Because water expands as it freezes (which is why ice floats). The peak in the middle is because it freezes from the edges inward, and the last slush to freeze gets pushed up by the squeezing in.
If you want the real answer: on a cosmic scale water is legit super weird. Not only does it do the thing with the density when it freezes, it also crystallizes weird in a bunch of other ways. Plus it can dissolv, like, nearly anything? Which among other things means it can be any arbitrary pH. Also its surface tension is off the hook! And it combines in weird ways with other molecules, and handles electricity strangely, and a bunch of other stuff. Oxygen and hydrogen both have super unique properties and when you put em together they do weird shit, and also water is really the best way to store them for later use, otherwise the hydrogen floats into space and the oxygen gets stuck making metal rusty.. Plus due to all of that the chance you would have liquid water on a planetary surface is really low.
But it's only because of all that weirdness that it can do the chemistry things it does that let carbohydrate based life happen. So these little bags of lipid-enclosed water that learned to build refrigerators on this one weird water planet have been fooled into thinking it's super normal and common, because they can only function where it already is, right up until it decides to grow spikes in their kitchen.
So be thankful for your ice spikes! Without them we wouldn't have made it out of the Precambrian era.
no subject
Date: 2021-08-17 11:20 pm (UTC)no subject
Date: 2021-08-24 02:13 am (UTC)no subject
Date: 2021-08-24 03:09 pm (UTC)no subject
Date: 2021-08-17 11:20 pm (UTC)no subject
Date: 2021-08-24 02:12 am (UTC)no subject
Date: 2021-08-18 12:58 am (UTC)Excursion forces. Somebody has to go investigate whether the carton of ice cream is worth invading.
Or, more seriously, what
larryhammer said.
no subject
Date: 2021-08-24 02:12 am (UTC)no subject
Date: 2021-08-18 01:38 am (UTC)no subject
Date: 2021-08-24 02:12 am (UTC)no subject
Date: 2021-08-18 01:47 am (UTC)no subject
Date: 2021-08-24 02:12 am (UTC)no subject
Date: 2021-08-24 12:51 pm (UTC)But it's only because of all that weirdness that it can do the chemistry things it does that let carbohydrate based life happen. So these little bags of lipid-enclosed water that learned to build refrigerators on this one weird water planet have been fooled into thinking it's super normal and common, because they can only function where it already is, right up until it decides to grow spikes in their kitchen.
So be thankful for your ice spikes! Without them we wouldn't have made it out of the Precambrian era.
no subject
Date: 2021-08-18 11:47 am (UTC)no subject
Date: 2021-08-24 02:13 am (UTC)no subject
Date: 2021-08-18 10:12 pm (UTC)no subject
Date: 2021-08-24 11:17 am (UTC)