This animation is about one of the most significant problems in the history of mathematics: the brachistochrone challenge.
If a ball is to roll down a ramp which connects two points, what must be the shape of the ramp’s curve be, such that the descent time is a minimum?
Intuition says that it should be a straight line. That would minimize the distance, but the minimum time happens when the ramp curve is the one shown: a cycloid.
Johann Bernoulli posed the problem to the mathematicians of Europe in 1696, and ultimately, several found the solution. However, a new branch of mathematics, calculus of variations, had to be invented to deal with such problems. Today, calculus of variations is vital in quantum mechanics and other fields.
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The USGS has just released a gorgeous new geologic map of Mars, combining data from four separate spacecraft to paint a rainbow-like spectrum of terrain and texture upon the red planet.
See those four bulges on the left side of the spherical projection? Each of those four mountains, Olympus Mons, Ascraeus Mons, Arsia Mons, and Pavonis Mons, are taller than any mountain on Earth, including Mauna Kea (which rises more than six miles from the ocean floor).
As close as you will ever be to a nuclear explosion
THIS IS FUCKING TERRIFYING
No thank you.
The columns of smoke in the foreground are telephone poles boiling
This is way cooler to look at than it should be
Science side of Tumblr would like to add:
Heat is generally transmitted in 3 forms: conduction, convection, radiation.
The fact that the telephone poles and wires are boiling away well before the shockwave hits them indicates that the heat from the explosion has not reached them by convection (much slower than the speed of sound) or by conduction (at best, comparable to the speed of sound), but purely by radiation. In other words: the explosion is bright enough to boil everything.
reblogging again for what engineer—cat said
Rape has become endemic in South Africa, so a medical technician named Sonette Ehlers developed a product that immediately gathered national attention there. Ehlers had never forgotten a rape victim telling her forlornly, “If only I had teeth down there.”
Some time afterward, a man came into the hospital where Ehlers works in excruciating pain because his penis was stuck in his pants zipper.
Ehlers merged those images and came up with a product she called Rapex. It resembles a tube, with barbs inside. The woman inserts it like a tampon, with an applicator, and any man who tries to rape the woman impales himself on the barbs and must go to an emergency room to have the Rapex removed.
When critics complained that it was a medieval punishment, Ehlers replied tersely, “A medieval device for a medieval deed.”
- Half the Sky, Nicholas Kristof
REBLOGGING THIS. x1,000,000,000,000,000,000,000
A medieval device for a medieval deed - yes.
This is perfect
BLESS THIS PERSON
I BOW TO THIS INTENTION
Can we talk about how beautifully this turns rape culture on its head? Instead of “If they weren’t dressed like that they wouldn’t have been raped” THIS IS LITERALLY “IF THEY HADN’T TRIED TO RAPE SOMEONE THEY WOULDN’T HAVE SPIKES IN THEIR DICK”*
That bold bit~