Ask Ethan #16: What are Variable Stars?

“To be is to be the value of a variable.” –Willard Van Orman Quine It’s the end of the week once again, and the very end of our Year In Space 2014 Wall Calendar giveaway! So for this week’s Ask Ethan column, after dipping into our question/suggestion box, I’m very pleased to let Vera from … Read moreAsk Ethan #16: What are Variable Stars?

What is the Big Bang all about?

“Twinkle, twinkle, quasi-star Biggest puzzle from afar How unlike the other ones Brighter than a billion suns Twinkle, twinkle, quasi-star How I wonder what you are.” –George Gamow The Big Bang is one of the greatest, revolutionary ideas in all of modern science, but it’s also one of the most successful ideas as far as … Read moreWhat is the Big Bang all about?

How Big is Our Observable Universe?

“The mind, once expanded to the dimensions of larger ideas, never returns to its original size.” –Oliver Wendell Holmes When General Relativity supplanted Newton’s work as our theory of how gravity works in the Universe, it didn’t just change how we view how masses attract, it gave us a new understanding of what the questions where … Read moreHow Big is Our Observable Universe?

How can we see black holes?

“According to the special theory of relativity nothing can travel faster than light, so that if light cannot escape, nothing else can either. The result would be a black hole: a region of space-time from which it is not possible to escape to infinity.” –Stephen Hawking You may have encountered objects that are the same … Read moreHow can we see black holes?

The Cosmic Microwave Background? Not always…

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, … Read moreThe Cosmic Microwave Background? Not always…

Faster-than-light travel: is it possible?

Apparently, this is becoming a good place for people to get their questions answered! My friend Brian, recently wanted to know what the possibilities were for faster-than-light travel. Specifically, he was interested in it because he wants humans to do it. Brian: but otherwise how will we ever have a civilization like that in Star … Read moreFaster-than-light travel: is it possible?