Physics
oracknows | November 7, 2011Ever since starting my blog nearly seven (!) years ago, I've concentrated mainly on skepticism in medicine, in particular examining various implausible medical claims that proliferate on the Internet and in our media like so much kudzu choking out science and reason. The reasons are two-fold. First, it's what I'm interested in. Second, it was at the time an "underserved" blogging niche that allowed me to align my skeptical interests with a niche that allowed me to establish myself as a blogger. Ultimately, I became interested in the anti-vaccine movement and somehow found myself becoming one…
esiegel | November 4, 2011"They credited us with the birth of that sort of heavy metal thing. Well, if that's the case, there should be an immediate abortion." -Ginger Baker
As hard as it may be to believe, take a look outside. I don't mean a glance, I mean to take a real look. At all the things there are to see -- the rocks, trees, mountains, skies, clouds, Sun, water, and everything alive -- all of it.
Image credit: Fir0002/Flagstaffotos, under the GFDL.
Now ask yourself, "what's it made of?"
At a fundamental level -- like everything else you know of -- everything on Earth is made of atoms. Oxygen, Hydrogen,…
esiegel | October 28, 2011"Every true, eternal problem is an equally true, eternal fault; every answer an atonement, every realisation an improvement." -Otto Weininger
The best measurements of the distant Universe -- out beyond our galaxy -- have led us to the current picture of exactly what our Universe is doing: expanding and cooling, with its galaxies progressively getting farther and farther apart.
Image credit: Molly Read for the University of Wisconsin-Madison.
But what does that mean for our past?
If we're expanding and cooling, that means our past was less expanded and less cooled, or as we like to think of…
krandall | October 27, 2011By Dr. Gerry Harp, Senior Astrophysicist, Center for SETI Research, SETI Institute, and Gail Jacobs
Trained as a quantum mechanic, Dr. Gerry Harp was deeply interested in possibilities for using the multiple telescopes of the Allen Telescope Array to generate steerable "beams" on the sky -- beams that could be far smaller than any single antenna could produce. Such beams don't emit anything, but work in reverse by capturing only energy that comes from the sky in a certain direction. Gerry joined the SETI Institute in 2000, practically at the telescope's inception and uses the telescope for…
esiegel | October 26, 2011"Where there is no patrol car, there is no speed limit." -Peter Beckmann
You've of course heard the news that the OPERA collaboration in Italy has measured what appears to be neutrinos moving faster than the speed of light.
Image credit: Raoul Pop.
The way they did it was pretty straightforward. Shoot a pulse of protons moving at ultra-high energies -- at speeds indistinguishable from the speed of light -- into a fixed target.
Image credit: The OPERA collaboration's recent preprint.
They'll produce all sorts of high energy particles: baryons, mesons, electrons, positrons, muons, and more…
drorzel | October 26, 2011
"I work around the clock-- 1043 Planck times per second-- providing the gravitational attraction to hold this galaxy cluster together. And some baryonic cosmologist wants to explain me away as a modification of Newtonian gravity?
"I have been silent for 13.7 billion years, but no more.
"I AM THE 96%"
(Original Pandora Cluster image from NASA)
drorzel | October 23, 2011It's been a while since I posted anything science-y, and I've got some time between flipping pancakes, so here's an odd thing from the last few weeks of science news. Last week, there was an article in Nature about the wonders of string theory applied to condensed matter physics. This uses the "AdS/CFT" relationship, by which theorists can take a theory describing a bunch of strongly interacting particles in three dimensions (such as the electrons inside a solid), and describe it mathematically as a theory involving a black hole in four dimensions. This might seem like a strange thing to do,…
esiegel | October 22, 2011"I see miracles all around me
Stop and look, it's all astounding
Water, fire, air and dirt
Fucking magnets, how do they work?
And I don't wanna talk to no scientist,
Y'all motherfuckers lyin', and gettin' me pissed." -Insane Clown Posse
While music certainly has the power to be uplifting, the Insane Clown Posse simply won't make the cut for this site. You'd do better listening to LZ Love's song,
Lift Me Up,which just might do it for you. Even so, it's nothing compared to the power of physics! In particular, the following fantastic video has been making the rounds. Have a look!
I first ran…
esiegel | October 21, 2011"By now you must know that your father can never be turned from the Dark Side. So will it be with you." -Emperor Palpatine, Return of the Jedi
You've heard about dark matter. It's the notion that the Universe is somehow very much different than the small corner of it that we're most familiar with.
Photo credit: International Astronomical Union, retrieved from bbc.co.uk.
When we look at our Solar System, we can add up all the rocky planets, the gas giants, the asteroids, moons, and comets, as well as the entire Kuiper belt, and find out just how much of our neighborhood is dark.
And we can…
esiegel | October 18, 2011"If my theory of relativity is proven successful, Germany will claim me as a German and France will declare that I am a citizen of the world. Should my theory prove untrue, France will say that I am a German and Germany will declare that I am a Jew." -Albert Einstein
One of the most famous scientific developments in the 20th century was the revelation that the Universe had a speed limit: the speed of light.
Image credit: United Visual Artists / Tom Oldham.
