Read Never Mind the Bullocks, Here's the Science Online
Authors: Karl Kruszelnicki
(iii)
A E F
is a 108:1 triangle (similar to
A B C
– from pic 4)
(iv)
C D F
is a 108:1 triangle (from pic 2)
(v) Therefore
A E F
and
C D F
are Similar Triangles
These triangles all have the same height:base ratio—about 108:1. So they are all Similar Triangles.
Now remember that when the Moon crosses the Earth’s shadow, the shadow is 2.5 times bigger than the Moon.
The Ratio of the Moon’s Diameter to Earth’s Shadow at that Distance
We measured this back in Step 8, using a simple water clock and our eyes.
And now, in six amazing steps, we put it all together to measure the Distance to the Moon.
1) AEF and CDF are Similar Triangles (from pic 9).
2) EF/DF = 2.5/1 (from pic 10).
3) AF/CF = 2.5/1 (Similar Triangles, from pic 9), therefore AF = 2.5 x CF.
And Finally, the Distance to the Moon
4) Now AC = AF + CF. But AF = 2.5 x CF (from Step 3 above), therefore AC = (2.5 x CF) + CF = 3.5 x CF. By the way, CF is the Distance to the Moon. (We are so close now.)
5) But AC = 1,372,000 km (from pic 7).
SO THEREFORE
6) CF = 1,372,000/3.5 = 392,000 km.
Congratulations! You Measured the Distance to the Moon!
This figure is within a few per cent of the true value!
I am so impressed by the wisdom of those Ancient Greeks. Aren’t you amazed how ‘easy’ it was to measure the distance of the Moon! And it took only 10 minutes out of your life (after the Ancient Greeks did all the hard yards).
References
Gingerich, Owen, ‘Astronomy in the age of Columbus’,
Scientific American
, November 1992, Vol 267, No 5, pp 66-71.
Gingerich, Owen, ‘Review of
Inventing the Flat Earth: Columbus and Modern Historians
by Jeffrey Burton Russell’,
Speculum
, July 1993, Vol 68, No 3, p 885.
Morison, Samuel Eliot,
Admiral of the Ocean Sea: A Life of Christopher Columbus
, Boston: Little Brown, 1942.
O’Neill, Brendan, ‘Do they really think the earth is flat?’, BBC News Magazine, 4 August 2008, http://news.bbc.co.uk/2/hi/uk_news/magazine/7540427.stm.
‘Passing of an eccentric’,
The Skeptic
(Australia), Winter 2001, Vol 21, No 2, p 4.
Russell, Jeffrey Burton,
Inventing the Flat Earth: Columbus and Modern Historians
, New York: Praeger, 1991.
Schlereth, Thomas J., ‘Columbia, Columbus, and Columbianism’,
The Journal of American History
, December 1992, Vol 79, No 3, pp 937-968.
In these politically correct times, you have to be careful with your language. For example, it’s no longer proper to refer to a popularly believed story as an ‘Old Wives’ Tale’—instead you have to call it an ‘Information Item from a Mature Female Domestic Engineer’.
There is a lot of Useful Knowledge in the general population—there’s even a special name for it: ‘The Wisdom of the Commons’. But, some of the Information Items that get passed on can sometimes be wrong.
For example, what of the claim that using lemon juice on battered fish is good for you? This claim suggests that the lemon juice destroys or dissolves the fat or oil in which the batter has been fried. This dissolved fat, with all of its kilojoules, is supposed to vanish magically, leaving you with a slim waist.
That’s a lot to ask from a lemon.
History of the Lemon
Lemons are fairly new to the West, probably coming to us from Arabia or India. They were not known to the ancient Greeks or Romans. They reached Spain and North Africa around 1000-1200 AD. And the Crusaders found lemons growing in Palestine, and began bringing them back to Europe. The lemon
was being commercially grown in the Azores by 1494, with most of them shipped to England.
Today, a commercial lemon tree can deliver about 1,500 lemons each year.
Lemon—Fact and Fable
The juice of the lemon is rich in vitamin C (50-60 mg per 100 g of raw lemon pulp) and quite acidic (pH 2-3, thanks to the citric acid).
However, some people claim that lemons will cure everything from leaking bile ducts and stomach ulcers to smallpox and AIDS, with appendicitis, cardiac palpitations and the common cold thrown in. As always, the ever popular ‘sexual weakness’ is on the list of potentially treatable woes.
And yes, also included on the list is the ability of lemons to magically dissolve away fats.
