expansion
Tag archives for expansion
What Happened Before The Big Bang?
Posted by Ethan on October 15, 2012 
“The aim of science is not to open the door to infinite wisdom, but to set a limit to infinite error.” -Bertolt Brecht One of the most frequent questions I get about the Universe — as a cosmologist — isn’t quite about the Big Bang in and of itself. The Big Bang is a remarkable…
If it comes back to you, it’s yours!
Posted by Ethan on September 10, 2012 
“Not even light can escape such hollowing, this huge mass in a small space. Even the Milky Way with its open arms is said to have a black hole at its heart.” -Susan B.A. Somers-Willett Our Milky Way is home to us all. With its hundreds of billions of stars, massive spiral arms, dust lanes,…
Another Trip Around the Sun
Posted by Ethan on August 3, 2012 
“How old would you be if you didn’t know how old you are?” -Satchel Paige Today marks another year and another trip around the Sun for me. For you, and me, and everything on Earth that makes it through another year on this world, there’s a whole lot we get to experience. Some things are…
Empty space has more energy than everything in the Universe, combined
Posted by Ethan on July 26, 2012 
“Nothing exists except atoms and empty space; everything else is just opinion.” -Democritus of Abdera When you take a look out at the Universe, past the objects in our own solar system, beyond the stars, dust and nebulae within our own galaxy, and out into the void of intergalactic space, what is it that you see? What…
Astronomers make use of… molecules?
Posted by Ethan on May 14, 2008 When I think of molecules, I think of Conan O’Brien doing his skit where he plays Moleculo… the molecular man! I don’t think of astronomy, and I certainly don’t think of the leftover radiation from the big bang (known as the cosmic microwave background)! But somebody over at the European Southern Observatory put these two…
Energy Conservation and an Expanding Universe
Posted by Ethan on April 11, 2008 So, what’s the deal with this one? startswithabang.com reader Scott Stuart asks the following question: I was reading “The First Three Minutes” last night and came across an interesting section about blackbody radiation and energy density. The author states that as the universe expands, the number of photons running around (in the CMB, for example)…
Is Dark Energy the same as Acceleration?
Posted by Ethan on April 10, 2008 In a comment on my last post, What is Dark Energy, Kendall asks the following, which is such a good one I think it deserves its own post: I thought the expansion was accelerating? Aren’t you saying that it is on its way down to 85% of its current rate? Sounds like expansion is slowing,…
What is Dark Energy?
Posted by Ethan on April 9, 2008 You’ve all heard these words before. Dark Energy. But what is it, and why are we stuck with it? Let me start by telling you a story. Imagine, for a minute, that you have a candle. You know everything about this candle, including how bright it is and how far away it is from you.…
Say Goodbye to Virgo…
Posted by Ethan on March 13, 2008 Aaah, the Virgo cluster. A huge cluster of hundreds of galaxies, and our closest large neighbor in the Universe. People have known for a long time that although Virgo is still redshifting away from us, it isn’t quite as fast as we would expect from the Hubble expansion rate of the Universe. Does this mean…
The Universe is Accelerating?
Posted by Ethan on March 12, 2008 Sure, there’s dark energy, but what does that really mean? First off, there’s the bizarre phenomenon we see: very distant objects appear dimmer than we expect in a Universe filled with just matter and space. This supernova (above) should appear much brighter for how distant it is, based on what we know about supernova. This…
