Recent comments in /f/askscience

Turingading t1_ja34nzh wrote

Reply to Water on Earth is not Constant. Why ? by ItsDivyamGupta

When you breathe you create water. You take oxygen from the air and it reacts with hydrogen in your mitochondria to produce water.

This is very overly simplified but the takeaway point is that plants aren't the only things that can create or disassemble water.

If you burn hydrogen gas, you make water. If you run an electric current through water, you generate hydrogen and oxygen gases.

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Darkeyescry22 t1_ja348ma wrote

Reply to comment by SportsCommercials in How old is the ISS REALLY? by gwplayer1

Wouldn’t this make it a quarter of a second older than it would have been? Or is the observer someone on earth?

Also, do you know the calculation for general relativity? Is that effect (from being farther from earth) near the same order of magnitude, or much smaller?

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kidnoki t1_ja342iv wrote

Reply to comment by Chiperoni in Would two people who look identical but who are not related have similar matching DNA? by OhMyThiccThighs

They actually tested this, a famous photographer Francois Bernell, searched the world to find "twins". These twins were people unrelated, but looked identical. They followed up the art project with a research experiment to look into their DNA and found that they actually did share more genetic material than the average person.

"Dr. Esteller found that the 16 pairs who were “true” look-alikes shared significantly more of their genes than the other 16 pairs that the software deemed less similar. “These people really look alike because they share important parts of the genome, or the DNA sequence,”

https://www.nytimes.com/2022/08/23/science/doppelgangers-twins-dna.html

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Sammy81 t1_ja33zcs wrote

Reply to comment by ziptested in How old is the ISS REALLY? by gwplayer1

That’s unusual. Usually the bird has a GPS receiver. In your case, the satellite clock usually has an epoch from which it counts time (time zero, set to something like 1958). This time is then adjusted by a parameter called deltaUT1, which is a tenth of a second resolution correction based on Earths rotation. The time dilation due to relativistic effects is minor, but an unsynced onboard clock that is not corrected will drift due to the clock a noticeable amount within just a few months. I would think Mission Control would have constant issues commanding it to take data at certain times (if it were an imaging bird for example) unless they synced the clock periodically.

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