All concrete collapsing, massive drops/increases in pressure that can shatter your eardrums, untreated metals cold welding, full UV rays going through an Ozone layer that no longer exists, planes fall out of the sky… oh and yeah the Earths mantle just fucking collapsing in on itself and essentially dissolving as its composition has an enormous amount of oxygen
Even just maybe… gaseous oxygen could be interesting.
How big would the drop in atmospheric pressure actually be at ground level? I don’t know how to calculate that beyond… feels like lower than 20%, but could whatever number still be enough to induce barotrauma? How do we apply that potential change in atmospheric pressure to the ocean and tides, and how bad is that sudden shift, massive tsunamis or just slightly higher tides? I feel like a lot of measuring equipment would be fucked for a bit, how bad could it be if every altimeter/barometer/etc was unreliable for 5 seconds? Effect on contained systems feels more predictable, I know nitrogen inflation is a thing you can get in some places, but most are just air, feels like a 20% drop in tire pressure worldwide for 5 seconds is going to have to cause a spike in road accidents.
Would the increased radiation be enough to create a global sterilizing affect for important bacteria/etc and what’s the worst that could happen there?
What happens if every combustion engine in use stops working for 5 seconds? How much does that affect power plants/our energy infrastructure?
There’s lot of industrial applications, I know that welding and steel production can require pure oxygen. Medical and research applications too. How bad is it if the oxygen supply on all of those worldwide fails suddenly?