gravitational radiation
catdynamics | February 11, 2016In 2011 Daniel Holz gave a Heinz R. Pagels Public Lecture at the Aspen Center for Physics on the topic of Gravitational Waves. The talk is one of the better explanations of what this is all about, with a bonus introduction!
catdynamics | February 11, 2016LIGO and allies have also provided a bunch of fun useful stuff:
Have We Detected Gravitational Waves Yet?
Stretch and Squash
Black Hole Hunter
Einstein@Home
Gravitational Waves 101 - Markus Pössel's excellent visualizations.
The Data
The Papers
SXS - Simulating eXtreme Spacetimes visualizations
The Chirp - courtesy of Georgia Tech GR group
catdynamics | February 11, 2016February 11th was a good day.
I spent the day at the "Dynamics and accretion at the Galactic Center" Conference at the Aspen Center for Physics, where about 75 physicists have spent the week talking about black holes and stuff.
This morning we watched the LIGO press conference, frantically deciphered the papers, and had a LIGO Science Collaboration member give us a very good rundown of what the situation is.
Over the last few months, LIGO has been making some very good outreach material to explain what is what:
LIGO: A Passion for Understanding a film by Kai Staats
LIGO: Generations
LIGO…
esiegel | May 8, 2013"No valid plans for the future can be made by those who have no capacity for living now." -Alan Watts
"They do not see what lies ahead, when Sun has faded and Moon is dead." -J.R.R. Tolkien
One of the most amazing facts about the Universe is that, despite only having spent a few hundred years studying the fundamental constituents and forces of what makes us up, humanity has been able to accurately figure out just what all this actually is.
Image credit: ESO / S. Brunier.
The laws of nature are almost completely understood in a few, very important senses. We know that our Universe is about…
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…
catdynamics | October 27, 2010There is a beautiful pulsar paper coming out in Nature tomorrow, 28th of October issue (Demorest et al 467, 1081, 2010)
Green Bank Telescope measurements of PSR J1614-2230 show it to be a 3ms binary pulsar with a white dwarf companion in an orbit aligned near perfectly edge on to our line of sight.
Measurements of the Shapiro Delay provide a measurement of the mass of the white dwarf, allowing the mass of the neutron star to be calculated from the known orbit of the white dwarf.
The resultant inferred mass is 1.97 +/- 0.04 solar masses.
click to embiggen
This is a very nice result.
There…