과학 [MP3 for IELTS Listening] ABC - Mobile Phone Cooks Egg

[초롱이]

Mobile Phone Cooks Egg
 
Subscribe to the Great Moments in Science Podcast: 
 

It started about a year ago, but really took off over the last few months. My email inbox began filling up with the latest shock-horror story about the dangers of mobile phones. This particular email, and it was always exactly the same, was called "Microwavinganegg". It claimed that if you put a mobile phone near an egg, then the radiation from the mobile phone would actually cook the egg. So the email claimed that the radiation from a phone cooks the proteins in an egg– and then it asked the chilling question, "Imagine what it can do to the proteins in our brains…"

The email came with quite detailed instructions. Place an egg in an egg cup, sandwich it tightly between two mobile phones facing each other, and then get one phone to call the other phone for 65 minutes. It even gave a timetable – nothing much happens for the first 15 minutes, the egg begins to get warm around 25 minutes, the egg is hot to the touch by 45 minutes, and it is actually fully cooked and ready to eat by 65 minutes.

On one hand, the email attachment had no identification as to who wrote it, or what university or school they were attached to, AND it was full of bad grammar, misplaced apostrophes and atrocious punctuation. But on the other hand, it seemed quite reasonable. After all, regular infra-red radiation can cook your toast.

It also seemed ridiculously easy to my 8-year-old daughter Lola and me to prove – or disprove. So we drew up a table on a sheet of paper, on which we noted when we made the phone calls, and the temperature of the egg. Then we made the first of seven 10-minute calls - on our telephone plan, the first 10 minutes of each call are free. By the time we got to 40 minutes, my daughter was bored with the complete lack of any heating of the egg, and gave up colouring-in our result sheet. And by 70 minutes, there was no detectable (to our fingertips, at least) heat change in the egg – and certainly nothing like the heat associated with a cooked egg. And the insides were still runny.

I did it again the next day with an accurate thermometer. After 70 minutes sandwiched tightly between two operating mobile phones, the temperature of the egg hadn't budged by a single degree – and the egg was definitely not cooked.

It was not surprising.

Firstly, consider the power needed to cook an egg. Mobile phones put out a maximum of 2 Watts of peak power in tiny blips. But these little blips last only for a fraction of a second, and then the phone stops transmitting. So when you average the power put out by the phone over a second or more, you get an average power of 0.25 W, one quarter of a watt. But this power level is used only when the phone is at its maximum distance from the base station. When it's close to a base station, the power the phone transmits can drop to as little as two-thousandths of a watt. This is a lot less than the 600-1,000 Watts of your typical microwave oven. If your two mobile phones were transmitting their maximum power, and all of their power went only into the egg, it would take some 40 hours to cook an egg – providing that the egg did not lose any heat into the local environment. In fact, the British TV show, Brainiac, did this experiment with 100 phones – and got absolutely no warming of the egg.

Second, mobile phones do transmit not to each other. Instead, all mobile phones transmit to a base station. So it makes no sense to have the egg between the phones – it's just a psychological thing to scare you.

So how did it all start?

This myth was started by Charlie Ivermee, a 61-year-old archiver at a legal firm in Southhampton in the UK. He has a web page, and writes under the name of Suzzanna Decantworthy, who resides in the fictional village of Wymsey. Charles has a background in electronics – and he 'fessed up to starting this myth. He found the whole concept of "mobile phone fries your brain" really silly, which is why he wrote this send-up story about cooking eggs with your phone. He was more than a little surprised that people actually believed such a silly story.

What amazes me is that people believe a story so easily disproved in one hour by an 8-year-old with one egg and two mobile phones.