What does mercury being liquid at room temperature have to do with Einstein’s theory of relativity? | The Curious Wavefunction, Scientific American Blog Network

What does mercury being liquid at room temperature have to do with Einstein’s theory of relativity? | The Curious Wavefunction, Scientific American Blog Network:  From Niels Bohr’s theory of atomic structure we know that the velocity of an electron is proportional to the atomic number of an element. For light elements like hydrogen (atomic number 1) the velocity is insignificant compared to the speed of light so relativity can be essentially ignored. But for the 1s electron of mercury (atomic number 80) this effect becomes significant; the electron approaches about 58% of the speed of light, and its mass increases to 1.23 times its rest mass. Relativity has kicked in. Since the radius of an electron orbit in the Bohr theory (orbital to be precise) goes inversely as the mass, this mass increase results in a 23% decrease in the orbital radius. This shrinkage makes a world of difference since it results in stronger attraction between the nucleus and the electrons, and this effect translates to the outermost 6s orbital as well as to other orbitals. The effect is compounded by the more diffuse d and f orbitals insufficiently shielding the s electrons. Combined with the filled nature of the 6s orbital, the relativistic shrinkage makes mercury very reluctant indeed to share its outermost electrons and form strong bonds with other mercury atoms.

The bonding between mercury atoms in small clusters thus mainly results from weak Van der Waals forces which arise from local charge fluctuations in neighboring atoms rather than the sharing of electrons.

New Type of Clock Keeps Time by Weighing Atoms

New Type of Clock Keeps Time by Weighing Atoms: The researchers start with a puff of cesium atoms that falls through space toward a detector. Along the way, the atoms encounter pulses of two opposing lasers with slightly different frequencies that gently nudge the atoms without making their inner structure change. The pulses split the cloud in two, and one half of the cloud falls as normal. The other gets pushed up away from the first half and then gets pushed back toward it to catch up.

Here's where the relativity enters. From the perspective of the un-nudged half of the cloud, the second half moves away and then moves back. Because that second half is moving at a few centimeters per second, its time should appear to slow down just a bit thanks to the weird time dilation predicted by Einstein's theory of special relativity. So the quantum wave for that half of the cloud oscillates slightly slower than the one for the first half of the cloud.

When the clouds recombine, that difference in oscillations affects how they overlap and "interfere." If the researchers tune the difference in the two lasers' frequency just right, the recombining waves will interfere "constructively" so that the cloud falls into the detector...

The real value of the approach may come in redefining the kilogram...

A Slower Speed of Light | MIT Game Lab

A Slower Speed of Light | MIT Game Lab; A Slower Speed of Light is a first-person game prototype in which players navigate a 3D space while picking up orbs that reduce the speed of light in increments. Custom-built, open-source relativistic graphics code allows the speed of light in the game to approach the player's own maximum walking speed. Visual effects of special relativity gradually become apparent to the player, increasing the challenge of gameplay. These effects, rendered in realtime to vertex accuracy, include the Doppler effect (red- and blue-shifting of visible light, and the shifting of infrared and ultraviolet light into the visible spectrum); the searchlight effect (increased brightness in the direction of travel); time dilation (differences in the perceived passage of time from the player and the outside world); Lorentz transformation (warping of space at near-light speeds); and the runtime effect (the ability to see objects as they were in the past, due to the travel time of light).

New Scientist TV: Seeing Relativity: Mind-bending tour of the solar system

New Scientist TV: Seeing Relativity: Mind-bending tour of the solar system: The tour starts in an orbit high above the surface of the Earth. As you move further away, oceans turn green and continents look red due to the Doppler effect. Passing by Mars, its surface changes colour dramatically. Then, as you speed up, Jupiter appears smaller than it actually is due to time dilation, since you're seeing what it looked like in the past, when it was further away. A small window in the lower right of the video shows the planet's actual appearance for comparison.

Flying towards Saturn, its rings look distorted and, as you reach light speed, everything around you is compressed to a single spot.

Faster-than-Light Neutrino Puzzle Claimed Solved by Special Relativity - Technology Review

Faster-than-Light Neutrino Puzzle Claimed Solved by Special Relativity - Technology Review: But the tricky part is keeping the clocks at either end exactly synchronised. The team does this using GPS satellites, which each broadcast a highly accurate time signal from orbit some 20,000km overhead. That introduces a number of extra complications which the team has to take into account, such as the time of travel of the GPS signals to the ground...
Although the speed of light is does not depend on the the frame of reference, the time of flight does. In this case, there are two frames of reference: the experiment on the ground and the clocks in orbit. If these are moving relative to each other, then this needs to be factored in...
Van Elburg calculates that it should cause the neutrinos to arrive 32 nanoseconds early. But this must be doubled because the same error occurs at each end of the experiment. So the total correction is 64 nanoseconds, almost exactly what the OPERA team observes.

