No, I'm not going to "enter my email to continue." Looks an interesting article, but, no, sorry, modal sign ups that continue after a refresh lead to a page close. :/
Turn off JS -- or leave it off by default -- and such annoyances tend to naturally disappear. (When the page content also disappears, that's usually when I leave.)
Just switching to reader mode works for me, though it gets rid of images too. (Admittedly the pictures are what generally draw me to National Geographic.)
Also, for some reason I always assumed the Challenger Deep was in the mid Atlantic Ocean. It’s not, it’s a few hundred miles southwest of Guam in the Pacific Ocean.
The middle of the Atlantic is the Mid-Atlantic Ridge, where (as you can tell by the name) the ocean is shallower than on either side. The ridge is pushed up by convection from below and by the rocks being warmer there. The gentle slide of the ocean crust down from spreading centers helps drive the spreading.
As a software engineer, one the reasons I like to write tests is because it forces me to think about everything that could go wrong.
Once I write tests for all the things that could go wrong and verify the correct behavior, I feel a lot better than if I only test the happy path (when everything goes right).
I wish software developers would take more time to think about how things could go wrong.
PMs shouldn't have any input in how development is run (that's an EMs role). Dev time should be quoted to them including the time to test otherwise you're implying testing is optional and can be skipped
Writing down everything that can go wrong is the only proper response to Murphy's Law.
Only when you've written them all down, do you have a list of things to actively expect to go wrong, and prevent or mitigate.
It is the difference in handling risk between using knowledge, skill, technology, and planning to manage risk, vs relying on Pure Dumb Luck and hoping to get away with something.
I don't quite understand why an instrument imploding was such a unique inadvertent experiment? I would have thought that part of normal seafloor mapping was using sonar/ultrasound anyway, or pneumatic charges or something similar.
yeah you would think if it was so useful they could have planned an experiment like this. maybe it's illegal to set of underwater explosions on purpose for a research institute?
I attended a talk at Nat Geo by the engineers who built the drop probes enclosed by glass spheres. A few interesting bits as I recall them:
The glass is made in two hemispheres and the contact surface is ground flat. There’s no glue or mechanical attachment; the hemispheres are carefully lined up by hand and then they pull vacuum. Atmospheric pressure alone keeps them mated prior to submersion. Then of course they are pushed together harder and harder as they descend.
The engineers talked a university into letting them use their hyperbaric chamber for testing. One of the prototypes failed at high pressure, which sounded like a bomb going off. The glass was reduced to tiny slivers, which the university was still finding in nooks and crannies years later. (The Nat Geo team was not allowed back after that.)
The probes were timed on the bottom by using thin steel wire to attach the weight. Basically the wire would rust until it broke, then the globe would float to the surface and start broadcasting a radio beacon for pickup. They adjusted the time by varying the thickness of wire.
They also stuffed the globes with LED lights and used them as “sun-like” sources of illumination for underwater cave photography.
> the hemispheres are carefully lined up by hand and then they pull vacuum.
I'm guessing it was not very close to vacuum? The article mentions air explicitly:
> As the instrument's glass collapsed under the weight of five miles of water, it released a pocket of air that oscillated under pressure before splintering into a veil of tiny bubbles.
Yes, sorry, I meant they created a pressure differential by sucking out some air; that is called pulling vacuum even if you don’t remove all the matter (hard vaccum).
You don’t need to pull a vacuum for this. If the glass is sufficiently flat and clean, the pieces can be attached with a process called ‘contact bonding’ where the surfaces are close enough to be attracted by Van der Waals forces.
It feels more similar to wringing gauge blocks (or other very flat surfaces) together, though it is more disputed how that works. You can separate the two objects if you pull them apart with a reasonable force (or more typically shearing and some leverage) and if you imagine the atomic scale structure of the surface, the crystal lattice will break down as atoms on the edge have bonds going into the material rather than free electrons hanging out waiting for another atom to bond to.
I don’t know if cold welding is really welding but contact bonding is certainly not like welding.
AFAIU cold welding is like welding in that the two materials which were separate atomic matrices become one, as atoms from one 'object' do not care if their neighbours are from a different 'object', if they are close enough to be attracted to each other. It only works if the material does not have an oxide layer at it's surface, which is why it's been observed to happen in space (and apparently caused issues with joints no longer being able to move, or something like that).
So - interesting, turns out it is done, and in this very area too. I read the 1960 report of their dive[1], linked to in the parent article. And it talks about "800 TNT explosions" preceding their dive in the Trieste.
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