Penrose's Cyclic Cosmology

I found this an interesting article for those of you interested in cosmology and pre-Big Bang era.

Interview with MIT Physics Professor Walter Lewin

Watch this YouTube video, if you are also interested in being a wonderful physics teacher.

Grant Funding

With NSF deadlines looming (November 15th-ish, have you started yours yet?), this is an interesting look at the inner workings of the grant funding process for the American Cancer Society:

Research funding: Making the cut

Kelle at AstroBetter remarks that this is very similar to the situation in NSF review panels. Some good things to think about when writing proposals, especially for those of us who haven't sat on panels yet.

In the upcoming week, I'll be submitting my first postdoc application (meeps!) and embarking on a fun research trip. Hopefully both will provide some good blog fodder!

Liouville's Theorem in the galaxy?

As you might remember, the Liouville's Theorem in statistical mechanics and Hamiltonian mechanics states that "the phase space distribution function is constant along the trajectories of a system". In other words the density in phase space remains constant along a dynamic trajectory.

Now, suppose that we have an isotropic distribution of energetic charged particles hitting our galaxy (lets assume that the galaxy is a sphere of radius R). These particles will be deflected by the magnetic field of the galaxy and some of them will hit the Earth. So, we get a new distribution of charged particles at Earth, which is not isotropic anymore.

But then an interesting question comes to mind. Does the Liouville's Theorem remain true in this case? Is our new non-uniform distribution conserved in the 6-dimensional phase space? Has the momenta changed in a way to cancel out the changes in the canonical coordinates?

What do you think?

What I do....

I am currently studying terrestrial gamma ray flashes (TGFs). They were first discovered in 1994 by BATSE as intense gamma ray flashes with time scales on the order of milliseconds and energies up to at least 40MeV. TGFs are associated with high lightning activity and more specifically with intracloud lightning. Their existence has been confirmed by RHESSI and GBM in recent years. I currently have three weather boxes on the roof of Nicholson Hall with three NaI detectors in each box monitoring the sky. Currently, we see an increase in count rate when thunderstorms pass directly over LSU's campus. Interesting....

x-shaped head

Hubble Space Telescope is just amazing. From January to May 2010, HST took images of a point like object with a long dusty tail, living between the orbits of Mars and Jupiter. As you can see in the images below, this object has an x-shaped head, which states that something stranger than a comet outgassing might have happened to shape this weird x.

"Astronomers think a smaller rock, perhaps 10 to 15 feet wide, slammed into the larger one. The pair probably collided at high speed, about 11,000 mph, which smashed and vaporized the small asteroid and stripped material from the larger one. Jewitt estimates that the violent encounter happened in February or March 2009 and was as powerful as the detonation of a small atomic bomb.", Nasa Science News.

There is yet no good explanation for this x shape. But they plan to use HST next year to observe this object again and study its evolution.

The Nobel Prize in Physics 2010

The Nobel Prize in Physics 2010 was awarded jointly to Andre Geim and Konstantin Novoselov "for groundbreaking experiments regarding the two-dimensional material graphene"

Link

Proposal Time!

(Image by Flickr User LobsterStew)

No, not that kind of proposal! The telescope kind!

(Morning from the 30" at McDonald Observatory. That's the 107" dome, the Moon, and Venus.)

NOAO Semester A Proposals are due next Thursday. I am (all of a sudden) writing two, one for Kitt Peak:

(Image credit: NOAO/AURA/NSF)

And one for Cerro Tololo:

(Image credit: T. Abbott and NOAO/AURA/NSF)

What about you? Are you writing any observing proposals?

Strange Spiral Structure

This is the "astronomy picture of the day" on September 14th.

I thought this spiral structure on the left of the picture is so amazing that it is worth to study more about and find out what made this strange spiral structure. This image has been taken by Hubble Space Telescope in near-infrared light.

And you can read more about the picture here. Let us know if you had any idea about this weird spiral structure.

A New Solar System

Chris shared some news on facebook yesterday about recently discovery of two new solar systems. I thought it was interesting enough to read a little more about it and make a post on it here.

One of these new systems, is Kepler-9, which has been studied by Matthews Holman at Harvard-Smithsonian Center for Astrophysics and his colleagues from different institutes. They published their paper in Science on August 26.

This new system has two Saturn-size planets, which they called them Kepler-9B and Kepler-9C, and there is a possibility of observing a third smaller planet with a radius of 1.5 times the Earth's radius.

This discovery has been made by Kepler, Nasa's first mission capable of finding Earth-size and smaller planets around other stars.

Below, you can read the abstract of this new Science online published paper.

"The Kepler spacecraft is monitoring over 150,000 stars for evidence of planets transiting those stars. We report the detection, based on 7 months of Kepler observations, of two Saturn-size planets that transit the same Sun-like star. Their 19.2- and 38.9-day periods are presently increasing and decreasing at respective average rates of 4 and 39 min per orbit, and in addition the transit times of the inner body display an alternating variation of smaller amplitude. These signatures are characteristic of gravitational interaction of two planets near a 2:1 orbital resonance. Six radial velocity observations show that these two planets are the most massive objects orbiting close to the star and substantially improve the estimates of their masses. After removing the signal of the two confirmed giant planets, we identify an additional transiting super-Earth-size planet candidate with a period of 1.6 days."

