Astronomy
esiegel | February 7, 2014"That which you create in beauty and goodness and truth lives on for all time to come." -Denis Waitley
It's been another spectacular week here in the Universe, and I'm pleased to take on another one of your wonderful questions in yet another Ask Ethan column! (Keep sending in your questions and suggestions if you have them.) This week's question comes from Robert Scott, and it's one of the simplest yet also the most puzzling:
I love looking at the beautiful long-exposure pictures of the Milky Way on the internet. I also love pictures of galaxies. One of my favorites is of Andromeda. I've…
esiegel | January 10, 2014“The fact that we live at the bottom of a deep gravity well, on the surface of a gas covered planet going around a nuclear fireball 90 million miles away and think this to be normal is obviously some indication of how skewed our perspective tends to be.” -Douglas Adams
Even though our main blog has moved, I'm so glad that the questions and suggestions have still been pouring in, because it's time for another entry in our Ask Ethan series! Today's question comes from professional physicist Marty Olsson, who asks:
I have been bothered for a long time why the Milky Way looks curved, sort of like…
catdynamics | January 6, 2014You are at university.
Do you like stars, and stuff?
We revisit old ruminations on career paths 'cause it is topical...
Another rehashed blast from the past.
Should you do astronomy as an undergrad? (the following is in part shamelessly cribbed from a colleague’s previous freshman seminar for our majors):
Do you like stars and stuff?
If not, you probably should look for an alternative to astronomy, on the general principle that at this stage of life you should at least try to do things you actually like.
If you do, good for you.
Now, do you have the aptitude?
Professional astrophysics/…
catdynamics | January 6, 2014So, now you’re at university, and you’re thinking about heading for grad school …
A seasonal revisit of some old rumblings*
*NB: this discussion should not be construed to be anything but hypothetical ramblings, they do not reflect in any way the official position of any academic institution, department or graduate program, especially not the one I am part of!
So You Want To Be An Astrophysicist? Part 1.5: thinking about grad school
Posted by Steinn Sigurðsson on January 16, 2012
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So, now you’re at university, and you’re thinking about heading for grad school …
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esiegel | December 30, 2013"Tomorrow is the most important thing in life. Comes into us at midnight very clean. It's perfect when it arrives and it puts itself in our hands. It hopes we've learned something from yesterday." -John Wayne
There's a lot to look forward to on the precipice of the new year, and many of us will be up until midnight to ring it in. Well, if you're up that late, why not step outside and take a look at one of the deep-sky wonders of the Universe that won't be visible in the early part of the night for months! This Messier Monday, a near-moonless sky will greet you until the pre-dawn twilight, and…
esiegel | December 27, 2013"Never waste your time trying to explain who you are to people who are committed to misunderstanding you." -Dream Hampton
Perhaps no word in the English language generates as much misunderstanding as the word theory. In scientific circles, this word has a very specific meaning that's different from everyday use, and -- as a theoretical astrophysicist myself -- I feel it's my duty to help explain exactly what we mean when we use it. In this week’s Ask Ethan column, I'm pleased to pull out of our question/suggestion box the question of Ripley, who asks:
I often see that because there is no "100…
esiegel | December 24, 2013"Bethany: Is your house on fire, Clark?
Clark: No, Aunt Bethany, those are the Christmas lights." -National Lampoon's Christmas Vacation
Ahh, Christmas. It's easy to forget how much the invention of the light bulb in 1879 reduced the number of tree fires in people's homes. It was a mere three years later that people began decorating Christmas trees with strings of lights instead of candle flames, and as you can imagine, the reduction in open flames atop fresh kindling had its benefits, and caught on like wildfire. Trees now routinely sport previously unfathomable numbers of lights, limited…
esiegel | December 23, 2013"A sister is both your mirror - and your opposite." -Elizabeth Fishel
With 110 deep-sky wonders to choose from in the Messier catalogue, our long-running series on Messier Monday promises to keep us busy for some time to come! As we've finally passed the winter solstice here in the Northern Hemisphere, many new spectacular sights await skygazers in the early part of the night. As it's also the 1-year anniversary of when we adopted a little sister for our dog from the local humane society, I thought it would only be fitting to highlight the little sister to last week's Messier object.
Image…
esiegel | December 22, 2013"We especially need imagination in science. It is not all mathematics, nor all logic, but it is somewhat beauty and poetry." -Maria Montessori
The Universe has some wonderful sights to show you if you know how to look for them, and that's maybe most apparent when you look at some of the amazing images from the Hubble Space Telescope. Here on Earth, however, the onset of winter for many of us brings a little bit of scarcity with it, something Drive By Truckers can help you relate to with their song,
When The Well Runs Dry.
You might not think these two things are related -- the wonders of…
esiegel | December 20, 2013"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 Italy know that her question was the winning one, as she asked:
I saw the video you posted about the variable star RS Puppis, by the Hubble Space Telescope, and I really would like a post about what exactly are variable stars.
