
It’s the birthday of Newton, inventor of physics! He wrote daring equations; confounded his critics!
Actually, the date on the calendar when Sir Isaac was born was Christmas Day, 1642 – hence “Newtonmas.” However, England at the time was still on the Julian calendar, while most of the rest of Europe had converted to the Gregorian. Thus, it was ten days behind in its reckoning of the date at that point, and what was Jan. 4th, 1643 for Rome et al. was Dec. 25, 1642 for the Brits. (Also, it gives me an excuse for procrastinating and writing this post ten days late.)
I recently wrote about the Royal Society of London’s 350th anniversary, for which they’ve made available 60 seminal scientific articles from that span to celebrate the occasion. Over the holidays, I killed some time on and in various airplanes and airport lounges reading some of these, and I thought I’d write a little bit about one in particular: Namely, an article that was, so far as I can tell, the first one that Newton ever published, the beginning of his glorious scientific career, and one of the most impressive papers I’ve ever read.
In this 13-page article, the 29-year-old Newton solves several of the most baffling and long-standing mysteries about the nature of light at the time. He did so through a very simple and straightforward application of the scientific method; through clear and simple reasoning, he was able to come up with an impressively large number of explanations. There is nothing complicated in the paper – no partial differential equations or Ricci tensors; it involves shining lights through pieces of glass and some basic algebra and geometry. This is research that a smart 7th grader should be able to conduct for a science fair today.
But part of its genius was Newton’s ability to observe the simple and deduce the profound where no one ever had before; to step back, disregard common wisdom, and tackle things simply and one step at a time. All with no equipment other than two triangular glass prisms and a window shade. From so simple a beginning, he was able to deduce that:
1.) Prisms diffract light, because circular incident beams emerge creating oblong spots.
2.) That a second prism will reverse the refraction of the first and recreate the spot of light.
3.) That these light rays traveled in perfectly straight lines.
4.) That intervening objects, reflections, or transmissions do not affect the color of this light.
5.) That single colors of light from the prism can’t be individually refracted or combined back into white light;
6.) but that the entire range of colors can. Thus, white light is composed of individual rays of different colors, and these colors are differently refractable.
7.) And the inherent color of all objects is due to their selectively reflecting one or more of the individual colors incident on them – i.e., color is not something an object adds to the light, but an inherent property of the light itself.
8.) Also, this is why rainbows exist. Explained here for the first time.
You’d think that’d be enough for one paper for most people, but
9.) he also takes a two-page sidestep to reinvent the frakking telescope! Yeah, this 29-year-old pauses to say, “Oh, by the way, this is why all existing telescopes produce colored rings around objects, and always will. But if you design them this way instead, the problem will go away.” And all large telescopes today still use this design.
10.) Oh, and another thing: There was no known way to make mirrors for this new kind of telescope of sufficient quality to make them better than the lenses, even with the color problems. That’s OK – he just takes some time off from Cambridge, because of the plague, and invents a new way to polish perfect mirrors . . . at the same time he was inventing calculus!
I’m 31, and I can barely understand the calculus this guy invented on a school break (of course, he wasn’t constantly distracted by the latest iPhone app or YouTube video).
To be fair, I should also point out that Isaac Newton was also a giant anti-skeptic: he was a religious fanatic, producing in his lifetime more writings on theology than science; a huge crank, devoting half a century to alchemical and occult pursuits; and a cantankerous old bastard that no one liked, who prossibly died a virgin. (However, to be fair to my being fair, alchemy was largely inseparable from chemistry at the time, theological pursuits were nearly universal among natural philosophers, and being a completely unlikable jerk has no bearing on whether or not you are correct.)
Anyway, happy 367th birthday, Izzy!