Fans of the sci-fi genre have been known to be… picky. Sure, we want our trail mix of starships, androids, cleverly disguised social commentary, “big thought-provoking ideas,” and snappy banter from severely conflicted cyborg characters. We also want, somewhere in the middle, an enormous, spacey McGuffin to keep the plot moving at warp speed. But all that’s a given; That’s the minimum essential goods. What most discerning fans demand is a level of authenticity; We want to know exactly “how” that tractor beam works, “how” that near-light speed engine runs, “how” that police telephone booth is really bigger on the inside. In other words, we want an author who knows what they’re talking about when it comes to the techy stuff—even if that stuff is totally imaginary! And not just Wookiepedia-level knowledge, either. Basically we want a genuine physicist like Michio Kaku whispering into the writer’s ear, telling them how all this stuff could, theoretically, work. Hard sci-fi answers these questions with its emphasis on technical accuracy and scientific detail.

The Stars My Destination from Alfred Bester launches with its hard luck protagonist, Gully Foyle, trapped and adrift on a dead vessel named Nomad. Foyle’s not too bright, but he’s able to survive the attack which crippled the ship, then cling to life for half a year before his rescue. Unfortunately, Foyle’s life doesn’t get any better when he’s “rescued” (aka kidnapped) by a “cargo cult” which tattoos his whole face—with tiger stripes! Escaping the cult, he’s taken for interrogation by the powerful Presteign, the Nomad’s rightful owner… who very much wants to learn what happened to the ship’s precious “PyrE” cargo (which is needed to turn the tide in an ongoing war effort). Bester’s grungy, pulp speculative fiction tale of revenge has been lauded for its early use of such concepts of psionics and teleportation (“jaunting,” as it is called—a term Stephen King borrowed for his own short story, “The Jaunt”). The novel also explores real life phenomena such as synesthesia, a very rare condition by which a person’s sensory experience may stimulate a normally unrelated sense or cognition (such as a person who sees numbers as colors). Not the first hard sci-fi novel, The Stars My Destination nonetheless broke the mold in terms of its raw, pre-cyberpunk style.

Meticulously detailing two centuries of terraforming Mars? Novels that can do that must certainly be considered hard sci-fi! But a novel trilogy that can do it while still entertaining the reader is a rarity indeed. Kim Stanley Robinson pulls it off in Red Mars, Green Mars, and Blue Mars. By focusing the stories around the troubled lives of the terraformers themselves, the award-winning books have still managed to sneak in ample exploration not only of sociological concepts but, more to the point here, very hard-hitting science. Genetically-engineered plant life and bacteria designed to survive the harsh climate of Mars and to build an atmosphere? Check. Genetically-altered beasts of burden, built to help the planetary ecosystem evolve? Check. Genetically-tweaked humans who can live longer, breathe in the thinner atmosphere, and see in dimmer light… you guessed it! Big check. Robinson went to great lengths to describe the application of all these theoretical technological advances, to bring them as much to life as the colonists brought life to the (formerly) red planet!

According to Larry Niven, by the year 2850 someone will have built a flat, artificial “world” comprised of a ring 600 million miles in circumference, around a (relatively) small star. Taking this fascinating, though perhaps overly-ambitious, concept with a grain of salt, Ringworld lets us tag along with the 200 year old Louis Gridley Wu as he embarks on a mission of exploration. But if accidents are frequent with real world space travel, you can predict they’re going to happen even more often in novels… which why the Lying Bastard crashes smack into the Ringworld upon arrival! Finding themselves trapped, the crew must discover the lost secrets of the civilization they find inhabiting the Ringworld, for most of said creatures don’t even remember that they live on an artificial surface.

Offering a truly endless plethora of plausible far-future gadgetry and scientific notions such as hyperspace shunts, stasis fields, brain-stimulating tasps, Boosterspice, and impact armor to name only a handful, Ringworld (and its subsequent other “Known Space” sequels) is a fan favorite when it comes to imaginative hard sci-fi… once you get past the idea of what genre junkies label the “Big Dumb Object” of the Ringworld itself.

