More on the Fine Structure Constant

Bonker writes "Neat news from the Beeb. It turns out that data collected from observation of quasars indicates that the fine structure constant of the universe, aka 'Alpha', may have changed since the universe began. It may have been very slightly smaller than it is right now. The article hints that other constants we're familiar with, such as high, holy 'c', may also vary over time. Of course values can't have changed dramatically, because that would mean that low-weight atoms such as carbon would be unstable, and without carbon, there wouldn't be anyone around to measure the fine structure constant anyway." We ran a story about this last year. It looks like the team has continued to check their work for errors and hasn't found any yet.

Comments

Re:Speed of light

[bravehamster]

(OT I know, but I couldn't let this go)

No. c is the speed of light in a vacuum. The slowed light down by passing it through a certain material.

Actually, this is also, technically, incorrect. The speed of light is a constant. Always. Light always moves at light speed. Now, the time it takes for light to pass through various mediums is different, but this is not because the light is being slowed down. It's because the light is hitting the atoms in the medium and is kicking the electrons in the atom to a higher energy state. When the electron falls down from its higher energy state, it in turn release a particle of light. You could go so far as to say that it's the same particle of light. With denser mediums, light takes longer to get through. In the sun, for example, the plasma surrounding the fusion core is so dense, the light from that fusion takes many millions of years to reach the surface. During those millions of years, the light is always moving at light speed. It just keeps running into stuff.

some background on 'alpha'

[ChenLing]

alpha is the coupling constant for the electromagnetic force.
In other words, it determines the "strengh" of the electromagnetic force. It is important because
a) it has no units (it's just a number, approximately 1/137)
b) it is easy to measure to a great degree of accuracy
c) it can be measured using a variety of different experiments
d) many fundamental phyiscal constants (such as c - the speed of light in a vacuum, e - the charge of an electron, and h - the Planck constant.

So a change in alpha would mean a change in one of the fundamental constants of physics.

For more information, you can read NIST's wonderful description.