Drive-By Posting!

It's almost the start of classes for the fall semester here! Toss in some strange funding deadlines and public data that needs to be analyzed sooner rather than later (so as to avoid getting scooped), and things are a bit crazy. (Not like they are ever boring...) But here's a neat thing that popped up in my Google Reader:

An 18 Billion Mile Journey is Almost Complete!

Next July, the planet Neptune will make its way back to the point in its orbit where it was originally discovered by Johann Galle and his assistant (probably a grad student, ha!), located within one degree of the position predicted by Urbain Le Verrier. Cool!

Making Heisenberg's Uncertainty Principle Less Uncertain

WATERLOO, Ontario, Canada, August 2010 - A recent paper published in Nature Physics by PI postdoctoral researcher Roger Colbeck and colleagues at several European universities has made Heisenberg’s uncertainty principle — one of the central (and strangest) features in quantum physics — a lot less uncertain in some situations.

One question addressed by the uncertainty principle is whether it is possible to predict both the position and momentum (or other pairs of observables) of a subatomic particle. In its original formulation, the uncertainty principle implies that it is not. However, the paper shows that in the presence of quantum memory, a device capable of reliably storing quantum states, it is possible to predict both precisely. Intensive research efforts are currently focused on producing such a memory and there is hope that one will be available in the near future.

To illustrate the main ideas, the paper outlines an imaginary “uncertainty game” in which two people, Alice and Bob, begin by agreeing on two measurements, R and S, one of which will be performed. Bob then prepares a particle in a quantum state of his choosing. Without telling Alice what he has done, he sends the particle (over a channel) to Alice. Alice performs one of the two measurements (chosen at random) and tells Bob which observable she has measured, though not the measurement’s value. Bob wants to correctly guess the measurement value. If Bob had only a classical memory (e.g. a piece of paper), he would not be able to guess correctly all of the time — this is what Heisenberg’s uncertainty relation implies. However, if Bob is able to entangle the particle he sends with a quantum memory, for any measurement Alice makes on the particle, there is a measurement on Bob’s memory that always gives him the same outcome. His uncertainty has vanished.

The paper provides a new uncertainty relation valid in the presence of a quantum memory. More precisely, it proves a lower bound on the uncertainties of the measurement outcomes which depends on the amount of entanglement between the measured particle and the quantum memory. This had been conjectured by former PI researcher J.C. Boileau and J.M. Renes in 2008 (http://arxiv.org/abs/0806.3984) but was unproven until Colbeck et al’s work.

There are a number of potential applications arising from this work, notably for the burgeoning field of quantum cryptography. Although it was realized in the 1970s that the uncertainty principle could be used as the basis for ultra-secure communications, most quantum cryptographic approaches to date have not made use of it directly. The results may also yield a new method of ‘witnessing’ entanglement. Creating entangled states between particles (such as photons) is notoriously difficult, and once created, the states are easily destroyed by noise in the environment. A more straightforward witnessing method would be of great value to experimentalists striving to generate this precious resource, a necessary step towards developing quantum computers.

___________________

ⁱ Entanglement is a property of two or more particles which links them such that when one particle is measured, it collapses the state of the other (no matter how far away it is). Certain observable properties of the particles are shared in the sense that a measurement of that property on one of the particles implies the value of that property on the other. However, these correlations cannot be classically explained and are often referred to as nonlocal correlations. Although counterintuitive, the existence of entanglement has been experimentally confirmed many times.

Reference: http://www.perimeterinstitute.ca/News/In_The_Media/Making_Heisenberg%27s_Uncertainty_Principle_Less_Uncertain/

a short report

Japanese Spacecraft Approaches Venus:

On Dec. 7, 2010, the Japanese Spacecraft named "Akatuski" will enter the orbit of Venus. The rocky and dusty surface of Venus has a temperature of about 500 Celsius and its atmosphere contains of about 95% of Carbon Dioxide plus Nitrogen, Sulfuric Acid and a small amount of other elements. Getting data from this mission makes it possible to study the atmosphere's structure and dynamics in more details.

Earth's Magnetic Fields

When a rock forms, its iron compounds (I think most of the rocks have small quantities of iron compounds) align with the Earth's magnetic field and become magnetized. Geologists can measure the age of the rock by different methods and they have collected data covering a period of at least five million years. Surprisingly it has been found that the magnetization directions of different rocks are not the same, indicating that during the last five million years the Earth's field direction has reversed several times.

These variations led me think about the origin of the Earth's magnetic field. I am studying so much about galactic and extragalactic magnetic fields these days. May be it is good to start from the Earth!

"heliophysics"

"A few years ago, scientists coined the term "heliophysics" to describe the emerging science of the sun-Earth system. As a nod to the importance of the topic, NASA has set up a dedicated Heliophysics Division at HQ in Washington DC, and the United Nations declared 2007 the "International Heliophysical Year" (IHY) in hopes of spurring global involvement in this new field."

Reference: here!

Also take a look at wikipedia!