Proposed Spacetime Structure

Spacetime, which consists of three dimensions of space and one time dimension, is such a large, abstract concept that scientists have a very difficult time understanding and defining it. Moreover, different theories offer different, contradictory insights on spacetime’s structure. While general relativity describes spacetime as a continuous manifold, quantum field theories require spacetime to be made of discrete points. Unifying these two theories into one theory of quantum gravity is currently one of the biggest unsolved problems in physics.

In an attempt to better understand spacetime, a new possible structure of spacetime has been proposed on the Planck scale. Spacetime could be both discrete and continuous at the same time, conceivably satisfying general relativity and quantum field theories simultaneously.

This theory is inspired by information theory, since information can also be simultaneously discrete and continuous, the underlying mathematical structure of information theory in this framework is sampling theory - that is, samples taken at a generic discrete set of points can be used to reconstruct the shape of the information (or spacetime) everywhere down to a specific cutoff point. In the case of spacetime, that cutoff would be the natural ultraviolet lower bound, if it exists. This lower bound can also be thought of as a minimum length uncertainty principle, beyond which structural properties cannot be precisely known.

In the study, a sampling theory that can be generalized to apply to spacetime was developped. In this it shows that a finite density of sample points obtained throughout spacetime’s structure can provide scientists with the shape of spacetime from large length scales all the way down to the natural ultraviolet cutoff. Further, it shows that this expression establishes an equivalence between discrete and continuous representations of spacetimes. As such, the new framework for the sampling and reconstruction of spacetime could be used in various approaches to quantum gravity by giving discrete structures a continuous representation.

But it is very hard to obtain experimental data that could guide the search for the theory that unifies quantum theory and general relativity.

New Malaria and Cholera vaccine?

A University of Central Florida biomedical researcher has developed what promises to be the first low-cost dual vaccine against malaria and cholera.
There is no FDA approved vaccine to prevent malaria, a mosquito-borne illness that kills more than 1 million people annually. Only one vaccine exists to fight cholera, a diarrheal illness that is common in developing countries and can be fatal. The lone vaccine is too expensive to prevent outbreaks in developing countries after floods, and children lose immunity within three years of getting the current vaccine.
The development team genetically engineered tobacco and lettuce plants to produce the vaccine. Researchers gave mice freeze-dried plant cells (orally or by injection) containing the vaccine. They then challenged the mice with either the cholera toxin or malarial parasite. The malaria parasite studies were completed in fellow UCF professor Debopam Chakrabarti's lab.
Untreated rodents contracted diseases quickly, but the mice who received the plant-grown vaccines showed long-lasting immunity for more than 300 days (equivalent to 50 human years).
Results from the National Institutes of Health-funded research are published in this month's Plant Biotechnology, the top-ranked journal in the field.
Clinical trials are needed. But if it works then it could be yet another example of plants delivering life-saving medicines.
Producing vaccines in plants is less expensive than traditional methods because it requires less labor and technology. And distribution to mass populations would be easy because it could be made into a simple pill, like a vitamin, which many people routinely take now. There is no need for expensive purification, cold storage, transportation or sterile delivery via injections.

Greece agrees with austerity

Greece has agreed the outline of a €24bn austerity package, including a three-year wage freeze for public sector workers, in return for a multibillion-euro loan from the eurozone and the International Monetary Fund, according to people familiar with the talks.
Final details of the measures, which were intended to slash the budget deficit by 10-11 percentage points of gross domestic product over the next three years, were still being worked out.
Negotiations with officials from the IMF, the European Commission and the European Central Bank are due to be completed at the weekend and the measures will be presented for approval by the Greek parliament next week.
The package also includes an increase in value-added tax, the second this year.

Greek two-year bond yields, which have an inverse relationship with prices, fell more than 3 percentage points to 12.74 per cent, while the stock market rose 7.14 per cent as confidence grew after it was reported on Wednesday that the EU and IMF were preparing a €120bn loan to bail out ­Athens.
Greece faces exceptionally strict monitoring by the EU and IMF because of its poor record of implementing previous economic reform programmes:
-Three-year reform programme
-Two to three percentage points increase in value-added tax
-Three-year public sector pay freeze; recruitment frozen
-Abolition of ‘13th and 14th monthly salary’ for public sector workers; 5 per cent cut in allowances
-No renewals for short-term public sector contracts
-Closure of more than 800 out-dated state entities
-Opening up of more than 60 ‘closed-shop’ professions
-Overhaul of pension system: raising average retirement age to 67 for men and women; cutting state corporation pensions.
-Privatisation: sales of state corporations; flotations on Athens stock exchange; sales and leasing of state-owned properties
George Papandreou, prime minister, was last week forced to activate the EU-IMF rescue package after three previous rounds of austerity measures failed to convince financial markets that Greece could bring its public finances under control.
On top of the wage freeze, public sector workers will lose their “13th and 14th month” salaries, paid at Christmas and Easter, and see further cuts in allowances.
Greece’s swollen public sector, which employs about 13 per cent of the workforce, will be gradually reduced through a recruitment freeze, the abolition of short-term contracts and closures of hundreds of outdated state entities.

Hubble's Deepest View to Date Unveils Never Before Seen Galaxies

NASA's Hubble Space Telescope has broken the distance limit for galaxies and uncovered a primordial population of compact and ultra-blue galaxies that have never been seen before.

The deeper Hubble looks into space, the farther back in time it looks, because light takes billions of years to cross the observable universe.

This makes Hubble a powerful "time machine" that allows astronomers to see galaxies as they were 13 billion years ago, just 600 million to 800 million years after the Big Bang.

The data from Hubble's new infrared camera, the Wide Field Camera 3 (WFC3), on the Ultra Deep Field (taken in August 2009) have been analyzed by no less than five international teams of astronomers. A total of 15 papers have been submitted to date by astronomers worldwide. Some of these early results are being presented by various team members on Jan. 6, 2010, at the 215th meeting of the American Astronomical Society in Washington, D.C

The faintest galaxies are now showing signs of linkage to their origins from the first stars. They are so blue that they must be extremely deficient in heavy elements, thus representing a population that has nearly primordial characteristics.

The existence of these newly found galaxies pushes back the time when galaxies began to form to before 500-600 million years after the Big Bang. This is good news for astronomers building the much more powerful James Webb Space Telescope (planned for launch in 2014), which will allow astronomers to study the detailed nature of primordial galaxies and discover many more even farther away. There should be a lot for Webb to hunt for.

The deep observations also demonstrate the progressive buildup of galaxies and provide further support for the hierarchical model of galaxy assembly where small objects accrete mass, or merge, to form bigger objects over a smooth and steady but dramatic process of collision and agglomeration. It's like streams merging into tributaries and then into a bay.

These galaxies are as small as 1/20th the Milky Way's diameter, the masses are just 1 percent of those of the Milky Way. The results show that these galaxies at 700 million years after the Big Bang must have started forming stars hundreds of millions of years earlier, pushing back the time of the earliest star formation in the universe.

The teams are finding that the number of galaxies per unit of volume of space drops off smoothly with increasing distance, and also found that the galaxies become surprisingly blue intrinsically.

The ultra-blue galaxies are extreme examples of objects that appear so blue because they may be deficient in heavier elements, and as a result, quite free of the dust that reddens light through scattering.

Hubble's WFC3/IR camera was able to make deep exposures to uncover new galaxies at roughly 40 times greater efficiency than its earlier infrared camera that was installed in 1997. The WFC3/IR brought new infrared technology to Hubble and accomplished in four days of observing what would have previously taken almost half a year for Hubble to do.