetic force, so the force on the charge is of magnitude.