Ben Bova must surely have carpel tunnel after typing this encyclopedic series! With an inventory too expansive to list here, we’ll summarize the collection of novels as follows: Mars, Jupiter, Venus, Mercury, Saturn… hopefully you’ve spotted the trend in his book titles. But don’t let the simple titles fool you; The Grand Tour series is a grand endeavor indeed, in fact one unmatched in terms of the space colonization theme. With a couple handfuls of recurring characters and organizational entities exhibiting varying degrees of hospitality and hostility (Humphries Space System, Global Economic Council, International Green Party, to give you a taste of the names), Bova isn’t shy about exploring religious themes in-depth as well (his future features many new Daoist and Islamic movements). But certainly the star of the series is the very solar system itself, as colonists venture out further into the wilderness of space seeking other forms of life… and interestingly enough, signs of such life, either current or long extinct, are generally found right in our own backyard of celestial bodies. Because otherwise what would be the point of 22 novels?

So you like your sci-fi ideas big? Me, too, and Tau Zero delivers the goods in spades! Poul Anderson takes his space colonization crew and, rather than taking the standard tactic of either crashing them or safely landing them on their destination, he recklessly chooses to introduce a third option—damage the ship in such a way that it cannot even slow down enough to land anywhere. The Leonora Christine was only supposed to be gone for five years (their time), or, due to time dilation, 33 Earth years. As it happens, their Bussard ramjet engines sustain grave damage, and cannot be shut down nor repaired… at least, not in this galaxy! With no choice but to seek a safer region of space to attempt repairs, the crew makes the fateful decision to keep going, leaving the Milky Way—and any hopes of ever returning to Earth—far back in their rearview mirror. But the far space they find themselves in doesn’t contain enough matter for them to decelerate, either… meanwhile, the ship continues to accelerate as they creep up on the speed of light, eventually traversing billions of years within the span of a few moments. With a title you need a physics degree to even understand, Tau Zero guarantees to take you on one helluva ride… you just might never get dropped back off, is all.

Iain M. Banks’ 1990 novel Use of Weapons was born with such a convoluted narrative structure that the author had to shelve the first draft for years. As he put it, one would have to “think in six dimensions” to comprehend the plot of his space opera. Luckily the final cut only requires half that! With two story arcs moving along opposing timelines to meet in the middle, the reader is kept guessing as they unearth the twisted account of Cheradenine Zakalwe, in one timeline the commander of an army in a time of civil war, and a Special Circumstances operative in the other. Use of Weapons features an “anarchist utopian” society known as the Culture, whose scientific and technological achievements place it in a unique position to dominate other societies (benevolently, of course). Artificial intelligence (a given, perhaps), matter and energy manipulation, nanotech, teleportation, warp drives, even personality “backups”—these are child’s play to the Culture, which is featured in several of Banks’ novels, and allows him to show off his own uncanny ability to extrapolate current tech trends and predict the potential outcomes in his series.

Like many authors, Andy Weir was mired in rejections from publishers, and decided to put out The Martian as a self-published Amazon Kindle book. Against the odds, the gamble worked and the book sold 35,000 copies (at .99 cents apiece, he likely netted $12,000 in profits). This made the publishers sit up and lick their lips, and Weir was able to make a $100,000 deal with Crown. Soon the heavily-researched and realistic space mission to Mars novel landed on The New York Times bestseller list; The movie rights were snatched up by 20th Century Fox. A true Cinderella story in actuality, The Martian’s literary hero sadly isn’t so charmed. Astronaut Mark Watney’s crew left his believed-dead body on Mars as they escaped a lethal storm. As Watney is left to figure out how to survive in the barren wastes, NASA meanwhile realizes their blunder and plans a rescue attempt. Ultimately re-establishing communications with the stranded engineer, both rescue crew and Watney himself risk life and limb to bring home the “Martian.”

Hari Seldon is a smart guy. So smart, in fact, the Trantorian math professor created a system he calls “psychohistory” to predict the fates of billions across the galaxy… so long as they aren’t aware they’re being watched and analyzed, that is. In Isaac Asimov’s wildly influential Foundation series Seldon predicts, in a collected series of short stories, the rise and fall of the Galactic Empire. No big deal. Not content merely to observe, the professor maps his own 1,000 year plan to replace the doomed Foundation as it struggles against crisis upon crisis. Based on his readings of the Roman Empire, and influenced by his studies of chemistry and social sciences, Asimov considered his expansive tale to be “the struggle between free will and determinism.” According to his thesis, if science could predict the mass behavior of molecules, it should also be able to work out the fates of human societies on a grand scale. To this end, the Foundation stories seek to reveal the very fundamental (or “foundational,” if you will) laws of human nature itself… but against the backdrop of the sparkling cosmos.

