gravitational
Tag archives for gravitational
A thought experiment for the relativity skeptics
Posted by Ethan on January 9, 2013 
“Great spirits have always encountered violent opposition from mediocre minds.” -Albert Einstein It may be hard to believe, seeing as how it’s been our leading theory of gravity for nearly a century now, but Einstein’s General Relativity is possibly the most frequently challenged scientific idea of all-time. Of course, it’s emerged victorious from each and…
Black Hole Kicked Out of Galaxy
Posted by Ethan on April 29, 2008 No, not because it was too young to drink! Scientists at the Max Planck Institute for Extraterrestrial Physics were looking at some X-ray objects, and discovered something really weird: a very bright X-ray source moving out of a galaxy at nearly 3,000 kilometers/second! This thing is a goner. If our Sun were moving at even…
Why Do We Only See One Side of the Moon?
Posted by Ethan on April 29, 2008 And if the band you’re in starts playing different tunes I’ll see you on the dark side of the Moon. One of my favorite readers, Zrinka, asks us why we’re only able to see one side of the Moon from Earth. Seriously, look at the different phases; we always see the same side of the…
Gravitational Waves: Inflation or not?
Posted by Ethan on April 17, 2008 Nothing gets past you, does it? A scientific paper came out earlier this week, and I took a look at it, sighed, and Jamie asked me, “What?” And I said to her, “When I see bad science, it just makes me a little bit frustrated and sad.” Of course, I had no intention to write…
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)…
Somethin’ Neat about our Galaxy
Posted by Ethan on March 26, 2008 So last week I was up at Pacific University in Portland, OR for a job interview. As part of a faculty interview, you have to lecture on a topic for undergraduates, but they give you the topic just a couple of days before. My topic was Gauss’ Law, which talks about the relationship between an…
The Cosmic Microwave Background? Not always…
Posted by Ethan on February 7, 2008 The Universe isn’t a static place. Although the laws of nature (physics, chemistry, biology, etc.) don’t appear to change over time, everything in the Universe appears to evolve, and changes over time. One of the simplest ways that this happens is through Hubble expansion. General relativity tells us how the Universe expands, and more specifically,…
