Science...

[watervole]

 I love reading Becky Chamber's novels, but I'm finding a common flaw in several of them - perpetual motion machines.

Sidra human form AI, in A Closed and Common Orbit, generates power by harvesting kinetic energy when she moves, but the energy cost of moving will be far greater than that harvested - and that's not allowing for the power requirement of data processing, etc.

Ships in the fleet generates energy from water flowing from the centre to the outside - the ships used to spin, so it would effectively be flowing downhill - but that same water would have to be pumped back uphill for recycling.

Similar problem with the first Monk and Robot book.  No way are a couple of small solar panels going to power his bike (which is pulling a fair size load) and the other stuff he has with him.

 

Who has spotted similar gaffes in other novels?

 

Comments

[igenlode]

It might work if you had energy being supplied by interaction with an external force, space tethers being the obvious example, where you're getting 'free' energy from gravity and centrifugal force -- in practice you're presumably slowing the rotation of the planet slightly, so it's not a perpetual motion machine. You can 'harvest' energy by doing a slingshot around a planet, likewise imparting energy to the projectile at the cost of a tiny bit of the planet's own momentum...

[watervole]

True, but none of her novels are using that approach.

[kerravonsen]

That is... I mean at least with comic-book science, they have their technobabble to create perpetual motion machines. This stuff is Just Wrong.

The Matrix also failed with this, because using human beings as batteries, however much poetic justice it is, would not work, because it takes more energy to keep a human alive, than the energy they would get out of it. (In my fix-it headcanon, it isn't that they're using humans as batteries, but human brains as computers, to run their virtual world on.)

[watervole]

With you totally on humans as batteries - perpetual motion again.

[jesuswasbatman]

Supposedly that was the original plan, but studio executives thought that using the humans' brains for computation would be too hard for the mass audience to understand.

[kerravonsen]

(sigh)
They're doing cyberpunk virtual reality and they thought the audience wouldn't understand?

[watervole]

Yeah, that rather bemused me too!