Posted on 12/28/2016 6:25:39 PM PST by Steely Tom
Who doesn't love a good mystery story? What happens when that story is 5 milliseconds long and comes from a place millions of light-years away?
This episode of _Conversations with an Astrophysicist_ Dr. +Katie Mack and +Scott Lewis dig into the mysterious *Fast Radio Bursts* that have been observed over the past few years. Astronomers are still seeking out the source of what these seemingly random blasts of radio light, but Katie & Scott are on the case to discuss what we know, and hopefully narrow it down a bit.
Even though it is almost two years old, it gives a lot of background about FRBs; they are explained here on a pretty technical level, but those with some knowledge of physics and astronomy will find it easy to follow.
For some reason, the main hosts of this video do not mention their guest, Dr. Emily Petroff, who comes across as very, very knowledgeable, as well as ambitious and hard working. It appears that Dr. Petroff is actually the discoverer of FRBs, which is cool since she looks and sounds about seventeen years old. I'm sure she's actually a bit older than that.
The "hosts" of the video are Scott Lewis, who works for the Space Telescope Science Institute, and Dr. Katherine (Katie) Mack, who is on the faculty of the University of Melbourne, in Australia.
I think this is a lovely video because it sounds exactly like what an episode of Big Bang Theory would be if actual real scientists were sitting around discussing their research.
They explain many things about FRBs. I'll summarize them here, as best I can:
Also interesting to me is that Professors Petroff and Mack are both working in Australia, yet both seem to be from the United States, at least judging by their accents.
- FRBs are real, not artifacts or instrument malfunctions. They've been detected at several radiotelescopes.
- They take the form of extremely rapid, swept-frequency pulses, lasting a few hundred milliseconds, and sweeping at a rates in the range of several megacycles per millisecond.
- They probably originate from sources outside the Milky Way galaxy (aka "our" galaxy).
- FRB sources are very bright and very small (Dr. Petroff opines that they may be as small as a few hundred kilometers across).
- To see such enormous luminosity at such long wavelengths is very interesting, and very challenging to explain. So challenging to explain, in fact, that ascribing them to extraterrestrial technology is actually one of the easier explanations.
- Dr. Petroff actually shows a map of where they think these sources are, with respect to our galaxy.
- They believe the signals are red-shifted, and that the red-shift is about unity, which means that the frequencies observed here on Earth are actually about one-half the frequencies that were emitted at the source.
- Their sources may be magnetars, which gets me excited because I think magnetars are about the spookiest things in the universe; spookier even than black holes.
BTTT
Great summary, and agree on the magnatars.
Ping.
Thank you! Very nice of you to say.
In another thread, the tabloids had aliens billions of light year away trying to contact us. No one has called that fake news yet and it will become the truth to the Art Bell types out there.
http://www.freerepublic.com/focus/f-chat/3508892/posts "Scientists pick up deep space signals which could PROVE aliens are trying to contact humanity
Makes you wonder what the aliens will make of our first
signal?
“LUCY, you got some esplaining to do!”
What about “Oh, the humanity!” ?
Agreed...thanks for taking the time to write such a lucid and concise summary. It sure beats “Auto-Excerpt” ;>)
“Quick” or “brief” would be better than “fast”.
I think they’re created by a strong particle/ray colliding with space junk. That could be ruled out (or in) by a telescope distant from Earth.
Nice to have mysteries.
It would be helpful to have a bit more basic info. What kind of signal? How is it more promising than plain old static? Is it a modulated signal? If not, it’s crap, and only smoke and mirrors, in the quest for another gubmint grant.
From Steely Tom's explanation:
"They take the form of extremely rapid, swept-frequency pulses, lasting a few hundred milliseconds, and sweeping at a rates in the range of several megacycles per millisecond."
Would you consider "swept frequency pulses" to be "modulated" -- or would the sweep have to revere, as well -- to suit you?
reverSe...
Swept or only a tiny segment of emissions from a natural resonator which is spinning?
When and if we receive communication from extra terrestrial life it will be simple. It will not be language. It will be signals that correspond to the make up of atoms. One signal would represent a proton, another signal will represent a neutron and a third will represent an electron. Three different signals could then convey the entire periodic table. There will be no two way communication due to the vast distance. It will simply be a signal that says “we are here, and hope you hear it.”
All advanced civilizations (and we are not advanced but merely in our scientific infancy) will understand atomic structure and that is what they would first convey to show they are sentient beings. They might even have more complex information in the same bursts that we can not detect due to our limited science at this time.
It must be put in perspective of the rate of advances in science. 20,000 years ago we lived in caves, had no written language nor history least it be oral. The man that lived in those caves is genetically almost identical to us today. Today we send men to the moon, fly airplanes at Mach III, have harnessed atomic energy for good and bad. We are but at the very beginning of scientific knowledge and advancement. Imagine a civilization that is 20 million years older than us, or for that matter 70 million as was the age of the dinosaurs.
I suspect space is filled with information from these civilizations if they exist and I think they do. At present we do not have the technology to pick up and decipher the message. I suspect they do not care if we can not as we would be rather uninteresting.
The simplist universal communication would be binary. On, off.
The most popular radar waveform is “linear frequency modulation”, LFM, in which the frequency increases linearly with time. For instance, the frequency of a one millisecond pulse might start at 3200 MHz and finish at 3201 MHz, increasing linearly throughout. This form of modulation gives you the energy of a one millisecond pulse, and the range resolution of a one microsecond pulse.
A signal from three billion light years away was transmitted long, long ago in a galaxy far, far away.
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