Uploads from xkcd's What If?

Watch and track your favorite playlist.

Curated by: xkcd's What If? (82 videos)

Currently Playing: What if you tried to hit a baseball pitched at 90% the speed of light?

A careful reading of official Major League Baseball Rule 6.08(b) suggests that in this situation, the batter would be considered "hit by pitch", and would be eligible to advance to first base. ©2025 xkcd, inc.

Tracks in this Playlist

How long could you drive towards the sunset?
What if the Moon were made of Protons?
Weird and worrying questions
What if half the human population ate the other half 🍽️
How long could the human race survive on only cannibalism?
What would a rainbow be like on Tatooine?
What if you used a microwave as a snowblower?
What if we turned the moon into a black hole?
What if everything was antimatter EXCEPT Earth?
What if you funneled the Niagara Falls through a straw?
What if you had literally had all of the world's money?
What if you dropped a bowling ball in the Mariana Trench?
What would the world's largest cities be like if the land masses were rotated by 90 degrees?
What would your country be like if the land masses were rotated by 90°?
Could you power a house with the radioactivity from bananas?
What would Earth's climate be like if the land masses were rotated by 90°?
What would happen in Minnesota if the world rotated by 90 degrees?
Why is the sky blue?
What would happen if the Sun went dark?
What if you kept digging downward?
Which path would the three wise men have walked?
Where would the three wise men go if they followed a planet?
What if you floated upwards 1 ft every second?
How many elevators would you need in a billion-story building?
What if we built a billion-story building?
What if you made a jetpack using rifles?
What if you teleported to the Sun?
What if you printed all of Wikipedia?
How long would you survive with no DNA?
What if we teleported the oceans to Mars?
What if you drained the oceans?
Can you power your computer by typing?
What if everyone on Earth was in the same place and jumped at the same time?
Could you swim in a spent nuclear fuel pool?
What if ALL the sun’s power was focused in one place?
Could you use a laser as an umbrella?
What if you tried to hit a baseball pitched at 90% the speed of light?
Can you drive west to lengthen the sunset?
What would happen to the Earth if it suddenly stopped spinning?
What would happen to the population if the Earth suddenly stopped spinning?
Could we survive eating only humans?
How detailed would the Hubbles images be if it looked at Earth?
Could the Hubble take a photo of you?
What if the Moon were made entirely of electrons?
How fast could a vehicle go around a track - but the racer does not have to survive.
How fast could a human accellerate (while staying alive)?
What if you had a mole of moles?
Petition to send a swimming pool to the moon!
Circumference pop quiz!
Could this be the last surviving human light source?
Why Space Is Actually Warm!
Could We Harvest Power From Lightning?
What if the moon turned into a black hole?
Is there such a thing as a magnitude 0 earthquake?
How high could the magnitude of Earthquakes go?
What if you funneled Niagara Falls through a straw?
What if you used a flamethrower as a snowblower?
What if you literally had all the money in the world?
What if the sun suddenly went out?
What if the Earth rotated 90 degrees?
What if the wise men kept walking after Jesus’s birth?
What if you built a billion-story building?
What if we put a pool on the moon?
But what if we tried MORE power?
What if everyone pointed a laser at the moon?
What if Earth grew 1cm every second?
What if a glass of water were LITERALLY half empty?
Could you survive a nanosecond on the Sun?
What if we teleported the oceans to Mars?
What if you tried to print Wikipedia?
What if you drained the oceans?
If all humans died, when would the last light go out?
What if all the lightning on Earth struck the same place at once?
What if everyone jumped at once?
What if you swam in a nuclear storage pool?
Would a Submarine Work as a Spaceship?
Could you make an umbrella out of lasers?
What if you threw a baseball at nearly light speed?
What if Earth suddenly stopped spinning?
What if NASCAR had no rules?
What would a magnitude 15 earthquake be like?
What if we aimed the Hubble Telescope at Earth?