dark energy
esiegel | March 1, 2013"The mind, once expanded to the dimensions of larger ideas, never returns to its original size." -Oliver Wendell Holmes
When General Relativity supplanted Newton's work as our theory of how gravity works in the Universe, it didn't just change how we view how masses attract, it gave us a new understanding of what the questions where and when actually mean. It gave us the very fabric of spacetime.
Image credit: Christopher Vitale of http://networkologies.wordpress.com/.
What this meant is that no longer could we view objects like matter and radiation as existing in some fixed, grid-like…
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 2, 2013"Everyone carries a piece of the puzzle. Nobody comes into your life by mere coincidence. Trust your instincts. Do the unexpected. Find the others." -Timothy Leary
Here we are, on planet Earth, the product of generations of civilization-building, maybe four-billion years of evolution on our world, around 13.7 billion years into the existence of our observable Universe.
Image credit: Paranal Observatory, ESO / Babak Tafreshi.
The Universe, quite possibly, didn't have to be exactly the way it is. It didn't have to have the laws of physics be exactly what they are, with the masses and charges…
esiegel | December 28, 2012"People hear the happy story, but the truth is they could all disappear in the blink of an eye. The threats just keep coming." -Todd Steiner
It's taken generations of scientists, examining the night sky for millennia, to comprehend the full size and scope of what's out there in the Universe.
Image of the southern Milky Way, by A. Fujii.
Out beyond the planets and stars, outside of the Milky Way itself, is a great cosmic abyss filled with still-uncounted galaxies that stretch for billions of light years across the Universe.
Image credit: 2P2 Team, WFI, MPG/ESO 2.2-m Telescope, La Silla, ESO…
esiegel | December 14, 2012"And in the end
The love you take
Is equal to the love you make." -Paul McCartney
Every once in a while, I throw the chance out there (on facebook, twitter, or google+) to ask me whatever questions you want. Yesterday, for some insane reason, I invited people across all three platforms to ask me whatever they liked, with a dual promise that I'd not only answer them, but that the best ones would receive a free "The Year In Space" calendar for 2013, courtesy of the Planetary Society.
Image credit: The Planetary Society.
So I got a ton of questions, and now I'll do my best to answer them as…
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 19, 2012"When you look at the stars and the galaxy, you feel that you are not just from any particular piece of land, but from the solar system." -Kalpana Chawla
Welcome to this week's Messier Monday, where I pick a new object out of the original catalogue of 110 "faint fuzzies" designed to help comet-hunters avoid confusion with these fixed, extended night sky objects.
Image credit: The Messier Objects by Alistair Symon, from 2005-2009.
In previous weeks, we've focused on a variety of objects, including a globular cluster, an open star cluster, a supernova remnant and an active star-forming nebula…
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 8, 2012"You have to have a canon so the next generation can come along and explode it." -Henry Louis Gates
When it comes to stars, their fates are very well known. Every single star that's massive enough to fuse hydrogen into helium in its core will someday run out of fuel and die.
Image credit: NASA, ESA, F. Paresce, R. O'Connell, & the HST WFC3 Science Oversight Committee.
The very brightest and most massive stars -- about 1-in-800 of all stars -- will die in a spectacular, core-collapse supernova when their core burns fuel all the way through iron and finally runs out of room to go.
This…
esiegel | October 31, 2012"A cosmic mystery of immense proportions, once seemingly on the verge of solution, has deepened and left astronomers and astrophysicists more baffled than ever. The crux ... is that the vast majority of the mass of the universe seems to be missing." -William J. Broad
Despite the wondrous, luminous sights of the night sky, we've learned that normal matter -- protons, neutrons, electrons and the like -- make up only 4% of the total energy in the Universe.
Image credit: Large Suite of Dark Matter Simulations (LasDamas) simulation; Vanderbilt.
The galaxies and clusters of galaxies lighting up…
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 23, 2012"It is always wise to look ahead, but difficult to look further than you can see." -Winston Churchill
We've come a long way in this Universe. Over the past 13.7 billion years, we've formed the light elements out of a sea of protons and neutrons, cooled and expanded to form neutral atoms for the first time, gravitationally collapsed hydrogen and helium gas clouds to form the first stars, borne witness to generations of stellar deaths and rebirths, lived through the formation of hundreds of billions of galaxies and the clustering together of thousands or more galaxies into clusters, filaments,…
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…
catdynamics | August 7, 2012Back at the LHC Shows the Way workshop at the Aspen Center for Physics - more discussion of Higgs alternatives and peculiar branching ratios.
No, the branching ratios for the different decay modes of the 125 GeV boson that is putatively the Higgs are not anomalous at a statistically significant level, but, they are off a bit.
So, theorists go wild with ecstatic speculation - it is fun and not yet ruled out by data, what else can we do!
This morning Fan on 2:1 for Naturalness at the LHC? by Nima Arkani-Hamed, Kfir Blum, Raffaele Tito D'Agnolo, JiJi Fan
Later there will be discussion on jet…
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 19, 2012This is an enhanced version (with some upgraded images and text) of an article I first wrote over two years ago. It is just as valid today as it was back then, only today, I have a special offer to go with it. Next week, a bunch of cosmologists and myself are getting together and all writing about dark energy. And I want you to have your say.
So at the end of this post, ask your dark energy questions. Ask anything and everything you ever wanted to know about dark energy. I'll choose the best one (or, space & time permitting, more than one) and write a special post on it for you then.…
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 | January 11, 2012"I soon became convinced... that all the theorizing would be empty brain exercise and therefore a waste of time unless one first ascertained what the population of the Universe really consists of." -Fritz Zwicky
Making the entire Universe isn't easy. Even with 13.7 billion years of time, general relativity and all the known particles in the Universe, we still can't reproduce all the observations we see today.
Image credit: Canada-France-Hawaii Telescope LenS team.
What does it take to get galaxies to form and cluster together the way they do in the Universe?
The large-scale structure in the…
esiegel | December 14, 2011"I am undecided whether or not the Milky Way is but one of countless others all of which form an entire system. Perhaps the light from these infinitely distant galaxies is so faint that we cannot see them." -Johann Heinrich Lambert
One of the greatest discoveries of the 20th Century was that many of the great, faint, extended nebulae in the night sky were not merely objects within our own galaxy, like the stars. Rather, these objects were many millions of light-years distant, and were entire galaxies unto themselves.
Image credit: Boren-Simon 2.8-8 ED POWERNEWT Astrograph Image Gallery.…
esiegel | December 2, 2011"I have long held an opinion... that the various forms under which the forces of matter are made manifest have one common origin; or, in other words, are so directly related and mutually dependent, that they are convertible, as it were, one into another, and possess equivalents of power in their action." -Michael Faraday
For centuries, the idea that you can't get something for nothing was floating around long before we knew about the most important conservation law in all of the Universe: the Conservation of Energy.
Image credit: Mr. Torgerson's 6th grade class.
For example, the ball…