Articles Blog

Can you call a cell phone in the microwave?

Can you call a cell phone in the microwave?

(VOICEOVER): This episode of “Physics Girl” is
supported by Squarespace. Share your passion
with the world. Putting my phone
in the microwave. Do not turn it on. Dianna Cowern. All right. It’s in there. [GASPS] It’s ringing. Oh, definitely ringing. Oh, look at that. This was surprising to me. The microwave let through
a cellular signal. My thinking before I did
any research on the subject is that a microwave should
act like a Faraday cage. The basic idea of
a Faraday cage is that, when an electric field
or some electromagnetic waves like those from a cell
phone hit the enclosure, they cause electrons in the
metal to move and create an electric field to exactly
oppose and to cancel out the external field. So whatever’s inside
feels nothing. I thought that microwave
should act like Faraday cages, keeping signals out and
microwave radiation in when you’re cooking your food. But this one obviously leaks. So I had to try more microwaves. Do you think it’s going to rain? OK, [INAUDIBLE]. I think it will. DIANNA COWERN:
You think it will? And you’re going to call me? [RINGING] Mm. It’s not ringing. It’s ringing. Yeah, so it’s not ringing. Oh my gosh. It’s ringing! How this is happening? Now we have to figure
out why this is. It depends on the microwave. I wanted to know why, but
I was also really curious what part of the
microwave is leaking. DIANNA COWERN
(VOICEOVER): So we first tested what I was sure would
be a good Faraday cage. DIANNA COWERN: Nothing? KYLE: Two rings
and voicemail, so I don’t think it went through. DIANNA COWERN (VOICEOVER): Then
we covered the whole microwave door in aluminum foil. DIANNA COWERN: This
is what happens to my friends’ microwaves
when they ask me to dogsit. [CHUCKLES] It’s not ringing. So it’s leaking somewhere
around the microwave door. So microwave– not a
good radio wave cage. DIANNA COWERN: Microwave. Right. DIANNA COWERN: Right? Those are receiving microwaves. Are they? OK. Time to figure
out what frequency of electromagnetic radiation
cell phones and microwaves are using. That’s what Kyle and
I weren’t sure about. Because if microwaves are
getting in at my phone, is microwave radiation getting
out while I’m cooking my food? That’s what we all
want to know, right? I’m Samy Kamkar. In general, I call
myself a hacker. So you– so this receives
radio frequency signals. This receives and transmits. This device is awesome. It measures and emits
radio frequency signals between 1 megahertz
and 6 gigahertz. Our cell phone and
microwave radiation should be in that range. And we’re using
the gqrx software, which is a spectrum analyzer, to
look at a range of frequencies. Samy first demonstrated
the device to me with a car key fob, which also emits
radio frequency signals. When I actually hold this down,
we can actually see a signal. We see two frequencies. DIANNA COWERN
(VOICEOVER): The numbers show the range of frequencies
you’re looking at. Above that is a live view of
the signals in that range, like these two peaks
from the key fobs. And down below, it records
when you detected signals. DIANNA COWERN: I don’t know
why it’s so cool to see it in graph form, but it is. SAMY KAMKAR: It is so
cool, because, yeah, you know you can finally
visibly see it, right? So you just change
it to 700, which is one of the
cellular frequencies. So we have a phone
call going on. SAMY KAMKAR: Hello,
hello, hello. DIANNA COWERN: And
every time we talk, you can see some of the
signals coming up. Now, what happens
to that signal when we put my phone and the HackRF
detector in a Faraday cage? This is, like, legit. Yeah, yeah, this is like
a legit Faraday cage. There is a match. So if you look closely,
that’s a metal mesh. DIANNA COWERN: All right, I’m
going to put my phone in here, and then I want to close it and
see what happens to the data. So– SAMY KAMKAR: It’s
already way less. DIANNA COWERN: Yeah, nothing. My phone is still on, but it’s
not transmitting anything– SAMY KAMKAR: Oh, interesting. DIANNA COWERN: –with
is interesting. SAMY KAMKAR: So we’re not
seeing it trying to communicate. DIANNA COWERN: Yeah. SAMY KAMKAR: Right? Just radio silence. DIANNA COWERN: Yep,
Faraday cage works. So let’s go up to
2.4, where we know there’s a bunch of [INAUDIBLE]. DIANNA COWERN: Yeah. So we see– we see blips. DIANNA COWERN
(VOICEOVER): And that’s where Wi-Fi is on the spectrum. A common Wi-Fi frequency
is 2.4 gigahertz. So now we’ve seen what happens
to the cell phone signal when you put it in
a real Faraday cage, and we’ve gotten great
measurements of that. It’s time to figure out what
frequency microwave oven radiation is. But first– The phone’s in your microwave. I think the phone call will not
go through, because I believe my microwave is awesome. DIANNA COWERN: Let’s see. Moment of truth. It’s still not ringing. AUTOMATED VOICE: Your
call has been forwarded– SAMY KAMKAR: Yes! DIANNA COWERN: Can we
try one more thing? Because I actually
haven’t tried this yet. On this experiment, I turned
cellular frequencies off, I turned Wi-Fi
on, and I had Samy call me through the
Wi-Fi network on FaceTime to see whether Wi-Fi
signals get through. FaceTiming now. [PHONE RINGING] Oh, look at that. Wow, so 2.4 is still
reaching through my microwave. DIANNA COWERN: Which
is interesting, because Wi-Fi is
closer to microwaves that you use to cook your food. Hmm. Did you hear that? One of the most surprising
things about all of this for me was that Wi-Fi
uses 2.4 gigahertz, and most microwave ovens
use 2.45 gigahertz. In fact, your
microwave oven probably says 2450 megahertz on it. On older microwaves that leaked
a lot more, and we don’t have, I think– DIANNA COWERN: The regulations? Yeah, as many
regulations on that. You would actually find that,
let’s say, older Wi-Fi would– your Wi-Fi would
just go out when you would microwave something. DIANNA COWERN: No way. Checks out. So there’s just one
more thing to try. We’re going to keep the spectrum
on the same 2.4 gigahertz range and see whether we can detect
any microwave oven radiation from outside the microwave. SAMY KAMKAR: Three,
two, one, start. So now I’m going to stop. Stopped. DIANNA COWERN: Yep. SAMY KAMKAR: Definitely. DIANNA COWERN:
Definitely leaking. You can see it right there. Well, there it is. At least this microwave
oven leaks a small amount. So should you be worried? Well, the FDA
regulates microwaves. And they even allow for
a small bit of leakage. And remember, microwave
radiation is not ionizing. So it couldn’t damage
your DNA directly. The risk is of heating
up your tissues, but that’s only with
super-concentrated amounts of microwave radiation. You’re in more danger
of burning yourself on the water you heat
it up in the microwave. So I have some last thoughts
on this whole experience, which was that the result
of the experiment depended on the microwave. But there were some things
I didn’t keep constant, like the age of the
microwave, where the microwave was in
the house, how close it was to a cellular tower. So these things
might have affected the results of the experiment. The other thing
that was interesting is that, with Samy’s microwave,
the cellular frequencies did not get through. But the microwave
frequencies did. Now, this might be
demonstrating a property of Faraday cages, which is that
there can be holes in the cage. But they should be much
smaller than the wavelength of the frequencies
you’re trying to block. So since cellular frequencies
have a longer wavelength than Wi-Fi frequencies,
it’s possible that we were seeing a
hole that was somewhere between the wavelength
of those two signals. Physics works. Happy physics-ing, and
thank you for watching. “Physics Girl” is
supported by Squarespace. If you have an idea
or project you’re itching to show the world–
you should– Squarespace provides tools that help
people showcase their passions with a customizable landing
page, website, or online store. They also offer domains,
hosting, and customer support. Start your trial at Thanks again to Samy Kamkar,
who let me use all of his toys. You can check out his
YouTube challenge. It’s called Applied Hacking. I’ll put the link
in the description. And thank you to
ArcAttack for letting me use the lightning
Faraday cage footage.

100 thoughts on “Can you call a cell phone in the microwave?”

  1. that us for do not turn on…..hmm…oh that right for do not turn on is for look like a hear it is for there phone and is great right?

  2. Both cellular and wifi transmit on multiple frequencies… There are a wide number of standards (3G, LTE, etc) that your phone can try to connect to the local tower and then even within technologies like LTE there are multiple frequency bands.  For instance AT&T 4G HSPA and HSPA+ use 850Mhz(Band 5) and 1900Mhz(Band 2) bands but it all depends on area if they own a license. LTE uses Band 17(700Mhz), Band 5(850Mhz), Band 2(1900Mhz), Band 4(1700/2100Mhz) currently.  Similarly, your home wifi uses 2.4Ghz on the old standard but newer 5G devices transmit/receive on 5Ghz… so your friend's microwave could have been letting that through.   The net is that the faraday cages used by microwaves have holes in them (so you can see the food) and those holes determine the frequencies that they block (wavelength needs to be smaller than those to get through).  Enjoy your show and your enthusiasm.

  3. Not sure if this was mentioned in another comment but it seems particularly difficult to stop microwave oven interference with Wi-Fi if the microwave oven uses Inverter technology (certain GE and Panasonic models). I wonder what particular thing about inverter technology makes it "noisier"? Presumably it's not the design of the door or other parts of the oven enclosure itself, but perhaps the fact that the microwave energy is continuous and adjusted in power level instead of cycling on and off like conventional microwave ovens do.

  4. This is what tortures me everyday in public as a sensitive leukemic. I have to dope myself up to handle being in public because of iPhone addicts. TERRIBLE TRUTH…

  5. 1. Cell phone distance to tower? No consistancy from location to location.
    Wifi was in the house where the cell tower may have been miles away or right near the house for different locations.
    2. Cell phone antenna and receivers are more sensitive then ever. They can pick up insainly small signals.
    3. Digital. Adds even more "sensitivity" to the phone system, allowing even weaker signals to be used.

    4. The amount of leakage is small considering most ovens are 800 to 1000 watts.
    5. Look into db attenuation and power. You will find an amazing fact about the effeciency of doubling your power, or how little of a difference 500 watts to 1000 watts make when compared to the difference between 0.5 watts and 1watt. "Weak" cell signals attenuated 30db are still very readable to a tower that is close.

    6. 2.4 ghz and 2.45 ghz is 50 mhz apart….. take a look at how much and how different 50 mhz can make.

    I really like what you do and the channel you have, however 1st rule of science…know and/or control the variables.

    Lastly…. us crabby old guys have insane knowledge… feel free to ask sometime. May make reasearching easier.

  6. Are you kidding? 2.4Ghz vibrates your DNA to pieces!!! You can most easily see this in sperm which is essentially pure DNA.

  7. I tested this. My flip phone ring, but my friends iPhone did not. The microwave also interferes with Wi-Fi.

  8. OH GOD THIS EXPLAINS A LOT OMG. I used to work somewhere with a walk in freezer and if i had my phone in my pocket it would lose signal when i went in the freezer but come back when I came out. It also blocks wifi signal so if you were trying to get wifi and standing on the opposite side of the freezer from the router you couldn't get signal. Amazing!

  9. It might be worth choosing a microwave oven by putting your phone in it and ringing it while in the store?

  10. At my tech school, our teacher went into a discussion on microwave ovens. Some of the questions from the class were a little surprising. He explained the grid of circle holes in every door. That the size of the holes, and the pattern matter. The holes being just small enough for waves not to fit through. Someone asked a question, and he took it the other way. "What if there was no grid, there?" "Then you wouldn't be able to see your food!" (Meaning it'd have to be solid!)

  11. So this video taught me that my microwave and phone emit sound that's so high I can't even hear it. That's actually weird

  12. Hopefully this is teaching the average person to be less trusting of technologies that we are assured are 100% safe for us, and demand better.

  13. I can detect my microwave oven on my cheap wireless headset. Very weak. must be within 2 feet or so to get anything at all.

  14. A microwave oven is not a Faraday cage because the door seal is non-conductive. Microwaves would leak out through the door seal except that in the door frame there is a profiled strip of aluminium called a quarter wave choke, which absorbs radio waves of a specific wavelength and is designed to absorb the wavelength used by the oven. This means that if the phone in the oven is using the same wavelength it will be blocked (or at least it should be), but if it using a significantly different wavelength it will get through.

  15. The issue may not be between microwaves, it may be the signal strength of the surrounding cell phone towers that your phone is communicating with. To be sure you should gather the different microwaves in the same place, and see if the results are the same.

  16. Physics Girl, Thanks for all your hard work. Love your stuff. Could you or anyone reading this explain why the fact that DNA isn't damaged that there is no damage to our health from microwaves? I have tne following article about the effects of microwave energy on the brain. I am not a scientist and admittedly much of this was over my head, but that which I could understand seemed to be disconcerting regarding our health. I am open to the possibility that this article is misguided, and if it is why is it wrong? Thanks.

  17. One time I was going to heat up chicken in the microwave was still off and it started popping like it was heating up it was on the plate

  18. Im surprised that shes saying that microwave is not harmfull and and just heating our cells. Pff. I have the pdf copy of the 1964 military experiment documentation about the effect of RF and microwave exposure on humans. That ranges from memory loss to dizziness and other negative health effect such as tumors. The list is long. The regulations servs corporate interest….

  19. No sure why folks are surprised. A microwave oven is not RF tight. It has leaky gaps like a hinged door, specific wire mesh, etc…

  20. So I was trying to prove something to my dad then I said something about how if I put my phone in the microwave it wouldn't work but it did and I felt like I lost that argument

  21. My HF 35C HF-Analyzer (800MHz-2700MHz) goes off the chart (above 2000 microwatts/square meter) when turned on "peak" signal with the range on 1999 microwatts/square meter, with my Cuisinart model CMW-100 microwave cooking. And no wonder, (though I knew it spewed out radiation, I didn't know why until tonight), I just found out that the door on my oven is loose even when it is closed! The leak is so bad that I had some time ago put up a faraday cage in my condo, with aluminum foil wrapped around both sides of large pieces of cardboard. This reduces the radiation hazard dramatically! But I still sit several meters (and even more feet) away from the oven when it is cooking. I think it's time I get another microwave.

    This oven, which was supposedly a "refurbished" unit I bought used from an appliance sales and repair shop around last December. A true "refurb" would come in it's original box with the owner's manual. But this had neither. What it DID have was a loose screw in the back that required a special screwdriver I had to buy to tighten it. I believe I had actually paid somebody's past due repair bill. My previous unit was a new one from Sears that sold new (in 2013) for $54. After four years, it would cook EVEN WHEN THE DOOR WAS OPEN, despite the FDA standard to have two "failsafe" latches to make sure that never happens. Needless to say, I scrapped it right away. My point is this: the quality of microwaves has gone downhill since I bought my first one new in 1983, which was still working well in 2006, when I gave it away.

  22. Err how do you see the signal come up when you talk in the phone?? A mobile phone is not AM Amplitude Modulation. It would show a constant signal on the graph as since 2g and up phones are digital. Maybe you should leave Radio to the professionals

  23. I wonder why she hasn't looked into the EMF secondary cancer risks. Direct is obviously not an issue. But secondary is just as bad.
    If I hit a baseball with a bat, the bat has much affect on someone when the ball hits them upside the head.

  24. Great video, although my thoughts about that leakage similar to wifi was the signal frequency interferes with a cellular frequency involved in cellular repair not cell phone cell, by cells in your body that repair genetic damage that can cause things like cancer. Jimmy Gonzalez "Cell Phones Cause Cancer"

  25. Try the dollar bill test. Put a dollar bill half way in and half out close the door see if you can pull it out. Move it around usually it is a place where the seal is not complete. As always fabulous explanations. Thank you.

  26. The main problem with the microwave is that it alters or destroys some nutrients on a molecular level. That type of power does break bonds.

  27. i tried this test a few yrs back and i thought my phone wouldnt work but it did why do we endanger ourselves with pure ignorance

  28. Anyone else think that Samy is kinda a hot nerdy guy.

    Anyway, I always stand back from the microwave as I know the older they get the more leaky they supposedly become.

