169 If everyone in the world disappeared except 35 random people, how long would it take for one of them to realize they're not alone? 2018-08-22T03:53:13.777

135 Everything alive in the world dies this instant. Without bacteria to decompose anything, what happens to the remains? What does this look like? 2018-04-19T10:59:48.727

81 How can a colony of teleporters make the most money while keeping their teleportation a secret? 2018-05-04T14:05:17.187

63 Is it possible to kill all life on Earth? 2019-05-28T01:42:45.893

62 A 40km diameter alien saucer is floating 2km above the ocean for a long time. What are the effects on the sea ecosytem below? 2017-12-12T15:49:36.827

54 Reasons why healthy people would intentionally want to get infected? 2017-09-17T08:51:39.123

51 If an FTL spacecraft entered Earth orbit, how long would it take for humans to build a FTL spacecraft? 2016-02-16T18:14:44.363

50 How long would people live in the US if an immortality treatment was available? 2014-12-14T16:30:26.327

49 Would a squad of soldiers who can shapeshift into T. Rexes be useful in a modern battle? 2017-10-27T18:06:38.663

47 How early was the Earth liveable for today's humans? 2014-11-16T21:05:26.967

46 Where on Earth is it easiest to survive in the wilderness? 2019-09-03T23:01:44.457

45 What would happen if the Earth struck a tiny but immovable object 2018-05-23T13:17:55.513

42 Where should I land my invading fleet? 2015-11-22T16:30:50.987

41 Papers, please: Can characters trapped in our reality acquire enough paperwork to be legal? 2015-07-10T05:32:19.640

41 How long would it take until we realise that people stopped dying from natural causes? 2017-01-03T10:51:57.797

36 What are the effects of slicing the Earth in half with a particle beam? 2018-07-13T19:01:19.113

34 Which direction of slightly tilting the Earth will be most destructive? 2018-07-05T17:07:40.633

34 Is there a hypothetical scenario that would make Earth uninhabitable for humans, but not for (the majority of) other animals? 2019-03-16T18:23:43.770

33 Could we reach the earth's core using today's nuclear arsenal? 2016-07-04T16:26:48.050

31 What computational resources would work for a 550-year climate forecast of our earth? 2015-02-15T19:56:05.200

31 What would be the consequences for Earth if the moon disappeared? 2015-04-20T05:00:16.020

31 If rain magically started falling over the Sahara, what would happen? 2018-01-20T01:07:02.020

30 Would evolution happen the same exact way if Earth restarted? 2018-06-20T06:30:58.447

28 Hiding a subterranean alien megastructure 2017-10-24T01:40:24.557

28 Best place on Earth to fake being on a distant planet? 2020-02-22T22:44:16.373

27 What natural protections could a small oceanic island have against tsunamis? 2017-03-21T23:09:13.680

27 What would Earth's Land look like in the year 3000? would there be any significant changes at all in 1000 years? 2018-03-23T06:01:42.833

27 Building a road to escape Earth's gravity by making a pyramid on Antartica 2019-05-31T08:51:37.493

26 What would it take to build a bridge that crosses North Atlantic Ocean from Canada to Spain? 2014-11-05T05:14:23.510

26 Can a human survive acceleration from 0 km/h to 310 km/h, and then back down to 0 km/h, all in 500 meters? 2017-08-04T11:56:59.873

25 Can planets die of old age 2015-01-15T15:32:19.123

24 How could a human civilization have happened to live underground, in Antarctica? 2016-05-26T10:24:17.770

24 Could human civilization live 150 years in a nuclear-powered aircraft carrier colony without resorting to mass killing/ cannibalism? 2019-06-24T15:00:49.400

23 What's the highest population the Earth could possibly sustain? 2015-06-19T18:31:12.217

23 How to tell if the entire Earth is just a copy? 2020-01-05T07:06:20.863

21 Effects of a non-rotating Earth 2015-02-20T17:44:44.590

21 Why would Earth be long-term unsuitable for an advanced alien species that's already colonized it? 2019-11-22T23:14:34.947

20 Repopulating the world from a single couple - what would it really be like? 2015-08-03T23:41:11.883

20 Is it possible to remotely hack the GPS system and disable GPS service worldwide? 2019-05-22T17:20:01.363

20 How large would a mega structure have to be to host 1 billion people indefinitely? 2019-06-18T17:08:53.917

18 How to survive for a day if everyone is trying to kill you 2016-09-20T13:29:20.800

18 How long will it take for the amount of living to exceed the dead population? 2016-12-26T17:13:11.673

18 Can visible light be blocked while still allowing for light for plants to survive to pass through? 2018-05-14T04:56:32.523

