Every study performed on insect counts has concluded that overall insect populations are declining, though there is not complete global coverage of data. One study in Germany found that the flying insect population had decreased by 75% from 1990 to 2015.
A 2019 survey of 24 entomologists working on six continents found that on a scale of 0 to 10, with 10 being the worst, all the scientists rated the severity of the insect decline crisis as being between 8–10.
Nothing scares me quite as much as the thought that I might live to see global ecological collapse.
If you think about it, when was the last time you saw a lighting bug. I’ve never seen a firefly in my entire life despite living in a country that had native species.
I didn’t see any until I made my front yard a designated butterfly spot ( making i don’t have to follow by laws about lawn maintenance) now I see tons.
When I was growing up in the 1970s there were thousands of lightning bugs at night. Any time going outdoors after sunset I could see hundreds of lights winking on and off every few seconds, in fascinating patterns that I loved to look at. Later at night the bugs would fly higher or stop flashing
It was such an ordinary part of life, but movies and tv at the time don’t capture that very well .
Now its gone, for most areas
Saw a documentary about a Chinese billionaire on TV a couple of years ago. He was born poor in some village and worked his way up, owning dozens of factories now. He was super busy, grumpy to the people around him and very torn. He asked the camera if he is part of the solution or part of the problem, he couldn’t tell. Told us he misses the sounds of frogs in the evening, when he was playing with his friend in the forests and fields that are now industrial parks. Made me cry, what are we doing?
pave paradise, and put up a parking lot
Combinatorics scares me, the immense size of seemingly trivial things.
For example: If you take a simple 52 card poker deck, shuffle it well, some combination of 4-5 riffles and 4-5 cuts, it is basically 100% certain that the order of all the cards has never been seen before and will never been seen again unless you intentionally order them like that.
52 factorial is an unimaginable number, the amount of unique combinations is so immense it really freaks me out. And all from a simple deck of playing cards.
Chess is another example. Assuming you aren’t deliberately trying to copy a specific game, and assuming the game goes longer than around a dozen moves, you will never play the same game ever again, and nobody else for the rest of our civilization ever will either. The amount of possible unique chess games with 40 moves is far far larger than the number of stars in the entire observable universe.
You could play 100 complete chess games with around 40 moves every single second for the rest of your life and you would never replay a game and no other people on earth would ever replay any of your games, they all would be unique.
One last freaky one: There are different sizes of infinity, like literally, there are entire categories of infinities that are larger than other ones.
I won’t get into the math here, you can find lots of great vids online explaining it. But here is the freaky fact: There are infinitely more numbers between 1 and 2 than the entire infinite set of natural numbers 1, 2, 3…
In fact, there are infinitely more numbers between any fraction of natural numbers, than the entire infinite natural numbers, no matter how small you make the fraction…
Natural numbers being infinite, how it be possible for the values between 1 and 2 to be “more infinite” ?
It’s called countable and uncountable infinity. the idea here is that there are uncountably many numbers between 1 and 2, while there are only countably infinite natural numbers. it actually makes sense when you think about it. let’s assume for a moment that the numbers between 1 and 2 are the same “size” of infinity as the natural numbers. If that were true, you’d be able to map every number between 1 and 2 to a natural number. but here’s the thing, say you map some number “a” to 22 and another number “b” to 23. Now take the average of these two numbers, (a + b)/2 = c the number “c” is still between 1 and 2, but it hasn’t been mapped to any natural number. this means that there are more numbers between 1 and 2 than there are natural numbers proving that the infinity of real numbers is a different, larger kind of infinity than the infinity of the natural numbers
Your explanation is wrong. There is no reason to believe that “c” has no mapping.
Edit: for instance, it could map to 29, or -7.
because I assumed continuous mapping the number c is between a and b it means if it has to be mapped to a natural number the natural number has to be between 22 and 23 but there is no natural number between 22 and 23 , it means c is not mapped to anything
Then you did not prove that there is no discontiguous mapping which maps [1, 2] to the natural numbers. You must show that no mapping exists, continugous or otherwise.
Yeah, OP seems to be assuming a continuous mapping. It still works if you don’t, but the standard way to prove it is the more abstract “diagonal argument”.
But then a simple comeback would be, “well perhaps there is a non-continuous mapping.” (There isn’t one, of course.)
“It still works if you don’t” – how does red’s argument work if you don’t? Red is not using cantor’s diagonal proof.
Yeah, that was actually an awkward wording, sorry. What I meant is that given a non-continuous map from the natural numbers to the reals (or any other two sets with infinite but non-matching cardinality), there’s a way to prove it’s not bijective - often the diagonal argument.
For anyone reading and curious, you take advantage of the fact you can choose an independent modification to the output value of the mapping for each input value. In this case, a common choice is the nth decimal digit of the real number corresponding to the input natural number n. By choosing the unused value for each digit - that is, making a new number that’s different from all the used numbers in that one place, at least - you construct a value that must be unused in the set of possible outputs, which is a contradiction (bijective means it’s a one-to-one pairing between the two ends).
Actually, you can go even stronger, and do this for surjective functions. All bijective maps are surjective functions, but surjective functions are allowed to map two or more inputs to the same output as long as every input and output is still used. At that point, you literally just define “A is a smaller set than B” as meaning that you can’t surject A into B. It’s a definition that works for all finite quantities, so why not?
