In the last couple of weeks, I have a lot of conversations with people about the more esoteric parts of physics. It occurred to me that the majority of them were based on speculative semi-technical papers. These are the sort of articles that anyone with a working knowledge of college math can understand, but present ideas that are so brain-hurting that people feel the need to weigh in on them. I excluded the Einstein-Podolsky-Rosen paper on whether quantum mechanics is complete, for example, because it’s just too technical for this purpose.
Hopefully nobody will jump down my throat if I don’t correctly give precedence in all cases, and hopefully everybody will help me out if there is a particularly outstanding example that I’ve neglected. Finally, me including them should not be mistaken for necessarily advocating them. And now, in chronological order:
- 1935: Erwin Schroedinger’s eponymous cat. Okay, so the paper itself is pretty technical, but you can skip all of that and go down to a couple of short paragraphs in section 5. The basic question is: Can randomness and uncertainty at the quantum affect us at the macro level? QM’s answer: maybe.
- 1957: Hugh Everett’s Many Worlds Interpretation of quantum mechanics. This one’s pretty technical, too, but I can save you the effort of slogging through the equations by explaining it thusly: Everett proposed that the weirdness in quantum mechanics could be explained if there were a myriad of parallel universes which could interfere with our own at the quantum level. At every instant, universes branch off from one another: one universe for one quantum state, another universe for the other. Needless to say, this provided very good fodder for science fiction. One final comment: true or false, Everett never suggested that there was any way we could visit these parallel universes.
- 1960: Freeman Dyson’s description of a “Dyson Sphere,” a hypothetical home for a super-civilization which collects all of the light from its central star.
- 1974: Brandon Carter’s “Anthropic Principle” (click on the “print” button near the bottom to view). Even (hell, especially) among physicists, the idea that our very existence says something profound about the universe is highly taboo. That doesn’t stop people from speculating about it, however.
- 1979: Freemon Dyson’s speculation that as our universe seems slated to expand forever, we can imagine a time in the future when super-descendants of ours engage in individual thoughts spanning eons. More generally, he wants us to take the end of the universe seriously.
- 1997: Rich Gott’s Grim Reckoning, his argument explaining how long Cats, the Berlin Wall, and Humanity could have been expected to last based only on the assumption that you aren’t special.
- 2003: Max Tegmark’s hierarchy of parallel universes. Tegmark certainly didn’t invent the idea of parallel universes, and this isn’t his only version of this idea, but it is a fairly compelling argument about why there might be an identical “you” only 10^10^29m away (or even closer!).
Honorable mention (because you can’t get a free copy online):
- 1961: Frank Drake – The Drake Equation. Paraphrased (wrongly) in the movie version of Contact, Drake provides a means for estimating the number of intelligent species currently living in the Galaxy. This was an extension of Fermi’s paradox, “Where is everybody?” This was originally presented in a talk, and I’ve never seen it written by Drake in paper form.
- 1978: John Wheeler – Delayed Choice Experiment. Basically, this is an adaptation of the classic double slit experiment in which a particle/wave (photon, electron) can be retro-actively forced to behave like a particle by observing it after the fact! I’m not going to do it justice in this limited space, but let me just say that, strange as it seems, Wheeler’s experiment has actually been performed by Vincent Jacques in 2007, and Wheeler was proven correct. The connection between observer and experiment is tricky, indeed.
Again, please let me know if you feel I should insert any of your favorite cocktail party gems.