Q & A
esiegel | April 25, 2012"Through that last dark cloud is a dying star... And when it explodes, it will be reborn. You will bloom... and I will live." -The Fountain
I want to start off by letting you all know that I, myself, do not have any children of my own. I have taught children, adolescents and adults for nearly a full generation now in varying capacities, and while each learner is different, there's one science fact that universally seems to shatter each and every one of them.
Image credit: the bloggers at Dear Kugluktuk.
The fact that the Sun, our Sun, the bringer of warmth, light, energy, and the sustaining…
esiegel | January 26, 2012"The diversity of the phenomena of nature is so great, and the treasures hidden in the heavens so rich, precisely in order that the human mind shall never be lacking in fresh nourishment." -Johannes Kepler
So said the man who, in 1604, discovered the supernova that was the last to be seen, visually, within our own galaxy. Although it's likely that two others occurred subsequently, they were not visible to human eyes, and only with powerful telescopes were their remnants discovered.
But earlier this week, the first supernova of the year was discovered, in a galaxy 25 million light years away,…
esiegel | November 23, 2011"Time and money spent in helping men to do more for themselves is far better than mere giving." -Henry Ford
Here in the United States, it's American Thanksgiving, our annual harvest festival. Traditionally, it's the one day out of the year where we spend it with the people most important to us, and give genuine appreciation for the good things we have in our lives. And there is so much to be thankful for.
Image credit: NASA, ESA, and the Hubble Heritage Team (STScI / AURA).
Last year, I gave thanks to the entire Universe, from the smallest subatomic particles and the laws that govern them…
esiegel | May 25, 2011"We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special." -Stephen Hawking
You're probably familiar with the standard picture of our Universe. You've heard it all before: that the Universe we know of -- stars, planets, atoms, etc. -- is less than 5% of the Universe's total energy. That most of the matter is dark matter, and that most of the energy in the Universe isn't matter at all, but dark energy.
But recently, we've started to discover a couple of interesting things about the atoms in the…
esiegel | April 12, 2011"I could have gone on flying through space forever." -Yuri Gagarin
It was April 12th, 1961, or fifty years ago today, that Yuri Gagarin became the first human being to leave Earth -- the ground, the atmosphere, the stratosphere -- and to soar into outer space.
Image credit: GETTY images.
What was unimaginable just half-a-century ago has become an amazing journey full of accomplishments, setbacks, disasters and unmitigated triumphs.
And to recap some of our greatest achievements, I thought I'd make up a fun little ten-question quiz for you, with answers (and pictures) below! Ready?
1.) What…
esiegel | February 4, 2011"How'd the moon get here? Look, you pinheads who attacked me for this, you guys are just desperate. How'd the moon get here? How'd the sun get there? How'd it get there? Can you explain that to me? How come we have that and Mars doesn't have it?" -Bill O'Reilly
Once upon a time, humans looked at the tides -- going out and coming in -- and we had no idea what caused them. At high tides, the sea level would rise, and the coast would get swept up by the oceans, while at low tides, the water would recede, leaving tidepools behind.
Image credit: smugmug.com.
Low tides and high tides would each…
esiegel | February 2, 2011"One creates from nothing. If you try to create from something you're just changing something. So in order to create something you first have to be able to create nothing." -Werner Erhard
One of the oldest adages in existence is you can't get something for nothing, as over a million websites will tell you, including not-so-subtly, cartoonstock.
And, most often when people bring this up to me, it's in an attempt to prove the existence of God -- and the insufficiency of the Big Bang -- by pointing to the Universe.
Image credit: chaospet.
Well, let's take this question as seriously as our…
esiegel | January 5, 2011"The size of the universe is no more depressing than the size of a cow." -David Deutsch
But it is bizarre, I'll give you that. The most common scientific question I get asked is how, if the Universe is 13.7 billion years old, and the speed limit of the Universe is the speed of light, why do I say the observable Universe is 93 billion light years across?
In other words, why is this picture of the Universe wrong?
I've tried to answer this before, and so have others, but perhaps it's time for another -- more conceptual -- attempt. This is one of the most mind-boggling things about relativity.…
esiegel | December 16, 2010"The most important scientific revolutions all include, as their only common feature, the dethronement of human arrogance from one pedestal after another of previous convictions about our centrality in the cosmos." -Stephen Jay Gould
Tuesday, I talked about an alternative theory to cosmic inflation.
Whereas cosmic inflation gives you a uniform, flat Universe, that's the same temperature everywhere, with a predictable spectrum of fluctuations, the alternative model gave none of those things, but did give those regions of concentric rings with low fluctuation amplitude.
In detail, of course,…
esiegel | December 9, 2010"Black holes are where God divided by zero." -Stephen Wright
Yesterday, I told you about all the evidence for the Black Hole at the center of our galaxy. In particular, we see multiple stars orbiting a single point that emits no light of any type at all.
And, perhaps unsurprisingly, the comments became very active. So let's take a look at some of what was said, and let's see what we can further learn about black holes from answering your questions.
