On Saturday I gave a lecture, newly minted, on how Einstein is perceived in the public eye, and on how the numerous misconceptions about Einstein affect the way many non-experts believe that science is actually carried out. Doing the research for the lecture involved, among other things, going back to some original sources I’d never read or had only read a long time ago, looking a bit at Einstein’s notebook from the period around 1912 (online here), and re-reading large portions of a wonderful biography of Einstein that I’m afraid was written by a physicist for physicists — and consequently largely unreadable without technical background, but a must-read for anyone who has that background. I refer here to Abram Pais’s famous biography: “Subtle is the Lord…”, whose title refers to Einstein’s famous quip: “Subtle is the Lord, but malicious He is not.” (You can read about the origin of this quip in Pais’s book.)
I also enjoyed tracking down some videos online of various physical effects that Einstein explained, or that he predicted in advance. These included videos (linked below) of
- Brownian motion, the random motion of relatively large particles in a suspension such as milk, which Einstein explained in 1905 as due to the battering of those particles by molecules of water — an observation from which he pointed out that one could calculate the size of molecules [then still in dispute] using just a basic microscope and a stopwatch [to paraphrase Pais].)
- Particles from cosmic ray showers that, traveling near light speed, are able to reach the earth’s surface only because time dilation (an effect of Einstein’s 1905 special relativity that slows the ticking of clocks attached to fast objects) lengthens the time between when they are created and when they decay (i.e. disintegrate into other particles).
- The photo-electric effect, whereby high-intensity high-frequency light can cause electrons to pop out of a metal, but high-intensity low-frequency light cannot. Einstein proposed in 1905 that this might be explained by light being made from packets of energy, “light-quanta” (nowadays called `photons’): he suggested that high-frequency light is made from high-energy packets and low-frequency light is made from low-energy packets, so that low-frequency light, no matter how intense, cannot give the electrons a sufficient kick to get them out of the metal.
- The absorption of light one quantum (i.e. photon) at a time, in accordance with Einstein’s 1905 suggestion; this video shows these quanta exhibit both wave-like and particle-like properties, which Einstein was considering already around 1909.
- Photos (not videos) showing the bending of light by gravity, which Einstein was considering in the 1911-1915 period; these include both the small effect predicted by Einstein on the apparent positions of stars due to the sun’s gravity (the observation of which made Einstein famous among non-scientists in 1919) [however the veracity of the link has been questioned by a commenter so I've removed it until the situation is clarified] and the much larger effect of gravitational lensing, whereby a large galaxy or cluster of galaxies can dramatically distort the image of a galaxy or other object that lies far behind it.
Most of these videos and photos are on websites that contain more detailed explanations of the physics involved.
Preparing the lecture also reminded me that my memory is pretty bad. Though I read Pais’s book carefully twenty years ago, I had failed to remember a number of key points. I had forgotten, for instance, that the great physicist Planck, among others, recognized the importance of Einstein’s first relativity paper within just a few months of its appearance in 1905; I had forgotten the brevity of Einstein’s second 1905 paper on relativity, despite having read it before; and I forgot that Einstein in 1917 was perhaps the first to recognize, and be disturbed by, the presence of unpredictability in the early quantum theory of light. There were quite a few other lapses. I do hope I won’t forget these facts a second time.
The lecture wasn’t recorded (at least not with my knowledge or permission), but the positive response gave me confidence that I should give the lecture again at a later date… perhaps in the fall sometime.
Thanks again to the New York City Skeptics for the invitation and the organization of the event! And thanks also to everyone who attended; I very much enjoyed the question and answer session.