MOSTLYODD
The curious and the unexplained — strange history, famous hoaxes, bizarre disappearances, and the odd corners of science and the natural world.
From vanished expeditions and elaborate hoaxes to forgotten inventions, unsolved disappearances, and the stranger corners of science and the natural world, MostlyOdd digs into the strange-but-true — pairing well-sourced, curiosity-driven deep dives with a richly illustrated cabinet of curiosities. Follow your curiosity.
Curiosity & Oddity Tools
Free tools for the incurably curious — a coincidence probability calculator, an oddity (1-in-X) probability calculator, a weird science fact generator, a strange phenomenon analyzer, a bizarre world record tracker, and an unusual animal trait identifier.
Coincidence Probability Calculator
Put real numbers on a 'what are the odds?!' moment — run the birthday paradox for any group and any set of outcomes, or find the chance that at least one of N rare 1-in-X events happens, shown as a percentage and as '1 in X'
Oddity Probability Calculator
Turn '1 in X' odds into a probability, the number of times to expect it across a population, and a plain-language comparison to genuinely documented long odds — lightning, the lottery, a royal flush, a shark, a four-leaf clover
Weird Science Fact Generator
Step through a hand-checked collection of genuinely true, delightfully strange science facts across space, biology, physics, and the human body — filter by field, with a one-line explanation of why each is true
Strange Phenomenon Analyzer
Browse real, documented natural and atmospheric phenomena — ball lightning, the Brocken spectre, sailing stones, Morning Glory clouds — filtered by type and by whether science calls each one explained or still debated
Bizarre World Record Tracker
Explore genuinely unusual, documented world records — the longest attack of hiccups, the largest ball of twine, the most tattooed person, the oldest verified human — filter by category and sort by year or title
Unusual Animal Trait Identifier
Meet real animals with genuine superpowers — the immortal jellyfish's biological immortality, the tardigrade's cryptobiosis, the mantis shrimp's 16 photoreceptors, the axolotl's limb regeneration — filter by trait or search for one
The Cabinet of Curiosities
Wander an immersive cabinet of curiosities — strange artefacts and famous hoaxes alongside forgotten inventions, the sites of unsolved mysteries, and the odd specimens of science and the natural world, each in its own gallery, so you can get to know the stories behind the strange-but-true: where each curiosity came from, why it still puzzles us, and what the reputable sources actually say.
Tour the museum →From the Journal
Fresh, well-sourced deep dives into strange history, famous hoaxes, bizarre disappearances, and unsolved mysteries, plus the odd corners of science and the natural world — the stories that are stranger than fiction, and the reputable sources behind them.
Taking the Water from A Waterfall: The Dry Niagara Falls
Autumn 1969, the Niagara Falls verged on collapse. So was the prediction made by the United States Engineering Corps. They believed that the constant rushing of the water was causing damage at the base of the cliff, destabilising the rock. Year on year retreat due to erosion was fine, but any major rock collapse could […]
Wasps and Mind Control
The jewel wasp (Ampulex compressa) is a bright, iridescent creature; one with a particular way of making sure its larvae get food. A mixture of hunting, poison and mind control make up its impressive repertoire. It starts when a female wasp finds a cockroach. Upon finding the cockroach the wasp descends and stings it twice. […]
Think It, Feel It
It is possible to catch leprosy from an armadillo if you are a human or an armadillo. Were you to handle an infected armadillo and contract the disease unwittingly you might never notice, around 95% of humans are immune to leprosy. Even if you did contract leprosy it could easily be stopped early on. That […]
The Nuclear City In The Ice
800 miles from the North Pole, in the middle of the cold war, in the Greenland Ice sheet, America was building. Lashed daily by w inds of up to 200 km/h the US Army Corps of Engineering slowly dug out their trenches and sunk in the buildings. In October 1960 they were finished, Camp Century was […]
The Frog Test, the Birth of the Pregnancy Test
From urinating on various grains and seeing what germinated in Egyptian times to burning ribbons in the 17th Century, pregnancy tests have historically been unreliable. Then the 20th Century came, and it brought science. In the 1920’s the presence of hCG, a chemical produced by the placenta, was discovered to be a way of telling […]
The Immortal Jellyfish
Leave a jellyfish out in the sun for long enough, and it will evaporate. Over 95% water, jellyfish are ludicrously simple creatures. They have no brain, no lungs and no eyes. Assemble some tentacles, a stomach cavity, an umbrella head and you are nearly done. For respiration they just have skin thin enough to let […]
Keep Learning
Plain-language explainers on the science behind famous hoaxes, how historians and investigators separate fact from legend, and the curious phenomena that keep researchers guessing — everything you need to dig deeper and tell the strange-but-true from the merely strange.
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