For decades, the kilogram all around the world was calibrated to the Prototype Kilogram, a 1 kg physical cylinder housed in France. Over time, despite being kept in a vacuum-sealed case in a climate-controlled secure vault, it was found to actually be steadily losing mass due to normal degradation just from existing.
Nowadays, it’s no longer as much a concern due to the kilogram being formally defined relative to universal physical constants.
Some species of flatworm practice what is known as “penis fencing” to reproduce. All of them are hermafrodite and in order to mate they must duel with their sharp penises and try to stab eachother to inject sperm inside, impregnating the loser, but often also killing it.
For decades, the kilogram all around the world was calibrated to the Prototype Kilogram, a 1 kg physical cylinder housed in France. Over time, despite being kept in a vacuum-sealed case in a climate-controlled secure vault, it was found to actually be steadily losing mass due to normal degradation just from existing.
Nowadays, it’s no longer as much a concern due to the kilogram being formally defined relative to universal physical constants.
Some species of flatworm practice what is known as “penis fencing” to reproduce. All of them are hermafrodite and in order to mate they must duel with their sharp penises and try to stab eachother to inject sperm inside, impregnating the loser, but often also killing it.