108
votes
Accepted
Car headlights in a world without electricity
Back in the day before portable electric lights, carbide lamps were used: A mechanism dripped water onto carbide, which then gave off acetylene gas, which burned in a controlled fashion. This was used ...
- 16.4k
94
votes
Accepted
Does my shipboard computer slow down as I approach light speed?
This is a pretty interesting topic, and one of the things that makes special relativity so mind blowing. But the answer is:
From your perspective on board the ship, the computer will function just as ...
- 3,383
92
votes
Accepted
How do I explain a unicorn discharging powerful electricity at a distance?
The unicorns are symbiotic with a jumping spider species, residing on the horn.
The horn is kept at (or can be quickly charged to) a sufficient high potential, and the jumping spiders can be directed ...
- 296k
83
votes
Do all devices go out at the same time in an EMP attack?
Last summer, a lightning bolt struck a tree right outside my apartment building (so close that I hit the floor). As you may be aware, lightning creates a small EMP blast. The power went out ...
- 2,742
66
votes
Charging phone in medieval times
Maybe use -
A Galavanic cell , which uses chemicals which are available during medieval times .
This electrolytes in this case is zinc sulfate and copper sulfate , but it can be also any other ...
- 1,911
66
votes
Accepted
How can a ghostly being who can't be remembered for longer than 60 seconds secure access to electricity?
People remember account numbers:
She's not in as bad of a place as you might think. semi-normal life (and the electricity she needs) is not so far away. Just because you can't remember meeting ...
- 64.1k
60
votes
Accepted
I was thrown into the middle ages, how do I power my time machine?
The first piece of good news is that witch burning is much more an Early Modern phenomenon than a Medieval phenomenon. The second piece of good news is that you can pass for a very respectable ...
- 93.8k
57
votes
Electric power system connecting the Earth and the Moon
Shortly said: no.
Longer said:
The latest What If answered a very similar question to yours, stating that it is not possible, for various reasons:
In real life, we can't put a metal pole between ...
- 296k
54
votes
Building a phone charger 500 years ago
You could emulate Volta's pile if you could find some zinc and copper metal, and some acid, however the purity of such items might be pretty questionable. Which means you might get more voltage than ...
- 1,149
49
votes
Accepted
Advantages of an electrified sword?
The first day your hero rabbits score some terrific wins against their shocked enemy.
The next day your rabbits notice a peculiar wire running from the each sword blade of their opponents... running ...
- 43.9k
48
votes
Accepted
How useful would a hydroelectric power plant be in the post-apocalypse world?
On September 28 2003, Italy experienced a nation wide black out.
After three hours, energy was restored in northern regions. Electricity was restored gradually in most places, and in most cities ...
- 296k
46
votes
How can you justify a steampunk society in which electricity exists and the understanding to use it (though rudimentary) is present?
Steampunk Done Right
A lot of steampunk stories focus too heavily on the whole steam part of the deal. You got gears and brass tubes and stuff on everything from chairs to pens to steam powered ...
- 21.2k
44
votes
Accepted
How does legendary mage avoid self electrocution while disregarding hidden rules?
Tricky Mage:
Your unique mage has worked out the basics of electricity, and has used this knowledge to design unique gear. It's not that other mages CAN'T do what he does, it's just that he's not ...
- 64.1k
42
votes
Accepted
Why would we use direct current instead of alternating current?
Reverse the War of the Currents.
In the late 19th century, Thomas Edison supported the use of direct current, and his company, Edison General Electric, attempted to use it on a large scale. A major ...
- 102k
40
votes
Accepted
Could robots live in Antarctica?
NOTHING more dangerous and Formidable to anything in existence, or more dangerous to life is self than are LAWYERS!
Somehow you will have to get around the Antarctic Treaty. Or perhaps in your world ...
- 6,382
39
votes
How do I explain a unicorn discharging powerful electricity at a distance?
The solution is Lasers
Simply, much like a Narwhal* the Unicorn can shoot lasers out of it's horn. From there, it's not too much of a stretch to allow for the possibility of an Electric Unicorn to ...
- 7,476
38
votes
Accepted
Would a large number of people simultaneously turning on a load of 3 kW be sufficient to bring down the electricity grid across 500 sq km?
Yes and No
Would you believe this occurs at a predictable time every day in the UK?
During the break at the end of popular soap operas a significant percentage of the population of the UK puts the ...
- 118k
38
votes
Accepted
Would lightning bolts be effective against modern military vehicles?
Not effective at all.
Now - let's be charitable, some of the electronics inside modern military equipment don't like being struck by lightning and so you may get some reduced functionality if she gets ...
- 32.2k
37
votes
Car headlights in a world without electricity
The obvious retro answer would be to use carbide lamps which work by dripping water onto a chamber of calcium carbide producing acetylene as was used on the original versions of the Model T Ford:
...
- 26.9k
35
votes
How can a ghostly being who can't be remembered for longer than 60 seconds secure access to electricity?
Become a Real Ghost
Other answers work if our hero can still communicate in written form. In that case she can still maintain a job, home, and access to electricity. This answer is in case you want to ...
- 66.2k
33
votes
Building a phone charger 500 years ago
Don't try to charge the battery inside the phone.
Build a 10 cell lemon battery with copper and lead electrodes, which produces ~4.35V with a maximum current of about 1~5mA. Remove the battery ...
- 431
31
votes
How much energy would this robot need?
You probably got confused between calories and dietary Calories, which are actually kilo-calories.
An average person is on about 2,000 kcal a day - which is approximately 8.37 million joules.
700 watt-...
- 32.2k
29
votes
Why would we use direct current instead of alternating current?
Actually, DC is superior to AC in almost every way, there's no loss due to induced currents, no frequency synchronization issues, less wiring, etc. And this is totally not counting the fact that all ...
- 917
29
votes
Would room phones work in a hotel during a blackout?
Maybe yes and maybe no
Old-style analog telephones are powered by the telephone network; old-style urban telephone networks (the so-called POTS, Plain Old Telephone System) generally have a power ...
- 93.8k
28
votes
Lightning-powered vehicles - are they possible? Are they realistically usable for everyday transport?
So the maths works
A lightning bolt contains ~5 gigajoules of energy, or as Wikipedia helpfully tells us 38 gallons of gasoline. So if you could get a lightning bolt to hit you, and could store all ...
- 44.3k
28
votes
How can a ghostly being who can't be remembered for longer than 60 seconds secure access to electricity?
Inspired by Daron's answer, live with someone elderly who has a somewhat shaky memory anyway. Rather than never be seen, you can pop in to the living room and have a nice chat if you want some human ...
- 830
28
votes
Would lightning bolts be effective against modern military vehicles?
Your mage is not much more dangerous than your average infantryman
Fighter jets, helicopters, warships, and submarines are all speced to take the occasional lightning strike and be fine. These are ...
- 101k
28
votes
Is there any reason a society might use electric boilers and steam engines in their trains rather than electric motors?
For train locomotion, straight-electric is vastly superior to electrically-generated-steam in many circumstances.
Electric locomotives are much lighter than comparable steam, making infrastructure ...
- 28.9k
27
votes
Charging phone in medieval times
It looks like your primary problem is measuring voltage accurately which is tricky with only medieval resources at your disposal.
The actual construction of an analog voltmeter is actually not too ...
- 721
27
votes
Does my shipboard computer slow down as I approach light speed?
Approach the speed of light with respect to what?
Right now there is an electron flying around in a synchrotron somewhere which is moving at an appreciable fraction of the speed of light with respect ...
- 93.8k
Only top scored, non community-wiki answers of a minimum length are eligible