September 2, 2009
So, I have a small confession for you, my readers. Since I first started writing this blog, I have always solicited questions, and promised to answer the best ones. Recently, this has come back to bite me, as I've started getting more questions than I possibly have time to answer. However, the ones…
August 31, 2009
Okay, as many of you had heard, I've got a new job as a full-time Professor. And not only am I pretty excited about it, I thought I'd share with you one of the more interesting things I taught on the first day.
I got this idea from talking to Michael, the chair of the department (and this is not…
August 30, 2009
Ain't no sunshine when she's gone.
It's not warm when she's away.
Ain't no sunshine when she's gone
And she's always gone too long anytime she goes away.
Bill Withers' song Ain't No Sunshine has been covered by over 100 major artists since its release in 1971, but I think the original is still…
August 28, 2009
Yesterday, I showed you a picture of 100,000 nearby galaxies, which made me feel small, even when we just look at our (relatively) local Universe. Today, let's go down to the other end of the spectrum.
Electron microscopes have been around for a long time, and they've let us see some very advanced…
August 27, 2009
Ever wonder what it would look like if you took about 100,000 nearby large (i.e., Milky Way sized and larger) galaxies, reduced each one to a point, and mapped them? Well, at Swinburne University of Technology in Australia, they did this, from the point of view of where we are in the Universe. We…
August 26, 2009
On Monday, I posed a question to you as to why, when you photograph the Sun at the same exact time every day for a year, you get something that's shaped like a figure 8, like so:
Image credit: Tunc and Cenk Tezel.
We got a good number of thoughtful comments, many of which are on the right track,…
August 25, 2009
There's a new book out there, Why Does E=MC2 (and Why Should We Care?), by Brian Cox and Jeff Forshaw. One of Seed's editors, Elizabeth Cline, took a read through it and wrote about her experiences and what she learned. Is relativity, particle physics, and all the related science really…
August 24, 2009
I'm trying something new here: I'm going to give you a little bit of information and a teaser, and we'll see -- in the comments section -- whether any of you can figure it out.
Imagine that you went outside, each and every day at the same time, and mapped the position of the Sun. What would you see…
August 24, 2009
Once a week, all the top astronomy/space writers from around the net get together -- thanks to Fraser Cain at Universe Today -- and contribute their top stories to the Carnival of Space. This week, Mike Simonsen of Simostronomy hosts, and brings together some great stories in this week's Carnival…
August 22, 2009
New technology has led to breakthroughs in practically every aspect of our lives since the dawn of the industrial revolution. In nearly every case, it's for the betterment, in some way, of society. (And yet, I like my music best when it's acoustic, unprocessed, and barely produced at all.) Take…
August 21, 2009
Recently, a discussion started in one of my comment threads about whether the Big Bang was necessarily valid or not, and whether there were any reasonable alternatives. The answer is that not only is the Big Bang the best theory to explain the start and evolution of the Universe, it's the only one…
August 19, 2009
Last year, while watching the Beijing Olympics, I was blown away by how much faster Usain Bolt was than everybody else:
He became the first man to run the 100 meter dash in under 9.7 seconds. Now, I thought, that's really, really fast. But then, just a few days ago, there was a race between the "…
August 18, 2009
This week's Carnival of Space introduced me to a new site, Habitation Intention. As always, the collection of space-related stories from around the 'net is worth checking out, and I've got my top three picks for you.
1. Goodbye, Moon and Mars! What, you thought that my opinion was shared by many?…
August 17, 2009
About four months ago, the Mars Rover Opportunity was driving around Mars at about 50% power, as five years of accumulated Martian dust on its solar panels was disastrously affecting its ability to acquire power:
But a fortuitous, powerful gust of wind knocked much of the dust off, boosting…
August 14, 2009
Sometimes, things happen that either:
I don't agree with,
I have different information than other people (sometimes more, sometimes less, sometimes just different), or
need to be spoken out against,
and that's when it's time to argue. Sometimes, there's no way around it, and I need to put myself…
August 13, 2009
Okay. Yesterday, I explained to you that the only thing that determines how the Universe expands is the amount of energy density in it. But many of you wanted more details. So, by popular demand -- including one insistence that there is no equation that tells us how the Universe expands -- here is…
August 12, 2009
So, the Universe started with a bang. Everything was hot, dense, and expanding.
