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17-Year-Old Radio Astronomy Mystery Traced Back To Kitchen Microwave
New submitter Bo'Bob'O writes: The BBC reports that the scientists at the Parkes and Bleien Radio Observatories in New South Wales, Australia, have tracked down earth-based signals that had been eluding observation for 17 years. These signals, which came to be called Perytons "occurred only during office hours and predominantly on weekdays." The source, as it turned out, was located right inside the antenna's tower where impatient scientists had been opening the kitchen microwave door before its cycle had finished. As the linked paper concludes, this, and a worn magnetron caused a condition that allowed the microwaves to emit a burst of frequencies not expected by the scientists, only compounding the original mystery.
I'd like to know which brand of microwave lasts 17 years?
Thar she blows! Typo off the starboard bow! Give it the trusty nitpick, er, harpoon...
...and it takes a finite amount of time for the capacitors to discharge and the transformer fields to collapse.
"National Security is the chief cause of national insecurity." - Celine's First Law
I worked at Jodrell Bank (the largest radio telescope in the UK) for a summer almost 10 years ago, and their on-site kitchen microwave was surrounded by a Faraday cage to prevent the microwave from interferring with signals picked up by the telescope.
To imply that astronomers had no idea that the microwave could be responsible is just a lie, this is a well-known problem that was solved a long time ago.
A professor once told the class he was tasked with finding the source of intermittent "garbage" characters emanating from a data entry work-station. After checking and swapping all the hardware, IT staff couldn't find the cause. So he sat to observe the work-station in action. Turns out the data entry lady had large bosoms that occasionally bumped the keyboard.
Table-ized A.I.
I had a friend who was bemoaning how his "crappy" AT&T DSL service would flake out every evening at about the same time, and he'd had techs out to replace his DSL modem twice, re-do the wiring to his house, everything! He asked me whether I was happy with TWC (I wasn't), because he was fed up and was going to switch.
We got talking in general. I asked him whether he'd also done any renovating around his house, no matter what type. He admitted that he'd recently replaced all of his exterior house lights with CFL equivalents, and I asked him whether any were on timers, sensors, etc. He admitted that there was an exterior flood light on a light sensor.
I asked him if that sensor turned on that lamp about the same time of day his DSL service flaked out. His expression dropped. He replaced that one light with an incandescent, and the problem went away.
They did not spend millions of dollars looking for the microwave oven,
Time on a radio telescope and the associated equipment (including supercomputer time) is not free. Perhaps a bit of hyperbole, but not excessive considering the venue of my comment.
and they knew all along that the signal was man-made.
I'll yield on that one. The paper says the properties of the signal "suggested" it was in the near field. It was only TFA (BBC) that says:
Figuring out precisely which item made it is the kind of thing that gets you in the newspapers,
Figuring out that a microwave oven generated microwave signals picked up by a microwave antenna at the same building may make the newspapers in Australia, but in advanced countries it wouldn't. OTH, we do have to own the idea that people in the US don't seem to understand that cell phones use radio waves, so nobody is completely innocent. The difference is that these are radio astronomy scientists and the cell-phone ignoramii are mostly Joe Sixpack and his cousin Bubba types.
Can you begrudge them their 15 minutes of fame?
You think someone becomes famous because they discover the obvious? You ought to read the paper. It's a hoot.
First, they used a communications receiver with a directional antenna that made a full circle every 20 minutes and obtained 0.1 sec of data at any given frequency. That they thought this receiver would observe RFI that lasts for 200ms and occurs rarely (three events during Jan-Mar 2015) is, well, not flattering to their experiment design qualifications.
Then they tested three microwaves at three locations by looking for emissions while heating a cup of water for 10 - 60s. Interestingly, they found perytons during this test. What they couldn't figure out is how the microwave they were testing at the time could have gotten a signal to the antenna -- it was blocked. A real puzzler. Then they found out that they had forgotten their control protocol for the experiment. Someone was using one of the other two microwave ovens while they were testing the third. Basic science: if you want to test object A for causality, you don't allow object B to be used at the same time. Corollary 1: if you're just going to come up with reasons why the observations were impossible, why bother making them in the first place?
Long story short: a facility that needs to avoid RFI at microwave frequencies took no precautions to avoid RFI at microwave frequencies and spent a lot of time (where the Beeb comes up with 17 years I can't determine) trying to figure out where the RFI they were seeing came from, and quite a bit of time analyzing what they knew was RFI so they could distinguish what they already knew was RFI from signals they already know are galactic in origin.
Anyone who knows that radio waves aren't magic and that microwave ovens are called microwave ovens because they use microwave radiation is scratching his head wondering why they didn't just get rid of the microwave ovens 17 years ago and not put 17 years worth of scientific research into galactic radio phenomena in jeopardy. The fact that they now have to defend the observations of FRB as real could have been prevented by one simple rule: no sources of RF on site. That they've publicly admitted they didn't take this obvious, basic preventative measure isn't "fame".