Alastair Reynolds’ Revelation Space ranks not only in our Best Hard Sci-Fi books, but also in the "Most Terrifying Sci-Fi Books"! Space archeologist Dan Sylveste is a wanted man; He’s got a crew looking for his medical expertise and a killer paid to take him out. But Sylveste is also a busy man; He’s after the mysterious reason for the death of the Amarantins, a 900,000 year old civilization! Onboard a “lighthugger” ship, the Nostalgia for Infinity, Sylveste is convinced by one of the crew—Ilia Volyova—to assist her with their dying captain. Meanwhile the murderous Ana Khouri bides his time to carry out the assassination of the archeologist as the ship nears the planet of Resurgam, home of the extinct ancient civilization Sylveste is studying. But a far worse nemesis than Khouri awaits him and the rest of the crew… the very entity responsible for the Amarantin’s demise, and possibly untold more deaths. With the author’s doctorate degree in Astronomy and work experience at the European Space Agency, Reynolds doesn’t have to prove his street cred to anybody, but for any doubters the hard science of this novel will turn anyone into a believer.

Joe Haldeman may be the only author on this list with a Purple Heart from his Army days. Clearly his time in Vietnam influenced his writing, as he worked through the renowned University of Iowa Writers' Workshop. Haldeman is best known for The Forever War, about a war between mankind and an alien race called the Taurans. The hero, William Mandella, signs up with the service but barely survives the somewhat lethal training environments new recruits are run through. Returning home from a quite lopsided victory against the Taurons, Mandella and his peers discover that, due to the time dilation effects of their interstellar adventures, decades have passed on Earth and they no longer fit into the society which has changed in their absence. Volunteering for further missions, Mandella continues to leapfrog ahead of his fellow humans until he becomes the longest surviving combat troop in the war… despite his actually being a pacifist! Intriguing in its method of tackling and critiquing wars in general, The Forever War is also heavily-laden with believably-crafted technology. After all, Haldeman isn’t only a writer; He’s also a professor at MIT.

One of my personal favorites from childhood, Arthur C. Clarke’s Rendezvous with Rama features yet another “Big Dumb Object,” in this case a mysterious, 30-plus mile long cylindrical spaceship with no one onboard. Much of the book covers the discovery of this odd object in space, as it passes Jupiter, then Mars. The survey ship Endeavour is in close enough range to attempt a rendezvous with the cylinder as it approaches the orbit of Venus. But as the ships meet and the Earthly crew enters “Rama,” its ominous mysteries only multiply. Within the hollow vessel are building structures, and even a vast Cylindrical Sea… but still no life forms. The whole place appears to be a ghost town floating aimlessly through the cosmos. Without giving too much away, it is safe to say that Rama retains its enigma status—and thus sustains the novel’s suspense—until the very end. While some have criticized the book for being too technical and “realistic,” it stands apart in the respect that it offers the reader a genuine feel of awe and wonder at the discovery of an alien object, the first signs that mankind might not be alone in the universe. It’s that sense of childlike wonder which most similar genre novels take for granted.

With Professor X of the X-Men, and so many other telepathic characters running around the world of fiction, we often forget there once was a time such literary persons were a rarity. But in 1953, rare they were—and so The Demolished Man stood as somewhat groundbreaking when it was published. In it, there is a class system of “Espers,” people with various degrees of extrasensory perceptive abilities. Most can only read minds; A few—the “middle class”—can see into the pre-conscious domain of others’ thoughts. But reserved for the highest class of Espers are all the positions of authority. Police and government workers hire only the best; how else to maintain control of all the others? Nonetheless the story stars a wealthy psychopath named Ben Reich who pairs off against a rival he intends to kill—but only if he can keep the mind-reading cops off his tail long enough! If not, the unexplained fate of “demolition” awaits him… whatever horrors that might entail! An enlightening blend of sci-fi and crime storytelling, Bester’s world-building, ultra-detailed riff on the hard-boiled detective novel is ripe with unsettling psychological overtones and more than enough advanced sci-fi concepts to keep those neurons firing!