There’s a hot buzz in the astrophysics community right now. It appears that the inflation concept, including possibly inflation faster than the speed of light, may be confirmed to a 99.99999% level. That’s a stunning level of confidence and it shows that a lot of what we suspected about the known universe and the Big Bang is true.
The timeline of the universe as our current understand is as follows.
The Plank epoch is the first 10-43 seconds of the universe. The four fundamental forces we know now (strong nuclear, weak nuclear, electromagnetism, and gravity) were combined into one force due to the extreme temperature.
The Grand Unification epoch is from 10-43 to 10-36 seconds. By this point the universe has been expanding for one billionth of one billionth of one billionth of one billionth of one billionth of a second. The temperature drops as it cools and the universe crosses the ‘transition temperatures as it does so. Just as a freezer cools water past the transition temperature to ice, the universe does the same. Except that the fundamental forces “freeze out” of the hot universe. Gravity falls out first and becomes a force. Then strong force falls out.
The electroweak epoch is next and runs from the grand unification epoch to about 10-12 seconds. The temperature of the universe has come down to 10,000,000,000,000,000,000,000,000,000 Kelvin. The weak nuclear force and the electromagnetic force split apart in this cool temperature.
At some point in this process, the inflationary period began and ended. This was probably triggered a phase transition (a drop in temperature past a certain value) that began a process of hyper inflation. In this process, the universe expanded by at least a factor of 1026. This hyper-inflationary period explains why the universe is 13.798 ± 0.037 billion years old, but is 46 billion light years in radius (centered roughly on us). The universe literally expanded fast-than-light.
But, the universe was already pretty large and so this transition didn’t happen all at once throughout the entire universe.
In a phase transition, even though the entire system is primed for the transition, it doesn’t happen simultaneously throughout the system. You can see this if you can supercool water to below 0°C. The water can remain a liquid below the freezing point of water. But any little bump or something falling into the water will set off a chain reaction and the entire container can freeze solid in just a few moments.
Notice the “freezing front” in the bottle of water? Now, think about that being a front of hyper-inflation. At the front (and just behind the front, the universe is expanding at faster than light rates (as we measure it now). As the front moves along, it’s setting up pockets of universe material that begin expanding. This isn’t just happening in a straight line as in the bottle, but along an expanding sphere.
This is what modern cosmologists call the multiverse. There are potentially infinite numbers of “universes” that we can never see. They are just beyond this wave front of hyper-inflation that may still be going on. We don’t even have to have been in the first universe to have had this happen.
I know this is somewhat mind-numbing. I’ve had lots of practice trying to imagine four spacial dimensions and playing games with flatland in my head.
So, we can see light that has come to us from 46+ billion light years away, it’s been travelling for 13 billion light years. That’s pretty much our limit. Because the universe was inflating faster than the speed of light at some point, the light from any part of those other universes cannot ever reach us. Therefore, what’s beyond the visible edge of our universe is forever beyond out ability to see.
I say ‘edge’ here because it’s a concept that people are familiar with and can understand, but it’ not really the ‘edge’ of the universe. Edge implies the end of something. The universe is everything.
OK, so back to the research that has everyone excited… well all the geeks excited.
Light can be polarized. That is, all the waves of EM radiation can be oriented in the same direction. Polarized lenses in glasses only allow light in one direction to enter. Since most light is evenly mixed among all possible directions, polarized lenses reduce the amount of light and reduce glare. Light from the early universe is slightly polarized.
Gravity waves such as would be produced by various inflation models, result in specific patterns of polarized light. The result are little spirals of polarized light.
The r parameter is the measure of how much “swirliness” is in these patterns. Earlier estimates suggested that the value of r would be under 0.11. Which, for various highly technical and mathematical reasons, would eliminate some of the more popular models of inflation. This was an estimate though, not a direct measurement.
The researchers spent over two decades making measurements with increasingly sensitive radio telescopes in Antarctica. After all this research, they determined that the value of r is 0.20. Which means that the most favored models are back in contention.
The researchers were so startled to see such a positive result that they didn’t publish for over a year to confirm and recheck. They also considered alternative explanations for the patterns they found. Much of the time spent using a Harvard-based supercomputer to check their math and analysis.
Here’s a video of one of the researchers, Chao-Lin Kuo, telling Dr. Linde (who first described the modern version of inflation) about the discovery.
Unfortunately, inflation is pretty much the limit. Inflation has wiped away all the information that existed before it.
Again, this still needs more research. The Plank mission may be able to confirm the result in a few months.
This result doesn’t mean that the multiverse notion is proven, but it is strong evidence supporting it.
