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Science
Some questions sit just on the edge of known physics. Others are clean applications of a formula you already met in school. Science experiments on IfSketch keep those two kinds of question separate: if we are extrapolating, we say so. If we are calculating, you can see the inputs.
Featured in Science
What If Gravity Stopped?
Weight vanishes; velocity does not. Earth goes straight, air expands, people float. A thought experiment with a timer.
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10 interactive experiments.
What If Gravity Stopped?
Weight vanishes; velocity does not. Earth goes straight, air expands, people float. A thought experiment with a timer.
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What If Humans Could Breathe Underwater?
Depth still costs about one atmosphere every ten metres. Gills and oxygenated liquids are different thought experiments.
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What If Humans Didn't Need Sleep?
Recover the hours you currently sleep, as clock time only. No health claims. Compare with gaining one extra hour a day.
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What If Humans Could See Infrared?
Set a long-wavelength cutoff and use Wien's law. Body heat peaks near 10 μm, not in near-IR superhero vision.
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What If Humans Could Fly?
A hover-power estimate from weight and wingspan. Muscle-powered human flight is borderline; history agrees, barely.
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What If Sound Travelled Twice as Fast?
Scale 343 m/s and watch thunder delay, conversation lag and a concert hall shrink in time — not in bricks.
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What If Light Travelled Slower?
Slow light as a local delay, then admit that changing c globally would break atoms. Slow glass and a new c are different ideas.
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What If You Fell Through the Earth?
Uniform-density Earth, no friction: about 42 minutes to the other side. With friction, you do not oscillate.
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What If You Could Stop Time?
A narrative thought experiment. If time stopped, light would not move and you could not see. The walking-distance numbers are a story, labelled as one.
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What If You Travelled at the Speed of Sound?
343 m/s at sea level, about 295 m/s at 11 km. Distance is speed × time. A boom is a shock, not a jet performance sim.
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