(my very long answer -hope it helps!
)
Chris,
I have to say I've never heard of that before. A search on Google seemed to yeild very little info.
However, I think we can apply a little of our own minds to this and logic some of it out. I doubt you will ever find a formal study on the topic.
If we do suspect hoax, then we've got to assume a motive. Although I can't see what motivates anybody to start e-mail/web hoaxes, it seems there are lots of them out there. Whatever gets them going their goal is sure -to frighten or fool as many people as possible into believing something they made up.
These seem to always play on people's emotions and therefore usually involve missing kids, religion, politics, money, something shocking, etc. The nature of e-mail and the web means there is no telling what type of people will be getting the message so the subject has to be somewhat universal. For instance a warning about cell phone solicitors appeals to a lot of people whereas touting the hazards of phonograph needles is not likely to get forwarded.
The note has to sound like uncommon knowledge while at the same time sound believable. A message that says that you are likely to get in a bad accident and die if you drink and drive is not news to anyone but it is believable. On the other hand, to say drinking more than two cups of milk and driving is equally deadly would certainly be surprising, but it simply isn’t believable. So you have to come up with something that is incredible, but plausible. Here is a third: “Drinking Red Bull energy drinks and taking ibuprofen can cause light-headed-ness and even short black-outs so don’t drive if you do this or you could die.” Here you have something that many people would have to at least think twice about. Who really knows what goes into those energy drinks? Maybe energy drinks are OK by themselves, but mixing them could cause problems.
Now we have a situation that is both new and interesting (if it were true) and possible. If you write about three or four paragraphs about this happening to someone you know and even include a picture of a wrecked automobile (which you got from the web), you now have a nice e-mail hoax to send out to the world.
So let’s look again at the elements of the Cactus/radiation situation. Here we have something everyone can relate to; the computer screen. People have questioned radiation from CRTs (cathode ray tubes) for years. My grandmother used to warn me not to sit so close to the TV when I was a kid for this reason. In addition, many people have worn themselves out staring into a computer monitor for too long and probably felt like some sort of radiation has affected them. We also have something that most people are intrigued by, but know little about –a cactus plant. These plants are succulent and spiny. They absorb water so it is not too much of a leap to imagine that they’ll absorb radiation with their thick fleshy tissue. The spines also could play a role in fending off the deadly rays. Certainly many sci-fi movies/shows have “cast” cacti for the part of alien vegetation. So we now have the ingredients of a good hoax.
We must think about how the Electro-magnetic(EM) energy would exit a computer monitor and affect us. It must travel from the emitter to the other side of the glass to make the image we see. As all EM radiation including visible light, ultraviolet, infrared, gamma, x-ray, etc it is either blocked by something directly in its path or it travels through it. This is why the dentist goes in the other room when you get x-rays. The EM radiation travels from the emitter through your head and onto the film. Some is scattered about the room and that is why you have to wear the lead vest. There is no substance known that you could place in the room that would attract the x-rays to it.
Likewise with your computer monitor. The EM radiation is primarily visible light and some infrared. This travels through the glass of your monitor and into your eyes. That is the image you are seeing. There is also no substance you could put in the room would draw the emissions away from your eyes and attract the light to it. You could put something between you and your monitor such as a piece of paper or a sheet of lead and thus block some or all of the emissions headed in your direction.
Now consider the other object in question –the cactus plant. A cactus plant is made up of primarily water, some organic molecules (such as cellulose), and maybe a few other trace chemicals. These substances will indeed block many forms of EM radiation if they are between the emitter and you. Much like you block the EM from hitting the back of your office chair while you are sitting in it. However there is no reason to think that EM radiation that is traveling towards you from your monitor will in turn be pulled into and absorbed by a cactus plant that is sitting next to your monitor. Such a substance does not exist. After all, if it did absorb the electro-magnetic radiation, you would not be able to see anything on your screen because visible light is included in the EM spectrum.
We can therefore conclude that the suggestion is a hoax. We can take that one step further and say the burden of proof falls on those who claim it to be true. After all it should be easy to demonstrate if it is a valid hypothesis.
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