14 In the vacuum of space, radiant heat can't go anywhere because there is nothing to carry it away. On the moon, wouldn't the astronaut's boots be like particles in an atmosphere and take the heat?

15 Why don't birds get electrocuted sitting on power lines?

16 What is a Hohlraum used for?

17 What is the maximum theoretical speed limit of a bullet?

18 Why are engines measured in horsepower? Why not bears, cheetahs, and sharks?

19 Why does an electron spin 1/2 need two full rotations instead of one to return to its original state?

20 If a newborn baby could accerate away from earth at 1G (so they could also live in a normal gravitational environment) for a 100 year lifespan, how many earth years would pass across their life due to time dilation?

21 In mathematics, it is possible to calculate problems in infinite dimensions. Is this just another failure of logic or might this be useful for anything other than giving students a headache?

22 Can anything survive passing through the event horizon of a black hole? How does this process occur?

23 Pi is irrational so does that mean it’s impossible to draw a line that’s exactly pi centimetres long?

24 If they could make a rocket in space spin like a bullet, would that create imitation gravity?

25 How do you explain in a simple language why the ISS doesn't fall to the earth?

26 Why have I never been taught about Nikola Tesla in highschool? And why does he not appear in any physics book?

27 What is the equation of the square wave?

28 If GPS satellites can have their clocks resynchronized from the ground, why did engineers bother with complex relativistic corrections instead of just syncing them regularly?

29 Why isn't alchemy considered a science?

30 What’s the closest thing on Earth that resembles a black hole, if there is anything at all?

31 How did Lorentz derive his "Lorentz transformation" without actually understanding relativity? Was it just a trick?

32 How high would two towers need to be, one on the East Coast and one on The West Coast, for a wire strung from one tower to the other to not touch the ground?

33 It is said that gravity propagates at the speed of light, does this mean that if our sun were to vanish in an instant the earth would still faithfully follow its orbit round the now missing sun for 8 or 9 minutes.? To me this seems very unlikely

34 Why is electrical engineering so hard and complex?

35 What is dark energy and dark matter? If it can be explained in simple language yet in detail?

36 Does general relativity imply that space and time may be converted into one another the same way matter and energy can? At limiting conditions, are space, time, matter, and energy all one?

37 How fast would a spaceship have to travel to reach Mars in three hours?

38 Is there any proof that time travel really exists?

39 Why is spacetime curved?

40 Light is both particle and wave so shouldn't the speed of light in wave form exceed than in particle form due to wave form having more distance to travel?

41 If you had a sphere of pure Iron-56 as wide as the sun, would it start burning like a star? Would it stay solid like a planet or would it do something else?

42 Is the speed of light the fastest possible speed for any type of object, or is it possible for something to travel faster?

43 Is there a maximum mass for a star?

44 If wings are attached to a helicopter, does it become a plane?

45 Why couldn't we harness electricity directly from nuclear fission or fusion rather than using steam turbines?

46 What makes it nearly impossible to maintain contact with a generation ship once it reaches far distances like 4 light years away?

47 If Gravity curves space-time according to Einstein, why shouldn't electromagnetism do the same too?

48 How fast would aliens need to travel to realistically colonize the entire Galaxy, and why is even near-light-speed travel not enough?

49 Does electromagnetic radiation (visible light) accelerate? When a light bulb is turned on, how does a photon go from 0 to 300,000 km/sec?

50 I always wondered if the Titanic had been thrown into reverse, as fast as possible, would the water inside had gone forward and out of the ship through the seam?

51 If I shine an intense light at a group of atoms for 1 billion years, will life eventually form?

52 How fast would we actually need to travel to reach the nearest Galaxy in 10 years, and is there any technology that could make this happen?

53 What happens inside of black holes according to the best current theories?

54 Why isn't Nikola Tesla's dynamic theory of gravity used instead of Einstein's relativity theory?

55 How did the turbulence in the National Physics Laboratory’s wind tunnel mislead designers like Sidney Camm about wing thickness?

56 I’ve often read that the singularity of a black hole is not a point in space, but rather something that lies in the future of anything crossing the event horizon. If that’s the case, then where exactly is the mass of the black hole located?

57 Why does hydrogen have no neutron with a short answer?

58 Can pointing a mirror at the sun cause it to burn out?

59 Does the hypothesis that dark matter kills a few people every year on Earth have any credibility?

60 I often read on Quora that, according to Heisenberg’s uncertainty principle, particles don’t have well-defined trajectories or precise positions and momenta at the same time. But if that’s true, how can they still have kinetic energy?

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