It's 13.7 billion years later now, and our Universe is cold and sparse. The temperature of the leftover glow from the big bang -- which used to be over 10^30 degrees -- is now down to 2.7 Kelvin, just barely above…
August 12, 2009
It wasn't all that long ago that I wrote a five-part series on Hubble's old camera, WFPC2. I call it "The Camera that Changed the Universe." Part 1 focused on Hubble showing us just how deep, rich, and full of wonder our Universe is. Let's remember how this happened.
The first thing we did was take…
August 11, 2009
When you go outside at night, on a clear night away from all lights, you see the sky the same way the ancients did: full of stars.
Now, if you looked up periodically, you would find that the sky appears to rotate! Some constellations rise while others set, and one point -- either due north or due…
August 11, 2009
This week's Carnival of Space comes from New Frontier News, which has the oddest banner I've seen on a serious science website in a while:
The top three entries this week? As chosen, fairly arbitrarily, by me?
1. Pluto: planet or not? Apparently, the IAU got together again, for the first serious…
August 10, 2009
There's a good reason for it, I promise! Allow me to explain. You see, every so often, a comet zooms in from the Kuiper Belt. As it approaches the Sun, it heats up, displaying a spectacular tail.
What is this "tail" actually? It's tiny, tiny fragments of ice and rock that make up the comet. You…
August 7, 2009
When I issued my Charity Challenge to you a few weeks ago, I had no right to expect the support that all of you have given me. So listen to Michael Chapman singing Memphis in Winter while I give you what you gave for:
We have reached:
101 separate donations,
at least $3,260 in new donations…
August 6, 2009
Every once in awhile, a question makes it to my inbox that's too good to ignore.
A friend and I were joking about being "older than dirt" and he asked a question I thought you might enjoy: "Hey, ask Ethan how old dirt is and how it got here."
You did the smart thing by coming to me, because the…
August 5, 2009
The Wall Street Journal has just reported that over 1,000 people in the Americas, according to data released by the World Health Organization, have died from the Swine Flu. They seem to think you should be alarmed.
The global A/H1N1 swine flu pandemic has claimed 1,154 lives since the outbreak was…
August 5, 2009
Last week, we began talking about understanding the size of the Universe, and we continued this week with some information on distances and motion in the Universe. This brings us to my favorite application, which leads to the Hubble expansion:
Redshift. You see, whenever an atom or molecule emits…
August 4, 2009
Those of you who've been reading this site regularly know that we've been very busy of late, finishing our series on the last 100 years, working on raising money for charity, and discussing the deep issues of distances and motion in cosmology. But there is a whole lot of other space news buzzing…
August 3, 2009
At the end of last week, I wrote a post explaining how the Universe is so big (93 billion light years across) when it's only 13.7 billion years old. The key visualization is to think of space as being the surface of an expanding balloon, while all the things in the Universe (stars, galaxies, etc.)…
July 31, 2009
I am altering the deal. Pray I don't alter it any further.
Ahh... good old Star Wars. So, I am altering the deal. Two weeks ago, I told you all that we were having a charity challenge, and that if I got 100 of you to donate either money ($10 minimum) or time (4 hours minimum), I would shave my…
July 31, 2009
I get a certain question every so often, and it's one of the most difficult questions any cosmologist faces. Today, I try to tackle it. It goes something like this:
If the Universe is 13.7 billion years old, and nothing can go faster than the speed of light, how is it that we see things that are 46…
July 29, 2009
Sure, sure, everyone knows that stars twinkle. You look up at the night sky, and pretty much any star you look at appears to fluctuate in its brightness and intensity very rapidly, giving it a "twinkling" appearance.
Why does this happen? It definitely doesn't have anything to do with the star…
