89 Are there logical gaps in the periodic table in which you could insert a new mystery element for use as a fuel? 2016-02-29T19:42:39.907

87 Lembas bread (2000 Calories per bite) 2016-09-21T16:35:14.897

74 How Long Could an "Eternal" Fire Last? 2017-07-26T18:20:18.073

70 Is it possible to make an alloy that melts at low temperatures and solidifies at high temperatures? 2017-01-16T14:27:55.573

68 Mineral that explodes when cooling down 2017-05-02T18:34:21.293

68 Is there a real life substance like movie acid? 2017-05-30T14:29:32.430

57 What could a self-sustaining lunar colony slowly lose that would ultimately prove fatal? 2019-05-21T17:29:09.607

54 What could cause sugary rain? 2017-12-15T22:04:01.047

50 Could Cobalt bind to nitrogen the same way iron would to oxygen in an alien respiratory system? 2018-08-06T01:39:19.333

46 Time Warp: Modern chemist as court alchemist 2018-11-28T06:06:35.917

43 What would the periodic table of a 4-Dimensional universe look like? 2015-03-26T23:44:50.543

39 Doing chemistry under water? 2019-11-11T04:31:53.217

38 What would be the necessary conditions to rain bubbles? 2018-12-11T01:17:52.517

37 Are diamond berries possible? 2015-04-28T04:06:13.390

36 Only Three Books: Restarting Chemistry after civilization collapses 2018-01-09T16:27:47.720

33 How to replace a fictional element to the periodic table? 2018-02-07T22:48:11.123

32 Solid material made from human blood 2017-05-08T12:07:01.307

32 What should be done with the carbon when using magic to get oxygen from carbon dioxide? 2019-08-28T01:42:58.917

31 A medieval fantasy adventurer lights a torch in a 100% pure oxygen room. What happens? 2019-09-09T17:23:59.777

30 How could indestructible materials be used in power generation? 2019-04-02T18:59:25.197

28 The students have blown up the school using stuff that looks like snow. How? 2020-01-17T07:55:31.583

27 What elements would be created in a star composed entirely of gold? 2019-10-16T14:03:56.587

26 Is there a material or method to allow "swimmable" coins? 2019-12-05T22:26:39.597

25 Hydrogenenic Photosynthesis: Strategies for animals 2015-09-13T14:56:13.127

24 What are some plausible super materials? 2015-11-15T03:54:06.453

24 Chlorine Trifluoride as a Space Weapon? 2019-01-29T15:31:09.630

23 Realistic geological and chemical composition of an edible planetary surface 2018-11-13T18:22:46.807

22 Is homicidal smiley gas possible? 2016-08-22T16:08:11.263

22 The Least Interesting Substance 2018-03-02T17:07:40.987

22 Where would space habitats get their oxygen from? 2018-09-02T23:06:02.120

22 Plausibility of helium dominated atmospheres on super-Earths 2019-08-06T14:06:48.143

21 How can I keep my Love Potion formula from being stolen? 2016-02-23T20:57:59.377

21 How can I create explosions without using oxygen? 2017-08-21T11:56:14.380

21 Is it dangerous for a ship's crew to get stranded in a nebula? 2018-09-04T16:47:18.510

21 How long would it take a body to decay and the bones to fall to the ground from a tree? 2019-01-14T00:24:40.453

21 Assassin's bullet with mercury 2019-04-03T17:31:31.710

21 Could there be a material that inverts the colours seen through it? 2019-05-12T17:14:04.140

20 Initial conditions for a fluorine hellscape 2017-05-11T03:26:44.597

20 Is there any reason to use tungsten crucibles? 2018-08-08T16:51:37.313

20 What kind of "fog" could be harvested (and processed) for fuel? 2019-08-28T20:11:42.760

19 Would a river running through a large salt deposit turn red? 2017-10-03T22:02:00.843

19 Blue soil (aka dirt) in an earth-like planet? 2017-10-08T15:21:22.563

19 Eating Titan's oceans 2019-12-15T15:48:47.020

19 A character steps outside in the upper atmosphere of Venus- how sunburned is he? 2020-01-14T23:29:48.203

18 Understanding which materials can be found on planets 2018-02-14T11:00:05.297

17 How would I transport an atmosphere? 2015-02-18T22:08:08.127

17 Starbuilding: What is lacking in the logic behind Cosmos 2 star system generation algorithm? 2016-05-05T12:00:08.287

17 Could a microbe plausibly generate lift gas for manned balloon flight? 2018-02-01T17:23:30.597

17 Regrowing body parts: What are the costs? 2018-07-26T12:57:13.607

16 Oxygen - 100% plant-free! 2016-03-01T11:43:58.477

16 As we increase the size and mass of a world, at what point does it become impossible for a rocket to achieve an orbit or escape velocity? 2016-04-18T00:18:17.860