According to biochemists, when a fat is broken down into its constituents, the ‘ester bonds’ are broken, leaving behind three fatty acids and one glycerol molecule. But to do this, you need either a strong hydroxide, or a strong hot acid. Lemon juice is an acid. It is easy to make your lemon juice hot—by using, for example an oven, a stove top, a microwave or a hot poker. But it is definitely not a strong acid. If you heat it up, you just get a hot, weak acid. Therefore, lemon juice simply cannot break down fats.
Lemon Juice Removes Mercury From Fish!
Nope, it doesn’t.
It has been claimed that lemon juice could remove mercury from fish. It would supposedly release mercury from its bound state, allowing it to be wafted away on the wind once it had been converted to a volatile state. Unfortunately, the research by Dr J.N. Morgan and his colleagues at the National Exposure Research Laboratory of the US Environmental Protection Agency in Ohio showed that this did not happen.
But it would have been nice if it had…
The Zing Phat Info
There’s no denying that lemon juice on fish adds zing, but unfortunately there are no fat-fighting benefits to be had from it.
A typical molecule of fat showing its structure.
Twist in Myth
In fact, if the myth were true, and if lemon juice could break down fats, it would produce more kilojoules, not fewer. It would do this via two pathways—saving your body from having to burn kilojoules, and then enabling more kilojoules in your gut to cross into your bloodstream.
In the first case, under normal conditions, your body has to manufacture the strong internal acids that can break down fats. It takes many kilojoules of your metabolic energy to make these strong acids. These kilojoules are then subtracted from your daily total. But if lemon juice really did break down fats, you wouldn’t have to make these strong stomach acids. If you didn’t burn up extra kilojoules to make these strong stomach acids, you would have these extra kilojoules left over, and they would add to your waistline.
In the second case, just imagine that you have eaten a very fatty meal, and the fat is sitting in your gut. There are times when this fat does not end up on your waist. Suppose that you have eaten so much fat that you get a minor bout of diarrhoea. In this case, some of the fat exits at the other end into the toilet bowl—which means that it did not get into your bloodstream and then onto your waist. The medical name for this is ‘steatorrhoea’—abnormally
fatty stools which leave the fatty residue sometimes found in your toilet bowl.
But if lemon juice breaks down or dissolves the fat in food, the big collections of fat have turned into many smaller collections of fat—with a much larger surface area. The larger surface area means that they are more easily absorbed from the gut. Once you break down fats, the fatty acids and the glycerol do not magically vanish into a black hole, never to be seen again. No, they are still in your body, and are ultimately broken down into kilojoules which, once again, appear on your waistline.
If you really want to get rid of the obvious fat in meat, it’s easy: get a knife and slice off the visible fat. And for fish, most of the fat comes from frying it in batter or crumbs. So get a fork and pick off the fatty batter or crumbs, or simply grill the fish.
Fat, Juicy Lemon Lie
So how did this myth start? Well, nobody really knows. Perhaps it arose because lemon juice has some useful properties. For example, lemon juice can break down the amines in fish into nonvolatile ammonium salts, so neutralising the fishy odour. And, second, the acid in lemon juice can hydrolise the tough fibres of collagen in meat, making it more tender. These are real properties of lemon juice.
Perhaps these real properties of lemon juice gave us this fat juicy lemon lie.
And there’s no denying that a twist of lemon juice gives fish an extra zing. But as far as Fat-Fighting Properties go, someone has been squeezing more than the truth from the humble lemon…
Lemon Juice Fades Tattoos!
Sorry, but this is a lie. Lemon juice does not fade tattoos, even if you throw in some exposure to sunlight.
Dr Chapel and his colleagues tested this on rats that had been shaved and tattooed. Lemon juice plus sunlight made no difference to tattoos that were made with Indian ink.
References
Chapel, J.L., et al., ‘Lemon juice, sunlight, and tattoos’,
International Journal of Dermatology
, September 1983, Vol 22, Issue 7, pp 434-435.
Morgan, J.N., et al., ‘Effects of commonly used cooking practices on total mercury concentration in fish and their impact on exposure assessments’,
Journal of Exposure Analysis and Environmental Epidemiology
, Jan-March 1997, Vol 7, No 1, pp 119-133.
It seems the mere whiff of authority can turn something that is quite obviously silly and lacking credibility into something that people believe.
A good example is the erroneous claim that red (and blond) hair is caused by recessive genes, and will soon vanish from the human gene pool. For the same reason, blue eyes will also supposedly disappear.