Eureka!

By Simon Shapiro

I had a "Eureka" moment last night. It was probably triggered by my recently reading a comment by Isaac Asimov that the most exciting phrase in science is not "Eureka" but "That's funny ...".

Unable to sleep, my mind turned to the apocryphal story of Archimedes getting into a bath and noticing that the water overflowed. Supposedly he realized that this effect would allow him to determine (without destroying it) whether the king's crown was made of pure gold or whether the maker had cheated the king by replacing some gold with silver. All Archimedes had to do was immerse the crown in a full container of water and measure the water that overflowed. That would give him the volume of the crown. Then, by doing the same with a lump of gold which was the same weight as the crown, he would know whether the gold crown had been adulterated with a less dense metal.

Archimedes runs naked into the streets of Syracuse

And, supposedly Archimedes was so excited by this insight that he ran home naked, shouting "Eureka" ("I have found it"). My Eureka moment? The sudden thought that it seemed unlikely that Greek technology of the day would have made it a slam dunk to measure the differences in overflow water between pure gold and adulterated gold.

Even less able to sleep, I got out of bed (not naked) and stumbled (not ran) to my computer. I looked up the densities of gold and silver and calculated what the difference in volume would be if a two pound crown were made of pure gold or 90% gold and 10% silver. It would be 2.25cc - less than half a teaspoon! Maybe not impossible for Archimedes to measure - but definitely not easy. Seems more like a "Maybe I can do this with a lot of careful work" than a "Eureka" moment.

Something else suspicious about the story. It's not such an amazing insight that when you dunk something into water, the water level rises by the volume of the dunked object. (Assuming the object doesn't absorb water - dunking a doughnut doesn't do it). In fact crows are smart enough to use that knowledge to raise the water level in a jar. That's the basis of one of Aesop's fables, which were told about three hundred years before Archimedes was born. Archimedes would have heard those fables, which were written down in his lifetime - the third century BCE.

The Crow and the Pitcher, illustrated by Milo Winter in 1919. The crow drops pebbles into the jar
until the water surface is high enough for him to drink from the jar.

I did some more research.

Archimedes wrote a lot about his discoveries but never mentioned the crown. The "Eureka" story was first written down two hundred years after his death by a Roman writer, Vitruvius.

Others have also been skeptical about Vitruvius' story. 430 years ago, at the age of 22, Galileo writes a short paper called "The Little Balance". He not only writes about his skepticism but he describes how Archimedes most likely would have solved the problem. Galileo describes a hydrostatic scale which could have used to determine the composition of a crown. It's based on Archimedes' insight (not, as far as we know, shared by crows or even chimpanzees) that the weight of water displaced by an object exerts an upward force on the object.

Galileo floats a guess at Archimedes' hydrostatic scale.

The object being measured is on the right. It's balanced initially by the weight, d, on the left. When the object is immersed in water, it "becomes lighter" and the weight d must be moved to position g to balance it. The weight difference (which is the weight of the displaced water) can be read directly off wire coils wrapped from e to f.

And finally I could fall asleep.

Thoughts on WiFi, Science and Science Reporting

Posted by Gillian O’Reilly

Recently, the Ontario English Catholic Teacher's Association called for an end to new WiFi setups in the province's 1,400-plus Catholic schools, saying computers in new schools should be hardwired instead. The union – which represents 45,000 teachers – cites research by the World Health Organization and said the “safety of this technology has not thoroughly been researched and therefore the precautionary principle and prudent avoidance of exposure should be practised.”

Here are two stories on it:

 http://www.theglobeandmail.com/news/technology/tech-news/ontario-catholic-teachers-union-urges-ban-on-classroom-wifi/article2336605/

http://toronto.openfile.ca/blog/curator-blog/curated-news/2012/oecta-releases-policy-wi-fi-schools-complete-alarmism-and-sketch

I must admit that I have a little trouble with the WiFi topic because I know someone whose family seems to have been affected by WiFi (grown child with seizures, a grandparent with other issues) and who is very concerned by it.

I am basically agnostic/skeptic on this issue. The only detailed media I have heard about it was a CBC Sunday Edition program that was not very scientifically presented – lots of personal anecdotes from thoughtful and sincere people who have had dramatic encounters with WiFi, one scientist who has talked a lot about this issue and, it seemed, a lack of probing into the scientific details (more the fault of the journalists than the fault of the people concerned about the issue).

On the opposite side, all I have heard are health bodies who say there is no problem. Any one with a memory knows that there have been lots of times that we've been told something was no problem when in fact it was -- but that's history, not science. Again, no real science reporting on how they arrived at that conclusion.

As someone who comes to science from an arts background, my general approach to science is that "there are more things in heaven and earth than are dreamed of in your philosophy." There are all sorts of new and interesting things being discovered all the time (like a sea sponge that makes a structure of glass! cool, eh?) and scientific thinking changes all the time. The point is to try to be intelligent about it, whether or not one has a science background oneself.

For instance, and to take a dramatic example, it wouldn’t have taken a scientist to ask a few questions to the now-disgraced anti-vaccine campaigner Andrew Wakefield; it would only take a logical, intelligent thinker. How big was your sample, Dr. Wakefield? (Twelve.) Is that a useful sample? (No.) Do you have any conflicts of interest in this matter? (Yes.) You wouldn’t even have to ask, Is it possible you falsified the data? (Yes.) It’s a pity the editors of The Lancet, a peer-reviewed medical journal, didn’t ask these questions before they published his report.

So I'm quite prepared to believe that WiFi is a problem and I'm quite prepared to believe that it isn't – as long as I'm told something about the science behind it. I don't want to be told (like my friend) that if I'm concerned, I should go out and get a tinfoil hat. I don't want to be mollified by an official "there is no problem." And I don’t want people feeding me quotes that they haven’t sourced properly.

I simply want science reporters and institutions like OECTA to do what they are supposed to do – ask the tough, logical, scientifically literate questions these issues demand and present the answers to those questions to me clearly. That way I, and the folks making policy decisions on these topics, can do some intelligent informed thinking, whether we are scientists or not.