Tag Archives: Caltech

Simulating Extreme Spacetimes

Thanks to Dave Groce for sending me the following link to the Caltech-Cornell Numerical Relativity collaboration; Simulating eXtreme Spacetimes (SXS):


Caltech SXSSource: SXS

From the actual website (not the image above), click on the yellow “Admit One” ticket and you’re on your way.

Under the “Movies” tab, you’ll find many video simulations that help visualizes a range of interactions between two black holes and between a black hole and a neutron star. Following is a direct link:


A movie visualizing GW150914, the first ever gravitational wave detection on 14 September 2015, is at the following SXS link:


At the above link, you also can listen to the sound of the GW150914 “in-spiral” event (two black holes spiraling in on each other).  You can read more about the detection of GW150914 in my 11 February 2016 post.

On the “Sounds” tab on the SXS website, you’ll find that different types of major cosmic events are expected to emit gravitational waves with waveforms that will help characterize the original event. You can listen to the expected sounds from a variety of extreme cosmic events at the following SXS link:


Have fun exploring SXS.


Anyone Can Quantum

Nobel Laureate Dr. Richard Feynman is famously quoted as saying, “I think I can safely say that nobody understands quantum mechanics.” University of Southern California (USC) graduate student Chris Cantwell, the inventor of Quantum Chess, is seeking to change that view by demonstrating that, in the right framework, anyone can grapple with some of the basic concepts of quantum mechanics. In particular, Chris Cantwell views Quantum Chess as a means of “demystifying the quantum world through play.” In Quantum Chess, all of the conventional chess moves are allowed as well as certain quantum moves for all pieces except pawns.

Quantum Chess isn’t a game you can purchase right now, but the short video, “Anyone Can Quantum,” provides an entertaining demonstration of what quantum gameplay will be like in the near future. This video was created by Caltech’s Institute for Quantum Information and Matter (IQIM) (‪http://iqim.caltech.edu) in association with Trouper Productions (‪http://trouper.net). In the video, actor Paul Rudd (Ant Man) challenges Stephen Hawking to a game of Quantum Chess for the right to give the keynote address at Caltech’s 26 – 27 January 2016 special event, “One Entangled Evening: A Celebration of Richard Feynman’s Quantum Legacy.”

You can view the almost 12 minute video at the following link.


Here are a few of screenshots from the video.

Quantum chess match announcement

Quantum chess players

Quantum superposition is demonstrated by “Schrodinger’s king”, which could be in two places at one time.

Without superposition                                                      With superposition

Without superposition             With superposition

Quantum entanglement of the king & bishop enabled a bishop to move through a king.

Without entanglement                                                  With entanglement

Without entanglement           With entangelement

Resolution of the game required a quantum measurement to determine the winner.

For those of you who can’t wait to play a real game of Quantum Chess, Chris Cantwell has launched a Kickstarter funding program. Find out details at the following link:


You can find out more about the 26 – 27 January 2016 Caltech event, One Entangled Evening: A Celebration of Richard Feynman’s Quantum Legacy,” at the following link:




100th Anniversary of Einstein’s General Theory of Relativity and the Advent of a New Generation of Gravity Wave Detectors

One hundred years ago, Albert Einstein presented his General Theory of Relativity in November 1915, at the Prussian Academy of Science. Happy Anniversary, Dr. Einstein!

Today, general relativity is being tested with unprecedented accuracy with a new generation of gravity-wave “telescopes” in the U.S., Italy, Germany, and Japan. All are attempting to directly detect gravity waves, which are the long-predicted quakes in space-time arising from cataclysmic cosmic sources.

The status of four gravity-wave telescopes is summarized below.

