Recent comments in /f/askscience

ThomasEdmund84 t1_j9rzc2q wrote

Reply to How can Doctors tell if one of your kidneys isn't working? by FineLetMeSayIt

> EDIT: To piggyback this logic, why don't we have more 'spares' of other organs. Why is the redundancy factor only built into kidneys?

Its likely to do with trade-offs between the resources the human body needs to grow and maintain vital organs and also how feasible having redundancy is.

e.g. lungs are perhaps semi-redundant, obviously having one lung = much reduce physical capacity and isn't great, but we do have two.

My physics might be a little off - but I think its counter productive to have two hearts? Human digestive system already has lots of failures in its complex system so doubling up would probably mean more room for errors.

Two brains? Forget about it.

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jedadkins t1_j9rqjvz wrote

Reply to comment by mfb- in What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl

Yea this really seems like a problem of scale, ~2.5m tonnes of aluminum needed to reach the lower bound is an insane amount. Maybe once we start actually commercializing space it could be an issue but by then we should have a better option then just crashing stuff to get it out of orbit

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KeyofE t1_j9rmvyd wrote

Reply to comment by Whako4 in Why is urine yellow? by nateblackmt

Mixing colors from the opposite side of the color wheel (blue and orange, green and red for example) makes brown,so if you mix a bunch of colors together, you are likely going to mix some that are across from each other.

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bladeelover429 t1_j9rlkmr wrote

Reply to What will be the environmental impact of de-orbiting 42,000 Starlink satellites every five years? (Explanation in post) by OvidPerl

Well, from purely a chemistry standpoint, aluminum metal burning up in the atmosphere would mostly create aluminum trioxide. The EPA doesn't consider it to be a dangerous substance, and I can't come up with other reactions with Atmospheric gasses that would form anything significant.

Now from a climate standpoint- large amounts very tiny particles do have a measurable effect on global warming. If we're burning up a mass of aluminum on the same order as all of the meteorites that enter the atmosphere, then the effect is probably negligible, however. But I only say this because I haven't yet seen any climate models that consider particles added by meteorites. This could mean that it's either too difficult to model or its just not important enough. Climate change is notoriously difficult to model, unfortunately.

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