Big Bang
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…
esiegel | July 5, 2012"We knew that we had indeed done something that was very different and very exciting, but we still didn't expect it to have something to do with physical reality." -Gerald Guralnik, co-developer of the Higgs mechanism
Might as well make this entire week "Higgs week" here on Starts With A Bang, given how important yesterday's discovery/announcement was! It isn't every day, after all, that you see a theoretical physicist on the 7PM news. (Video here.)
Image credit: KGW.com.
(So proud of Portland, OR's local TV station, KGW NewsChannel 8, for being willing to promote science to the whole city…
esiegel | March 27, 2012"Think binary. When matter meets antimatter, both vanish, into pure energy. But both existed; I mean, there was a condition we'll call 'existence.' Think of one and minus one. Together they add up to zero, nothing, nada, niente, right? Picture them together, then picture them separating--peeling apart. ... Now you have something, you have two somethings, where once you had nothing." -John Updike
Looking out at our Universe, at the myriad of stars, galaxies, and, well, "stuff" in our Universe, it's hard not to ask yourself where it all came from.
Image credit: Rogelio Bernal Andreo, retrieved…
milhayser | February 21, 2012
On Dynamics of Cats, Steinn Sigurðsson flags a few foreboding articles on the future of NASA. Sigurðsson says the orbiting telescope Galex, or Galaxy Evolution Explorer, will be shut down later this year despite continuing to function. NASA has withdrawn from the international research mission known as ExoMars, and many other "2011-12 programs appear effectively suspended pending the 2012-13 budget, to the point where an entire funding cycle will be lost for some lines." Meanwhile, Ethan Siegel conjures up an apt scenario on Starts With a Bang, writing "Let's pretend that, for all of our…
esiegel | February 8, 2012"It took less than an hour to make the atoms, a few hundred million years to make the stars and planets, but five billion years to make man!" -George Gamow
Let's pretend that, for all of our history on Earth, we had never once bothered to look up with any instruments beyond what our own eyes could offer. Imagine that all the technology we'd have would be the same -- telescopes, electronics, GPS, etc. -- as would our fundamental scientific knowledge -- Einstein's General Relativity, the Standard Model of Particle Physics, etc. -- but we had just never bothered to turn our attentions toward the…
esiegel | January 9, 2012"If you go through a lot of hammers each month, I don't think it necessarily means you're a hard worker. It may just mean that you have a lot to learn about proper hammer maintenance." -Jack Handey
The most common type of question I get asked by people genuinely wanting to know more about the Universe goes something like, "Hey, I saw such-and-such-a-story about some fanciful-sounding-theory, and that could be the explanation for this-weird-thing-that-we-see. What do you think about that?"
Well, here's the thing.
Image credit: Contemporary Physics Education Project.
We've got a set of laws…
esiegel | December 30, 2011The size and age of the Cosmos are beyond ordinary human understanding. Lost somewhere between immensity and eternity is our tiny planetary home. -Carl Sagan
If the story of our entire Universe's history, from the last stages of inflation and the Big Bang up to the present day, were to be compressed into one calendar year, what would it look like?
As 2011 comes to an end, here's my final present of the year to you.
(As always, click for a more readable, higher-resolution version.)
Happy new year to all; may you all enjoy our shared story and journey while you celebrate. See you in 2012!
esiegel | November 14, 2011"We don't understand how a single star forms, yet we want to understand how 10 billion stars form." -Carlos Frenck
When we look out into the distant Universe, we're also looking back into the Universe's past. The farther away an object is, the longer it's taken its light to travel from it to our eyes. And each time we observe something farther away than anything we've seen before, we're looking farther back into the past -- closer to the Big Bang -- than ever before.
Image credit: NASA, ESA and A. Felid (STScI).
The earliest thing we've ever been able to see -- of course -- is the Cosmic…
esiegel | October 24, 2011"Science is facts; just as houses are made of stone, so is science made of facts. But a pile of stones is not a house, and a collection of facts is not necessarily science." -Jules Henri Poincaré
The higher you fall from, the faster you'll be moving when you hit the ground.
Image credit: Marianne Holland.
Seems like the most obvious thing in the world. You know this intuitively, of course, based on all your experience in the world. Drop an egg from too great a height and it breaks.
While you wouldn't be afraid to jump off of a diving board like the one above, jumping from a greater height…
esiegel | August 16, 2011"Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had happened." -Winston Churchill
It's often said that you can't get something from nothing. And while this may be true for most practical applications of your life, it isn't true for our physical Universe.
