7 Mind Boggling Sci-Fi Thought Experiments

At its best, science fiction is the only genuine consciousness-expanding drug. So said the master, Arthur C. Clarke, who gave us 2001: A Space Odyssey. When science fiction is at its worst, you get Prometheus.

But to really have your mind-boggled by sci-fi, movies are always an inferior choice. It is in novels and short stories that an author can truly embark on glorious flights of imagination and challenge the reader to go with them as they attempt to find a logical answer to the question “What if?”

What if aliens invaded from Mars, asked H. G. Wells? What if a doctor could reanimate life, asked Mary Shelley? What if we created robots that had to obey three strict laws, asked Isaac Asimov?


The best sci-fi isn’t scantily clad women (I’m looking at you again, Ridley Scott) flying around in spaceships and Han Solo shooting Greedo first. The best sci-fi is the product of thought experiments finding rational answers to all the “what ifs?” This list includes some of the most consciousness-expanding of those experiments.

There are spoilers, of course, but I’ve tried to keep them to a minimum.

1. Flatland by Edwin Abbott (1884)

Dubbed “the last original idea” by Jasper Fforde, the main character in Flatland: A Romance of Many Dimensions is a square. And I don’t mean he wasn’t hip, I mean he was literally a square living in a 2-dimensional reality and haunted by dreams of trying to persuade 1-dimensional lines that he exists.

Flatland by Edwin Abbott

Then the Square is visited by a Sphere and the possibility of 3-dimensions awakens his mind to new and dangerous ideas.

Weird and funny, it wasn’t properly appreciated until Einstein got us to start thinking in 4-dimensions almost 40 years later.

2. Liar! By Isaac Asimov (1941)


(i) A robot may not injure a human being or, through inaction, allow a human being to come to harm

(ii) A robot must obey the orders given to it by human beings, except where such orders would conflict with the First Law

(iii) A robot must protect its own existence as long as such protection does not conflict with the First or Second Law

Asimov’s laws of robotics and the stories he wrote based on them are works of sci-fi genius. The ultimate series of thought experiments, Asimov wrote over 30 stories and novels taking his simple rules and finding as many ways as he could of getting round them.


Liar! was one of the first robot stories and tackled the meaning of the word “injure” in the first law. The assumption is that it refers to physical injury, but what if a robot could sense and understand human feelings? What if it knew that telling someone the truth would cause them an emotional injury? Painfully sad, Liar! is the biggest must-read on this list.

3. A Case of Conscience by James Blish (1953, 1958)

I’ve always wanted to say this: “ontogeny recapitulates phylogeny”. Thirteen whole syllables in three words which make little sense even when taken individually. Put them together and your brain melts trying to decode the meaning.

A Case of Conscience by James Blish-001

In slightly plainer English, these three words express the theory that the developmental stages of an organism from conception to maturity mirror that organism’s historical evolutionary stages. Phew! This now discredited theory suggests that the human embryo, for example, looks like a fish for a few weeks of its development and later looks like a monkey, each stage resembling one of our distant evolutionary ancestors.

A Case of Conscience by James Blish-002

A Case of Conscience explores humanity’s first contact with a race of aliens which develop through their phylogenetic stages after birth, giving an unavoidably obvious account of their evolutionary origins. The Catholic priest in the party views this as a slap in the face to God’s creation and condemns the entire species as heretical.

Expanded from its 1953 short story to a slightly disappointing novel in 1958, A Case of Conscience nevertheless remains a challenging read.

4. Ubik by Philip K. Dick (1969)

How to choose one book for this list from the man who admitted to spending most of his writing career on speed? While A Scanner Darkly is one of the great books about the dangers of drug-addiction, Ubik‘s nightmarish world leaves indelible images of a really bad trip.

Ubik by Philip K Dick

At the centre of the story is the question of what happens to people who are in suspended animation, or perhaps even just on life-support. What do their minds do and where does their consciousness go when it doesn’t have a body to keep it occupied?

Not for the faint of heart or for anyone who fancies sleeping soundly ever again.

5. Timelike Infinity by Stephen Baxter (1992)

None of Baxter’s books are an easy read, but Timelike Infinity takes the cake with its subplot featuring “The Friends of Wigner”.

Timelike Infinity by Stephen Baxter-001

In reality, Eugene Wigner was a Hungarian physicist who extended the Schrödinger’s Cat thought experiment (see 4 Weird Facts About Quantum Physics). Wigner imagined that he had a friend who actually put his cat into a booby-trapped box and then opened the box to see whether it was alive or dead. The question was: did the cat’s fate become reality when the friend opened the box or only after the friend telephoned Wigner to tell him the results of the experiment? Who makes the final measurement?

Timelike Infinity by Stephen Baxter-002

In Baxter’s twisted imaginings, The Friends of Wigner believe that there is some Ultimate Observer who, at the end of time, will look back at the whole of history and decide which version it likes the best. It will decide which cats live and which ones die and it is the duty of every species to make sure their history stands out and will be picked.

And that’s before we’ve got to wormholes and time travel and tachyon versions of superior alien intelligences turning people into immortal quantum wave-functions so they can fulfil their destiny of helping humanity to escape a dying universe…

6. Luminous by Greg Egan (1995)

Greg Egan writes books about advanced mathematics and quantum ontology. Surprisingly, there are people who will read that sort of thing.

Luminous by Greg Egan

Luminous is a tongue-in-cheek short story that tells of a conflict between two different universes with incompatible systems of mathematics. This may not sound like much of problem until you realise that a misplaced 1+1=5 could destroy the entire universe!

Though not to everyone’s taste, it was popular enough that Egan wrote a sequel, Dark Integers, in 2007.

7. Honourable Mentions

Just enough space to mention a few books that didn’t quite make it onto the full list.

Honourable Mentions-001

First up there’s the telepathic policeman in The Demolished Man by Alfred Bester. Of course he knows whodunit, but how does he prove it?

Honourable Mentions-002

None of Kurt Vonnegut’s books make much sense, but The Sirens of Titan has the advantage that it features a chronosynclastic infundibulum. Yes, yes it does.

Honourable Mentions-003

In Tau Zero, Poul Anderson tells us what happens when a damaged spaceship has to keep on accelerating closer and closer to the speed of light.

Honourable Mentions-004

Ursula Le Guin is a master of poetic imagery but, in The Lathe Of Heaven, an offhand mention of distant elephants screaming in fear stands out in my memory. It’s also about a man whose dreams become reality.

Honourable Mentions-005

American Gods by Neil Gaiman takes an old idea (that Gods only exist because we believe in and worship them) to new levels with the invention of modern American-made Gods of the TV and the Internet.

All hail the all-powerful Internet!

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