As time goes by, Science Marches On. Science fiction and science fantasy march along dutifully behind it, picking up whatever the latest "hot" science is and putting it to work as Applied Phlebotinum.
This happy state of affairs lasts only a certain period of time, however. Phlebotinum becomes so last decade when it becomes a cliche, when the real science itself becomes better understood by the general public such that they are more likely to recognize scientific BS when they smell it (and lose their Willing Suspension of Disbelief), or when a new and more intriguing science comes along to take the place of yesterday's phlebotinum.
This can lead to readers of speculative fiction having difficulty reading works written a few decades ago and taking them seriously, because "everyone knows lightning can't do that, and neither can radiation!" They didn't when the work was created, but oh well. That's one of the difficulties you face when you write in this particular genre.
The phenomenon of outdated phlebotinum tends to dog comic book superheroes in particular, at least if they have "science!" as any part of their background. (The magical and alien ones have less trouble with this - for now.) Often as part of a Cosmic Ret Con brought on by a Crisis Crossover, a hero or villain will have his or her origin story updated to use a newer form of phlebotinum if the old one has gotten too stale and moldy for modern audiences. Compare Meta Origin.
Here is a rough timeline of phlebotinum through the ages. The decades are very approximate — earlier isolated examples may exist. Also, the expiration date of various phlebotinum varies widely; some types wear out in a decade while others are still in use thirty years after their introduction. "Soft" sci-fi can get away with using scientific theories that "hard" sci-fi has given up on, and of course a particularly clever writer may decide to dig up some rusty old phlebotinum and put a new shine on it, just for kicks. So isolated examples of old phlebotinum in new bottles show up from time to time even though that particular phlebotinum is well past its sell-by date.
- Early Phlebotinum:
- Mechanical gears and optics (E. T. A. Hoffmann, L. Frank Baum).
- Steam power.
- Electricity, particularly lightning. (Frankenstein's Monster)
- Jules Verne was HUGE on electricity, with some of its uses proposed by him not being realized even today — all-electric ship-sized helicopter anyone?note
- Mesmerism (Edgar Allan Poe's The Facts in the Case of M. Valdemar) Do note that as originally understood (at least by its creator), Mesmerism was not hypnosis, but rather an intricate ritual combining mysticism and electricity to adjust what Mesmer called a person's "animal magnetism", or "life force"; it was not until later that it was realized that all of his electrical apparatus and magnetism theories were pointless, and he had instead accidentally invented hypnosis in the experiments/rituals.
- Vivisection or radical surgery (The Island of Doctor Moreau)
- Radio waves and microwaves
- Eugenics (achieved through selective breeding, not via later laboratory methods). The Nazis pretty much destroyed the popularity of this phlebotinum, though they had help from Social Darwinists in other countries as well. When it resurfaces, it tends to be used by villains or the otherwise morally ambiguous.
- Chemistry Can Do Anything, particularly the pharmaceutical type (Super soldier serum; Dr. Jekyll's formula), although the Silver Age The Flash got his powers by having a bunch of random chemicals spilled all over him at the same time he got hit by lightning — two phlebotina for the price of one! Note that all of the DCU speedsters were later retconned into being powered by the mystical "Speed Force", probably to stop the endless process of phlebotinum decay going on with their "scientific" origins.
- Mathematical formulae (source of the original Johnny Quick's speed, and much of the "magic" in H.P. Lovecraft's works.)
- 1950s-1970s Phlebotinum
- Nuclear energy, including bombs, reactors, and genetic mutation.
- Polarity reversal
- Untapped mental potential.
- Heavily popularized by John W. Campbell, editor of Astounding Science Fiction, which became Analog; he was extremely open-minded towards the paranormal and encouraged his writers to use it—and that meant most important writers in science fiction for several decades.
- Indigo Children also tend to be popular in Japanese works, due to a belief that the atomic bomb blasts of World War II altered the DNA of unborn children and subsequent generations.
- Curved space
- Transistors (predecessor to Nanomachines).
- 1980s-1990s Phlebotinum
- Genetic Engineering and Bio-Augmentation.
- Black Holes
- Chaos Theory
- Eugenics (Made a brief resurgence during this time, with race and IQ being a popular discussion in The '90s. Also,
sociobiologyevolutionary psychology explained everything.) Often retitled as "Evolution in action", so as to try to make it seem "natural" and proper.
- Virtual Reality
- Liquid Crystals (a minor example, but a few Soviet stories from that time feature LC AIs).
- 2000s Phlebotinum:
- Carbon nanotubes
- Isolinear whatever
- Dark matter
- Dark energy
- Quantum mechanics: Listen to a believer in some supernatural phenomenon or other explaining why it "really" is scientifically plausible and the word "quantum" will inevitably come up. Quantum mechanics has the advantage of having been around for 90 years (so everyone has a vague idea of what it is) but still requires advanced mathematics to actually understand. Even then, due to the existence of several interpretations of QM, some of which seem quite weird, but are ultimately derived from the same principles as the "most common" (Copenhagen) interpretation, there is fertile ground for quite a few mysteries.
- "Junk" DNA: 95-99% of our DNA is not currently expressed as proteins. Fiction likes to repurpose it as disk space for a message from ancient alien visitors and the like. In reality what we have found so far is old genes we don't use anymore (no longer being, say, fish), ancient malware (viral retrotransposons), regulatory code that indirectly controls gene expression, "introns" in the middles of genes that make it harder for viral DNA to latch on to them, and information-poor repeating sections we still don't understand but which might be as unglamorous as physical spacers to aid the gene expression pathway.
- Relatedly, epigenetics might go this way (what with the hype about it in the popular press).
- Particle Accelerators. In particular, the LHC.
- Amorphous metals
- Smart materials
For specific examples of the uses of various phlebotina, see:
- Chemistry Can Do Anything
- Genetic Engineering Is the New Nuke
- I Love Nuclear Power
- Lightning Can Do Anything
- Magical Particle Accelerator
- Quantum Mechanics Can Do Anything