17 What would life be like if everyone was judged on a point system like SE? 2015-03-04T04:55:46.907

17 Everyone gets an IQ of 300. What are the downsides? 2015-08-30T15:25:14.667

17 Benevolent aliens will help us all- on one condition. Can we end all wars? 2016-01-29T03:48:19.530

17 What would be the tallest possible height for humanlike creatures in earthlike conditions? 2016-08-14T23:15:06.487

17 Would Earth's extraterrestrial colonies have a higher average intelligence? 2016-12-05T15:41:36.177

17 Could flying insects re-enter the Earth's atmosphere from space without burning up? 2019-03-01T22:28:21.913

16 Would it be possible to raise a piece of land from the ocean's floor? 2014-12-13T22:24:11.817

16 What would happen to the Earth if Gravity disappeared? 2015-07-14T21:15:12.073

16 We're in the mountains. Where do we hide? 2017-04-28T13:45:44.890

16 At what temperature should the earth be cooked to prevent human infection? 2019-06-13T19:29:43.777

15 What impact is required for a visible (from Earth) ejecta plume on Earth's Moon, and would the Moon survive? 2016-12-15T20:44:49.277

15 2 weeks and a tight budget to prepare for Z-day. How long can I hunker down? 2019-07-29T14:30:28.520

14 What would have to happen in order to force us to live in the ocean? 2014-10-17T23:16:11.683

14 What are the expected impact on Earth ecosystems by mining activities in the Moon? 2014-12-05T15:05:47.640

14 Building a (solid) ring around the earth 2014-12-19T12:20:54.090

14 Could we still live if Earth's spin speed slowed down by 90%? 2015-01-07T19:49:36.570

14 What could cause Earth to slowly fall out of orbit? 2015-01-11T19:24:48.803

14 How would a solid shell surrounding Earth affect the climate? 2016-08-23T20:02:48.780

14 Let's evolve whales and dolphins back onto land 2016-12-11T15:01:05.137

13 Could intelligent life on Earth have been seeded by precursor aliens? 2014-10-30T20:54:04.427

13 If the North and South Poles' ice melted instantly, what would be the effect on humans and other animals? 2014-12-04T23:35:56.333

13 How can I explain a sudden abundance of naturally-occurring beer? 2015-06-28T00:34:19.937

13 How can I successfully prove magical link? 2015-09-03T18:24:06.400

13 The evolution of neon kittens 2016-03-09T19:55:47.953

13 If this earth were cube shaped would it be possible during Magellanic era using a float ship to figure out that the earth is cube shaped? 2018-08-30T03:02:34.917

13 Is this state of Earth possible, after humans left for a million years? 2019-05-09T06:24:18.920

12 What would happen in North America if California became drier? 2014-11-04T18:08:28.003

12 What would a pair of Death Stars do to Earth? 2014-11-23T19:21:52.613

12 Mr. Fusion reality has a global warming problem 2015-09-10T09:21:05.873

12 What does it take for us all to just get along? 2016-04-26T20:02:21.860

12 How to make the Earth red again? 2018-04-06T09:09:12.723

12 Where would a dense population of human beings live underground? 2018-06-12T20:38:30.347

11 If there was a majority of land on earth (66 percent land), how would it affect the animals and plant? 2014-12-12T02:14:44.877

11 Would a rotating ring (halo) help regulate the habitability of a tidal locked planet? 2017-02-12T02:07:33.897

11 Could an object from space crash into Earth and set off a majority of the nuclear bombs created? 2018-06-20T02:54:23.407

11 What would be the effect(s) of this asteroid? 2019-12-19T17:55:35.380

10 If Earth spin decreased, how can I get it spinning faster? 2015-01-08T00:09:59.277

10 How much TNT do you need to blow up Mount Everest? 2015-01-19T10:48:02.067

10 What could cause vegetarianism to be outlawed? 2015-05-31T12:34:08.273

10 A really (really, really) big cliff 2015-08-05T08:58:25.230

10 I want to eliminate the Earth's axial tilt. How do I do it? 2015-09-28T22:30:48.637

9 What if the earth were physically split in half? 2015-06-03T00:21:44.243

9 What would our planet look like with unlimited and cheap (i.e. almost free) energy? 2016-02-02T10:59:10.417

9 How can I wipe out life in oceans? 2016-08-22T21:44:37.190

9 Could circa-1600 humans have domesticated or tamed kangaroos? 2017-10-18T18:48:22.157

9 To Conquer the Earth by Appearing Ship 2018-08-06T16:28:24.873

9 Mechanism for high geographical change but not killing everything 2018-10-05T12:48:35.873

9 If the Earth was part of an ultimate solar system, what would the sky look like? 2019-01-27T12:33:58.997

9 What would Earth look like at night in medieval times? 2019-06-21T22:06:34.417

9 Incoming Rogue Planet! When do we see it? 2020-01-06T07:52:32.840

8 What would be the effects of the common house cat rapidly acquiring flight ability? 2014-10-26T01:12:11.357

8 Where would be the best spot to reveal your floating island fortress? 2015-03-21T02:18:14.417

8 Sci-fantasy; terraforming the earth, and magic nanomachines 2015-04-16T10:33:11.157

8 How many people can live on the oxygen provided by Earth? 2015-12-04T16:34:09.180

8 Earth after mass extinction event by asteroid 2016-01-05T05:48:24.197

8 How could I make a portal to parallel universes as scientifically realistic as possible? 2016-11-28T20:32:55.153