gravity
esiegel | February 4, 2013"The thing's hollow—it goes on forever—and—oh my God—it's full of stars!" -Dave Bowman, 2001: A Space Odyssey
Back in October, we began a new, weekly series here called Messier Monday. Each Monday, we've taken a look at one of the 110 deep-sky objects that make up the Messier Catalogue, nebulous objects that might potentially be confused with comets by unaware comet-hunters.
Image credit: Lee Kelvin and Grant Miller, via http://star-www.st-and.ac.uk/~lsk9/.
These objects include stellar remnants, star-forming nebulae, young star clusters, ancient globular clusters, and distant galaxies far…
esiegel | February 1, 2013“It surprises me how disinterested we are today about things like physics, space, the universe and philosophy of our existence, our purpose, our final destination. It’s a crazy world out there. Be curious.” -Stephen Hawking
One of the most existential questions humanity has ever asked is the question of our origins: where do I come from? Inspired by Ben Kilminster's writings, here's the entire history of the Universe -- that's led up to the existence of you -- in just 10 sentences*.
Image credit: Amber Stuver of http://www.livingligo.org/.
1.) At some point in the distant past**, the…
esiegel | January 18, 2013"The cosmos is all that is or ever was or ever will be. Our feeblest contemplations of the Cosmos stir us—there is a tingling in the spine, a catch in the voice, a faint sensation, as if a distant memory, or falling from a height. We know we are approaching the greatest of mysteries." -Carl Sagan
If you looked out at the planets in the Solar System orbiting our Sun, you'd expect that if you know where they are right now and how quickly they're moving, you can figure out exactly where they're going to be at any time-and-date arbitrarily far into the future. That's the great power that comes…
esiegel | January 11, 2013"Every man has a right to utter what he thinks truth, and every other man has a right to knock him down for it." - Samuel Johnson
I have a six-sided die. I'm going to roll it ten times, and record each roll. And when I'm done, I'm going to have an incredibly rare, bet-you-can't-reproduce-it result!
Image credit: random.org's dice roller.
Look at that! Ten rolls of a six-sided die, and I got: 3, 2, 3, 5, 5, 5, 4, 1, 4, and 3! What a glorious, odds-defying sequence of events!
In fact, if you took a fair six-sided die and rolled it ten times, you'd have less than a 1-in-60,000,000 chance of…
esiegel | January 9, 2013"Great spirits have always encountered violent opposition from mediocre minds." -Albert Einstein
It may be hard to believe, seeing as how it's been our leading theory of gravity for nearly a century now, but Einstein's General Relativity is possibly the most frequently challenged scientific idea of all-time. Of course, it's emerged victorious from each and every one of those challenges, making a slew of unintuitive predictions that have been spectacularly confirmed each time they've been tested.
Image credit: Miloslav Druckmuller (Brno U. of Tech.), Peter Aniol, and Vojtech Rusin.
This…
esiegel | December 7, 2012"If you wish to make an apple pie from scratch, you must first invent the Universe." -Carl Sagan
The Universe is a lot like an extremely intricate cake. We view it today as a snapshot in time, now that it's complete.
Image credit: Blogger user Hilly of http://makesbakesfakes.blogspot.com/.
We can view the whole thing from one point of view, determined by where we happened to be located. But we can also look intricately inside certain sections of it, so long as we have the right tools.
Image credit: Blogger user Hilly of http://makesbakesfakes.blogspot.com/.
But if we truly want to…
esiegel | November 28, 2012"Summer ends, and Autumn comes, and he who would have it otherwise would have high tide always and a full moon every night." -Hal Borland
Of course you know the danger that would befall us if the Earth ever got too close to the Sun, as the Perry Bible Fellowship shows, atop. But have you ever stopped to think about the Moon in our skies, and what would happen if the Earth and Moon were closer together than they actually are?
Image credit: NASA / Galileo mission.
While photos such as this -- from the Galileo spacecraft -- accurately show the relative size and illumination of the Earth and…
esiegel | November 21, 2012“We live in an atmosphere of shame. We are ashamed of everything that is real about us; ashamed of ourselves, of our relatives, of our incomes, of our accents, of our opinions, of our experience, just as we are ashamed of our naked skins.” -George Bernard Shaw
All that is real about ourselves is nothing to be ashamed about; quite to the contrary, it's something to be eminently thankful for. This very existence is all we have, and while it's minuscule compared to the entire Universe, it required the entire Universe to bring us to the point where it's possible for us to exist.
What do I mean by…
esiegel | November 16, 2012"Other than the laws of physics, rules have never really worked out for me." -Craig Ferguson
Earlier this week, evidence was presented measuring a very rare decay rate -- albeit not incredibly precisely -- which point towards the Standard Model being it as far as new particles accessible to colliders (such as the LHC) go. In other words, unless we get hit by a big physics surprise, the LHC will become renowned for having found the Higgs Boson and nothing else, meaning that there's no window into what lies beyond the Standard Model via traditional experimental particle physics.
Image credit:…
esiegel | November 7, 2012"It's a brilliant surface in that sunlight." - Neil Armstrong
Indeed, all that glitters so brilliantly in the cosmos does so because of the stars that have formed throughout it.
Image credit: NASA, ESA, and the Hubble SM4 ERO Team.
Over the 14 billion-or-so years that our Universe has been around, we've formed hundreds of billions of stars in our galaxy alone.
