The topic, science: the stuff of all my dreams. It demands patience, creativity, a willingness to work hard, to get things wrong, to be serious and silly, and to validate through evidence. This week has been a real news-making one…. lots going on in the world of astronomy and cosmology. Let’s see if this can be untangled in some ways.
Astronomers collect data about the universe. We use telescopes, among other tools, to collect photons, those little packets of energy that travel at c, light-speed in a vacuum, and then convert all that to numbers. Telescopes collect all sorts of photons: visible ones (we call light), IR, UV, radio, x-ray, gamma-ray, and microwaves. Sometimes cosmologists have been seeking the results of all that data collection that astronomers have been doing. Cosmologists are those that work to better understand the start, evolution and end of the Universe… yep, the whole thing. It’s a daunting task.
Big Bang Theory? Yep – that is cosmology. Astronomers provided the needed observations to show that it was likely to be the start to the Universe. Edwin Hubble observed data which shows that gravitationally unbound galaxies are rushing away from each other at a pretty constant rate of expansion… now called Hubble’s Constant. Well, maybe it’s not as constant as we had thought back in the 1920s. Astronomers (well, actually some people working to better telecommunications on Earth) came up with observations of the cosmic microwave background – pretty solid evidence for the afterglow of the Universe’s boom.
This week, a new observation. This time, scientists used a facility called BICEP2 ( go here for their site: http://www.cfa.harvard.edu/CMB/bicep2/ ) located at the South Pole. Nice working conditions there, I bet! This instrumentation uses a set of devices called bolometers. Bolometers collect photons and measure the power (in Watts) received. A Watt is how much energy the system is receiving (in Joules) each second. These bolometers are a little special. They measure photons at microwave wavelengths. They also have the ability to look at how those microwave photons are oriented as they travel to the detector. This orientation is called polarization. If a photon vibrates in multiple directions as it travels, we say that it it unpolarized. If it vibrates in one direction, then it is called polarized. More on this here if needed: http://www.physicsclassroom.com/class/light/u12l1e.cfm
Going back some years, cosmologists were deeply concerned about several issues that the Big Bang theory presents: More on these issues? A great writeup is located here at Wikipedia. The key here is that Allan Guth (now an MIT professor) developed a solution to these which then became called the Inflationary Theory. This is not the only cosmological theory which solves the issues, but it is a strong one. This week, it becomes a little stronger. Reasoning? The Inflation theory predicts that we should see polarized photons in certain alignments that show the existence of gravity wave influences during the early moments of the Inflationary Period of the Big Bang. That is exactly what the BICEP2 experiment has done, found this pattern of polarization in the microwave background. It is pretty astounding and goes a ways to confirm that Inflation is the theory most likely to be correct, but wait! All good science needs confirmation with new and separate evidence. Here we go! Stay tuned to the ever-unfolding developments in cosmology and observational astronomy.
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