A Blog by Nadia Drake

Rogue Microwave Ovens Are the Culprits Behind Mysterious Radio Signals

Let’s be clear about one thing: Reheating coffee in the microwave is always a poor life choice. But it becomes especially unwise if you’re using a microwave oven near a radio telescope and you’re so eager for that icky, burnt and wholly unsatisfying taste that you prematurely pop the coffee out before the oven’s timer goes off.


You may have just unleashed a small but mighty radio signal that could be detected by a nearby, sensitive radio telescope. If you happen to be reheating your coffee at the Parkes Observatory in Australia, you could be contributing to the growing collection of mysterious radio signals known as perytons. Well, the collection of formerly mysterious radio signals: A study posted to the arXiv on April 9 identified microwave ovens at the Parkes site as the rather mundane source of perytons.

“It was quite surprising that it ended up being microwaves,” says study author Emily Petroff of Australia’s Swinburne University of Technology.

For years, astronomers had been puzzled by these brief but intense bursts of radio waves that in some ways appeared to be coming from deep space. There have been dozens of reported perytons, some dating back to the 1990s, and theories about the signals’ origin included ball lightning, aircraft, and components of the telescopes themselves.

But almost since the beginning, one thing has been clear about perytons: Despite mimicking a deep space signal, they’re produced by something that’s somewhere near Earth. Astronomers knew that perytons were locally grown because the signals simultaneously showed up in multiple viewing fields rather than arriving from a single point, as distant signals do. Just how close to Earth was a mystery until now.

Petroff and her colleagues discovered the source of perytons after they installed a real-time radio interference monitor at the Parkes telescope. In January, the telescope detected three of the signals – and the interference monitor picked up three simultaneous interference signatures. The team recognized the interloping frequencies as possibly belonging to a microwave oven.

When Petroff and her colleagues tested their hypothesis, they found they could create perytons on demand simply by opening the oven door before the timer had dinged.

Why is the impatience over a warming Hot Pocket important? If you open the microwave door before the timer goes off, the thing in the oven that produces microwaves – it’s called a magnetron – hasn’t had a chance to completely shut off. And so, the microwave oven is briefly transmitting radio waves into the open.

“Radio emission escaping from microwave ovens during the magnetron shut-down phase neatly explain all of the observed properties of the peryton signals,” the study authors write. They then identified the offending microwaves as the ones in the staff kitchen and visitors center at the observatory.

Sensitive radio telescopes, like the ones at Parkes, the Arecibo Observatory in Puerto Rico, and the National Radio Astronomy Observatory in Green Bank, West Virginia, can easily detect those rogue microwaves if the telescopes are pointed in the right direction.

“Microwave ovens are a problem for us – and none exist on site. They are prohibited,” says Arecibo director Robert Kerr. Other facilities that don’t ban microwave ovens altogether shield them in enclosures called Faraday cages, which are supposed to prevent detectable radiation from leaking out. In general, scientists try very hard to eliminate any potential source of Earth-based interference from mucking up radio astronomy data – and that means things like cell phones are a no-no near telescopes.

“Alas, radio telescope sites may appear to be occupied by Luddites,” Kerr says. “No microwaves, no cell phones, no wireless routers, no bluetooth printers or headphones, and – more due to funding – often no food.”

The U.S. Town With No Cell Phones or Wi-Fi

So, one of astrophysics’ more exotic mysteries has a surprisingly down-to-Earth solution. But what does this mean about fast radio bursts, perytons’ enigmatic cousins that truly appear to be coming from very, very far away and have no known origin? (A favorite speculation among readers is “aliens.”) Might they also be coming from Earth?

It seems unlikely, Petroff and her colleagues argue. The intricacies of the fast radio burst signals still suggest an extragalactic origin. And there are revealing differences in the time distributions of the two types of signals. As one might expect from a cosmological signal, fast radio bursts tend to show up rather randomly around the clock. But, perhaps unsurprisingly in retrospect, the peryton data show those signals “clustering near the lunchtime hour.”

Aha! A clue, Sherlock.

39 thoughts on “Rogue Microwave Ovens Are the Culprits Behind Mysterious Radio Signals

  1. This observation isn’t at all surprising to me because I predicted it in a meeting with those same astronomers about a month ago. In fact I published the prediction that the Parytons come from microwave ovens in at the Parke site last week at this website:


    We have a vast microwave network all around us. Our cell phones, though not powerful, influence the stronger transmitters and antennas of the cell phone towers. Add to that the many internet hubs and general communication webs.
    All these may have fast transients of largely unreported features. Radio astronomers had best study the transient background in detail, to eliminate false positives in their search for unusual astrophysical events,

    James Benford

    1. 1. Microwave Ovens: Proven To Be Dangerous And Deadly!!!

      2. Microwave Ovens: Remove Them From Your Kitchens!!!

      3. Why You Shouldn’t Be a Part of the 90% Of Americans Who Still Use Microwaves!!!

  2. some luddites may like to live in the radio free area near radio telescopes but a lot of them are just people with some sort of sensitivity to radio waves. Whether this is a real disease or merely a nocebo effect, well thats a different topic

  3. Creo q no solo estos aparatos usados por las personas a diarioausan emisiones q confunden a los astronomos los generadores electricos para soldaduras de CD q llegan a tener altos flujos de potencia podrian administrar ciertos falsos positivos con senales erroneas hay mucho en la tierra q puede crear falsos

  4. if opening the oven door before its shutdown is causing a problem with deep space exploration, can you imagine how bad it is for you to be standing right beside it when you open the door.

  5. Assuming the coffee isn’t bad to begin with, re-heating it in a microwave oven can be a very good idea. You don’t want to boil it. However, there’s no better way to increase the average kinetic energy of the molecules in a cup of coffee than using a microwave oven. You are off the beam on this one.

    (ND: I still say blech. But most of my family would agree with you.)

  6. So our current radio telescope technology isn’t capable of isolating a relative location origin for the signals it picks up? That there was confusion between an earth generated signal and what may stem from “space” is both sad and hilarious.

  7. @Wow Signal?
    Seems like a great question! According to Wiki, one million microwave ovens were sold in the US already in the one year of 1975. Wow was detected in 1977. The difference in frequency (1420 vs 1580) maybe could be explained by changes in microwave oven tech. Maybe the duration of 72 seconds vs 0.1 seconds could be explained by a microwave oven being active with an open door while heating the pizza slice?

    A potential research question is: Will the likely abolishment of microwave ovens at radio telescopes improve the nutritional health of radio astronomers who work at night or in isolated locations? 😀

  8. Fast Radio Bursts could be due to ETs opening their microwave ovens before the timer goes off to get at their space coffee, no?

  9. Little did anybody know that opening the door of the microwave, before the timer completed, would subject the user of a minute small amount of microwave energy. It would seem that microwaves would have a pause button that allowed the user to pause, stir the contents, and restart the microwave without having to reset the timer.

  10. Hm… I’m no scientist, but I think the signal was only recieved once for a period of only 72 seconds.

    It’s possible that somebody put something in a very nearby microwave for just over a minute, but I think that if that was the cause they would have discovered a lot more Wow signals. So I would guess probably not.

  11. There are many facilities that are using microwave energies to heat the atmosphere and lift the ionosphere.HAARP in Alaska and over 2 dozen around the world like it. Numerous towers are being put up all over cities that are meant for military applications, not cell towers. Sadly the advancement of technology is far exceeding the mental capacity of our fellow humans to use it wisely rather than worrying about the harmful effects it has on everyone.

  12. Similarities with fast radio bursts. Hmmm. Does this mean that the first signs of intelligent life on earth might be detected on some far away planet will be someone heating their coffee? Reverse true too?

  13. Please enlighten us as to how re-heating your coffee with a microwave oven is a “poor life choice?” The have been proven safe and do NOT destroy nutrients nearly as much as other cooking methods. If you have no direct answer to this, don’t perpetuate the myth of the dangers and food damages from microwave oven use. There’s to much of this B.S. already out here.

    (ND: Because it tastes gross.)

  14. David, When the door is opened the power is instantly shut off to the magnetron. If there is ANY energy emitted when the door is opened, it is still within the very conservatively accepted levels. Those space receivers are exceptionally sensitive.

  15. The background image of the radio telescope tells the real story, as the interference would come from HAARP emissions. The clouds in the background show HAARP radiation affecting the clouds. Microwave ovens inside of the tea room of the radio telescope could interfere as the standard of microwave ovens are ridiculous now due to the extreme increasing of the safety regulations, which are no longer stringent.

  16. Reminds me of Big Bang episode (Series 3 Episode 01 – The Electric Can Opener Fluctuation) where the guys feed Sheldon’s detector false data from the static caused by turning the electric can opener on and off.

  17. 72 seconds could’ve happened once in 1977 because of a malfunctioning microwave oven, I suggest. Some piece of food simply got stuck in that switch which the door uses to mechanically switch it off when opened. And because of that, the oven was either repaired or discarded, so the signal only happened once. We’re talking about early models here.

    It is only since a few years that radio telescopes have become sensitive enough to detect fast radio bursts, and thus fast food. Earlier the ovens only added to the length of the error bar because fast bursts were averaged out over longer periods of time of real cosmic signals. I wonder which consumer appliances the super sensitive radio interferometer SKA will detect…

    Maybe radio astronomers can sell their data to consumer marketing companies like Proctor & Gamble? Maybe mathematical statisticians can learn how to differ between a cup of coffee and a pizza slice?

    (We really need to get to the far side of the Moon, away from this lunacy)

  18. SETI, the Search for Edible Tasty Indian fastfood, focuses on precisely this same 1420 to 1720 MHz range, the so called water hole. And you can do it @Home!

    Nah, now I’m evil. Radio astronomy is hard. Or not astronomy. And SETI has skillfully discarded all ovens in space signals, even though they at times use the same telescopes which detected these FRB.

  19. > can you imagine how bad it is for you to be standing right beside it when you open the door.

    I can calculate it, and it’s safe.

    A Microwave oven is a resonant cavity. Microwave light bounces around inside it when the oven is on. These bounces don’t last forever. The food (or coffee) absorbs some, and the rest are absorbed electrically into the walls. How many light bounces take to be absorbed is called the Q factor of the cavity. An empty microwave can have a Q factor as high as 10,000. If you put food in the microwave, the Q drops as low as 100.

    When you open the door on the microwave it turns off and stops adding microwave light to the chamber. The light already in the chamber is absorbed incredibly quickly. For a empty microwave oven, this is around 45 microseconds. For a microwave with food in it, it can be as short as 45 nanoseconds.

    I cannot open my microwave in 0.000045 seconds. Yanking the door that hard would rip my fingers off. Opening the door is safe. If you are really worried then push the stop button first.

    There is a fantastic paper about microwave ovens that is pretty easy to understand. It is “Physics of the microwave oven” by Michael Vollmer. The numbers for this comment came from that paper.

    1. Elizabeth Green’s analysis assumes that the voltage on the magnetron turns off instantaneously and then the fields decay. That’s not what happens: voltage doesn’t turn off instantly; it probably takes several AC cycles for it to fall. As it falls, the electron cloud in the magnetron declines in density because the hot cathode which emits the electrons does not cool down instantly. It has to radiate heat away. The combination of these two effects means that you can open the door quickly enough to catch microwaves still being emitted into the oven. What’s more, the frequency of the microwaves depends on the voltage. Since the voltage is declining, the frequency drops as well. This likely explains the frequency decline observed at Parkes. (This is incorrectly called ‘chirping’ which means an increase in frequency, not a decrease.)

      James Benford

  20. Microwave ovens are on earth, not in space, the dish is facing the sky , not the ground, somehow this is not making sense, sounds like a cover-up.

    1. \\Microwave ovens are on earth, not in space, the dish is facing the sky , not the ground, somehow this is not making sense, sounds like a cover-up.\\

      well if astronomers’ radio antennas could not detect any radio signals from the ground, then why do radio antennas have huge areas surrounding them where radio sources like walkie talkies, cellphone towers, wifi routers and even gasoline engines are banned?

  21. Someone invented those incredibly pesky microwave oven alarms that sit and beep continuously if you don’t yank your coffee or tea out immediately. I don’t know why–what’s the emergency? You would only heat it up again. But it doesn’t surprise me that people pull the door open prematurely rather than listen to the beep.

  22. Nadia, I’m with you on this one; no matter how one messes with the settings, a warmed over latte seems to have acquired an alien taste; maybe that’s why it comes up on the radar 🙂

  23. What is the light nature spreading in the universe, which isn’t explains in Maxwell Lorentz equations? In these equations is supposed that light does represent chain perpendicular each other magnetic and electric fields which inducted each other…….that is right, but is it possible these fields to exist and spread in empty or absolute space? This theory suggests that the light can spread in vacuum, which is correct and hence in empty or absolute space, which is wrong, not only because according to USM http://www.kanevuniverse.com such absolute space doesn’t exist, but because of the nature of light spreading according to USM. This nature shows that any light touching with atom’s or nuclei’s matter is in fact dynamically interaction, which proof that to exist any object we have to have dynamically interaction with this object. Let begin with pages 70 to 84 USM http://www.kanevuniverse.com where in summarizing fashion the electrical field is inertial balance in orbital system (see fig.4, fig.5 part I USM) and the magnetic field is mechanical inertial moment of revolving mass, as to take into account that the quantity difference between the gravitational and electrical forces comes from the expansion of the universe (see part II USM). According to spectral analysis in atoms (pages 86 to 98 USM) and spectral analysis in nuclei (pages 151 to 174 USM), quantum stimulation in fact shifted orbital mass: electron in atom and nucleon in nucleus, from low to high orbit which is dynamically force (F=m.a) and therefore the light cannot spread and even exist in empty or absolute space where masses absent (that is related to the Higgs boson as well). But there is one question, if the magnetic moment is inertial mechanical moment of revolving mass, then which mass we should take in to account, the mass of proton or the mass of electron? The answer is both: the mass of electron defined additional mass in balance of orbital system, which is 1800 times or so smaller than the mass of proton which dominated the whole mechanical inertial moment of whole orbital system. So therefore if we accept the equations of special relativity in their known form, we can estimate that the dynamically interaction is approximate 1800 times weaker than the usual mechanical interaction between two massive bodies in strong coil magnetic field for example. If we multiply this coefficient with the time necessary to the light ray to reach this newly existed object, then we can estimate the error of the measured velocity of this object from our position of observation, because of this dynamically interaction. G.Kanev

