Questions tagged [electromagnetism]

Electromagnetism is the branch of science concerned with the forces that occur between electrically charged particles. Use this tag for anything related to electricity, electrical or magnetic fields (such as microwave radiation), etc.

Electro-Magnetic Force
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Electromagnetic force is one of the four fundamental interactions in nature, the other three being the strong interaction, the weak interaction and gravitation.

Electromagnetism is the interaction responsible for practically all the phenomena encountered in daily life, with the exception of gravity. Ordinary matter takes its form as a result of intermolecular forces between individual molecules in matter.

Electrons are bound by electromagnetic wave mechanics into orbitals around atomic nuclei to form atoms, which are the building blocks of molecules. This governs the processes involved in chemistry, which arise from interactions between the electrons of neighbouring atoms, which are in turn determined by the interaction between electromagnetic force and the momentum of the electrons.

James Clerk Maxwell
James Clerk Maxwell

Electromagnetism manifests as both electric fields and magnetic fields. Both fields are simply different aspects of electromagnetism, and hence are intrinsically related. Thus, a changing electric field generates a magnetic field; conversely a changing magnetic field generates an electric field. This effect is called electromagnetic induction, and is the basis of operation for electrical generators, induction motors, and transformers.

Electric fields are the cause of several common phenomena, such as electric potential (such as the voltage of a battery) and electric current (such as the flow of electricity through a flashlight). Magnetic fields are the cause of the force associated with magnets.

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Does a deep freezer use more energy when there is a layer of ice in it?

In light of the potential upcoming power shortages in Belgium, there are a lot of "tips" going around to save power during the cold months. One of them is to thaw out the ice in the deep freezer as, according to one of the power companies, a layer…
ratchet freak
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Do ionizing hair-dryers reduce frizz and drying time?

The new wave in Hair Dryer technology involves marketing benefits based on Ionization. Is there any evidence for any of this though? Conair® Turbo 1875: "Ionic technology helps enhance your hair's natural shine and eliminates frizz for…
Evan Carroll
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Is it illegal to use freely produced hydrogen in place of costly/taxed natural gas and gasoline, or to produce electricity?

updated to include using hydrogen in place of natural gas/gasoline, instead of solely to produce electricity. Note that while this question is somewhat about law, lawyers cost money, and I don't intend on trying this. I find this subject fun to…
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Have any "blockages" ever been observed in the body's EM field?

Crystal healing techniques speak of blockages in the body's electromagnetic field. Electromagnetic fields can usually be measured and observed. So, it seems to me, if a body's electromagnetic field experiences some sort of anomaly, it would be…
blueberryfields
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Did cows in Germany blow up their own barn by farting?

As reported by Reuters, Flatulent cows start fire at German dairy farm - police Methane gas from 90 flatulent cows exploded in a German farm shed on Monday, damaging the roof and injuring one of the animals, police said. High levels of the gas had…
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Do the mountains around this Norwegian valley act like a giant battery?

The Gizmodo website has this article about the UFO-like lights often seen at night in Hessdalen, Norway. The article, titled "Why Mysterious UFO-Like Lights Glow in this Norwegian Valley", says that But that strange bursts of light in the 1980s…
Ronnie
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Subway magnetic fields and laptop hard drives

I just heard a story of a guy who took the subway to transport his company's off-site data back-ups for storage. When the time came for restore after a disaster, the data was corrupt and erased. Being from New York City like I am, this makes me…
Abdu
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Do solar flares and/or geomagnetic storms affect human health?

I've read recently that magnetic storms cause: "heart failure, heart attack, strokes and insomnia". This comes from major newspaper in Lithuania (EU country), here is the link to the article (in Lithuanian). The evidence presented is increase in…
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Does aluminum foil safeguard your credit card from RFID attacks?

Evidence against Does Aluminum Foil Stop Identity Theft? Some sources say that if you actually have an RFID-enabled credit card, aluminum foil does the same job, if not better, than an expensive RFID-blocking sleeve. Other sources say that…
user16959
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Is keyless theft/relay theft a practical threat for vehicles with fob/keyless entry?

Some sites, such as AutoExpress, are warning about a method of breaking into vehicles with keyless entry by capturing and relaying the fob's signal. To quote AutoExpress: The process criminals use to steal a car via keyless theft – also known as…
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Are birds magnetically repelled from high-voltage power lines?

There is a board game from the 90's called 'Mind Trap' in which players must solve tough riddles. One of the riddles goes like this: Sid Shady claimed that he developed a special insulation for high powered electrical lines. He said the insulation…
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Does a mobile plugged in to the charger produce more EM radiation?

I've been hearing this a lot lately, but I can't seem to find anything to disprove (or prove) this claim. I know that a weak signal means the phone produces more radiation (which makes sense), but a lot of people I know constantly talk about how…
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Does "dirty electricity" cause cancer?

Research by Magda Havas, Ph.D., of Trent University in Canada, and U.S. epidemiologist Samuel Milham, M.D., links something called “dirty electricity” with diabetes, malignant melanoma, and cancers of the breast, thyroid, uterus and lung. Dirty…
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Can Dubai make it rain with drones that emit electric charges?

In this post from LinkedIn there is a video of a bunch of rain fall, the post says, Dubai is making it rain (artificially). Scientists in the United Arab Emirates are using electrical charges from drones to zap clouds and manipulate the weather to…
Evan Carroll
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Does the EM drive (electromagnetic drive) work despite the apparent lack of propellant?

In recent headlines, a supposed EM drive, or RF resonant cavity thruster, has been reported to produce thrust despite the apparent lack of any propellant. The drive is purported to work by pushing microwaves through a cone, thereby creating more…
user11643