I see the stars orbiting on their own orbits, but I mean, all orbits seem quite different to me, there´s no central point they are orbiting…
esiegel | August 2, 2010"The most useful piece of learning for the uses of life is to unlearn what is untrue." -Antisthenes
As many of you know, in addition to news about cosmology, space, astronomy, and physics, I'm also heavily involved in education. This includes, in various stages, teaching, curriculum design, and mentoring students. But I got the following message from Rita from the UK last week -- who's about to start her A-levels -- and I felt slightly ashamed. (Message edited slightly for clarity.)
I am interested in space, though currently my interest in it is not very specific. I am interested in the…
esiegel | July 21, 2010He was a dreamer, a thinker, a speculative philosopher... or, as his wife would have it, an idiot. -Douglas Adams
When I started writing about science online in January of 2008, I put the word out that I would accept questions from my readers. After all, I knew that there was a lot of misinformation out there, as well as the more insidious "technically correct but misleading" information about science.
In particular, I want to get the actual information that we know out there. As far as what I can contribute, I'm confident that I can add an expert voice for my specialties (physics, astronomy…
esiegel | July 12, 2010Yo ho! It's hot, the sun is not a place where we could live.
But here on earth there'd be no life without the light it gives.
We need its light. We need its heat. We need its energy.
Without the sun without a doubt there'd be no you and me. -They Might Be Giants
Ahh, the Sun. Beautiful and blinding to the naked eye, it's still the source of energy that gave rise to all of the life on Earth that we know.
Image credit: GOES satellite, in the X-ray.
The Sun emits energy all over the light spectrum, from long-wavelength radio waves (many meters long) to visible light to X-rays (just a small…
esiegel | July 1, 2010"Prediction is very difficult, especially if it's about the future." -Neils Bohr
As many of you know, the Big Bang is one of the most powerful scientific theories we have.
It's also one of the most unsettling. The idea that our entire Universe -- filled with practically a trillion galaxies -- is only three times as old as our Sun and was once compressed into the size of your thumb is pretty unsettling.
As an astute commenter noted earlier this week,
I'm asking what persuasive predictions BB has to its credit. Most usually the best I see is new observations favoring one BB variant over…
esiegel | May 3, 2010"An educational system isn't worth a great deal if it teaches young people how to make a living but doesn't teach them how to make a life." -Unknown
Every now and again, people with all sorts of backgrounds -- from some graduate school all the way to having not finished high school -- ask me about getting involved in Astronomy and Astrophysics. Often, people's interest simply come from looking up at night.
I'm not going to lie, this is a huge question, with many different answers. First off, let's start off assuming that you have no background in math, no background in physics, and that you'…
esiegel | March 23, 2010Note: I'm on vacation this week, so here's one from the vault. This article first appeared on my old website, back in February of 2009.
Some days the questions I get are easy, and some days I get questions from our longtime reader, Ben. This past week, there have been reports all over the news that our world may be a giant hologram. Let's take a look at what's going on.
In Hanover, Germany, there's an experiment called GEO600. These are two perpendicular lasers, and they shoot out for thousands of feet, get reflected, and come back to their original location to make an interference pattern…
esiegel | January 20, 2010I'm always happy to receive questions from those of you interested enough to ask them, and every once in a while one of them feels just right to write up an article about it. Today's comes from Brad Walker, who asks about the inside of gas giants. Specifically,
The question pertains to the insides of gas giants like Jupiter... My question is, supposing Jupiter is made of Metallic Hydrogen, and it was dragged close enough to the sun that its atmosphere evaporated, what would be left? How would it go from a very strange non-terrestrial core to a rocky body like CoRoT-7b? Why wouldn't the…
esiegel | January 12, 2010There are two mistakes one can make along the road to truth... not going all the way, and not starting. -Siddhārtha Gautama, a.k.a. Buddha
Last week, I started a new series on The Greatest Story Ever Told, about the origin and evolution of the Universe. In it, I asserted that inflation is the very first thing we can definitively say anything sensible about, and that it happened before the big bang. This runs contrary to a lot of statements out there by a lot of reputable people, including this "timeline" image from Discover Magazine:
Everything else aside, it's very important to remember…
esiegel | December 31, 2009Blue Moon
You knew just what I was there for
You heard me saying a prayer for
Someone I really could care for... -Richard Rodgers & Lorenz Hart
Tonight is the last night of 2009, there's a full Moon, there's a sliver of a partial lunar eclipse, and it's the second full Moon this month.
Q: Does having two full Moons in a month make it a Blue Moon?
A: In our modern times, yes, that's what we use that colloquialism to mean. The phrase "Blue Moon" is much older than that, dating back to at least 1528, where a pamphlet attacking the dogmatism of the church states:
Yf they say the mone is…
esiegel | December 3, 2009You're making me angry. You wouldn't like me when I'm angry. -Bruce Banner
Hey, LHC, what did those protons ever do to you? You take them, accelerate them to the fastest speeds we've ever accelerated protons to on Earth, and then smash them into one another with more energy than ever before!
The Large Hadron Collider takes bunches of protons, accelerates them in opposite directions inside its giant ring, and smashes them together -- ideally -- at the centers of these giant detectors.
At Fermilab, each proton would come in with an energy up to about 1.0 TeV, for a total collision energy of 2…