The higher the energy, the higher the frequency. By measuring their frequency, we can convert rays into musical notes.
Gamma ray bursts are some of the most powerful explosions in the universe
. A particularly explosive number back in 2008, the GRB 080916C, was captured by the LAT and is the basis for the musical track. During the brightest part of the explosion, the LAT detected 100s of gamma rays from the extremely-distant explosion. NASA converted the data to music and slowed the rates down by a factor of 5x to hear the individual gamma rays better
. Each was then represented by a different instrument (harp, piano etc) and along with the accompanying animation, illustrate the explosions journey.
“Outside the realm of human vision is an entire electromagnetic spectrum of wonders. Each type of light–from radio waves to gamma-rays–reveals something unique about the universe. Some wavelengths are best for studying black holes; others reveal newborn stars and planets; while others illuminate the earliest years of cosmic history.
NASA has many telescopes “working the wavelengths” up and down the electromagnetic spectrum. One of them, the FermiGamma-Ray Telescope orbiting Earth, has just crossed a new electromagnetic frontier….
“Fermi is picking up crazy-energetic photons,” says Dave Thompson, an astrophysicist at NASA’s Goddard Space Flight Center. “And it’s detecting so many of them we’ve been able to produce the first all-sky map of the very high energy universe.”
“This is what the sky looks like near the very edge of the electromagnetic spectrum, between 10 billion and 100 billion electron volts.”
The light we see with human eyes consists of photons with energies in the range 2 to 3 electron volts. The gamma-rays Fermi detects are billions of times more energetic, from 20 million to more than 300 billion electron volts. These gamma-ray photons are so energetic, they cannot be guided by the mirrors and lenses found in ordinary telescopes. Instead Fermi uses a sensor that is more like a Geiger counter than a telescope. If we could wear Fermi’s gamma ray “glasses,” we’d witness powerful bullets of energy – individual gamma rays – from cosmic phenomena such as supermassive black holes and hypernova explosions. The sky would be a frenzy of activity.
Before Fermi was launched in June 2008, there were only four known celestial sources of photons in this energy range. “In 3 years Fermi has found almost 500 more,” says Thompson.
What lies within this new realm?
“Mystery, for one thing,” says Thompson. “About a third of the new sources can’t be clearly linked to any of the known types of objects that produce gamma rays. We have no idea what they are.”
The rest have one thing in common: prodigious energy.
“Among them are super massive black holes called blazars; the seething remnants of supernova explosions; and rapidly rotating neutron stars called pulsars.”
And some of the gamma rays seem to come from the ‘Fermi bubbles’ – giant structures emanating from the Milky Way‘s center and spanning some 20,000 light years above and below the galactic plane.
Exactly how these bubbles formed is another mystery.
Note that these are generally run by individuals, and not all readings may be accurate. Do not panic because you see a high reading. Someone could be getting invalid readings.
Treat this for information purposes only, do not make safety decisions based upon it.
Today is: 2011-03-18, and the time is 05:16:12 UTC.
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Typical background radiation levels for most of the USA are in the 5 to 28 uR/hr range. Readings can be higher for brief periods of time due to normal variations in radiation levels. They can also be consistently higher for areas at high elevations, or with larger natural deposits of uranium, thorium, radon, etc.
The readings on this page were obtained using one of the Black Cat Systems radiation detectors:
Users of our detectors are welcome to add their site to the map. Contact us at info (at) blackcatsystems (dot) com for details on how.
A geiger counter lets you check the environment and items for radioactivity. You can use to check for the presence of radon on your house or basement, or even use it to go prospecting for uranium or other radioactive minerals. The GM-10 and other members of the geiger counter family can detect radioisotopes such as Polonium 210 which was used to poison Alexander Litvinenko.
A geiger counter works by detecting the ionization produced by a radioactive particle. Each time a particle of radiation is detected, the counter records this event. The number of events recorded over a period of time indicates the amount of radiation present. Often this is done over one minute intervals, resulting in the familiar “counts per minute” or CPM. The higher the CPM, the higher the radiation levels. You can read a more in depth description of how geiger counters work.
Radiation decay is a random event. That means that if the average reading is say 16 CPM, it will not remain a steady 16, but will bounce up and down. This is normal. The standard deviation is the square root of the average value, and the typical maximum range is plus or minus 3 standard deviations.
So, using the above example, the square root of 16 is 4, so the standard deviation is 4. 3 times 4 is 12. So we would expect the readings to be 16 +/- 12, or range from 4 to 28. That is to say, even if the radiation levels are a “constant” 16, the apparent readings of the geiger counter will range between 4 and 28. So if you suddenly see the reading jump from 16 to 25, that does necessarily not mean that the radiation level has increased.
Radioactivity is the emission of energy from the nucleus of certain nuclides or elements. Some naturally occuring radioactive elements include uranium and thorium and radon. A small amount of naturally occuring potassium is even radioactive.
There are three types of radioactive emissions:
Alpha – the least penetrating form of radiation, can be stopped with a piece of paper or a few inches of air. Alpha rays are the nucleus of a helium atom, and are produced by certain radiactive materials such as thorium and uranium.
Beta rays are more penetrating than alpha rays, and can be stopped by a few millimeters of aluminum or other metals. They are very fast moving electrons.
Gamma rays are the most penetrating form of radiation. Depending on their energy, they can travel through up to several inches of steel, and hundreds of feet of air. They are usually produced in conjunction with either alpha or beta rays.