Tuesday, January 11, 2011
I enjoy collecting mind-blowing - but true - science stories. See, for example:
Here are three amazing science discoveries which caught my eye today ...
Thunderstorms Make Anti-Matter
NASA announced today:
Scientists using NASA's Fermi Gamma-ray Space Telescope have detected beams of antimatter produced above thunderstorms on Earth, a phenomenon never seen before.
Scientists think the antimatter particles were formed inside thunderstorms in a terrestrial gamma-ray flash (TGF) associated with lightning. It is estimated that about 500 TGFs occur daily worldwide, but most go undetected."These signals are the first direct evidence that thunderstorms make antimatter particle beams," said Michael Briggs, a member of Fermi's Gamma-ray Burst Monitor (GBM) team at the University of Alabama in Huntsville (UAH).
"Even though Fermi couldn't see the storm, the spacecraft nevertheless was magnetically connected to it," said Joseph Dwyer at the Florida Institute of Technology in Melbourne, Fla. "The TGF produced high-speed electrons and positrons, which then rode up Earth's magnetic field to strike the spacecraft."
The beam continued past Fermi, reached a location, known as a mirror point, where its motion was reversed, and then hit the spacecraft a second time just 23 milliseconds later. Each time, positrons in the beam collided with electrons in the spacecraft. The particles annihilated each other, emitting gamma rays detected by Fermi's GBM.
Scientists long have suspected TGFs arise from the strong electric fields near the tops of thunderstorms. Under the right conditions, they say, the field becomes strong enough that it drives an upward avalanche of electrons. Reaching speeds nearly as fast as light, the high-energy electrons give off gamma rays when they're deflected by air molecules. Normally, these gamma rays are detected as a TGF.***
Click to view the three steps thunderstorms must take to produce bursts of anti-matter. [more]
But the cascading electrons produce so many gamma rays that they blast electrons and positrons clear out of the atmosphere. This happens when the gamma-ray energy transforms into a pair of particles: an electron and a positron. It's these particles that reach Fermi's orbit.The detection of positrons shows many high-energy particles are being ejected from the atmosphere. In fact, scientists now think that all TGFs emit electron/positron beams.
Science News adds the following quote:
“The idea that any planet has thunderstorms that not only produce antimatter but then launch it into space seems like something straight out of science fiction,” commented Steven Cummer of Duke University in Durham, N.C., who was not part of the study. “That our own planet does this, and has probably done it for hundreds of millions of years, and that we've only just learned it, is amazing to me.”
Scientists Store Data in E. Coli Bacteria
Agence France-Presse reported Sunday:
A group of students at Hong Kong's Chinese University are making strides towards storing such vast amounts of information in an unexpected home: the E.coli bacterium better known as a potential source of serious food poisoning."This means you will be able to keep large datasets for the long term in a box of bacteria in the refrigerator," said Aldrin Yim, a student instructor on the university's biostorage project....
The group has developed a method of compressing data, splitting it into chunks and distributing it between different bacterial cells, which helps to overcome limits on storage capacity. They are also able to "map" the DNA so information can be easily located.
This opens up the way to storing not only text, but images, music, and even video within cells.
As a storage method it is extremely compact -- because each cell is minuscule, the group says that one gram of bacteria could store the same amount of information as 450 2,000 gigabyte hard disks.
They have also developed a three-tier security fence to encode the data ....
"Bacteria can't be hacked," points out Allen Yu, another student instructor.
"All kinds of computers are vulnerable to electrical failures or data theft. But bacteria are immune from cyber attacks. You can safeguard the information."
The team have even coined a word for this field -- biocryptography -- and the encoding mechanism contains built-in checks to ensure that mutations in some bacterial cells do not corrupt the data as a whole.***
The Hong Kong group's work may have a more immediate application.
The techniques they use -- removing DNA from bacterial cells, manipulating them using enzymes and returning them to a new cell -- are similar to those used to create genetically modified foods.
But rather than changing the building blocks of an organism, the Hong Kong group allows extra information to piggyback on the DNA of the cell, after checking their changes against a master database to make sure they do not have accidental toxic effects.***
So is it possible that a home computer could one day consist of a dish filled with micro-organisms?
The group dismisses concerns that this could be dangerous, pointing out that despite E.coli's poor reputation, they use an altered form that cannot exist outside a rich synthetic medium.
In fact, says Chan, while safety rules are strict, more measures are taken to protect the bacteria from contamination than to protect the researchers from the bacteria.
However, Yim admitted that while the group's work is a "foundational advance", a petri dish PC is not likely to be on the market in the coming years, not least because the method of retrieving the data requires experts in a laboratory.
"It's possible," he said, "but there's a long way to go."
Half Animal, Half Plant
And Live Science reported last January:
A green sea slug appears to be part animal, part plant. It's the first critter discovered to produce the plant pigment chlorophyll.
The sneaky slugs seem to have stolen the genes that enable this skill from algae that they've eaten. With their contraband genes, the slugs can carry out photosynthesis — the process plants use to convert sunlight into energy.
"They can make their energy-containing molecules without having to eat anything," said Sidney Pierce, a biologist at the University of South Florida in Tampa.
"This is the first time that multicellar animals have been able to produce chlorophyll," Pierce told LiveScience.
The sea slugs live in salt marshes in New England and Canada. In addition to burglarizing the genes needed to make the green pigment chlorophyll, the slugs also steal tiny cell parts called chloroplasts, which they use to conduct photosynthesis. The chloroplasts use the chlorophyl to convert sunlight into energy, just as plants do, eliminating the need to eat food to gain energy.
The babies of thieving slugs retain the ability to produce their own chlorophyll, though they can't carry out photosynthesis until they've eaten enough algae to steal the necessary chloroplasts, which they can't yet produce on their own.
The slugs accomplishment is quite a feat, and scientists aren't yet sure how the animals actually appropriate the genes they need.