Tag Archives: gamma radiation

Astronomers Just Witnessed A Massive Cosmic Explosion… 12 Billion Years After It Happened

Supergiants are massive stars with huge amounts of energy, which causes them to expand rapidly. However, all stars eventually reach a limit, after which the gravity of the core is no longer able to hold the star together.

The explosion that follows is known as a supernova (or sometimes a hypernova, if it’s big enough). As the outer portions of the star explode off, the core collapses upon itself.

Nebulas are the remnants of a supernova explosion. This is the Crab Nebula. Click to enlarge

If a star is large enough, the extreme amount of energy produced by this inward collapse forces the star’s core to release high-energy gamma particles. These gamma bursts are the most powerful event so far discovered in the universe. But just how powerful is that?

Well, in just 10 seconds, these gamma ray bursts release more energy than our Earth’s sun will during the entire 10 billion years of its expected lifespan.

On April 19th, in the Davis Mountains of West Texas, the ROTSE-IIIb telescope (owned by Southern Methodist University in Dallas) detected the rare phenomenon in a corner of the sky.

Click to enlarge

The gamma ray burst, classified as GRB 140419A by NASA’s Gamma-ray Coordinates Network, came from a supernova that happened 12.1 billion years ago, not long after the Big Bang (estimated to have occurred 13.8 billion years ago).

Gamma ray burst have only recently been observed. Not only are they at extremely high frequencies, but they also have the shortest wavelengths on the electromagnetic spectrum, making them more difficult to detect. It wasn’t until the 90s that we created a telescope with the technology to detect gamma radiation.

The discovery was published in Science Daily earlier this month. You can read the full story here.

NOTE: The feature image is an artist rendering of a gamma burst. It is, however, based on detailed scientific study of the event.

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The Race Is On: Scientists Will Soon Convert Light Into Matter Via Einstein’s Famous Equation

Even if you couldn’t tell me the first thing about physics, you’re probably familiar with the equation E=mc2, Einstein’s famous theory of relativity that hypothesized (based off extensive observations) that light could be converted into matter and vice verse.

Then, in the 1930s, Gregory Breit and John A. Wheeler expanded on Einstein’s theory, arguing that it should be theoretically possible to accomplish this transformation using just two photons.

However, until very recently, it was thought that actually turning light into matter with just two photons was virtually impossible, since it would require colliding the two infinitesimally small light particles (which technically have no mass or volume) with one another, an extremely difficult task.

The breakthrough came in a scholarly article published in the journal Nature Photonics on May 18th which described a groundbreaking new “photon-collider”. The collider works by heating up a golden vacuum tube known as a hohlraum (a hohlraum is basically just a vacuum in which the radiative energy in the walls and the interior of the vacuum are at equilibrium).

As the hohlraum is heated, it begins emitting photons. Once there’s a significant “cloud” of photons in the hohlraum, a high energy laser is shot at another piece of gold. This laser heats up the gold target until it starts shooting gamma rays (photons) at extremely high speeds into the hohlraum.

Diagram of the photon-photon collider. Click to enlarge

If one of these high-energy photons collides with one of the photons in the hohlraum, the two annihilate one another, creating an electron and a positron, the electron’s antimatter equivalent which carries a positive charge (think of it as an anti-electron). Conversely, when an electron and a positron collide at high speeds, they annihilate to form pure energy, in the form of two photons.

Now that the process of colliding photons has been proven to be experimentally possible in the lab, physicists across the globe will be scrambling to be the first to successfully convert light into matter.

Somewhere, Einstein is smiling.

Read more from the L.A. Times here.

Organism Thriving in the Highly Radioactive Chernobyl Nuclear Reactor

In 1986, an explosion at the Chernobyl Nuclear Power Plant in what was then Soviet Ukraine released massive amounts of radiation into the air, which proceeded to spread over much of Europe.

It is generally considered the worst nuclear disaster ever and radiation levels remain very high today; the Ukranian government has estimated that the area will not be habitable for another 20,000 years.

Which is why scientists were shocked when they sent a robot into the reactor and found a black slime-like fungus not only surviving but thriving in the extremely radioactive environment in the heart of Chernobyl.

Upon analyzing samples, the researchers discovered that the fungus is rich in melanin, the very same chemical in human skin. But the craziest part is that the fungus is using the melanin like a plant does chlorophyll, but rather than the UV radiation that plants use from the sun to make energy, the fungus uses all the gamma radiation left behind from the nuclear fallout.

Sample of the fungus (Wangiella dermatitidis)

In lab experiments, researchers found that the fungus grew significantly faster when it was exposed to levels of radiation 500 times greater than normal levels.

These fungi might be on the next shuttle to the space station as well. Since radiation like that leftover at Chernobyl is prevalent in space, astronauts could use the fungi as a limitless food source on long missions or even for colonizing other planets.

To read more, check out the full story here.