The word “urchin” is derived from the Old French word herichun (later hérisson) for hedgehog. Sea urchins are literally just “sea hedgehogs”
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Red Dwarf is in its 13th season, too!
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Also, glass is not a liquid, as some people would have you believe.
It’s not a solid either though, it’s technically an “amorphous solid” which is actually a state midway between the two states of matter with some properties of both. (in that it’s not completely uniform and rigid like crystal, but not disorganized and free-flowing like liquid either)
That said the whole “old glass windows are thicker on the bottom, and therefore melting over time” thing is a total myth. It’s just a side-effect of the way the glass was blow, and the people installing the windows (not being idiots) were smart enough to know that if you want to get the window pane to stand straight, it’s easier to do so with the flat thick end of the sheet on the bottom.
Glass molecules move so slowly, the heat death of the universe will occur before a single pane of glass ever “melts” due to it’s slightly liquid-like properties.
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In about as many years, too, too.
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There are three types of mammals: placentals, marsupials and monotremes. The oldest of these are the monotremes and there are only 5 species left: the platypus and 4 echidnas. I’ve always found this interesting simply because the echidna looks nothing like the platypus, but the interior workings are essentially the same.
The platypus:
The echidna (isn’t it soooo cute? Look at that little tongue!)
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Don’t forget their dead uncle Allotheria.
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Mammal! Mammal!
Their names are called.
They raise a paw!
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This thread is great. Getting a peek into everyone’s interests and areas of expertise, it’s like watching a bunch of flowers bloom.
Here’s one: Roll a sheet of paper into a megaphone shape, tape a stick pin to the narrow end, then drag the needle over a vinyl LP (or just hold the paper still and rotate the record by hand) and you will hear the music. Not good for the record but it works!
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There is a cave in Italy, called the Cave of Dogs, that contains carbon dioxide. Tourists in the 1700-early 1800s would visit the cave with their pets, and as the animal was closer to the ground and thus more readily affected by the lack of oxygen, the poor things would pass out. The tourists, not the dogs, thought this was highly entertaining.
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When you get into distant galaxies, we know very little for certain. There are some really interesting objects called active galactic nuclei (AGNs) and they come in different flavors.
- Quasars
- Seyfert galaxies (type I and II)
- Blazars
- Radio galaxies
Each type has different characteristics, but one of the current hypotheses about these AGNs is that they’re all galactic cores where the black hole is actively taking in matter and the only difference between them is the angle at which we’re observing that activity.
The most distant object we have observed in the universe is a quasar that is about 13 billion light years away.
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Giant Spider Invasion has forever altered my perception of quasars; I’ve never been able to un-hear the astronomer butcher it as “quazers” to her class.
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Don’t forget their dead uncle Aldebaran.
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The word spaghetti is plural, and the Italian for a single strand is a spaghetto.
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I’m not sure I’m familiar with that. 
Besides, Aldebaran is a retired star, not a dead one. Not yet.
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How to harvest spaghetti from spaghetti trees according to the venerable BBC news show Panorama in 1957*
*it was actually an April Fool’s Joke which just goes to prove the BBC did have a sense of humor once upon a time. 
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I thought they blew it up with the Death Star.
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Alderaan.
“You would prefer another target, a military target, then name the system! I grow tired of asking you so it’s for the last time.”
Too bad he didn’t make the same mistake.
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Back in the 1890s, American railroad companies that were making the switch from 30 ton to 60 ton steam engines on occasion held publicity stunts in which they crashed their outdated engine models at big public events. One of the first of such instances was known as the Crash at Crush. An agent for the KS-TX-MO Railroad Company came up with the idea to crash two locomotives at top speed and stage the event as a way to make money and attract railway tourism. Approximately 20,000 people came to the festivities. Though the rail company did run tests to ensure the safety of this stunt, their calculated minimum safe distance of 200yds for spectators was still not safe enough. The locomotives collided at 45mph, telescoping the engines and causing the boilers to explode. The explosion razed the boxcars chained to both engines and sent debris flying into the crowd, killing two people.
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Sounds very similar to the ‘Gate of Hell’ or ‘Plutonium’ in Hierapolis.
It was a cave that the Romans built a temple around and used to sacrifice animals. Any animal that entered the “gates” mysteriously dropped dead, and only the priests could walk in and walk out again unscathed.
As with the Cave of Dogs it was built directly over a volcanic vent that constantly spewed forth a steady stream of CO2 (so much so that it sometimes appears as a visible mist.) But the Romans figured out, at least through a process of trial and error, that the invisible gas was heavier than air and stuck closer to the ground, so any animal that couldn’t stand upright would asphyxiate within minutes, whereas anybody who could keep their head up above a minimal height was generally okay.
Though due to the way the “gate” was set up, it could actually kill people too, as the CO2 concentration shifted depending on the time of day, as the sun’s heat would cause the gas to dissipate, so it was relatively safe around noon, but especially dangerous at dawn.
I’ve often thought it’s a shame the writers of Indiana Jones and the Last Crusade didn’t know about this trick, since it would have made for a much better version of the “spell out Jehovah with an I” collapsing floor trap (which would have been a pain in the ass to reset any time somebody made a mistake, and could have easily been defeated through patience and throwing bags of sand and/or disposable slaves at the problem.)
If you knew the gas concentration only rose to a certain height, you could just carve the letters onto stone columns of varying heights that you had to jump from, with the incorrect letters being a foot or two lower than the ones on the correct path. As long as the gas was steady, the trap would never need resetting and would be equally deadly, no matter how many people tried to cross it.
Just place some conveniently placed spear traps in the pit areas around the columns, and people who “chose unwisely” would inevitably start to get woozy, pass out, and then drop to their deaths.
Though somebody with a modern understanding of chemistry, would probably notice that if you crouched down you would immediately start to get woozy, and if you tried to throw a torch into the pit or hold it low to the ground to get a better look at one of the carvings, it would immediately burn lower and lower, sputter, and then go out.
And if you wanted to add some added tension, you could have one of the “correct” stone columns cracked and partially collapsed over the centuries, so there’s only about an inch or so or corner edge left, not enough for anybody to actually stand or jump onto. So Indy has to use his trusty whip to try to lift the broken chunk of stone out of the spike pit (while remaining standing upright the entire time, because crouching down means death) and chuck it on top of one of the incorrect stone columns to bring it to the correct height, and then use that as a stepping stone to bypass the broken one and reach the next safe letter.
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