Friday, September 20, 2013

Nima Arkani-Hamed Lectures

Nima Arkani-Hamed on developments in Physics and future vision

The Salam Lecture Series 2012, with a week-long series of lectures by renowned theoretical physicist Nima Arkani-Hamed. Giving his audience a panoramic view of 400 years of physics in his first lecture, Arkani-Hamed provided insights into the various concepts that have dominated the world of fundamental physics at different points in history. "Everything that we have learned [over the past 400 years] can be subsumed with a basic slogan, and the slogan is that of unification," he said. "More and more disparate phenomena turn out to be different aspects of the same thing." "Physics," he stressed "forces you to remove artificial distinction between disciplines.

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Sunday, September 15, 2013

Exploring Matter At the Dawn of Time

Physicist Paul Sorensen describes discoveries made at the Relativistic Heavy Ion Collider (RHIC), a particle accelerator at Brookhaven National Laboratory. At RHIC, scientists from around the world study what the universe may have looked like in the first microseconds after its birth, helping us to understand more about why the physical world works the way it does - from the smallest particles to the largest stars. See: Exploring Matter at the Dawn of Time and RHIC

Thursday, September 12, 2013

Detailed Characterization of Jets in Heavy Ion Collisions Using Jet Shapes and Jet Fragmentation Functions

The CMS detector has excellent capabilities for studying high-pT jets formed in heavy ion collisions. Previous CMS analyses have characterized the energy loss of hard-scattered partons traversing the medium produced in such collisions at a center of mass energy of 2.76 TeV using the momentum imbalance of di-jet and photon-jet events. In this paper, the fragmentation properties of inclusive jets with pT,jet>100~GeV/c in PbPb collisions are characterized by measuring differential and integated jet shapes, as well as charged particle fragmentation functions. A data sample of PbPb collisions collected in 2011 at a center of mass energy of sNN=2.76~TeV corresponding to an integrated luminosity of Lint=140 μb1 is used. The results for PbPb collisions as a function of collision centrality are compared to reference distributions based on pp data collected at the same collision energy. For both PbPb and pp collisions, jets are reconstructed with the anti-kT clustering algorithm with a resolution parameter of 0.3 and using ``Particle Flow'' objects that combine tracking and caloritmetry information. The jet shapes and fragmentation functions are measured for reconstructed charged particles with \pt>1~GeV/c within the jet cone. For the most central collisions indications of a broadening of the differential jet shape in PbPb collisions are observed, as well as a significant rise of the PbPb/pp fragmentation function ratio for the softest fragmentation products with pT<3~GeV/c. See: Detailed Characterization of Jets in Heavy Ion Collisions Using Jet Shapes and Jet Fragmentation Functions

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Hubble Movie Theater: Revelation

Take a thrill ride through 15 years of Hubble images, starting with Hubble’s first picture and ending with its anniversary image of the Whirlpool Galaxy. In less than three minutes, 800 Hubble images flash over the screen, sometimes as fast as 60 pictures per second.See:HUBBLE Site

Saturday, September 07, 2013

Catching Black Holes on the Fly

Black Holes Shine for NuSTAR Image Credit: NASA/JPL-Caltech
NASA's black-hole-hunter spacecraft, the Nuclear Spectroscopic Telescope Array, or NuSTAR, has "bagged" its first 10 supermassive black holes. The mission, which has a mast the length of a school bus, is the first telescope capable of focusing the highest-energy X-ray light into detailed pictures. See: Catching Black Holes on the Fly


Thursday, August 29, 2013

How to Find Black holes with Lasers

In February 2013 I was invited by the Institute of Physics to give a lecture in the famous lecture theatre of the Royal Institution of Great Britain as part of their Physics in Perspective series. I was to expect about 400 students and teachers from schools across the country. See: How to Find Black holes with Lasers


Tuesday, August 27, 2013

What Dirac And Feynman Had in Common?

"The adventure of our science of physics is a perpetual attempt to recognize that the different aspects of nature are really different aspects of the same thing" -- Richard Feynman
Should I be so bold to change the word in Feynman's quote as to suggest that "perpetual" be changed to "perceptual?" Conceptually, to be able to explain the Diagrams,  as a process unfolding?

"When I see equations, I see the letters in colors – I don't know why. As I'm talking, I see vague pictures of Bessel functions from Jahnke and Emde's book, with light-tan j's, slightly violet-bluish n's, and dark brown x's flying around. And I wonder what the hell it must look like to the students." Feynman, Richard. 1988. What Do You Care What Other People Think? New York: Norton. P. 59.

A Conformal Diagram of a Minkowski Spacetime

The question I raised in the Blog Post title is one that has to do with perception and how we can see in different ways. How did such a view of the natural world bring to light....anti-matter? Was it a conceptualization about time?

While Dirac spoke about projective geometry I could not but help to see that Feynman thought to use his diagrams to help see in "that kind of space."  As a layman, I could definitely be wrong.

You can picture all the directions in Minkowski space as the points in a three-dimensional projective space. The relationships between vectors, null-vectors and so on - - and you get at once just the relationships between points in a three-dimensional vector space. I always used these geometrical ideas for getting clear notions about relationships in relativity although I didn’t refer to them in my published works.Oral History Transcript — Dr. P. A. M. Dirac


Word Picture

Sunday, August 25, 2013

True North

What is your true north? What does your bird look like? If you find that you are confused on whether you are sensing the voice of intuition or the voice of ego, skip to 5 min 40 secs to get clarity on which it is. That is....if you want to skip the peacock story at the beginning. Ha! Enjoy.

  "The power of settings, the power of priming, and the power of unconscious thinking, all of those are a major change in psychology. I can't think of a bigger change in my lifetime. You were asking what's exciting? That's exciting, to me."


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Re-thinking an Alien World?

A distant super-Earth named ""55 Cancri e"" is wetter and weirder than astronomers thought possible. The discovery has researchers re-thinking the nature of alien worlds.