I really really really hope FRBs don't turn out to be as embarrassingly mundane as FMBs.
Canada's new radio telescope, built to explore the early universe, has turned out to be a handy hunter for the mysterious phenomenon called Fast Radio Bursts (FRB). These bursts from outer space were first picked up in 2007 (in data archived since 2001) by Australia's Parkes radio telescope, and only a few dozen have been …
They say FRB's are named for the detection date, but if astronomers start getting lots of them, that will need to be (ahem) updated. Still, it's way cool that the universe still has curve balls to throw at us! I'm old enough to recall when we thought things were starting to settle down. Hah!
And the MSM is already spouting off about aliens.
I think the media are locked into a permanent Silly Season. They might as well report aliens, Bigfoot and bombers on the moon, because that makes just about as much sense as most "real" news. If there's an afterlife Guy Debord must be laughing his head off.
Actually this means 'something small': if an FRB lasts 3ms then whatever made it is no larger than 1,000km across, which is tiny: the Earth's radius is more than 6,000km, so the things that do this are 1/12 the size of Earth or less.
Of course they are 'big' in terms of energy output. I remember reading about people's reactions when they first realised what the inferred power output of quasars were given how small they must be based on the rate at which they vary. That must have been a serious 'oh, fuck' moment for people I think.
if an FRB lasts 3ms then whatever made it is no larger than 1,000km across
I'm curious about how you've arrived at this figure. My understanding is that the mechanism behind FRBs is unknown, nad there are several postulated explanations. Is this making an assumption that they are caused by one of these postulated mechanisms, in which case, which one, and can you give more details?
To appear as a single event, the signal pulse can't last longer than the time it takes for light to travel from one side of it to the other. It takes light 3mS to travel 1000km, so something capable of generating a pulse a short as 3mS cannot be more than 1000km across.
Martin Gregorie's comment explains it very well.
But it's worth reading the history of the discovery of quasars in this regard. Quite early people understood that they must be physically compact because they vary on timescales of tens of hours, so they must be no larger than the Solar system. But the 'stars' associated with them seemed to have absolutely mad spectra. Someone then realised that no, they didn't have mad spectra, they had reasonably ordinary spectra which were hugely redshifted. That left two options: quasars were really far away, or they originated at the bottom of some very deep gravity well. The second doesn't really work: any star that massive will collapse, and people really knew that.
So that left one option: they were very distant. But if they were distant they must be extremely luminous: thousands of times as luminous as normal galaxies. And they must be small because they vary, so this power is coming from something the size of the Solar system, or smaller. There are hundreds of billions of stars in the Milky Way, so a quasar might be emitting a hundred trillion times the power that the Solar system emits, from a similar volume.
I don't know how fast people realised this (this must all be known as it's relatively recent), but this must have been a serious 'oh, fuck' moment: suddenly the universe was a different place. In particular this was one of the points when people really understood that black holes were not just this theoretical toy, because the only thing that explains that kind of power output from that kind of volume (fusion is laughably too weedy) is stuff falling into a black hole.
Astrophysics is the science othe sciences want to be when they grow up.
"Perimeter Institute for Theoretical Physics is an independent research centre in foundational theoretical physics located in Waterloo, Ontario, Canada. It was founded in 1999. The Institute's founding and major benefactor is Canadian entrepreneur and philanthropist Mike Lazaridis."
Anyone remember another company that Mike L started a long time ago??
Research In Motion.
He's a very smart guy.
Biting the hand that feeds IT © 1998–2019