Killer Cell Phones? Not.

According to a recent report by the World Health Organization (WHO), cell phones are a possible (note their use of the word possible) carcinogen, or cause of cancer. The WHO report states that radio and electromagnetic waves emitted by cell phones are a possible cause of brain cancer.

ELECTROMAGNETIC SPECTRUM

So first we need to know exactly what electromagnetic radiation is. Simple put, electromagnetic radiation is light. Not just visible light, mind you, but also radio waves, ultraviolet rays, infrared light, etc. First we'll need a bit of a description of light itself.
Light functions as either a wave or a particle; but for our current intents and purposes, we can just consider it to be a wave. A wave has two parts, frequency and wavelength, which are inversely proportional to each other according to the following equation f = c / λ.  f stands for the frequency, c is the speed of light in a vacuum (which is constant), and λ represents wavelength. This equation merely shows that as the wavelength gets bigger, frequency will decrease, and vice versa. now it's time for a diagram!

Right, so now some of you might be asking what all those numbers mean. The top section of the diagram is the wavelength/frequency. Frequency is how close together each oscillation is and wavelength is how tall. This picture doesn't show it, but as the frequency gets lower (further apart; I know, that means the number is getting higher. I didn't make up the system, don't judge me.) on the right side, the waves should be getting much taller (higher wavelength).The set of measurements below that wave are the wavelength measurements, in meters. So gamma rays are around 0.0001 nanometers (0.000000000039 inches). The rest of the graph just shows where each of our commonly used wavelengths are located on the electromagnetic spectrum, the bottom bit shows visible light.

ELECTROMAGNETIC RADIATION

Now a short segment on radiation. Radiation is defined by any set of energetic particles, energy, or waves traveling through a medium or space. This includes both light and sound, but usually just refers to visible and non-visible light. There are two types of radiation; ionizing and non-ionizing. Ionizing radiation is the stuff you always hear about on TV, the stuff emitted by nuclear waste that causes cancer. This type of radiation has enough power to remove electrons from cells, which can damage cells and DNA; when DNA is damaged enough like that, it causes cancer. Non-ionizing radiation is any radiation that doesn't have enough energy to change atoms; meaning that it is completely harmless. The only ionizing electromagnetic radiation is found on the short wavelength end of the scale, namely gamma rays, X-rays, and ultraviolet light. 

So now that we have an idea on what electromagnetic radiation is, what's causing it in cell phones, and why is it deadly? Any electronic device emits an electromagnetic field (EMF) as a result of the electrons flowing through it. There's nothing we can do about it short of putting our phones in a Faraday cage (which doesn't allow any electromagnetic signals to pass through it) which would negate the purpose of a cell phone. You may as well keep a rock in your pocket instead. Now that we know the cause, we need to know the effect. According to the WHO, cell phones are emitting an EMF on the microwave scale, same thing your countertop  microwave uses to heat up food. I'm sure most people reading this have been sunburned at least once. This was caused by electromagnetic radiation in the ultraviolet spectrum, emitted by the sun. But has anybody been sunburnt by any regular household light bulb? No, because they don't emit ultraviolet waves and visible light doesn't have a high enough frequency to be harmful. Microwaves(wavelength between 1 meter [3.28 feet] and 1 mm [0.039 inches], about the same as radio waves) and radio waves have an even lower frequency than visible light, they aren't ionizing. In fact, microwaves are technically a type of radio wave. The sun itself emits both microwave and radio radiation. I can't find any numbers on this radiation (it's apparently hard to measure what radiation is coming from the sun and what's coming from other sources), but I'm willing to guess that the giant ball of fire in the sky is emitting more microwaves and radio waves than your relatively puny cell phone.

I started talking about microwaves and bunched radio waves in there without explaining why. Radio waves are the wavelength used by cell phones to communicate with cell towers, satellites, etc. Now, I am no expert on this subject, so if concrete evidence contradicts my work, you should probably ditch that phone of yours. I'm just explaining how the WHO's hypothesis doesn't make scientific sense to me. 

Movie Misconceptions 2

Time for another common movie misconception! Fans of scifi movies and TV series will recall that spacecraft always have their engine running. You might say "Well, yeah Eric, if they stop their engines, they will stop moving." This statement is completely true when considering gravity and air resistance. See, according to Newton's first law, an object won't change velocity until acted upon by another force. This means that an object in motion will not slow down until something forces it to stop. When you roll a ball on the floor, it stops rolling after a few feet, assuming it doesn't hit a wall. This ball slows down and stops due to the forces of gravity and air resistance acting on it. A spaceship is subject to the same laws of physics; however, as I pointed out in the last post, gravity and air resistance aren't present in enough force in space to make a difference.

With this knowledge, we now know that a spacecraft won't slow down or speed up if the pilot shuts off the engines. But what would really happen if the engines are run constantly? The ship would continually accelerate until something, like a planet, forced it to slow down. I personally doubt that this ship will ever reach or surpass the speed of light, but that's another post. 

Movie Misconceptions 1

In many scifi movies, large spaceships are seen as slower and less maneuverable than their smaller counterparts. (Think Star Destroyer vs. Millennium Falcon.) When you really think about it, that doesn't make sense at all. The only time a smaller ship might be more maneuver when one is on-planet; as air resistance and gravity would have less of an effect on the smaller ship. Since there is no atmosphere in space, (that's why they call it 'space'. dur hur...) there isn't any air resistance, which is what makes large aircraft and watercraft slower and less maneuverable. Without gravity and air resistance, a large spacecraft should be just as fast and maneuverable as a small one with a comparable engine. As, according to Newton's first law, a body remains in a state of constant velocity until acted upon by an outside force. In our spaceship example, air resistance and gravity are the outside forces causing the larger vessel to loose speed and maneuverability. Since these forces aren't really present in space, the larger spacecraft will not loose speed or maneuverability. Quite the opposite in fact. A larger vessel can support a larger engine/generator/power supply thing, thus meaning it gains more thrust. Without the outside forces of air resistance and gravity acting against this thrust, the larger spaceship will possess an even greater top speed than the smaller vessel.