USA: Laser Interferometer Gravitational-Wave Observatory (LIGO)

LIGO is a multi-kilometer-scale gravitational wave detector that uses laser interferometry to, hopefully, measure the minute ripples in space-time caused by passing gravitational waves. LIGO consists of two widely separated interferometers within the United States; one in Hanford, WA and the other in Livingston, LA. These facilities are operated in unison to detect gravitational waves. The Livingston and Hanford LIGO sites are shown in the following photos (Hanford above, Livingston below):

ligo-hanford-aerial-02Source LIGO Caltechligo-livingston-aerial-03Source: LIGO Caltech

LIGO is operated by Caltech and MIT and is supported by the National Academy of Sciences. For more information, visit the LIGO website at the following link:


Basically, LIGO is similar to the traditional interferometer used in 1887 in the famous Michelson-Morley experiment (https://en.wikipedia.org/wiki/Michelson–Morley_experiment). However, the LIGO interferometer incorporates novel features to greatly increase its sensitivity. The basic arrangement of the interferometer is shown in the following diagram.

LIGO experiment setupSource: LIGO Caltech

Each leg of the interferometer has a physical length of 4 km and is a resonant Fabry-Perot cavity that uses a complex set of mirrors to extend the effective arm length by a factor of 400 to 1,600 km.

On 18 September 2015, the first official “observing run” using LIGO’s advanced detectors began. This “observing run” is planned to last three months. LIGO’s advanced detectors are already three times more sensitive than Initial LIGO was by the end of its observational lifetime in 2007. You can read about this milestone event at the following link:


You also can find much more information on the LIGO Scientific Collaboration (LSC) at the following link:


Italy: VIRGO

VIRGO is installed near Pisa, Italy, at the site of the European Gravitational Observatory (http://www.ego-gw.it/public/virgo/virgo.aspx). VIRGO is intended to directly observe gravitational waves using a Michelson interferometer with arms that are 3 km long, with resonant Fabry-Perot cavities that increase the effective arm length by a factor of 50 to 150 km. The initial version of VIRGO operated from 2007 to 2011 and the facility currently is being upgraded with a new, more sensitive detector. VIRGO is expected to return to operation in 2018.

You can find much more information on VIRGO at the following link:


Germany: GEO600

GEO600 is installed near Hanover, Germany. It, too, uses a Michelson interferometer with arms that are 600 meters long, with resonant Fabry-Perot cavities that double the effective arm length to 1,200 meters.

You can find much more information on the GEO600 portal at the following link:


Japan: KAGRA Large-scale Cryogenic Gravitational Wave Telescope

The KAGRA telescope is installed deep underground, in tunnels of Kamioka mine, as shown in the following diagram.

img_abt_lcgtSource: KAGARA

Like the other facilities described previously, KAGRA is a Michelson interferometer with resonant Fabry-Perot cavities. The physical length of each arm is of 3 km (1.9 mi). KAGRA is expected to be in operation in 2018.

You can find much more information on KAGARA at the following links:






Spitzer Space Telescope “Warm Mission” Continues

The Spitzer Space Telescope, an infrared space observatory, was launched on 8 August 2003 into an “earth-trailing” orbit around the Sun. It is one of four “Great Observatories” launched by NASA; the others being the Hubble Space Telescope, the Compton Gamma-ray Observatory; and the Chandra X-ray Observatory.

Spitzer_Telescope_Handbook013   Diagram source: NASA

The primary mirror is 85 cm in diameter, made of beryllium, and until May 2009, was cooled by liquid helium to 5.5 degrees K. With the on-board liquid helium supply exhausted, most of the instruments were no longer usable. However, the two shortest wavelength modules of the Infrared Science Archive (IRAC) camera remained operable at their original sensitivities. This allowed the mission team to continue with the “Spitzer Warm Mission”.

You can read about the design of the Spitzer Space Telescope at the following link:


An example of an image from the Spitzer Space Telescope is this view of Eta Carinae:

The tortured clouds of Eta Carinae  Photo source: NASA

You can see this and many other images from the Spitzer telescope, and related image data, at the following NASA / JPL / Caltech website: