Microwave Definition and 349 Threads

I am a truck driver. I have a 700 watt microwave in my truck that is powered by an inverter. At my house, I have a 1000 Watt microwave that just plugs into a regular wall outlet. I like to eat Campbell's Microwaveable Chili. Campbell's microwaveable chili comes in a can with a plastic lid...

As microwave communication systems send designated frequencies through the atmosphere, are water particles within the path of these systems agitated enough to increase their temperature?

Hello! I have an experimental setup in which I need to send microwaves (MW). I would like to reduce the unwanted scattering of the MW as much as possible and I was wondering what materials are best for this (in vacuum). For example, if I make some holders of metal (e.g. aluminum or steel) I...

I removed the high voltage secondary winding of a microwave oven transformer and replaced it with 9 turns of wire I need 2.1 vac 50 amps. Should I remove the shunts? I have a 100a bridge rectifier I need 3 vdc 50a for about 5 to 7 days. I don't think a MOT is 100% duty cycle so I plan to use...

Variations in the tamperatureo of the CMB are 1 part in 100,00. My understanding is that this was first measured by COBE, But was this value predicted? What were the ranges of estimates for its value before it was measured?

Hi, I am a material engineer and have a question about a formula derivation relative to microwave absorption. I really cannot figure it out after days of trying. This should be simple for a specialist. In this attached paper, how could one derive Eq(10) based on Eq (8) and (9)? Is k_2 in Eq...

I have noticed that every time my microwave is ON, my Wi-Fi connection freezes. It comes back as soon as the microwave stops. Is it normal?

I have tried to subtract the two values of y for the minimum intensities to find half the wavelength but I am really stuck. Any help would be appreciated thanks

I'm getting this type of device in mail, it is a passive microwave signal downconverter that converts a signal of up to 3.5 GHz to something that can be received with an RTL-SDR of upper frequency limit less than 1.5 GHz. Is it expected that I have to put the antenna-received high freq signal...

So this might be long question that requires some literature review but I will try condense it as much as possible such that hopefully I can get some help without the reader having to review the related paper. So I will start off by saying that I am involved in a honours thesis in which I need...

For this problem, The solution is, However, when they found the angle, they did not account for the uncertainty. I guess this is allowed still since the sine of the angle will still be greater than 1, correct? Many thanks!

Microwave auditory effect / Frey effect: https://en.wikipedia.org/wiki/Microwave_auditory_effect Hypothetically, if someone could send "v2k" to a person's brain, how could this v2k be blocked, practically? A tin foil hat? The EMF shielding fabric?

If I understand correctly, by reference say here, the results seem to relate to a survey of the Milky Way. 1. Is the Milky Way a 'closed' system? 2. Whether or not, were the surveys based on data from the visible Universe, or restricted in all or part to the data form 'within' the Milky Way.

The commonly called value of the temperature at recombination is 3000 K. According to this reference the process of recombination can be described by the Saha equation: 3.1. Recombination and the formation of the CMB Recombination happens quickly (i.e., in much less than a Hubble time t ~...

I recently made a repair to the door switches/bracket on our microwave oven (MWO). All is well, but later, after reinstalling a trim piece and checking the fit, I noticed that with the door closed and latched, that there was a bit of play (1/8"?) - I could push the door a bit further closed, and...

I've got no real physics education but I am interested in it from a popular science and layperson level. If anyone is able to help with this thought experiment. My question is, on a given microwave power setting and a fixed duration, is the heat transferred to the contents largely constant...

Hi, A little background before my question: I read that microwave oven frequencies are at 2.45 Ghz, or about a 12cm wavelength. Lately, 5G is using frequencies called millimeter waves, and these frequencies can be as high as 40Ghz. So, linguistically to me, it seems as microwave oven waves...

Hi, I have some questions about cosmic microwave background radiation, CMB, and I thought it's better to ask them together. I have combined all related content for each question to make the question clearer, understandable, and to provide proper context for any person like who stumbles upon...

Hi, The following is my basic understanding of blackbody radiation spectrum. The important sections are in boldface. Source: https://en.wikipedia.org/wiki/Black-body_radiation#Spectrum Question 1: The quote above says that at room temperature (let's say 20 C or 293 K) the emission is in the...

There is no possible measurement, no matter how clever, that can measure the one way speed of light. It is a synchronization convention. In this topic I would like to apply this idea on a specific case. I have a microwave oven with width L. In this oven I have a standing wave. $$E(t,x)=E...

Hi all! I was wondering, Is it possible, given a specific dipolar molecule, to create the perfect oscillating electric field so as to heat it and not, i.e. the water around it? What I'm basically asking is could there exist a specific microwave just for X and not all dipolar molecules without...

That is how much more power would it consume if one was to try and produce the same amount of heating power with just the waveguide holes and no walls, so no reflections?

Suppose we receive a cosmic microwave background (CMB) photon from space. According to the Big Bang model, this photon became free to travel when the universe was about 0.38 million years (Myr) old. At that time, it was about 42 million light years (Mly) away from our location. Because of the...

Hi, Never done much cosmology but reading around I have found several sources saying the early universe (pre roughly 300,000 years) the early universe was full of gamma radiation. Since the universe has expanded this gamma radiation has been red shifted into the microwave region. Other sources...

Hello. I was wondering if anyone could help me understand what just happened. I wrote a message ony mug, then microwaved water in it for coffee. I just noticed that a few letters are now duplicated below the message. It kinda looks like some moisture on the side lifted the ink up and ended up...

I tried to fix this physics problem. But i think I’m using the wrong steps.

Following on from the recent discussion on the gap size in the metal grill covering the door of a microwave oven, I thought up a way to actually enable one to see some of the standing microwave patterns going on in a typical oven . I bought a 20” x 20”cobalt chloride soaked cloth from Amazon...

What is the classical explanation for why the microwaves won't pass through the microwave door?

Hi. I've just read that microwave ovens were invented 75 years ago. The article mentions the following anecdote: Apparently, Percy Spencer discovered the heating effect of microwave radiation when a magnetron nearby melted a chocolate bar in his pocket. Is this story plausible, wouldn't you...

I've been searching for weeks and still with the doubt. I just know scientist look the content of the CMB and with general relativity calculates the expansion rate today that is 73 km/s/Mpc, but nowhere does it say how exactly. What does the contents of the universe have to do with the...

I believe most wireless router uses the same frequency as a microwave oven, yet microwave ovens heats up food while routers do not. If an energy of the light/radiation is only dependent on frequency, how is it that microwaves heats up food while wireless routers do not?

A DI-149 data acquisition module was used to record a microwave oven transformer (MOT) primary voltage and current time histories. The secondary of the MOT was open. The DI-149 analog input specs are: +- 10 volts full scale, 5000 samples per second for each channel (assuming two channels being...

Hi, everyone: I tried to find the PDF or djvu for this book. Unfortunately, it failed to get it. Could you please so kind send me a link if you have? Thanks.

The object you place in the microwave warm up because of the electromagnetic waves. How come the atoms of the air of the microwave do not warm up? Or do they only feel like they haven't warmed up, or do they not absorb the energy as much as the object you place in the microwave?

Hi, I have few questions about cosmic microwave background radiation (CMBD) and trying to find simple answer at a basic level. I really appreciate your help and time! The universe is almost 13.799 billion years old and currently has radius of around 46.5 billion light-years. It is said that...

What is the difference between those horns/waveguides and regular metal pieces with a same geometry? Why the microwave companies sell those parts at hundreds and thousands dollars? Why we cannot buy some metal sheets or pipes on McMaster-Carr with very low price and make some microwave...

So I know it's generally not a good idea, but I wondered what actually is the limiting factor. Does the magnetron heat up much more quickly? - and if so what's the physics going on that's causing it to heat up - is it increased current in the resonant cavities ? Also is it bad for the cathode...

Relative DC permeability of copper is 1. Conductors are considered dispersive and therefore the permeability should change with frequency. Where can I find data or how can I calculate permeability of copper in Ghz frequency range?

Hello! I am a student of the radio engineering faculty and now I am engaged in master's work. The purpose of my work is to find application for Ti3C2 in antenna technology. I found a lot of information from article http://advances.sciencemag.org/content/4/9/eaau0920 But I can't understand how...

The last couple days at work, one of the microwave ovens in the kitchen has been acting strangely. Today it seemed to get potentially dangerous, so I marked it "Out of Order" for now, and would like to figure out if it is hopeless, or if it can be recovered easily. I first noticed a couple...

If my understanding is correct... From Earth the cmb is fairly uniform around us. From a galaxy that is 12 billion light years away, would they also see a uniform distribution of the cmb? to add to that question, would the radiation be less redshifted. From my understanding on why we aren't...

I am working at retrofitting a microwave oven to produce steam for my 3 HP steam engine/generator. I have read estimates of 50-70% efficiency, but I am trying to verify those figures. Can anyone point me in the direction of calculating the efficiency myself?

A microwave transmitter, bouncing the microwaves off a parabolic dish, should have a small amount of acceleration due to the reaction of the microwaves against the dish. Would an arrangement of two dipole antennas, 1/4 wave apart and phase shifted by 90 deg., creating a cardioid pattern...

Photons are point-like particles with no size, but they have different frequencies. Photons with certain frequencies (like microwave photons) can not pass through the holes of the mesh on a microwave oven, so this confuses me. Photons seem to act like they have size at low frequencies. I have...

G'day. Recently we conducted an experiment in the microwave engineering lab where we were tasked to measure power in, what's called, a Directional Coupler. Here you'll find much on it. My concern with the setup is that we took our measurements on a VSWR meter by noting off the db scale. So...

Question of you radar guys.. My 14 year old Panasonic Microwave Oven suffered a magnetron end cap failure it commenced arcing and melted off a corner. I noticed it's not sealed, brand new ones have a hole in the end ... so I'm wondering just what does the endcap do ? I find plenty of...

So I recently picked up 40 of 10.525 GHz Microwave RADAR transmitters: I opened up one out of curiosity and had something like this (image attached) . I noticed some parts of the PCB aren't even connected to anything. How do the different shapes and sizes of the PCB interact with each-other...

Does the operation of a cylindrical microwave cavity resonator as described here, https://en.wikipedia.org/wiki/Microwave_cavity, depend on the speed of light being isotropic along the cylinder axis?

I'm new to PF, I have an engineering background, but am trying to understand how microwave plasmas are generated. I'm trying to work out if a tuned microwave waveguide can create a plasma in a specific point in the waveguide say over 30 seconds as the microwave energy heats up the waveguide thus...

Some fireworks in our microwave from peeling paint got me thinking... If you place a fork inside, arcs will form between the tines. Why? Presumably the EM field is inducing different potentials on each tine, and the pointiness concentrates the field enough to exceed the breakdown voltage there...