  29. Cop out at end. There are no safe levels. It is not just heat damages dna and effects cellular changes. Heat is an old thought using SAR to indicate damage. All microwave and WiFi effects cell damages. Go to wifiinschools dot com and read the research

  30. i have an iphone 3gs and my partner has an iphone 5c.
    if i put mine in the microwave and use hers to call it, it rings.
    if i put her phone in the microwave and use mine to call it, it dont ring…. WTF!!

  31. FYI In Europe this are the regulations :
    And second : microwaves can burn very deep and cause huge stress to the whole human body, even death, and for this reason are set those regulations .

  32. Hey, this is very interesting. In my case, I have a microwave in my dorm like 5 feet away from my bed. I heard microwave can interfere with wifi connection. The question, is the microwave going to interfere the signal when it is off? Does it dangerous for me if it was leaking while I spend almost more than 12 hours inside my dorm?

  33. Can you call a cell phone in the microwave?

    Wait! I have a question?
    Is the microwave ON?
    or OFF . . .


  34. The reason that some microwaves allowed the cell signal through, and the wifi, would simply be the signal strength, a wifi signal would have been a LOT stronger than the cell signal.

  35. microwave ovens definitely leak the radiation! I have an rf meter my reading goes from 0.002 u W/cm2 (micro watts per cm squared) to 26.000 u w/cm2 when I turn the (not old) oven on. (meter range is 50mhz-3.5ghz)

  36. it does act like a faraday cage for the specific frequency that the microwave tube operates at, but a cellphone signal is different freq.

  37. Bad video, wrong information.
    Mal vídeo, información incorrecta.

    Microwaves have a frequency of 2450 MHz. The frequencies of mobile networks in Chile are 850Mhz, 900Mhz and 1900Mhz for 2G (calls) and 700Mhz, 850Mhz, 900Mhz, 1900Mhz, and 2600Mhz for 3G and 4G.

    The microwave Faraday cage is designed to block 2450Mhz. Therefore, if a telephone signal could be a part of the 2600MHz of the 4G but the rest of the frequencies infiltrate.

    A non-electromagnetic energy source will become the electromagnetic part. If not, the light that is an EM wave could not come out through the microwave door to see how the food rotates.

    The explanation why sometimes calls and other calls is not that cell phones prioritize the fastest networks and those are the ones that receive the most interference from the faraday cage of the microndas. When the intensity decreases, they automatically search for another network with a better signal and register on the network if there is 2G coverage. There are periods where the phone is not available to receive calls. But it is something to wait or move the microwave and you can call.

    Los microondas tienen una frecuencia de 2450 MHz. Las frecuencias de las redes moviles en Chile son de 850Mhz, 900Mhz y 1900Mhz para el 2G (llamadas) y 700Mhz, 850Mhz, 900Mhz, 1900Mhz, y 2600Mhz para el 3G y 4G.

    La jaula de Faraday del microondas está diseñado para bloquear específicamente los 2450Mhz. Por lo tanto si bloquea una señal telefónica podría ser una parte de los 2600MHz del 4G pero el resto de frecuencias se infiltran.

    Una Jaula de Faraday no bloquea toda radiación electromagnética sino solo parte del espectro para la cual fue diseñada. Sino fuera ese el caso, la luz que es una onda EM no podría salir por las rendijas de la puerta del microondas para ver como gira la comida.

    La explicación al porqué a veces entra llamada y otras no es que los teléfonos celulares priorizan las redes más veloces y esas son las que más interferencia reciben de la jaula de Faraday del microondas. Al bajar la intensidad buscan automáticamente otra red con mejor señal y en que se registre en la red si es que hay cobertura 2G. Hay periodos donde el teléfono no está disponibles para recibir llamadas. Pero es cosa de esperar o mover de lugar el microondas y se podrá llamar.

  38. Wait a minute… So by having a sdr and an antenna tuned on 700Mhz you can spy phone calls??

  39. He's right about WiFi and leaky microwaves. One of my WiFi-connected computers goes off-line when I use my microwave. So far, nothing outside my oven has gotten fried. Except, maybe, my brain.

  40. i did that microwave test with a hack rf with popcorn in microwave. i could see on the spectrum when the corn popped

Leave a Reply

Your email address will not be published. Required fields are marked *