As a geophysicist I work with electromagnetism as a part of my everyday job. One of my favorite functions of my profession is taking time out to discuss the physics of electromagnetic (EM) waves. Scientists refer to EM-waves by another name, electromagnetic radiation. The word radiation usually scares the hell out of people therefore making people subjective to any spine-chilling misinformation.
A lucrative example of this is the belief that any amount of EM-radiation causes cancer. Specifically, cell phones, power lines and any other device that emits electromagnetic fields (EMF). These diabolical waves accused of causing all sorts of cancers and many non-descript afflictions. I am writing this to inform you that it is all b.s. Those who make these pseudoscientific claims do not understand the basic physics of EM-radiation.
The physical mechanism that creates EM-radiation (also called EM-waves, EMF, or simply light – different names same monster) are wiggling electric charges. The wiggling generates a self-reinforcing coupled electric and magnetic fields which form the wave and it’s frequency. The frequency is basically a measurement of how fast the charges are wiggled, the faster the wiggling, the higher the frequency. EM-waves are classified based on their frequency, scientists call this classification the electromagnetic spectrum (as seen below)
As you can see from the picture above, we are surrounded by EM waves. Everything from radio waves, to visible light to x-rays are a kind of EM-radiation. The only property separating them is the frequency of the wave.
Quantum physics tells us that all EM-radiation is emitted by photons. The energy of this wiggling photon or EM-radiation is determined by its frequency in the formula below
Energy = hf
where f is frequency and h is Planck’s constant, constant being the key word. Its value does not change no matter the frequency or anything else. Given that h is constant the only variable that can increase or decrease the energy of the EM-radiation is the frequency.
The pseudo-scientists argue that EM-radiation travels into your body, breaks the chemical bonds of your DNA and thus causes cancer. What they do understand is that there is a certain minimal amount of energy needed to break these chemical bonds. This bare minimum amount of energy is 10 electron volts, which is only produced by EM-radiation in the in the Ultra Violet (UV), or above, part of the spectrum. Most of the UV radiation you receive is from the sun. Thankfully our ozone layer absorbs 98.7% of UV radiation. The sunburn you have received this summer is thanks to the 2.3% of the UVA (UV long wave, or black light) that reaches the Earth’s surface. This UVA radiation has been proven time and time again to cause cancer. UVA causes cancer by doing what everyone fears your cell phone is doing, it disrupts your body on the molecular level.
Since UV radiation takes a lot of energy to produce, it is almost never used in commercial applications. UV is also easily dissipated, due to its high energy and small wavelength. It is constantly bumping into things and dying out. That is why your forearms get burned and the covered part of your body does not. UV can’t get past cotton tee’s.
Looking at the diagram above, all of the nasty cancer causing radiation is on the high energy part of the spectrum. The EM-radiation that is emitted by your cell phone, power lines, wi-fi and so on are in the radio wave region of the spectrum. This part of the spectrum is low frequency and therefore low energy. In fact the wavelengths are the size of buildings. Due to their size, they don’t go through your cotton tees they go over it. Currently the only thing on this planet at risk of cancer from cell phones is buildings. Cell phones waves bump into them all the time, and when they do you drop your call. So unless your DNA is the size of a 3 story building, you are in the clear.
To have a real life example of the size of EM waves, go look at your microwave door. You might notice that the clear opening in the door has a screen that has a lot of tiny holes in it. These hole are there to protect you, they keep the microwaves from leaving the microwave. Microwaves operate at a frequency of 2.45 Gigahertz with a wavelength of 12.25 cm ( 4.8 inches). My microwave door window has a screen with holes 1.3 millimeters in diameter (0.050 inch) , which is close to 1/100 of a wavelength of the microwave. When EM-radiation is forced toward openings with a width of 1/100 of its wavelength, the EM-radiation signal passing through the opening is almost undetectable. This is to prevent your face from cooking alongside your burrito.
If you still fear cell phone and other radiation I would like to leave you with this thought: you are constantly bathed in EM-radiation of higher frequency therefore higher energy when you turn on a light bulb, go out in the sunlight. This high frequency menace is called visible light. If you honestly fear EM-radiation, then I suggest taking a night job and getting use to moving about in the dark.
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