About time: Countdown to the theory of everything - New Scientist - New Scientist

About time: Countdown to the theory of everything: Carlo Rovelli, a physicist at the Centre for Theoretical Physics in Marseilles, France, has rewritten the rules of quantum mechanics so that they make no reference to time (New Scientist, 19 January 2008, p 26).

"For me, the solution to the problem is that at the fundamental level of nature there is no time at all," Rovelli says. In his view, quantum mechanics does not have to describe how physical systems evolve in time but only how they evolve relative to other systems, such as observers or measuring devices. "Physics is not about 'how does the moon move through the sky in time?' but rather 'how does the moon move in the sky with respect to the sun?'," he says. "Time is in our mind, not in the basic physical reality."

Neutrinos Travel Faster Than Light, According to One Experiment - ScienceNOW

Neutrinos Travel Faster Than Light, According to One Experiment - ScienceNOW: Over 3 years, OPERA researchers timed the roughly 16,000 neutrinos that started at CERN and registered a hit in the detector. They found that, on average, the neutrinos made the 730-kilometer, 2.43-millisecond trip roughly 60 nanoseconds faster than expected if they were traveling at light speed. "It's a straightforward time-of-flight measurement..."
...the tricky part is accurately measuring the time between when the neutrinos are born by slamming a burst of protons into a solid target and when they actually reach the detector. That timing relies on the global positioning system, and the GPS measurements can have uncertainties of tens of nanoseconds. "I would be very interested in how they got a 10-nanosecond uncertainty, because from the systematics of GPS and the electronics, I think that's a very hard number to get."

Physicists Dispute Table-Top Relativity Test: Scientific American

Physicists Dispute Table-Top Relativity Test: Scientific American: The debate comes down to whether a fundamental atomic oscillation, based on the rest mass of a cesium atom, can be used as a clock. The table-top setup relied on an atom interferometer, which tracked the offset in oscillations, or phase difference, of the cesium atoms as they flew on paths of marginally different heights. But Blanchet's team argue that the phase difference between any two atoms due to the fundamental oscillation will always be zero, and therefore could never be used to detect a gravitational redshift.

They say that the Berkeley researchers were instead using their interferometer as an accelerometer to measure a different aspect of general relativity: the universality of free fall. That is no less interesting in its own right, but it has already been tested to greater levels of precision.

First Observation of the Dynamical Casimir Effect - Technology Review

First Observation of the Dynamical Casimir Effect - Technology Review: But there is another phenomenon called the dynamical Casimir effect that has never been seen.

It occurs when a mirror moves through space at relativistic speeds. Here's what happens. At slow speeds, the sea of virtual particles can easily adapt to the mirror's movement and continue to come into existence in pairs and then disappear as they annihilate each other.

But when the speed of the mirror begins to match the the speed of the photons, in other words at relativistic speeds, some photons become separated from their partners and so do not get annihilated. These virtual photons then become real and the mirror begins to produce light.

Einstein's sceptics: Who were the relativity deniers? - physics-math - 18 November 2010 - New Scientist

Einstein's sceptics: Who were the relativity deniers?: A few years ago, I had the opportunity to access papers belonging to the physicist Ernst Gehrcke, one of the most outspoken critics of Einstein in Germany. As I delved into the material he had neatly collected in banana boxes, a whole world of anti-relativity emerged from hundreds of pamphlets, thousands of newspaper clippings, and piles of letters from Einstein's opponents across Europe and the US.

I discovered that the group opposing relativity was much broader than many historians believed till now, and that their tactics had much in common with those used by creationists and climate-change deniers today. Their reasons for countering relativity were also more complex and varied than is usually thought. Even Einstein misjudged the motivations of many of his opponents.

The One-Way Speed of Light Conundrum - Technology Review

The One-Way Speed of Light Conundrum - Technology Review: "One interesting question immediately arises: how do you measure the one way speed of light? It turns out there are various methods. One idea involves the emission and absorption of gamma rays by certain kinds of atoms in a solid. The process of absorption is very sensitive to the energy of the gamma rays. So if the speed of light (and therefore its energy) varies with direction, then the rate of absorption ought to change too.

In the 1960s and 70s, various physicists looked for a directional dependence by placing a gamma ray emitter at the edge of a rotating disc and an absorber at the centre. They then looked for any difference in the rate of absorption as the disc rotates but found none."

Cosmic clocks: Relativity's final test

This is about pulsars

http://www.newscientist.com/article/mg20527520.200-cosmic-clocks-relativitys-final-test.html

Why Einstein was wrong about relativity

http://www.newscientist.com/article/mg20026801.500-why-einstein-was-wrong-about-relativity.html