16 Is there an organism or chemical substance capable of petrifying humans? 2017-05-10T09:33:31.007

16 Possibility of airless spaceships being used for manned space combat? 2017-11-22T17:36:29.797

15 Chemical weapon to kill a werewolf 2017-10-29T22:16:52.500

15 I need a source of a psychoactive drug or substance in a fantasy world (no magic)? 2017-11-17T13:14:52.983

15 A blue flamestorm blasting through a system of big yellow caves? 2018-08-27T13:21:35.133

14 Drug which lets you forget everything 2015-10-19T17:25:48.667

14 What can I add to an oxygen/nitrogen atmosphere to make it unpalatable or poisonous to humans, yet stable and breathable to local creatures? 2017-04-21T06:46:51.943

14 Could I build a nuclear reactor based on Bernoulli's principle? 2020-01-14T02:43:56.867

13 Alternative absorption spectra for plants 2015-03-08T10:55:04.187

13 Blue Cryovolcanic Planet 2016-04-18T14:37:48.433

13 Would the atmosphere of an alien planet with the following mixture of gases be breathable to humans? 2016-06-20T06:37:57.183

13 Does anyone know of a poison that can be ingested and is undetectable in autopsy? 2016-12-31T15:26:04.393

13 How can I dissolve metal hinges safely? 2018-08-08T10:13:25.827

12 Alchemy in a Forest 2017-03-02T03:38:52.843

12 How can I make medieval folks addicted to food? 2017-04-17T17:52:34.633

12 Aluminium as body armor? 2017-12-02T15:30:23.973

12 How can I feed an entire population on corpses? 2018-12-20T17:44:05.147

12 The Sword in the Stone 2019-07-27T18:26:03.820

12 Is a carbon planet with seas of methanol on its surface scientifically possible? 2019-08-16T05:37:32.197

11 Chemistry in two spatial dimensions? 2015-10-14T08:31:20.693

11 How to get monsters with literal nerves of steel? 2016-03-23T19:03:14.440

11 What recreational drugs can be produced with limited resources and technology? 2016-08-24T12:04:04.627

11 What happens to excess Hydrogen? 2017-02-16T00:32:27.197

11 Could there exist a non-addictive drug giving the same pleasure as heroin? 2017-07-02T04:30:52.677

11 How much hydrogen and oxygen can I add to an atmosphere before it explodes? 2018-10-31T21:20:23.030

11 How would crystals be different in hyperbolic space? 2018-11-18T22:41:13.053

11 What color should the snow be in this chlorine world? 2019-02-15T00:32:36.173

10 How would modern firearms behave in a high oxygen atmosphere? 2016-06-05T19:48:00.867

10 Cryogenic grenades in medieval time 2016-08-26T12:42:25.730

10 What useful materials exist on a lifeless planet? 2017-02-16T05:12:02.297

10 Bio ChlorineTrifluoride Pyrogenesis 2018-03-24T13:10:29.823

10 Is it possible to make high-compressive-strength cement on Mars? 2018-12-01T22:32:27.930

10 Chemical process for a radiosynthetic Ganymedian organism? 2018-12-31T23:51:56.040

10 Membrane impermeable to $N_2$ but permeable to $CO_2$ and $O_2$? 2019-05-20T02:38:41.007

10 What type of chemical catastrophic event might reduce the bioavailability of iron? 2019-06-26T19:06:32.623

10 Why did the "Orks" never develop better firearms than Firelances and Handcannons? 2019-07-01T20:53:39.817

10 Would A Biological "Cold Haber" Process Deplete an H2/N2 World of its H2 or N2? 2019-07-22T19:05:23.330

9 What substances would be really valuable if transmuting material printers would exist? 2016-04-14T10:28:55.527

9 Outer Space Flamethrower 2017-02-26T01:10:39.220

9 Could a plant lure humans in by using 'sex pheromones'? 2017-07-11T18:41:09.427

9 How could a country broadcast digital data through tap water (instead of radio waves)? 2018-03-21T02:56:54.607

9 How do puffer lizards puff up into flight so quickly? 2018-04-30T20:50:00.213

9 A reciprocal metabolism is needed on a world overrun by crazy plants 2018-10-14T18:34:01.697

9 Redox Magic 1: Stone-age France 2018-11-12T03:26:18.133

9 What kind of transports would be invented in a world with an enhancer-material? 2019-01-20T18:08:37.557

9 Can the Meissner effect explain very large floating structures? 2019-04-03T19:02:49.587

9 Creating a chemical industry from a medieval tech level without petroleum 2019-04-25T16:38:09.857

9 Alternative to Magnesium's Role in Photosynthesis 2019-08-28T22:03:06.290