Clocking in at exactly 299,792,458 m/s, Einstein's theory of relativity states that any particle with mass can only approach -- but can…
drorzel | October 16, 2011In a lot of ways, the OPERA fast-neutrino business has been less a story about science than a story about the perils of the new media landscape. We went through another stage of this a day or two ago, with all sorts of people Twittering, resharing, and repeating in other ways a story that the whole thing has been explained as a relativistic effect due to the motion of GPS satellites. So, relativity itself has overthrown an attack on relativity. Huzzah, Einstein! Right?
Well, maybe. I'm not quite ready to call the story closed, though, for several reasons. First and foremost is the fact that…
drorzel | October 12, 2011Tuesday was the last day of the fifth week of classes (out of ten; for reasons that passeth all understanding, we started on Wednesday, so all the week-based deadlines fall on Tuesday). Accordingly, it seems like a decent time for an update on the active learning stuff I've been doing in my classes.
Each class has had one exam at this point, and a handful of labs. In the regular intro class, we're in Chapter 5 of Matter and Interactions, about to do curving motion, and in the integrated math-physics class, which only does half a term of physics, we're just dealing with non-constant forces,…
drorzel | October 5, 2011If you want to know how stressed and busy I've been lately, you don't have to look any farther than the fact that I've totally fallen down on the shameless self-promotion front: I was on a radio show, and forgot to post about it here. I know, bad blogger, no pageviews...
Anyway, I talked about the fast neutrino experiment on the phone to Clay Naff, who runs the Science Odyssey show on KZUM in Nebraska, and he used it as part of this past weekend's show. My interview is in Part 1, and Part 2 is Alan Kostelecky, who is an actual expert on this sort of thing.
For some odd reason, it…
drorzel | October 4, 2011The 2011 Nobel Prize in Physics goes to Saul Perlmutter, Brian P. Schmidt and Adam G. Riess "for the discovery of the accelerating expansion of the Universe through observations of distant supernovae." Ethan will presumably have a post with about a gigabyte worth of images in it shortly, or if you prefer your information in book form, you can read Richard Panek's The Four Percent Universe, which has lots of detail about what they did, including the rivalry between the different groups. As a bonus, the UK edition has a blurb from yours truly...
But that's not what you really want to know--…
esiegel | September 30, 2011"We should do astronomy because it is beautiful and because it is fun. We should do it because people want to know. We want to know our place in the universe and how things happen." -John Bahcall
Of course you're all going to watch the exciting Live interview with me on KGW tonight (streaming here; video should be posted after-the-fact here), but shouldn't we give you some extra fun facts about neutrinos?
Here we go...
Both photons and neutrinos are created in the core of stars. But while photons take tens of thousands of years to reach the edge of the Sun, neutrinos make the trip in just…
esiegel | September 28, 2011"If you ever drop your keys into a river of molten lava, let 'em go, because, man, they're gone." -Jack Handey
Take a look at our home planet, Earth, and one of the things you'll notice is that over 70% of the surface is coated in water.
Image credit: NASA / Apollo 17.
We all know why this is, of course: it's because the Earth's oceans float atop the rocks and dirt that make up what we know as land.
This concept of floatation and buoyancy -- where the less dense objects rise above the denser ones, which sink to the bottom -- does much more than just explain the oceans.
This same principle…
esiegel | September 26, 2011"The first principle is that you must not fool yourself--and you are the easiest person to fool. So you have to be very careful about that. After you've not fooled yourself, it's easy not to fool other scientists. You just have to be honest in a conventional way after that." -Richard Feynman
Last week, a collaboration of 160 scientists working in Italy wrote a paper claiming that their experiment shows neutrinos traveling faster than the speed of light. Although I wrote up some initial thoughts on the matter, and there are plenty of other excellent takes, we're ready to go into even deeper…
drorzel | September 24, 2011There have been a lot of pixels spilled over this faster-than-light neutrino business, so it might not seem like something I should take time away from pressing work to write up. It is the story of the moment, though, and too much of the commentary I've seen has been of the form "I am a {theorist, journalist} so hearing about experimental details gives me the vapors" (a snarky paraphrase, obviously). This suggests that there's still room for a canine-level write-up going into a bit more depth about what they did and where it might be wrong.
So, what did those jokers at CERN pull this time?…
drorzel | September 23, 2011The final sentence of the neutrino paper that everybody is buzzing about:
We deliberately do not attempt any theoretical or phenomenological interpretation of
the results.
From a somewhat older work in physics:
Rationem vero harum gravitatis proprietatum ex phænomenis nondum potui deducere, et hypotheses non fingo. Quicquid enim ex phænomenis non deducitur, hypothesis vocanda est; et hypotheses seu metaphysicae, seu physicae, seu qualitatum occultarum, seu mechanicae, in philosophia experimentali locum non habent. In hac philosophia Propositiones deducuntur ex phaenomenis, et redduntur…
esiegel | September 22, 2011"Nothing travels faster than light, with the possible exception of bad news, which follows its own rules." -Douglas Adams
My inbox is on fire today with messages about this story about neutrinos breaking the speed of light:
What's going on here? A group (a large group, mind you) of physicists known as the OPERA collaboration have made a neutrino beam, and have been studying it for the past few years.
Making a neutrino beam is the easiest type of beam to make, by the way. All you do is shoot a bunch of high-energy particles into the Earth, like so.
Image credit: CERN Neutrinos to Gran Sasso…