MessageToEagle.com - There is the ultimate speed limit of the universe, and no particle or piece of
information can go faster than that, according to Einstein's theory.
His famous theory withstood numerous tests over the past 100 years. Now, it's time for yet another experiment
to test Einstein's speed limit.
University of California, Berkeley, postdoc Michael Hohensee, graduate student Nathan Leefer and Dmitry
Budker, a UC Berkeley professor of physics,want to check whether some particles break this law.
Rare measurement material. A new type of highly sensitive search for violations of relativity requires the rare earth element dysprosium.
Scientists are improving the experiment to push the theory's limits even farther - and perhaps turn up a
discrepancy that could help physicists fix holes in today's main theories of the universe.
"As a physicist, I want to know how the world works, and right now our best models of how the world works -
the Standard Model of particle physics and Einstein's theory of general relativity - don't fit together at
high energies," said Hohensee of the Department of Physics.
"By finding points of breakage in the models, we can start to improve these theories."
Leefer, Hohensee and Dmitry Budker, a UC Berkeley professor of physics, conducted the test using a new
technique involving two isotopes of the element dysprosium.
By measuring the energy required to change the velocity of electrons as they jumped from one atomic orbital to
another while Earth rotated over a 12-hour period, they determined that the maximum speed of an electron - in
theory, the speed of light, about 300 million meters per second - is the same in all directions to within 17
nanometers per second.
Their measurements were 10 times more precise than previous attempts to measure the maximum speed of electrons.
Using the two isotopes of dysprosium as "clocks," they also showed that as the Earth moved closer to or farther
from the sun over the course of two years, the relative frequency of these "clocks" remained constant, as Einstein
predicted in his general theory of relativity.
Left to right, Dmitry Budker, Nathan Leefer and Michael Hohensee with their experiment to test Einsteinís speed limit. Photo by Andreas Gerhardus.
Their limits on anomalies in the physics of electrons that produce deviations from Einstein's gravitational
redshift are 160 times better than previous experimental limits.
Similar tests of Einstein's theories can be conducted in huge accelerators like the Large Hadron Collider (LHC)
in Switzerland, but such experiments are expensive, the colliders take a long time to build and still don't reach
energies high enough to where the theories could break down.
"You can try to probe these theories using big accelerators, but you would need to produce electrons with seven
times the energy of the protons at the LHC. Or you can look at high energy phenomena in distant stars or black holes,
but those are not in the lab and not fully understood," Hohensee said.
"Instead, We can look for evidence that the standard model or general relativity break at low energy scales in small
ways in a tabletop experiment."
Compared with existing tests, the revamped experiment by UC Berkeley physicists will potentially be a thousand times
more sensitive, the level at which some theorists predict special relativity might break down.
"This technique will open the door to studying a whole other set of parameters that could be even more interesting
and important," said Budker, who was among the first to use dysprosium's unusual electronic structure to test
fundamental aspects of particle physics.
Dangerous Apophis Will Reach Our Planet In 2036:
Will It Strike Earth?
A brief look into the future.
The year is 2029 and a very dangerous asteroid named Apophis is making its closest approach to Earth.
Humans are awaiting this moment with great anxiety as they will finally learn whether
the space killer will strike Earth when it returns in the year 2036.
Just how dangerous is Apophis really?