Neutrinos may or may not move faster than light, but regardless, they're special little things. They speed through the planet, and through you, and through everything; but, chargeless and puny, they interact with their surroundings so minimally that other particles hardly take notice.
These subatomic particles are so tiny and so imperturbable they're almost impossible to see, but they originate in some of the most violent and disruptive processes in the universe. Energetic neutrinos that originate in deep space, known as astrophysical neutrinos, escape from the dark centers of the universe's most powerful places — gamma ray bursts, blazars and quasars, and black holes at the centers of galaxies. They can serve as cosmic messengers from these tumultuous places, but first we have to find them, and this is excruciatingly difficult. So European scientists are planning to construct the second-largest structure ever built by humanity, just to look for them.
By Paul Vaska, as told to Flora LichtmanPosted 07.05.2011 at 1:59 pm 1 Comment
I'm an instrument builder, mostly, and I work on positron-emission-tomography devices: PET. Doctors use them to look for cancer, but neuroscientists use them too. In studies with lab rats, they inject a mildly radioactive substance into the rat, and the PET scan measures the gamma rays the substance gives off. This tells researchers what part of the brain the substance is in and what parts are active.
Thunderstorms produce beams of antimatter particles that rain into space, NASA scientists said this week, shedding more light on one of the weirdest Earth physics stories of recent memory.
Terrestrial gamma-ray flashes, which are brief, powerful bursts produced inside thunderstorms, apparently produce high-speed streams of electrons and positrons that are swept up in Earth’s magnetic field. Scientists are still not sure how TGFs work or how lightning enters the equation, however.
Doomsdayers and 2012 blog-keepers, take note. Astronomers at this week's American Astronomical Society meeting revealed that a massive white dwarf star in the throes of multiple nova is much closer to our solar system than once thought. When it does finally collapse into a type Ia supernova -- okay, if it collapses into a type Ia supernova -- the resulting thermonuclear blast will destroy life on earth. Seriously.
Whilst carrying out its normal workaday duties of scanning corners of the universe billions of light years from Earth, the Fermi Gamma-Ray Space Telescope has made a discovery that hits decidedly closer to home: lightning strikes on Earth carry the signature of antimatter.
Gamma ray flashes detected in terrestrial storms were of the decaying-positron variety, indicating not only that lightning can produce the antimatter equivalent of electrons, but also that somehow the electric field normally produced by a lightning storm somehow reversed.
NASA's Fermi Gamma Ray Space Telescope spent a year collecting data from a thousand gamma ray sources and came up with this, the best map to date of the extreme universe. It also gave Einstein a shot in the arm by confirming the scientist's theories of space-time.
Not to freak you out, but there's a gamma ray-blasting stellar mass pointed in your direction
By Matt RansfordPosted 03.07.2008 at 3:36 pm 6 Comments
Friends of the Dark Side, your time may soon be at hand. It seems we have a literal death star aiming in our general direction. The culprit is part of a binary star system—two stars which orbit each other—by the name of WR 104. Both are massive and very, very hot. One will eventually explode into a harmless supernova, providing us with a lovely astronomical light show. The other, however, might be deadly.
Swift is the first satellite explicitly designed to solve the mystery of gamma-ray bursts, the enigmatic explosions that have puzzled astronomers for decades. Practically every day, another burst randomly appears in the sky, flashing powerful gamma rays for anywhere from a fraction of a second to two minutes. Before the burst fades, Swift quickly locates it, rotates its telescopes and other satellites for observation, and relays the burst's location to ground-based telescopes, which study it in detail.