And I don't just mean some tiny part of it; I mean all of it. When you take a look at the Universe out there, whether you're looking at the wonders of this world or all that we can see for billions of light years, it's hard not to wonder -- at some point -- where it all came from.…
esiegel | July 29, 2011"It has been rightly said that nothing is unimportant, nothing powerless in the universe; a single atom can dissolve everything, and save everything! What terror! There lies the eternal distinction between good and evil." -Gerard De Nerval
(For Rich C. and Sili, for their questions on this post.)
The humble hydrogen atom -- one proton and one electron, bound together -- is the most common form of normal matter in the entire Universe. When you look out at all the galaxies in the Universe, what you're seeing is predominantly light coming from those simple hydrogen atoms fusing together at the…
esiegel | July 26, 2011"Birth and death; we all move between these two unknowns." -Bryant H. McGill
One of the most remarkable consequences of the Big Bang is that the Universe as we know it -- full of planets, stars, galaxies and life -- hasn't been around forever! Because the Universe is expanding and cooling, it was hotter, denser, and more compact in the past.
Image credit: SciencePhotoLibrary.
But these things that fill the Universe today weren't there in the very early stages of the Universe; they took time.
Gravity needed many millions of years to collapse these slightly overdense regions to a point where…
esiegel | July 6, 2011Poets say science takes away from the beauty of the stars -- mere globs of gas atoms. I, too, can see the stars on a desert night, and feel them. But do I see less or more? -Richard Feynman
Ahh, the stars that make up our galaxy, and the galaxies that make up our Universe. It's the simple power of the humble atom -- the protons, neutrons, and electrons that are the building blocks of everything on our world -- that powers all the stars and galaxies in the Universe.
Image credit: Antoine Vergara Astrophotography.
But it didn't need to be this way! Why is it that all the stars in our galaxy,…
esiegel | July 5, 2011"Through space the universe encompasses and swallows me up like an atom; through thought I comprehend the world." -Blaise Pascal
Whether you have or haven't seen the xkcd webcomic, height (or my old post referencing it), one of the things that I can't imagine not fascinating you is what you see the farther "up" you look.
So what I'm going to do is start off in the vicinity of Earth and go "up" by approximately a factor of 100 every time. Let's begin.
Ahh, outer space. Looking down at the Earth from a distance, what would you see? Well, other than the planet itself, you'd see the (literally…
esiegel | June 22, 2011"[I]f there were no light in the universe and therefore no creatures with eyes, we should never know it was dark. Dark would be without meaning." -C.S. Lewis
(For readers Mu and Bjoern.)
I've told you the entire history of the Universe, from before the Big Bang into the far distant future, and yet many of you noticed there was a conspicuous missing piece to the story: dark matter.
Living in halos around our galaxies and clusters, dark matter, at present, makes up 23% of the energy density of the Universe. This makes it second in overall importance to dark energy, which has become important…
esiegel | June 6, 2011"As far as I see, such a theory [of the Big Bang] remains entirely outside any metaphysical or religious question. It leaves the materialist free to deny any transcendental Being. He may keep, for the bottom of space-time, the same attitude of mind he has been able to adopt for events occurring in non-singular places in space-time... Science has not to surrender in face of the Universe and when Pascal tries to infer the existence of God from the supposed infinitude of Nature, we may think that he is looking in the wrong direction." -Georges Lemaître
Recently, David Dilworth has been getting…
esiegel | April 28, 2011"Listen; there's a hell of a good universe next door: let's go." -e. e. cummings
Sometimes, you just need to take stock of what we know, and appreciate how far we've come. A hundred years ago, we thought the Universe consisted of the stars and nebulae in our Milky Way. We thought Newton's Law of Gravity governed it all, and that the other forces -- electromagnetism and a few weird quantum things -- were all there was.
So why not -- all in one article -- go through the entire history of the Universe, from as early as we can say anything sensible to as late as we can say anything sensible? Let'…
esiegel | April 14, 2011"All of nature begins to whisper its secrets to us through its sounds. Sounds that were previously incomprehensible to our soul now become the meaningful language of nature." -Rudolf Steiner
For millenia, humans have looked to the heavens for answers about the cosmos.
Image credit: ESO/S. Guisard.
And one of the main reasons I write what I do for all of you is to help give you -- as I've said many times -- is an awareness and an appreciation for what we've learned, what we think we know, and how we think we know it.
Which is why I was a little bit confused when I read this article from…
esiegel | March 31, 2011"It took less than an hour to make the atoms, a few hundred million years to make the stars and planets, but five billion years to make man!" -George Gamow
Some people are never satisfied. After I wrote last time on the odds for cosmic inflation, I started noticing a flurry of comments on an older post about alternatives to the big bang. So, might as well go back to the basics, and ask what the odds are that the Big Bang is correct! Let's start by taking a look at what's out there in the Universe.
Image credit: Hubble Space Telescope.
Sure, we've got stars surrounding us: hundreds of…