User SF.

31 votes

Lifeform - resistant to gunfire but vulnerable to melee

answered Mar 26, 2015 at 11:53

26 votes

How would aliens in orbit know that communications from Earth are legitimate "official" communications?

answered Mar 4, 2015 at 8:20

20 votes

Accepted

How to keep an authoritarian state from scientific stagnation?

answered Apr 30, 2015 at 15:31

18 votes

How might the actions of descendants matter for their ancestors? (reverse causality)

answered Dec 7, 2016 at 10:28

18 votes

Is a condition leading to a cold-blooded human possible?

answered Mar 24, 2015 at 11:16

17 votes

How would the constant presence of an affable, undemanding immortal affect a society?

answered Apr 6, 2015 at 2:32

17 votes

Dwarven Clothing - Metal Only is uncomfortable, Cotton could be Deadly

answered Apr 17, 2015 at 11:56

16 votes

Accepted

Hiding own space program

answered Apr 16, 2015 at 8:01

15 votes

Air transport breaks down

answered Apr 12, 2015 at 21:24

15 votes

Accepted

How can I create a poison that kills a person after a specific amount of time, and is treatable by an antidote?

answered Apr 10, 2015 at 10:09

13 votes

Accepted

Faking first contact

answered Apr 28, 2015 at 8:29

11 votes

Accepted

Growing a city (literally)

answered Apr 10, 2015 at 22:16

11 votes

Accepted

Would white pupils/irises on an animal allow it to see properly?

answered Apr 17, 2015 at 8:21

10 votes

How powerful of a computer do I need to simulate and emulate a human brain?

answered Apr 10, 2015 at 11:03

10 votes

What power generation method is the best to sustain a hovering city?

answered Apr 17, 2015 at 13:26

9 votes

How to Catch a Dream Thief?

answered Mar 3, 2015 at 13:07

8 votes

Accepted

Dangerous salty creature killing the triffids

answered Mar 4, 2015 at 10:52

8 votes

Are diamond berries possible?

answered Apr 28, 2015 at 8:52

8 votes

What kind of recurring phenomena could cast darkness on a planet for days/weeks at a time?

answered Mar 3, 2017 at 14:08

8 votes

FTL travel is impossible. How is interstellar trade possible?

answered May 14, 2015 at 14:49

7 votes

Accepted

What phenomenon/situation would thwart the development of electronics by a society?

answered May 14, 2015 at 8:26

7 votes

Crystalline materials in someone's bloodstream -- what effect would they have?

answered Mar 10, 2015 at 13:05

6 votes

How could a human and an animal swap minds?

answered Apr 10, 2015 at 12:58

6 votes

How can I get my DeLorean to 88 miles per hour without a train?

answered Oct 26, 2015 at 15:24

6 votes

Accepted

What events could keep Zeppelins in the air today?

answered Mar 3, 2016 at 15:42

5 votes

Help! My Mother-in-law got Mind-Uploaded and now pesters me through the surround system

answered Feb 2, 2016 at 16:44

5 votes

Accepted

What would be a more efficient reservoir for biological hydraulics?

answered May 28, 2018 at 9:31

5 votes

Accepted

Rational justification for discrimination

answered Apr 29, 2015 at 10:20

5 votes

Can an ice age last for only 40 years?

answered Apr 9, 2015 at 1:37

5 votes

Uproot, Lift Up and Replant a City

answered Mar 19, 2015 at 10:30

Stack Exchange Network

66 Answers

Lifeform - resistant to gunfire but vulnerable to melee

How would aliens in orbit know that communications from Earth are legitimate "official" communications?

How to keep an authoritarian state from scientific stagnation?

How might the actions of descendants matter for their ancestors? (reverse causality)

Is a condition leading to a cold-blooded human possible?

How would the constant presence of an affable, undemanding immortal affect a society?

Dwarven Clothing - Metal Only is uncomfortable, Cotton could be Deadly

Hiding own space program

Air transport breaks down

How can I create a poison that kills a person after a specific amount of time, and is treatable by an antidote?

Faking first contact

Growing a city (literally)

Would white pupils/irises on an animal allow it to see properly?

How powerful of a computer do I need to simulate and emulate a human brain?

What power generation method is the best to sustain a hovering city?

How to Catch a Dream Thief?

Dangerous salty creature killing the triffids

Are diamond berries possible?

What kind of recurring phenomena could cast darkness on a planet for days/weeks at a time?

FTL travel is impossible. How is interstellar trade possible?

What phenomenon/situation would thwart the development of electronics by a society?

Crystalline materials in someone's bloodstream -- what effect would they have?

How could a human and an animal swap minds?

How can I get my DeLorean to 88 miles per hour without a train?

What events could keep Zeppelins in the air today?

Help! My Mother-in-law got Mind-Uploaded and now pesters me through the surround system

What would be a more efficient reservoir for biological hydraulics?

Rational justification for discrimination

Can an ice age last for only 40 years?

Uproot, Lift Up and Replant a City