Waves in space
As radio waves travel through the universe they pass through other galaxies and our own Milky Way before arriving at our telescopes.
The longer radio wavelengths are slowed down more than the shorter wavelengths, meaning that there is a slight delay in the arrival time of longer wavelengths.
This difference in arrival times is called the dispersion measure and indicates the amount of matter the radio emission has travelled through.
8th November 2018 at 11:19 am
In a recent ABC News article on FRBs, “”A single pulse can contain anywhere from two months to 80 years’ worth of energy from the sun,” said study lead author Ryan Shannon”. What happens to this energy when it hits Earth? How is it preserved/converted? Does it affect the atmosphere? How do we account for the impact and variability of FRBs in our atmospheric, oceanic and terrestrial models? So many questions!
12th November 2018 at 8:37 am
Thanks for your questions! We passed them on the team and this is their response:
“That “80 years of the Sun” amount of energy is the amount released by the FRB at its location in a galaxy far, far away.
As the energy travels (a very long way!) from its source to the Earth it gets weaker – like how when you drop a pebble in a pond, the waves spread out and get weaker.
By the time it arrives at the earth it’s extremely weak. It takes sensitive telescopes to detect it at all! It has a negligible affect on the Earth, or its atmosphere. The amount of energy released by a feather hitting the ground would be billions of times more than we collect with our telescopes to find an FRB.”
We hope this helps!
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3rd November 2018 at 7:19 am