
How we found the source of the mystery signals at Parkes Radio Telescope (2015) - cyberfart
https://theconversation.com/how-we-found-the-source-of-the-mystery-signals-at-the-dish-41523
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ComputerGuru
Does this mean microwaves don't stop quickly enough when opened early?

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ojosilva
It all depends on the microwave oven. The majority of ovens open with a
mechanical lever (in many cases, can be also be opened by hand by grabbing the
edge of the door) which will trigger a sensor that shuts down the emitter
while the door is opening. Depending on how fast the door was opened,
microwaves may still be bouncing around and could leak out.

OTH some ovens, like the more modern builtin cabinet microwaves, have an
electronic button that shuts down the emitter before triggering the door
latch/spring to open.

In any case, the duration and the amount of energy released during the opening
motion vs. emission lag will probably not be enough to significantly harm you
as dielectric processes need to establish a field to polarize molecules that
will heat up as consequence.

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derefr
Not enough to harm _you_ , but how about a nearby device with an antenna?

Would a microwave burst e.g. fry the speaker of a crystal radio (where the
antenna bridges nearly directly to said speaker) which happened to be tuned to
a radio-band frequency for which 2.4GHz is a harmonic?

Or, for regulated products like 2.4GHz wi-fi routers, does FCC “accepts
interference” testing take microwave bursts into account, or are we slowly
degrading some component in them every time we open microwave ovens near them?

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semi-extrinsic
Anecdata, but for 2 years I have had a Chromecast Audio and a cheap Creative
2.1 system about 20cm away from my microwave, which is the type where you can
just open the door to stop it. No problems so far.

Don't microwave ovens in large part depend on standing waves (resonant with
the chamber size) to deliver the power levels they do?

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tristanm
This is a good illustration of the core problem we have in "anomaly detection"
in data science. Often we are presented with a challenge that if solved, would
negate the presence of the challenge itself: We have to look for events that
aren't explained or predicted to exist by our current understanding of the
given system. To find them, we collect all events and evaluate their
likelihood under our best model, taking the least-likely as our "anomalous"
events. Then, once found, we have to explain them. But to explain them
requires that we understand the system well enough to predict the existence of
those events. If we did, we could have produced a better model, and that model
would have rated those events as more likely. So they wouldn't have shown up.
This contradiction seems to be inherent to the whole concept of anomaly
detection.

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whatshisface
It's not a contradiction. The anomalous events tell you to improve your model,
so while your model yesterday was insufficient your model tomorrow will not
be. If you're wondering why the model yesterday is not the best possible
already, it's because you make guesses about what's important and what's not;
guesses which are refined by correcting your model in the presence of
anomalous events.

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tristanm
If you start with a weak model that doesn't contain all the knowledge you have
available, your anomalies will contain many irrelevant or already known
things. If you start with a strong model representing the best current
understanding, then correcting the model is not so straightforward.

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Retric
Suggesting any model that’s not 100% consistent with all known information is
weak clearly misses the point. Models which can be automated in a reasonable
timeframe on limited hardware beat those who can’t.

The goal is to find interesting things in the data, not simply take years of
data and return “everything looks normal.”

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userbinator
_We still don’t know exactly what is causing the FRBs that started this whole
peryton investigation, although we find that they cannot be explained by the
same microwave ovens and many properties of FRBs point towards a genuine
astrophysical origin._

I wouldn't be surprised if those also eventually were found to be caused by
something on this planet.

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cyphar
The strange behavior of FRBs is that they appear to be point sources -- only
some of the "pixels" in the Parkes detectors are saturated when they are
detected. It seems (at least to me) very unlikely that something which looks
like a point source would be emitted from the local area. The way signals are
reflected off the dish[+] would mean that any local source would almost
certainly saturate all the "pixels" (as was the case with "perytons").

It could possibly be an atmospheric effect, but even then I think that might
still be too close (and thus too large of an angular diameter) to the detector
to only saturate one or two "pixels" rather.

[+]: The detector is in the stalk that is above the dish, and signals are
reflected off the dish and converge at the focus which is where the detector
is placed. So any local source is likely to envelop the entire detector unless
it is directly underneath the dish and is a very angle-sensitive effect.

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femto
A bit of trivia: "the support that holds the receiver above an antenna's
reflector" doesn't seem to have a word in the English language. At least one
couldn't be found when it was discussed on the Sydney Wireless mailing list 15
years ago. Is anyone aware of such a word?

At the time I proposed "yongcat", but it doesn't see to have caught on as it
draws a blank on all search engines!

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colechristensen
The source being microwave ovens being stopped by opening the door letting a
short burst of radio signal escape

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amelius
So the signal would appear only around dinner/lunch time, I suppose.

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sslayer
What about second breakfast?

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new4thaccount
I don't think he knows about second breakfast

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SketchySeaBeast
What about elevenses? Luncheon? Afternoon tea? Dinner? Supper? He knows about
them, doesn’t he?

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sizzzzlerz
TFA says that a peryton, a class of astronomical signal, is named for a
mythological beast, a winged elk. After first shuddering over the idea of an
elk flying over one's head, I went to Google to find more about this as I've
never heard of this beast before. Its source appears to be from author Jorge
Borges who claims to have found a reference in an medieval manuscript. There
appears to be no substantiating evidence elsewhere which is why it isn't as
well known as other creatures of mythology.

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psoy
Borges used to deliberately make up medieval sources and reference non-
existent works of literature. It's in his genre, see [1].

[1]
[https://en.wikipedia.org/wiki/Tl%C3%B6n,_Uqbar,_Orbis_Tertiu...](https://en.wikipedia.org/wiki/Tl%C3%B6n,_Uqbar,_Orbis_Tertius)

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dbg31415
* Navy pilots report unexplained flying objects | Hacker News || [https://news.ycombinator.com/item?id=20018535](https://news.ycombinator.com/item?id=20018535)

I saw this as the follow up article on the front page, and it got my hopes up.

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aussieguy1234
This is why you should not open a microwave without stopping it, unless you
want a dose of radiation

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eherot
Radiation which is, in small doses, mostly harmless, since it is of the non-
ionizing variety.

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kahirsch
(2015)

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sctb
Updated. Thank you!

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sudoaza
This is old news i remember this.