  24. I’m absolutely agree with the physically correctly statement by Stephen J. Crothers about “black hole” warm, worm or whatever! But I like to examine another issue connected with the time nature and whether in the universe is possible to synchronize the clocks and therefore whether there is possible to exist any worms (channels) of connecting? Let’s begin with this: To apply the special theory of relativity between two objects movement, the velocity between them has to be constant: dV/dt=constant which means that there absent acceleration da=0 which is correct in Einstein relativity. But that is the first weak point: if the acceleration between the two objects is equal to zero, then whether these two object exist each other or don’t? And if the answer is don’t, then how we can measure this velocity between two don’t exist each other objects? Obviously this is the problem of special relativity, because to exist each other the two objects have to dynamically interact, for example if we are one of the objects, to see another the light ray has to reach this object which is field (light) interaction. More over according to USM http://www.kanevuniverse.com in the spaces there is no empty space, which means that always exist dynamically interaction between all objects to be possible to exist each other.
    The second weak point is connected with the velocity equality of special relativity, namely when in equation: u_x=(W_x+V)/(1+(W_x V_x)/C^2 ) the two velocities of two objects are equal between and equal to the velocity of light, then we obtain that u_x is equal to the velocity of light C as well, which means that there no matter whether the coordinate is movable or not (see page 48 USM). But is it possible the two objects to possess velocity of light even they are light rays themselves and by this way to become indistinguishable each other? The answer is no, because the light velocity is different in different mediums (different object have to have different velocities) and that is why we need this:
    The problem of photon comes from this: The empty or absolute space doesn’t exist according to USM http://www.kanevuniverse.com because of the essence of creating the fields (all gravitation, electrostatic-magnetic and nuclear) and their interconnection regarding their quality essence and quantity sizes. So in the general relativity any where the velocity of light in vacuum must to replace with the velocity of light in empty space and because such empty space doesn’t exist, that is the main reason that such velocity can’t be reached. So obviously the photon can has mass in repose equal to zero only in empty space, which doesn’t exist in reality, then all real photons in fact are virtual photons (relativistic photons) which in low velocities, their masses inclined to zero, but they have some masses through interaction with the surrounding matter (the surrounding matter carry partially light ray – experiment of Fizau). This interaction is realizes by the electromagnetic field in accordance with the equations of Maxwell Lorentz and in accordance with the essence of the light ray shown in USM. So let see this:
    What is the time nature on the universe? We physically define the time as a quantity of movement, for example one year is the movement of Earth around the Sun in full orbital cycle. But what exactly is this movement? To clarify this let return to the relativistic quantum mechanics where we choose such measurement units that the constants of Plank, divided by 2π and velocity of light to be equal to 1, i.e. h/2π=c=1 (see page 345 USM http://www.kanevuniverse.com ). So according to the known equation: E=h.γ where γ is the frequency of the wave and E is the energy, we can write that the relativistic “cycle” energy: E=ω, where ω=2π.γ is the angular velocity (frequency). But ω has dimension: [s^(-1) ], which means that the time is converse proportionally to the cycle energy. But what about the next equation: E=N.t where N is the power of some process, it seems like the energy is proportionally to the time, but it isn’t so because if we replace the power: dE/dt=N, we see that the time is again converse proportionally to the “cycle” energy, but the “linear” energy is equal to the work made up in some process: E=A=F.s where (s) is the road which passes the force (F) and in this case it is the length of wave equal to: s=c/ω where c=1, so we can see that actually the time is proportionally to the distances (inside the cycle) as well and that is only about relativistic presentation of the examined functions. That is exactly how it is written here: What is the essence of the energy in the universe itself and from where it comes from and what is its value? From page 96, 97, 98 USM http://www.kanevuniverse.com follows that in the beginning of springing up of Our space the full energy is equal to zero for us. Then with thickening of the micro cosmos and expanding of macro cosmos due to the asymmetry of these coefficients, which depends by our position of observation in this case our living position, we have the illusion that the energy for us is increases, because we are close to the nuclei of the atoms rather than the stars and galaxy. But the macro cosmos expands more rapidly by the same reason, so full energy in our space is again equal to zero. So it is seen that the energy is “one reality in the illusion”, as well as the world itself! See USM http://www.kanevuniverse.com So by this very elegant way (haw has liking to said Einstein himself) is determinates one of the most mysterious physical phenomenon in the universe!
    So let return to the equation of time connection in the special relativity, (see page 47 USM): t^’=t/β;
    t=t^’/β As we can see the two times in movable and in immovable coordinates is fully replicable, then the time interval is equal to: ∆t=(t^’-t)=(t-t^’ ) (which means that the time can’t has vector – representation, or some direction in the space). And the relativistic energy is equal to: E=1/∆t So what will happen if the time interval is equal to zero? The energy will be infinity! But such event is impossible to exist physically, so obviously the time interval cannot be equal to zero!? It means that the velocities of the two coordinates cannot be equal between and equal to the velocity of light, i.e. if that are two light rays. So to avoid this contradiction in the special relativity we need again shown above new definition of light velocity in accordance with the absence of absolutely space. From here appears new question: “whether the simultaneously is really existing in real, but not absolutely space”? The answer is no, exactly because the absolute space doesn’t exist, which means that we always have interacting accelerations between all existing objects in the universe. So how we can synchronize two clocks to begin simultaneously? The answer is that in real, not absolutely space it is impossible! So obviously we can see that the special relativity equations are always approximately, which is physically orderly if we can always estimate the error!
    Of course again follows that the so called “big bang” conception is impossible to occur, because the time cannot be equal to zero in real space and therefore the time cannot begin in this phantasmagoria “big bang” point!
    Finally several words about the well known formula of full energy: E=m.c^2, which again is exact only in absolutely space (where we haven’t accelerations), but not in real space, where the exact formula is: E_m=0,98024mc^2 (see page 50, 51 formula 17, fig.13) USM http://www.kanevuniverse.com where appears the energy of connection in any orbital system, which is: 9,38 [Mev] related to the mass of proton and without the inertia of the revolving mass, which is compare well with the fig.12 page 51. The exact proof of this energy you can see in nuclear spectrum analysis: pages: 151 to 174 USM http://www.kanevuniverse.com G.Kanev

  25. Contrary to popular belief, there are a tremendous number of wifi systems installed in Green Bank, including in the few retail establishments in town.
    Many private homes have wifi now, and they challenge the Observatory to do anything about it.

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