Moon Clanger


Whistles from a Small Planetoid

Previous Entry Share Next Entry
Boing Boing's Bad Science Day
Moon Clanger
Over on Boing Boing, Cory Doctorow quotes from from a 'HOWTO' page explaining how to boil an egg with two mobile phones. He does refer to this as a 'claim' but I can't help thinking that a little critical reflection might not have gone amiss before repeating this story.

Let's do the elementary science on this.

An medium egg weighs about 50g, and we'll assume that it is mostly water and thus has a specific heat of about 4200 J/kg/K. In other words, it takes 4200 joules of energy to heat up a kg of egg by 1 kelvin (i.e. 1 degree C).

If we start with our egg at room temperature - say 20 deg C - then to boil it we have to increase its temperature by 80 deg C. The energy required to do this for a 50g (0.05kg) egg is:

E(boil) = 80 x 0.05 x 4200 = 16,800 J

This is how much energy we have to get into the egg to raise its temperature to boiling point. Now, one watt of power is one joule per second. So to do this in three minutes (180s) takes a power transfer of 16800/180 = 93W.

In other words, if you can get about 100W into a medium size egg, you will heat it up to boiling point in about three minutes. Except that:

- This assumes complete energy transfer into the egg. For heating it with microwave energy, this assumes that all the energy from the transmitter is going into the egg and that it is all absorbed. A microwave oven tries to achieve this by putting the food to be cooked in a reflective cavity where the only place microwaves can go is into the food. But even if you put an egg right next to an antenna in the open, only part of the energy will go into it - a lot will go the other way, or even through the egg without being absorbed.

- This also assumes that the egg loses no heat as it warms up. This is unrealistic, as it will be radiating away heat (faster as it gets hotter) and being cooled by air convection.

In summary, the idea that 4W worth of mobile phone power could boil an egg in three minutes is complete bollocks. But then a quick look around the web site in question might have suggested that it's not entirely serious.

Even without the detailed physics argument though, a moment's thought should have shown how unlikely this is. An egg is mostly water. Your ear is mostly water. If a mobile phone next to an egg could boil it in three minutes, what would it do to your ear during a typical phone call? (And this is presumably why the article calls for two mobiles, so that you suspect some sort of weird interference effect. This can happen, but it just localises the heating, not enhances it.)

Why do I care enough to even post about this? Because the general lack of science literacy frustrates me, and because the lack of critical thought or fact-checking on Boing Boing is - especially because the site is in other respects so engaging - really quite depressing.

On the other hand, Cory is generally extremely willing to correct himself when he turns out to be dead wrong. Why not email him a link to this post?

I have to confess I was a little bit cranky about this, hence my more-in-frustration-than-anger post. There was a general and a specific reason for this:

- I have been feeling more and more uncomfortable about what I see as 'WikiJournalism' - an apparent assumption that you don't need to validate sources or check facts on blogs, because your readers will do it for you. For a personal blog this may be fine, but I'm not sure how well this view scales to such a widely-read and respected site as Boing Boing.

- In light of this, I was a bit taken aback by Cory's accusation against Andrew Orlowski of a '"ready, fire, aim" approach to critical journalism' in this post, which I'd only just come across via this later one.

I've got a lot of time for Cory, and he's an acknowledged and valuable expert in the digital rights arena. But God, I wish he'd learn to check his facts. You can only fly so far on reputation alone, and I'd hate to see his being abraded away.

All journalism suffers from this, because papers can print rubbish, and no-one reads retractions published a week later. At least with wiki-journalism the refutation is much quicker and better tied to the article. The danger is trying to keep on the breaking wave (hardly an issue with egg boiling, but you know what I mean). Much better to follow days, weeks (or in the case of my reading, years) to allow those legions of critics to correct the misconceptions and thin out the dross.

The problem with ill-informed news is that it sounds more interesting than genuine stuff. Look at the whole area of urban myths. People used to worry that the public believed them as gospel, but the labelling of the genre shows that the public know they are just tall tales, not practical recipes. Look at the Mythbusters programme. Some of what they do is scientific rebuttal of ideas that anyone could do if they just got off their arses, like the magic powers of vodka and coke, but the big drawer is staging the big dangerous stunts that just sound fun. There is some element of public education. in the former, but I suspect the audience really tune in for the big bangs

I watched a Mythbusters recently, first time ever. They wanted to see if you would be safe from bullets if you dive into the water. Obviously not something you can really try at home.

Interestingly, the answer was yes - you are safe, under very little water, even from very very very big guns. (The smaller guns were actually more dangerous).

They were as surprised as I was.

I love Mythbusters. I've just found a source for torrents of the episodes I haven't seen yet, too, and have been pleasantly surprised that the US narration is not as annoying as I'd feared.

I think it's a wonderful series, and particularly loved the episode where they recreated Gerard Hoffnung's Bricklayer story.

However, there was one case where they debunked as a myth something I know to be true. They investigated a claim that you could 'hear' high-energy radio transmissions via your fillings, and decided that it probably wasn't feasible. Well, I can report from personal experience that if you inadvertently stand in the beam of an AR-3D air surveillance radar, even outside the nominal radiation hazard zone, it doesn't take long to realise that the 'zinggggg' you can half-feel, half-hear every ten seconds is perhaps related to the rotation rate of the radar dish!

