The CAST Eugenics Bureau Public Health Commission has determined that colorblindness is an undesirable trait that should be removed from the genome. But there’s no reason to waste cannon fodder ...

There are a few options. I'll assume a Niven-type ringworld with a radius of 1AU (i.e. the surface is the same distance from the sun as the Earth's surface). If a ring this size were simply in orbit,...

The majority of the nutrients we need (proteins, carbohydrates, fats) are carbon-based, and silicon-based life is presumed to have incompatible analogs instead (with silanes replacing alkane groups). ...

How about sonar? Obviously people in the age of sail did not have the technology in its modern form, and prior to the 17th century they didn't even have the basic physics to understand the principle. ...

Obviously, the pressure change between any two habitable places is not a problem if you take a week to make the journey. The issue is the suddenness of the pressure change. If the teleportation is ...

Obviously there are lots of unknowns here, but you can make some good guesses just by reasoning through the details (kind of like how, even if you'd never seen a planet, you could work out that all ...

A lot of real-world metals are not intrinsically valuable (like gold is, due to its scarcity), but become valuable in the right context. "Damascus steel" was once priceless, because it made the best ...

Transparency as such isn't important for greenhouses – it doesn't matter if you can see through the windows. Usually the purpose of a greenhouse is just to keep the temperature above freezing, for ...

You speak of "a community of highly intelligent, well-educated and mentally healthy people" as though it would automatically mean they weren't bad people, but unfortunately it doesn't. Stupidity, ...

Maybe the Elves and Dwarves hate each other, but it's like with the Skeksis and Mystics in The Dark Crystal: whenever an Elf is injured or killed, their counterpart Dwarf magically suffers the exact ...

Redrawing the original diagram to make it clear what I'm assuming the parted volume looks like: The section through the sea bed is specified to be a circular arc and so, given the constraints, we can ...

Suppose you're playing roulette and betting on red or black. Your ability is equivalent to saying that for every 32 spins, you get a "freebie". (Or equivalently, for a large number of spins, you ...

In terms of cultural reception, there are certainly precedents. Widespread sexist attitudes didn't really slow down Margaret Thatcher, for example; although there was still plenty of that around in ...

Cycling is more efficient because it eliminates the principal inefficiency of bipedal locomotion, which is that we use energy from falling to propel ourselves forward, but don't recycle that energy. ...

Psychoactive drugs can work in quite specific ways. For example, the parasitic fungi Ophiocordyceps unilateralis and Toxoplasmosis gondii alter the behaviour of infected ants and cats in ways that ...

You could call it a roof. Or perhaps an armilla? If you were going to get all hard SF about it, a rigid shell around a planet (or indeed around a star) wouldn't be stable, and would indeed fall onto ...

It's hard to know precisely what you mean, but I'll assume the net effect is that for someone watching from Mars, they see the contents of your bubble of space disappear for one second, and when it ...

The gases are much less of a problem than particulates. You could easily imagine drugs (or evolved adaptations) to make people less vulnerable to carbon monoxide, by increasing the oxygen capacity of ...

This is an active question in the real world, in the sense that political ideas have great power, and can't be physically harmed. Many people have at various times wished to kill ideas like communism,...

The premise makes some assumptions about human nature that I think are overly generous. Historically – even without a wall – all it takes to make Group A believe that Group B are savages is for Group ...

Yes. If we're talking about the ashes that would remain after a human body was exposed to kiln temperatures (> 1000°C), then we are talking about the mineral content, i.e. the calcium from bones. ...

In the 17th-century Midland Revolt, a man called "Captain Pouch" got a bunch of people to follow him by saying (or implying) that his purse contained some kind of document from the King authorising ...

Let's suppose you are traveling at 10% of light speed, and you need at least 0.1 seconds to react to a potential collision. That means you need to be able to spot a cold rock at a distance of (0.1 x ...

You could have a stable society where, say, 90% of the population is retired from work. That's only a problem if your economy depends on most people having jobs. But if the proportion of elderly ...

As you say, there is not a lot of research on the effects of acceleration, and what is known is based almost entirely on subjects (pilots) who were chosen to have an unusually low risk of ...

It takes a lot of energy to change the altitude of an object's orbit (or to tilt the plane of its orbit). So, if the original explosion wasn't powerful enough to send the fragments flying into space ...

If a non-sentient predator gets hungry, it will kill someone, so in that case this arrangement couldn't be stable. But if the predators are capable of long-term planning, then I don't see how this ...

Human vision is very sophisticated at filtering out colored illumination – basically, whether the sun is very red or very blue, our eyes and brains define the color of sunlight to be "white" and shift ...

As @Dave says, it makes sense for archival purposes to separate the physical object from its functionality. Original manuscripts of Shakespeare plays still exist in libraries, but they are extremely ...

You couldn't know that time was resetting flawlessly each time, because your own senses and memory aren't perfect, and if you used any kind of external instrument (like, trying to memorise patterns ...