An electron in the ground state will orbit at the speed of light. This is the electromagnetic equivalent of a black hole. For gravitational black hole, general relativity comes to the rescue to prevent planets from orbiting at the speed of light and beyond. For an electromagnetic black hole, general relativity comes to the rescue and saves element from having electrons moving faster than the speed of light.
However, even with general relativity, element would still have electrons moving faster than light. Clear wave behavior is critical to observing the wave patterns—atomic fringes—that are the key to measuring the recoil velocity. The LKB chose atoms that would occupy two stable atomic levels. A split second later, they would use another laser pulse to recombine these atomic halves or wave packets into one.
They measured the phase shift between these two different wave patterns to determine the recoil velocity and therefore determine the rubidium atom mass needed to calculate the fine structure constant. The LKB found that their measurement of the fine structure constant was in better agreement with the experimental value of the Standard Model than any before.
IT IS a well-kept secret, but we know the answer to life, the universe and everything. This immutable number determines how stars burn, how chemistry happens and even whether atoms exist at all. Now its mystery is deepening. Controversial hints suggest this number might not be the universal constant we had assumed, instead varying subtly over time and space.
If confirmed, that would have profound consequences for our understanding of physics, forcing us to reconsider basic assumptions about the structure of reality.
While arguments about the true significance of the findings rage, experiments looking both deep into the cosmos and at the fine-grained structure of reality in the lab are now set to deliver a definitive verdict — perhaps. The idea that constants of nature — things like the speed of light, strength of forces and the masses of various particles — might not be so constant has an illustrious history.
The fine structure constant, also known as alpha, is a case in point. Alpha lies at the centre of a theory Dirac initiated and Feynman worked on: quantum electrodynamics, or QED. This is the quantum theory of the electromagnetic force, and describes the interactions between light and matter. Alpha determines their strength. Change this number by a smidgen, and you change the universe. Go a bit further and nuclear fusion factories within stars grind to a halt and can no longer produce carbon, the element on which life is based.
Make alpha much smaller, and molecular bonds fall apart at lower temperatures, altering many processes essential to life. A large bugbear of physicists is the way our theories of nature require us to inject a set of arbitrary numbers to make them reflect reality. There seems to be no rhyme or reason for these numbers: they are just there, and we must measure them in experiments.
On Earth, at least, alpha keeps itself within strict bounds. It has appeared in various calculations in physics since the s, spurring numerous attempts to come up with a Grand Unified Theory that would incorporate the constant since. So far no single explanation took hold. Recent research also introduced the possibility that the constant has actually increased over the last six billion years, even though slightly. Skip to content Pixabay Key Takeaways. Paul Ratner.
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