Science News

Headlines

. Magnetricity
. Bandage that fights infection
. A big Diwali in deep space

Read more on them below. Also don't miss the article on the recent Field's medal winning work this year.

. Magnetricity

You know about magnets, and you know about electricity. Here is a new term for you: magnetricity!
Every magnet has two poles, the north and the south. This is true for all magnets. If you break a magnet into smaller pieces, then each small magnet ends up with a north and a south. 
But a recent experiment shows that even magnets can be broken up! In this new study, scientists, in a way, separate north poles from south poles. One pole without the other is called a monopole (mono- means one); the researchers also refer to these isolated poles as magnetic charges. After creating these monopoles, scientists were able to make them move through a material. True magnetic monopoles have not been found. These are only called monopoles because they mimic the behaviour of monopoles, but only in solids; they have no independent existence. This movement of magnetic charges acts a lot like a current of electricity, the researchers report. It is this flow that they have termed magnetricity, to distinguish them from true monopoles.
Electricity flows from generators and batteries through power lines and wires. That electric flow is not liquid -- it is a fast parade of tiny charged particles called electrons. Each electron is a negative charge, and electric current is the movement of many negative charges in the same direction.
In the recent experiment, the current did not come from moving electrons - it was magnetic, rather than electric. The scientists created the current in small crystals of a material called spin ice, which is made of unusual molecules shaped like pyramids with triangular bases. Imagine lots of these tiny pyramids linked together and you can imagine what spin ice looks like from close.
When one magnet switches direction, it causes other magnets to switch direction - like passing a signal down the line. The molecules stay put but a chain reaction gets going as the poles, like a relay, move down the line and through the spin ice.
That is what happens in the case of magnetricity. To get the magnetic flow going, the researchers applied pulses of a magnetic field to the crystal. As magnets flipped, they appeared to be passing a magnetic monopole down the line. This created a magnetic current. The scientists measured that current and discovered that it behaved almost exactly like an electric current. These magnetic currents can last for several minutes.
Perhaps, in future, we will have magnetic cars and magnetic lighting too!

. Bandage that fights infection
When you have burns, skin is exposed to infection, which can be dangerous. That is why, doctors often wrap burns in bandages for protection. But a recent study shows that a new kind of bandage can actually fight infection. Better yet, this new bandage can use the harmful bacteria against themselves -- in other words, the infection-causing organisms to cause their own deaths.
Scientists have developed a material that contains tiny capsules. To a bacterium, these capsules look like cells just waiting to be invaded. The capsules contain antibiotics, which are chemical compounds that can kill bacteria on contact. The bacteria attack the cells by releasing toxins, or poisons. But when the bacteria attack the capsules, the capsules fight back -- by releasing antibiotics that knock out any nearby bacteria.
Scientists tested the material on two types of harmful bacteria. One was a type of Staphylococcus bacteria; the other was a type of Pseudomonas bacteria. When researchers placed scraps of the new material in a Petri dish with the bacteria, the bacteria barely grew at all, which is unusual. This observation led the researchers to believe that the bacteria had attacked the fabric, and that the antibiotics had been released -- which kept the bacteria from growing.
The scientists want the bandages to work specifically only against dangerous bacteria, so they also tested the fabric on a harmless type of E. coli bacteria. When the scrap of fabric was placed in a Petri dish with E. coli, the bacteria grew quickly -- showing that the trap did not fool the harmless bacteria. The harmful bacteria probably released toxins that burst the capsules open, while the harmless E. coli left the capsules alone.
There is a long way to go before such healing fabric becomes practical for use in hospitals, but we may eventually have some good news for burn victims.

3. A big Diwali in deep space
Something has been going on in Draco constellation, in the northern part of the sky. A few months ago, astronomers observed what seemed to be a bright blowup there, which was nothing unusual in itself. It looked like a gamma-ray burst, which is a bright blast of powerful radiation that usually lasts about 30 seconds. Sometimes gamma-ray bursts last for hours. Gamma rays are the most energetic type of radiation in the universe, and astronomers suspect bursts of these rays can be emitted when a massive star dies.
But this recent explosion did not end after 30 seconds -- or after a few hours. A day later, it was still there. A week later, it was still there. A month later, the blast was going strong. During that time, it brightened and dimmed many times, and the bright pulses sometimes lasted hundreds of seconds. If it is a gamma-ray burst, it is breaking all kinds of records.
Some astronomers have a hypothesis to explain this: a black hole might have eaten a star that moved too close. We usually think about black holes as places where nothing can escape, but deep-space images show that powerful jets of radiation can shoot across the cosmos from the neighborhood of a black hole.
The suggeston is that as the black hole pulled in gas from the star, the black hole could have produced a blast of gamma rays and X-rays. The jet may have been pointed straight at Earth -- in which case our telescopes are looking right down the middle of the high-energy radiation stream.
The Hubble Space Telescope took a picture of the explosion and identified it as happening in the center of a galaxy 3.8 billion light-years away. (A light-year is the distance travelled by light in one year. To travel one light-year, you would have to go to the sun and back about 30,000 times.) That faraway galaxy probably has a giant black hole at its center, which could be the source of the radiation. The Hubble picture offers more evidence that the black hole gobbled a star and then sent out an explosion of radiation jets.
But this is only a suggestion as of now, and more observations and explanations are needed before we have a definitive answer. With tools and technology like the Swift satellite and the Hubble Space Telescope, the long-lived explosion may not be a mystery for long. On the other hand, the blowup could point to a deep-space occurrence that has never been observed until now.

--Compiled from several sources