Thank you very much Ethan!! :-)
So -- no burying the lede here -- there was a…
esiegel | December 18, 2013"In the depth of winter I finally learned that there was in me an invincible summer." -Albert Camus
As the year draws to a close, we approach a very special time of year, at least from an astronomical perspective. This Saturday, December 21st, will mark the Winter Solstice in the Northern Hemisphere (or the Summer Solstice in the Southern), or the date where the Earth's axis is tilted its maximal amount away from (or towards) the Sun, as viewed from an observer in the Northern (or Southern) Hemisphere.
Image credit: Mrs. Snyder at the Seven Hills School.
While it's pretty common knowledge…
esiegel | December 16, 2013"Do not look at stars as bright spots only. Try to take in the vastness of the universe." -Maria Mitchell
It's time again for Messier Monday, where we highlight the various wonderous deep-sky objects of the night, and show you how to find them against the expansive backdrop of stars. The (almost) full Moon is out tonight, polluting your night sky with as much light as a large-sized urban area, but that doesn't mean all of the 110 deep-sky objects that make up the Messier catalogue are off-limits!
Image credit: Mike Keith’s delightful (a)periodic table of Messier objects!
While extended…
esiegel | December 11, 2013"Where you used to be, there is a hole in the world, which I find myself constantly walking around in the daytime, and falling in at night. I miss you like hell." -Edna St. Vincent Millay
It was just a little while ago that we were all speculating wildly -- and optimistically -- about Comet ISON, as it plunged towards the Sun from its origins in the very, very distant Solar System. As its perihelion date (the moment of closest approach to the Sun) drew near, you may have noticed something interesting about photos of the comet: it's tail appeared to get longer and longer!
Image credit &…
esiegel | December 9, 2013"The proverb warns that 'You should not bite the hand that feeds you.' But maybe you should, if it prevents you from feeding yourself." -Thomas Szasz
But on this Messier Monday, you're lucky enough that you're about to be introduced to one of the great northern galaxies of the Messier catalogue that is feeding itself! There are 110 deep-sky, non-transient objects that make up the Messier catalogue, and a full 40 of them are galaxies, the most numerous and most distant of all the types of objects catalogued by Messier.
Image credit: Tenho Tuomi of http://www.lex.sk.ca/astro/messier/index2.…
esiegel | December 6, 2013"The results of my observation are best explained by the assumption that a radiation of very great penetrating power enters our atmosphere from above." -Victor Hess
You might think of the largest and most powerful particle accelerators in the world -- places like SLAC, Fermilab and the Large Hadron Collider -- as the source of the highest energies we'll ever see. But everything we've ever done hear on Earth has absolutely nothing on the natural Universe itself! For this week's Ask Ethan, let's take a look at the simple question of our reader David Hurn, who asks:
Ever since I was a young…
esiegel | December 5, 2013"Some say the world will end in fire,
Some say in ice.
From what I've tasted of desire
I hold with those who favor fire.
But if it had to perish twice,
I think I know enough of hate
To say that for destruction ice
Is also great
And would suffice." -Robert Frost
Depending on where you are in the world right now, you might really be feeling the effects of the emerging winter, as cold snaps, freezes and snowstorms take hold across the northern hemisphere.
Image credit: NASA's Scientific Visualization Studio, Goddard Space Flight Center.
But we can all be pretty sure that this is temporary,…
esiegel | December 2, 2013"Give me a man who says this one thing I do, and not those fifty things I dabble in." -Dwight L. Moody
While star clusters may dabble in a number of physically interesting things, there's one thing that they do above all others, and that is shine. For today's Messier Monday, where we spotlight one of the 110 deep-sky wonders of the Messier catalogue, let's take a look at one of the brilliant open clusters of stars that's recently formed in our neighborhood of the galaxy and that will appear all winter long: Messier 50.
Image credit: Greg Scheckler, using the robotic telescopes of http://…
esiegel | November 30, 2013"Unfortunately, I'm not one of those people who take pictures, you know, carry a camera. Because if I did I'd have stacks and stacks and stacks of different acts." -Edwin Starr
You've been outside enough to know that the deepest photos of the Universe -- of the night sky -- aren't quite the same thing you see when you open your gaze on even the darkest nights; there's often a lot more visible in the photos than there are to the unaided eye. As Earth, Wind & Fire would sing you (how's that for one from the vault), it might feel like you find yourself in a land called
Fantasy.
That's…
esiegel | November 27, 2013“I have announced this star as a comet, but since it is not accompanied by any nebulosity and, further, since its movement is so slow and rather uniform, it has occurred to me several times that it might be something better than a comet. But I have been careful not to advance this supposition to the public.” -Giuseppe Piazzi
So it begins again: the neverending debate about who gets to be a planet and who doesn't. Everyone can bring their own interpretation of the science to the table -- and everyone has their own preferred naming scheme -- but when I think about the Solar System, I try to…
esiegel | November 25, 2013"Anyone who keeps the ability to see beauty never grows old." -Franz Kafka
The night sky is our window into the Universe beyond the Solar System, and in some cases, even beyond our own galaxy! Perhaps the oldest useful collection of deep-sky objects, the Messier catalogue showcases 110 of the most prominent night sky wonders, a full 42 of which are located beyond our own galaxy. Today, for Messier Monday, let's take a look at one of the true rarities of the Messier catalogue: a globular cluster that's not a part of our own galaxy!
Image credit: Al Kelly of http://www.kellysky.net/; images…