Well... "In nature, most Turritopsis are likely to succumb to predation or disease in the medusa stage, without reverting to the polyp form." "Regardless, most individual medusae are likely to fall victim to the general hazards of life as mesoplankton, including being eaten by predators or succumbing to disease." Wiki I doubt if any of these jellyfish made it past some years (might be a century, but still) since they are very unprotected in a sense and can survive under very specific conditions. But yes, biologically they are considered immortal. Water bears though can even survive in space for some years. They are more indestructible and can live up to a millenium, I think.
Biological immortality doesn't mean you won't get eaten by a passing squid. They are, nonetheless, immortal without any external factors.
This is like the swordsman scene in Raiders of the Lost Ark, where there was supposed to be a long fight scene with the sword guy, but Harrison Ford had diarrhea so just took out his gun and shot him, and they decided to go with that (supposedly).
Mind you, the Greenland Shark is about as immortal as I'd want to be. There are ones currently alive that have been around for over 500 years, apparently! Can you imagine ...500 years lurking around the coast of Greenland, in the dark? Eating partly decomposed seals, which are apparently a big part of their diet. And they have no natural predators, so nobody's going to rescue them from this purgatory by killing and eating THEM. Yee gods.... I know that intellectually they're not the brightest light in the harbour, but man. Oh goodie, another dead seal floats by. That's MY day MADE! Woop woop. I'll go mark the calendar.
Sounds like some of the senior tenured faculty at the university that... a... friend of mine... works at.
American combat deaths in World War I totaled 53,402, but about 45,000 American soldiers died of influenza by the end of 1918.
Nearly 1 in 3 Americans is either: Anxious about flying (18.1%) Afraid to fly (12.6%) Of Those Afraid To Fly: 73% were fearful of mechanical problems during flight 62% were afraid of being on a flight during bad weather 36% were afraid of mechanical problems on the ground 36% were afraid about flying at night 33% feared flying over a body of water Source: “Fear of Flying: Impact on the U.S. Air Travel Industry” Robert D. Dean, Kerry M. Whitaker. Study sponsored by Boeing Commercial Airplane Company
How about "fear of sitting next to someone else's child on an international flight." My nightmare. I have lived this one...
I don't get the "afraid of mechanical problems on the ground" though. So are they perfectly fine once the plane gets into the air?
When raking, if you get a bunch of leaves and branches stuck to your rake, instead of removing it by hand, you can turn the rake around and scrape it off the ground. Yup.
It's a siphonophore! They're related to jellyfish. Also in the same group is the hyrda, which can regenerate and seems immune to age. Immortality candidate?