commanderquill

commanderquill t1_iy7ehpi wrote

Reply to comment by knowledge3754 in Eli5: Why do birds and fish come in such a spectacular variety of colors and shapes compared to other animals? by thetravelman888

Life is created, presumably starting from one species. Then there's an explosion of life. Now all kinds of life. Some have fins. Some have feathers. Some have feet.

Some develop into something else, as different to the ones with fins as humans are. But that design fails. Better to have fins. Now they have fins.

Humans come along and see it and go hey, that's a fish.

But this 'fish' maybe used to be a lizard and then became a fish. So it went:

Step 1: ancestor

Step 2: something else

Step 3: something else

Step 4: lizard?

Step 5: fish?

Meanwhile, 'fish' #2 went:

Step 1: ancestor

Step 2: fish?

So you have one fish that came from a lizard and one fish that came from something else entirely. As a result, you have one fish that has a shared common ancestor with humans say maybe one billion years ago and another fish that has a shared common ancestor with humans three billion years ago. That means fish #1 and humans are related by one billion years while fish #1 and fish #2 are related by three billion years.

Conclusion: some fish are more closely related to humans than to other fish, and the category of fish is meaningless.

This is also true of crabs and trees. Mother nature proves to us over and over again that crabs, fish, and trees are the most superior earthly life forms.

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commanderquill t1_ittt8e6 wrote

Reply to comment by Felinomancy in TIL Amedeo Avogadro's contribution to chemistry, known as Avogadro's law, did not initially receive much attention when he published his paper in 1811. It was only a century later that his work was recognized, when the King of Italy attended a meeting commemorating the paper's 100th anniversary. by dustofoblivion123

Ever wonder why the periodic table is in the order it is?

It's in that order because it's counting by the number of protons that are in the nucleus of an atom of that element. Each atom is characterized by how many protons are in its nucleus--if an atom has one proton, it must be hydrogen regardless of any other physical characteristic it has. Similarity, if it has six protons, it must be oxygen.

As it turns out, the more protons an atom has, the more neutrons it needs to hold those protons together (like the "glue" sticking two magnets of the same side together, or else those magnets will repel each other). In addition to that, the more protons it has (like the positive ends of many magnets) the more electrons it can hold (like the negative ends of many magnets). Their numbers match up very well too. Hydrogen has one proton per atom and each atom generally keeps one electron around. Oxygen has six protons per atom and each atom generally keeps six electrons around.

So, the further you go along the periodic table, the more electrons, neutrons, and protons each atom of each element contains. All of these things, while small and negligible to us, are pieces of matter and therefore do have some very very very tiny mass. So an atom of oxygen, with its six protons, six electrons, and some neutrons, will always weigh more than an atom of hydrogen, with its one proton and one electron. It's like taking six skittles vs six bowling balls. I could tell you, hey, these are both small spherical objects and you would agree. But although they're both spheres, they're different spheres, made of different stuff, and so they weigh different amounts.

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