Recent comments in /f/todayilearned

Nafeels t1_jb8u27y wrote

Same! I grew up watching shows like Air Crash Investigation/Mayday and I still study general aviation accidents today as a hobby as well. /u/admiral_cloudberg writes fantastic reports of it and if there’s one thing in common with these accidents it’s human error. Even simple mistakes such as forgetting to extend flaps, weight balance calculations and blocked sensors would often lead to fatal mistakes; which is why pilots are often trained to stay sharp and follow a set of procedures before resorting to their own judgment.

While I love the idea of flying cars as a little avgeek, as an engineer now I’m just hesitant to embrace the idea let alone thinking of ways to implement it with barely any nuisance to the end user.

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96_doomer t1_jb8pkv4 wrote

Ok I guess this make me more confused, cause then I'm thinking, well what even is time, like does time exist?

Is time just the movement of all existing stuff in the universe?

So if nothing is moving at all, does time move?

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Hattix t1_jb8nsuc wrote

Yes, and it isn't constant over time.

A magnetic field comes from a conductive fluid core which generates electric currents via convection and the core's rotation, so the object needs to be large enough to have a dense, fluid core and maintain it over time.

In the very early solar system most larger objects (non-asteroidal) would have had fluid cores and so likely magnetic fields, but these cool over time for smaller objects and they lose the field. Ganymede's core is on the lower edge of what could retain a magnetic field until the present day.

Coupled with differences based on core composition, we therefore believe Ganymede's core to be slightly larger than Mars'.

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