Image credit: ESO / Serge Brunier (TWAN), Frederic Tapissier.
Given that our galaxy is just one of at least hundreds of billions in the observable Universe, the number of stars that have formed over our Universe's history is a…
esiegel | October 17, 2012"The particle and the planet are subject to the same laws and what is learned of one will be known of the other." -James Smithson
The entirety of the known Universe -- from the smallest constituents of the atoms to the largest superclusters of galaxies -- have more in common than you might think.
Image credit: Rogelio Bernal Andreo of http://blog.deepskycolors.com/about.html.
Although the scales differ by some 50 orders of magnitude, the laws that govern the grandest scales of the cosmos are the very same laws that govern the tiniest particles and their interactions with one another on the…
esiegel | October 15, 2012“The aim of science is not to open the door to infinite wisdom, but to set a limit to infinite error.” -Bertolt Brecht
One of the most frequent questions I get about the Universe -- as a cosmologist -- isn't quite about the Big Bang in and of itself.
The expansion of the Universe in reverse; image source unknown.
The Big Bang is a remarkable idea, of course, that says that, based on the observations that the Universe is expanding and cooling today, it was hotter, denser, and physically smaller in the past. This gets particularly exciting when we extrapolate very far back in the history of…
esiegel | September 19, 2012"Science enhances the moral value of life, because it furthers a love of truth and reverence—love of truth displaying itself in the constant endeavor to arrive at a more exact knowledge of the world of mind and matter around us, and reverence, because every advance in knowledge brings us face to face with the mystery of our own being." -Max Planck
Our standard model of elementary particles and forces -- with the recent discovery of the Higgs boson now behind us -- has now had every expected particle within it discovered, and we can explain where the elementary particles get their masses from…
esiegel | September 10, 2012"Not even light can escape such hollowing, this huge mass in a small space. Even the Milky Way with its open arms is said to have a black hole at its heart." -Susan B.A. Somers-Willett
Our Milky Way is home to us all. With its hundreds of billions of stars, massive spiral arms, dust lanes, and orbiting globular clusters, it's no wonder that nearly everything we see in the night sky is contained within it.
Image credit: All rights reserved by Flickr user Greg Booher.
I say nearly everything, of course, because there are a few exceptions. The Andromeda Galaxy, for one, as well as the two…
esiegel | August 27, 2012"You must learn to talk clearly. The jargon of scientific terminology which rolls off your tongues is mental garbage." -Martin H. Fischer
I've always thought that the Universe is absolutely amazing; that everything from the tiniest indivisible particles all the way up to the largest structures and superstructures making up the Universe has an amazing story to tell, if only we can figure out its secrets.
Image credit: Boylan-Kolchin et al. (2009) for the Millenium-II simulation; MPA Garching.
When I first learned some of them for myself, I was a graduate student, immersed in the minutiae and…
esiegel | August 9, 2012"Who are we? We find that we live on an insignificant planet of a humdrum star lost in a galaxy tucked away in some forgotten corner of a universe in which there are far more galaxies than people." -Carl Sagan
Our night sky, quite literally, is our window to the Universe.
Image credit: Miloslav Druckmuller, Brno University of Technology.
Well, it's kind of a window to the Universe. I say only "kind of" because, with the exception of those two faint, fuzzy clouds in the lower right, everything else visible in the image above is part of our own Milky Way galaxy. In fact, practically…
esiegel | July 30, 2012"Black holes, which have no memory, are said to contain the earliest memories of the universe, and the most recent, too, while at the same time obliterating all memory by obliterating all its embodiments. Such paradoxes characterize these strange galactic monsters, for whom creation is destruction, death life, chaos order." -Robert Coover
Our Milky Way, the swath of light and dark that dominates the darkest skies here on Earth, contains a huge variety of stars: large and small, red and blue, from young to old to ancient.
Image credit: ESO / Serge Brunier, Frederic Tapissier, The World At…
esiegel | July 26, 2012"Nothing exists except atoms and empty space; everything else is just opinion." -Democritus of Abdera
When you take a look out at the Universe, past the objects in our own solar system, beyond the stars, dust and nebulae within our own galaxy, and out into the void of intergalactic space, what is it that you see?
Image credit: BRI composite-image of the FORS Deep Field, ESO, VLT.
What we normally think of as the entire Universe, consisting of hundreds of billions of galaxies, with about 8,700 identified in the tiny patch of deep-sky shown above. Each one of those galaxies, itself, contains…
esiegel | July 18, 2012"The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge." -Stephen Hawking
The Universe is a vast, seemingly unending marvel of existence. Over the past century, we've learned that the Universe stretches out beyond the billions of stars in our Milky Way, out across billions of light years, containing close to a trillion galaxies all told.
Image credit: NASA, ESA, S. Beckwith (STScI) and the HUDF Team.
And yet, that's just the observable Universe! There are good reasons to believe that the Universe continues on and on beyond the limits of what we can see; the…
esiegel | July 6, 2012"Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe?" -Stephen Hawking
After a long search spanning more than my entire lifetime (so far), the Higgs boson has finally been discovered at both detectors -- CMS and ATLAS -- at the Large Hadron Collider at CERN.
Image credit: CERN / Particle Physics for Scottish Schools.
For a little more on this, check out the earlier posts here celebrating Higgs week:
The Biggest Firework of them all: The Higgs
How the Higgs…