Physics
esiegel | September 14, 2012"I am always ready to learn, although I do not always like to be taught." -Winston Churchill
My very first time leading a classroom -- on my own -- was back in June of 2000. I was 21 years old, fresh out of college, and was teaching science in a middle school classroom. And I asked what I thought was an innocuous question, designed to pique their curiosity. I asked the class, "What are we -- you, me, and all human beings -- made of?"
I was expecting many possible answers common to all living things, ranging from "blood and guts" to cells, molecules, or atoms. From a scientific standpoint,…
drorzel | September 13, 2012Last week, in the post about fermion conduction, I left a reference hanging:
There’s nothing physically blocking the atoms from flying right through the channel– in fact, an atom that enters the channel will always exit the other side without slowing down along the way. This is termed “ballistic,” a term that will always have a special place in my heart thanks to an incident at my Ph.D. defense.
Which was what? Let’s just leave that hanging to see if anybody actually reads this far. I can explain it in a comment if people want to know.
A couple of people asked for the explanation in comments…
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…
drorzel | September 6, 2012So, it's been a while, but let's see if we can't hit the ground running with a good physics post. There have been a few notable physics events since I went on hiatus, but for a return to physics ResearchBlogging, we'll go with something near and dear to my heart, ultracold atoms. Specifically, this Science paper (free arxiv version) about passing atoms through a narrow channel. This is a cool bit of subfield-crossing physics, so let's dust off the Q&A format, and go through it.
Hey, dude, long time no see. So, what's the deal with this paper? Well, the title pretty much tells you what's…
catdynamics | September 1, 2012Ah, semester has started, and with it comes the grind of studying for the big test, where callow highschoolers finally get to see if they can make it in the big leagues.
Here we see them in lecture:
One of the 30 or so in class lectures before the test
Yes, football players go to lectures.
About football, as well as whatever other subjects they are taking.
The coach gets up there, talks about football and shit, and they all listen, and nod, and maybe take some notes, and check their cool pics on facebook, and text their friends, and nap... afterwards they go their separate ways back to their…
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 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 21, 2012"There is a single light of science, and to brighten it anywhere is to brighten it everywhere." -Isaac Asimov
One of the most spectacular and successful ideas of the 20th Century was Einstein's General Relativity, or the idea that matter and energy determines the curvature of spacetime, and the curvature of spacetime in turn determines how gravitation works.
Image credit: Hyper-Mathematics - Uzayzaman / Spacetime.
From the orbits of planets to the bending of starlight, General Relativity governs all gravitational phenomena in the Universe, and accurately describes every observation we've…
esiegel | August 17, 2012"We don’t understand how a single star forms, yet we want to understand how 10 billion stars form." -Carlos Frenk
The Universe has been around for a long time: nearly 14 billion years, to the best of our knowledge. When it was very young, there were absolutely zero stars in it, while today, there are hundreds of billions of galaxies, each of which contains anywhere from a few billion to many trillions of stars.
Image credit: NASA, ESA, and the Hubble Heritage (STScI / AURA) - ESA / Hubble Collaboration
The galaxy shown above, NGC 2841, is very similar to our own Milky Way. Approximately the…
esiegel | August 14, 2012"The colors of a rainbow so pretty in the sky.
Are also on the faces of people going by." -Louis Armstrong
It's no secret that white light is the light that we see when all the colors shine together and are seen at once. This has been known for over 400 years, when Isaac Newton demonstrated that white light could be broken up into all the known colors by dispersing it through a prism.
Image credit: Adam Hart-Davis.
All that we're doing is breaking white light -- in this case, sunlight -- up into all of its component colors. This can be done artificially (such as by configuring a prism) or…
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 | August 7, 2012"I am looking at the future with concern, but with good hope." -Albert Schweitzer
As you all know, the most ambitious interplanetary mission ever attempted -- Mars Science Laboratory -- successfully landed its Curiosity rover on Mars earlier this week. Last night, I had the opportunity to go on my local news and speak a bit about it, and as always, it was an absolute pleasure.
(Video credit: KGW / Ben Lacy / Carey Higgins / Steph Stricklen.)
Of course we got to talk about the rover itself and its science potential, and exactly how much more sophisticated it is than any of its martian…
jhalper | August 1, 2012Science magazine seemed to imply there was some grousing about the new Fundamental Physics Prizes awarded by billionaire Yuri Milner, but we in Rehovot think it’s a good thing. While one can quibble about which fields are still underfunded, we believe that any support for truly basic research -- the kind whose applications, if they exist, will be decades in the future, but which enlightens today us about the universe we live in – is most welcome.
It turns out that two (at least) of the nine winners have ties to the Weizmann Institute, and, completely by chance, we had recently written about…
catdynamics | July 31, 2012$3 million each for 9 theorists from Yuri Milner Foundation Fundamental Physics Prize
IAS big winner.
Milner Prize: Guth (MIT), Linde (Stanford); Arkani-Hamed, Maldacena, Seiberg and Witten (IAS); Kitaev (Caltech); Kontsevich (IASS); and, Sen (Chandra Institute).
String theory, inflation and quantum computing.
Heavy on IAS, the Techs and Russian expats.
All good choices.
Follows hard on the heels of the Simons Foundation Investigator awards.
Aleiner (Columbia); Brenner (Harvard); Glotzer (Michigan); Hastings (Duke); Hirata (Caltech); Kane (UPenn); Ooguri (Caltech); Pretorius (Princeton);…
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…
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…
pharyngula | July 4, 2012Sean Carroll live-blogged a seminar discussing the latest results, which meant he wrote down a heck of a lot of cryptic jargon I couldn't understand at all. But here's the bottom line:
Personal editorializing by me: we’ve found the Higgs, or at least a Higgs. Still can’t be sure that it’s just the vanilla Standard Model Higgs. The discrepancies aren’t quite strong enough to be sure that they really represent beyond-Standard-Model physics… but it’s a strong possibility.
Cool. The broad strokes of the Standard Model look OK, but there might be enough unexpected variance that some new physics…
esiegel | July 4, 2012"This is evidently a discovery of a new particle. If anybody claims otherwise you can tell them they have lost connection with reality." -Tommaso Dorigo
You've probably heard the news by now: the Higgs boson -- the last undiscovered fundamental particle of nature -- has been found.
The fundamental types of particles in the Universe, now complete.
Indeed the news reports just keep rolling in; this is easily the discovery of the century for physics, so far. I'm not here to recap the scientific discovery itself; I wrote what to expect yesterday, and that prediction was pretty much exactly what…