April 16, 2008
Ahh, stars. Giant furnaces of nuclear fusion. Doing the stuff our Sun does, burning hydrogen fuel into helium (among other things) and emitting lots of visible light and energy in the process.
But when we take a look at brown dwarfs, they aren't like normal (i.e., main sequence) stars like our Sun…
April 16, 2008
...just bring your own air and water. The BBC is reporting that the European Space Agency has determined that Marigolds, when planted in lunar soil, would be able to grow without adding any extra nutrients.
How cool is that?
April 15, 2008
I was doing a little research into the history of telescopes, and it was about a century ago that they finally realized how much more potential light-gathering power reflecting telescopes had as compared to the older refracting telescopes. On Mt. Wilson in California, astronomer George Ellery Hale…
April 14, 2008
Yesterday, my good friend (and SWAB reader) Brian wrote a great comment about the practical reasons to explore space, where he talked about the overall economic impact that Space Exploration has had on the economy, as well as the impact it has had on our knowledge and understanding of the Earth,…
April 14, 2008
The DAMA collaboration, an experimental team searching for dark matter via direct detection, is poised to report this week that they have discovered Dark Matter. And I'm here to pre-empt that by bringing you the truth: no, they haven't.
They take some very cold (cryogenic) atoms,
look for nuclear…
April 14, 2008
Over the past few months, I have been asked a number of questions about String Theory and the Universe, including from readers Benhead and Mastery Mistery. But now Jamie, whom I'm going to marry later this year, has been asking me about it, and so it's time to write something about the scientific…
April 12, 2008
Nothing to do with astronomy or physics (except for the perils of gravity), but this TV show is hilarious: Ninja Warrior. I don't get the channel G4 here in Tucson with expanded cable, but this is basically the Japanese version of the American Gladiators event: The Eliminator! If you have some…
April 11, 2008
Fraser Cain over at Universe Today sent out a question to the Astronomy/Astrophysics/Space communication community today. And he asks:
Why should we spend our time/money/resources on exploring space when there are so many problems here on Earth?
This is something that, for better or worse, I had a…
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…
April 10, 2008
In my mind, and in my car,
we can't rewind, we've gone too far,
pictures came and broke your heart,
put the blame on VTR.
And for those of you who are under the age of 25, VTR stands for Video Tape Recorder. This was the Buggles, who made the first music video that ever appeared on MTV, back when…
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, but still…
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. Like so:
Now if I…
April 7, 2008
Tonight, from 7:00 PM - 8:30 PM Pacific Time, I will be Dr. David Livingston's guest on his radio program, The Space Show! I have no idea how it's going to go or if I'll be able to communicate clearly on an audio-only format, as I've never tried before, but I'm really looking forward to the…
April 7, 2008
What's going to happen to all the stars in the Universe as they get older? Well, just as nothing can live forever, stars can't live forever also. Why? Because they run on fuel: burning hydrogen into helium, for example. When they run out of fuel, something's gotta give. Barbara Ryden reminds us of…
April 6, 2008
Ever seen the Horsehead Nebula? If you look at the easternmost star in Orion's Belt through a telescope, you're likely to see something like this (the star is just off the image to your left):
A pretty little nebula, to be sure, but it doesn't look all that spectacular. I mean really, there's a…
April 4, 2008
Take a look at this picture, and tell me where the brightest parts and dimmest parts are:
Well, obviously, just to the left of the color gradient, it gets darker than anywhere else. Also, just to the right, it gets lighter than anywhere else. And that's the way it is, isn't it?
Or is this an…
April 4, 2008
First things first: this week's Carnival of Space is up at Brian Wang's site, Next Big Future. You can find my post on Mars or Arizona? up there.
Now, what comes next for me, since I don't like it here in Arizona? Well, the Dangerman audition didn't work out (I never heard back), and I've been…
April 3, 2008
Two summers ago, I was in Les Houches, France, for a summer school that turned out to be one of the best experiences of my life. Seriously, we'd wake up every day and this was the view from the school:
Well, the University/Institution that ran the school sends periodic updates to me. And they…
April 3, 2008
Starts with a bang reader Dumb Ass Dave points us to this BBC article about the discovery of a planet that's only just forming around a new star. The planet is surely less than 100,000 years old, although the 1,600 year old figure quoted in the article is probably hogwash.
How do you find it? Take…
April 1, 2008
There's a graduate student that I'm sort-of mentoring/working with at Arizona, named Xiaoying Xu (hi Xiao!). She's bright and curious, and she asks some very good questions. She asked me one yesterday that's pretty tough to wrap your head around:
How do I explain to someone why light doesn't age…
April 1, 2008
There was a paper posted today that I thought was an April Fools' Day joke, entitled Was There a Big Bang? Ha ha, thought I, of course there was; I just wrote all about it two weeks ago. But no, this is a legitimate paper, or at least is attempting to be. (There was even a brief write-up on…
April 1, 2008
There are a number of parameters that we deal with in cosmology that have no dimensions; that is, they're just numbers. And yet, there are a remarkable number of coincidences that just "happen to be that way" in our Universe.
Douglas Scott, in this paper, points out some of the more puzzling ones…
March 31, 2008
Those of you who know me know that I'm unhappy living here in Arizona. The landscape and ecosystem of the Sonoran Desert, while beautiful to many, is too dry, rocky, and devoid of life for me to enjoy living here.
After my time here, I've decided that, were it somehow offered to me, I would…
March 28, 2008
I remember being a kid and taking karate lessons. How cool was it to go somewhere for the purpose of learning how to kick ass? It was fun, of course, and one of the things you learned how to do was to attack (strike, kick, and punch) with your entire body, not just with your limbs.
Maybe the…
March 28, 2008
There's a movie coming out on Creationism, Intelligent Design, and Evolution, called Expelled, and it's narrated/hosted by Ben Stein (right), a TV/film personality who is an overall intelligent guy (and used to have the TV show Win Ben Stein's Money), and used to be a Nixon speechwriter.…
March 26, 2008
WARNING: Sensationalism ahead! Are you kidding me, Newsweek? They really titled their article Will Physicists Find God? Presumably, the title is named because physicists are searching for the Higgs Particle, and the title is taken after Leon Lederman's (mediocre, IMO) book, The God Particle. Leon'…
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…
March 26, 2008
Last week, the brightest gamma-ray burst ever was observed. (See here.) I wanted to know what it was that caused this bright explosion that, despite it being at redshift z=0.94 (or about 7.5 billion light years away), it was visible on Earth with the naked eye!
Well, a scientific paper was written…
March 24, 2008
This is some very basic biology: when resources are unlimited and there are no pressures on a species, its population grows exponentially. There's also no evolution other than random mutations; without selection pressures (regardless of whether it's natural or artificial), the genetic information…
March 24, 2008
Cameras, CCDs, prisms, grisms, etc., are all some of the instruments that can go on top of telescopes to help us see things better. We haven't really increased the size of telescopes so much as we have the quality and ability of the apparatus that go atop them. Take a look at various pictures I've…
