I was reading a book about WWII on a plane. It was (happily enough) talking about various aviation-related oddities of the War. One involved a U.S. plane coming back from a bombing run or the like in Italy to an Allied base in N. Africa. Long story short, the guys got lost in fog and ran out of fuel (also lost radio contact). No one found the plane or knew what happened.
This is like 1943-44. Fast forward to some Western oil company prospecting in the high Lybian desert in the mid 1950s (I think – cite to follow once I have the book back in hand). They come across a well-preserved plane which turns out to be the missing aircraft. It seems to have crash-landed, not too destructively, but there are no remains of the crew. Well, despite the temptation to pull some spooky Bermuda Triangle stuff about the “missing crew,” the author eventually figures, convincingly in my view, that they either bailed out when they were low on fuel and thought they were over the Med. but were really way off course, or they survived the crash but wandered off and died of thirst, etc.
Yep. Makes sense. But, en passant, in describing how well-preserved the plane was, the author notes that “vacuum bottles were found in the cabin, with still-warm coffee inside.”
Huh? Are Thermoses <that> good at insulating? How long would piping hot coffee (let’s even say the crew brewed it onboard on the return from Italy) stay “warm” (and by “warm” I assume the author meant more than “ambient temperature of the Lybian desert.”) in a vacuum bottle as they existed in the mid-1940s?
I can just about believe that they might be found with something resembling coffee still in there (if it was poured in boiling hot, then sealed, it might be aseptic and last a very long time, as if ‘canned’), but there’s no way that the original temperature would be maintained for years.
It’s pretty unlikely, in fact, that even the liquid contents would survive; if it wasn’t aseptic, it would eventually ferment and produce gaseous products that would break the lining, plus the stopper on a thermos bottle of that era would have been sealed with cork and/or natural rubber, neither of which are particularly durable in the long term.
If the bottle was on it’s side the cork would be wetted which may help it maintain a seal for a very long time. This is why wine bottles are stored sideways.
I have a hard time believing that a generally available thermos from the 1940s could have thermal properties that were that efficient. If the liquid inside was still warm, I would suspect it was more a matter of the thermos being in the sun (remember, this was the Libyan desert) and heating up. A degraded vacuum seal could allow heat to sink in due to direct sunshine, but be released slowly when it was out of the direct sunshine.
However, it is possible to make a thermos that could keep coffee hot for a lot longer than 60 years. A friend of mine, while in college, worked for a company that manufactured containers for the cryogenics industry. (Minnesota Valley Engineering of New Prague, Minnesota that does a lot of work for the artificial insemination industry. Frozen bull semen and the like.) Anyway, he told me that the top-of-the-line containers were so efficient with thermal containment, he had calculated that boiling hot coffee would only loose a few degrees in a couple of thousand years. Granted, I’m taking his word for it, but given the complexity of storing liquid nitrogen, I believe it until someone proves otherwise. So the technology is there, but such containers aren’t available for regular use and a coffee thermos built like that would be damned expensive.
We shouldn’t be surprised at all that they found hot coffee in a thermos that had been out in the desert. What was the ambient temp? I’d be more impressed if they found a thermos of ice tea still refreshingly cool (or found the hot coffee in a plane abandoned on a glacier).
Indeed, it would probably stabilise at the average ambient temperature, which, if the container was found at night, would seem rather warm. Even so, I’m extremely skeptical about the story.
If they found it in the early morning, the ambient temp might have been rather cold. The thermos would store heat it absorbed during the day, so it would be quite a bit warmer than the air. Not too remarkable when you think about it, but it would seem impressive to the finders who were already amazed with the preservation of the plane. Surely the most impressive thing would be that the coffee hadn’t dried up, though!
A few degrees in a thousand years? I don’t understand quite how this would be thermodynamically possible for an earthbound containment vessel without introducing energy into the system in some fashion.
The plane was the “Lady Be Good,” a B24 that disappeared in April, 1943 returning from a bomb run from Benghazi to Naples. It was discovered not in the mid-50s, as I thought, but in 1959-60. My book must have been very old or very badly researched, because it made no mention of the fact that the crew’s remains apparently were found shortly after the aircraft. Sounds like they had a horrific journey.
Now, that cite refers to “drinkable coffee” and “canteens of potable water.”
This cite refers to the coffee as “still warm” (I again suspect that this must imply something more than “as warms as the surrounding desert,” but there’s obviously no way of proving what the author meant):
I may be remembering it wrong, but I can check with him this weekend. (Provided I rememeber to do that.) I think it had to do with several nested layers separated by vacuum boundaries and low conductivity supports. Anyway, I’ll ask him and try to post back next week. (Provided I remember…)
Hi. We’re here today at the crash site of the ‘Lady Be Good’ where we’ve switched the crew’s cold moldy coffee with Folgers Crystals. Here comes a search team. Let’s see if they can taste the difference.
I remember reading in Moon Shot (a book about Apollo 13) that the tanks that stored the LOX were insulated so well that the engineers calculated that if you filled them with ice, sealed them, and left the tank at room temperature, it would take something like 4 years for the ice to melt and an additional 2 or so years for the water to come up to room temp.
I haven’t read the book in years, so I may be misremembering the exact amount of time, but it was on the order of years.
astro, your skepticism was very valid. I really got the length of time wrong. (So, what’s an order of magnitude between friends?) When asked, my friend recalled that based on calculations, the high end cryogenic tanks could “keep coffee hot for 85 years.” As for what is termed hot (a drop from 100°C to 60°, 50°, 40°?) he couldn’t remember, but did remember the 85 years bit.
Of course, given the length of time they had actually never tested it and the numbers were based on extrapolation of short term loss rates. It’s still pretty impressive, but not as impressive as my mind had led me to believe. My apologies for the misinformation.