Thursday, February 23, 2012

Is light faster than sound?

One of my students asked today which is faster: light or sound? As some of you may know the answer is light, here's one of the more dramatic examples that I've seen. Watch for the time difference between the flashes (or light) of the explosion and the sound of the explosion.


Sunday, February 19, 2012

Heart struck by CERN proton beams for Valentine's day


Love may be all about chemistry, but that hasn't stopped particle physicists from making their own special Valentines. This heart has been pierced not by Cupid's arrow, but two proton beams smashing together within the CMS detector at the Large Hadron Collider.

Imperial College London researcher Tom Whyntie took data from one of the earliest collisions at the LHC and added simulated data that followed the path of a heart-shaped equation. He gave the picture to his girlfriend as a Valentine's day card in 2010 - they are now happily married.

Whyntie isn't the only one to mix particles with passion - Suzie Sheehy, a researcher at the Rutherford Appleton Laboratory in Oxfordshire, UK wrote a Valentine's day poem inspired by a heart-shaped simulation of 629 protons torn apart by a particle accelerator.

Source: New Scientist

Thursday, February 9, 2012

In Defense of the Bohr Model

Scientific American journalist Jennifer Ouellette writes about why we should hold on to the Bohr model of the atom despite it not actually being a real description of what an atom looks like...

One of the standout anecdotes in Carl Zimmer’s most excellent compilation, Science Ink (a.k.a. My Favorite Science Book of 2011 And Possibly Ever) occurs in the first few pages:
“A former student [physics major] got a tattoo of a cartoon atom on the back of one of his legs. He told me that the first day after he got it, he went to rugby practice, and was showing it to someone when one of the seniors on the team (also a physics major) walked by. The senior looked at it, and said, ‘Oh, please. The Bohr model?’ And walked off.”
Oh, snap! Guess that poor underclassman got told! And he must live with the shame of his naive physics knowledge on his skin permanently (barring modification or tattoo removal treatments). Welcome to Hipster Physics!
Seriously, though, this is not the first time a physicist has complained about the much-maligned Bohr model of the atom. It’s like a rite of passage, the day you learn that the eye-catching little diagram of a small nucleus orbited by electrons you see all around — from the logo of the US Atomic Energy Commission, to the scene changes in episodes of The Big Bang Theory — simply isn’t the most accurate model for the atom anymore among “serious” scientists (or science writers). And espousing it is grounds for mockery, usually in the form of polite snickers and chuckling condescension from those “in the know.”

Scale of the Universe

Here's a link to one of the coolest animations I've seen on the scale of things in the universe, from quarks to people to the limits of the observable universe.

http://images.4channel.org/f/src/589217_scale_of_universe_enhanced.swf

Wednesday, February 8, 2012

Assume a frictionless vacuum....


Static electricity in space


Expedition 30 astronaut Don Pettit uses knitting needles and water droplets to demonstrate physics in space during his mission on the International Space Station. This is part of the first video in a series for a partnership between NASA and the American Physical Society to share unique videos from the International Space Station with students, educators and science fans from around the world.

Thursday, February 2, 2012

Famous Irish Astronomer


THE ASTRONOMER Jocelyn Bell-Burnell is one of Ireland’s most accomplished scientists. While still a research student she discovered pulsars and went on to become a distinguished scientist who made important astronomical discoveries.

She is a true hero of Irish science for her many accomplishments and for her ongoing contribution to a better public understanding of science. Her discovery of pulsars is one of the famous stories in science and it is also one of the most infamous.

Read the full article in the Irish Times here.