The myth they tested was more specific than that, but they do do occasional episodes where they re-test things in light of comments from viewers. They say the comments come in via the web site, and that Adam and Jamie really do read their own discussion forum, so maybe you should take it up with them.

So what happened with the barrel of bricks?

It was set up with a rope over a pulley attached to a dummy. The first time it was dropped, it hit the ground and stayed put; the barrel cracked, but was held together by the external hoops and the force of the bricks inside pushing against the sides. So for the second run, the barrel was weakened by removing some of the hoops and a plank was propped up on its side to split the bottom of the barrel as it hit the ground. This time, the barrel did indeed spill all the bricks out and promptly shot off up again, and sure enough whacked the descending dummy on the way past.

I use Digital Distractions, which also has loads of UK classic comedy. A paragon site, except for the chaps's enthusiasm for cooking shows! Its keeping me sane in the US, as I don't need to watch local TV.

I think you get to claim that everyone ought to follow the fact-checking standards that mainstream news media say they follow (we'll leave aside the fact that they actually don't). Or you get to claim that "for a personal blog" it's okay to be more casual. But you don't get to, with any justice, assert that when someone's funky, home-made blog winds up becoming megapopular, somehow they have a different set of obligations, despite the fact that they never asked for those obligations and they never presented that personal blog as some kind of inerrant tribune.

I have a hot button about people who rag on me extra-hard for errors of fact, grammar, or temperament in online conversations, informing me that because of my big-deal position as a major SF book editor I have some obligation to live up to a higher standard of casual conversation which they've dreamed up for me. My news for those people is "piss off." I don't claim to be any more of a paragon than the next fan, and I don't see why the price of accomplishing whatever I've accomplished in my day job should be that I'm no longer allowed to hang out and shoot the breeze like everyone else. So perhaps you can see why I take a somewhat dim view of your attempt to impose a level of advance fact-checking onto Cory's blog which nobody imposes on other personal blogs. It is an important principle of civilization that we are not responsible for what we do in other people's dreams.

And you know, Cory did in fact refer to the egg-boiling thing only as a "claim." You hand-waved this fact away as if it makes no difference, but it makes all the difference.

You raise a very interesting point about at what point, and indeed whether there is a point, at which any form of personal or small-scale effort grows to the level where it somehow starts to acquire some degree of external accountability. This issues seems to be at the heart of Wikipedia's growing pains; some while back it became a de facto authoritative source, irrespective of what its founders or contributors intended.

Now my instinct as a communitarian is to feel that once any enterprise achieves a level of power, influence or popularity it is subject to some wider level of social accountability. But I can equally well see the enormous problems this can cause, and the sheer silliness that would ensue if any effort was made to put this into practice.

[As an example, I recall either watching or reading about a panel on sf publishing where an editor - and if it was you, my apologies for forgetting this - bemoaning the tendency of some unsuccessful writers to complain that his editorial policy should have a formal appeal process. "It does!" he replied - and named one of his main competitors.]

I'll concede that I've been rather harsh here. Boing Boing is as you say basically a personal website, and it's out of order for me to hold Cory to standards he hasn't himself set or sought to have imposed upon him. (I am worried, with my legal head on, that one day he'll say something online that will bring him closer than he might like to English libel laws, but then again that's his business, not mine.

Cory, if you read this, my apologies for misaimed crankiness. I'll go back to bed and try to get out on the right side, this time.

I share your communitarian impulses, but to my mind, if a personal weblog regularly and forthrightly posts corrections to errors of fact, it's done as much as it practically can for the larger community. Weblogs are conversations, not pronouncements from On High; if every post were fact-checked in advance the way the New Yorker supposedly does it, we'd lose at least as much social good as we gained.

I remember that panel. IIRC, the editor in question was the other Nielsen Hayden!

Maybe there's a resonance thing with the two phones? Of course, you want to line them up so that the egg is between the phone and the nearest cell tower. How much is the tower putting out? To both phones? What if you got three phones? Or made them into a pyramid, for extra mystical strength...

I think it was meant to be funny, but was missing that little "its an April Fool" hint. All you technical points are valid, and its obvious that either it won't work, or mobile users would have cooked ears.

I really wouldn't worry about people being deluded by the bad science in such puff stories as this. There are much bigger whoppers being told out there.

It does depend on the mobile. However, no phone you'll buy in the Western world will be able to cause that much harm, however I've seen radiation emmissions tables for some Asian market only phones which give out something like 10 times the radiation that ours do.

You might be able to do something with a seriously broken WCDMA phone, however, the energy calculation remains the same and you'll lose the battery before you do anything serious.

There is now an added correction on the boingboing article describing why this won't work.

"The egg shouldn't be between the phones, it should be between the phone(s) and the tower" shows a pretty poor grasp of how radio works, and she also misses the more significant point Simon made that the original claim couldn't possibly be true even if both phones were to put out 2W continuously and all of it was absorbed by the egg.


Log in