Cosmological time scale 1 Cosmological Time Scale 1
Cosmological time scale 1
- What I've done here is that I've copied and pasted a bunch of
- pictures that, uh, uh, signify events in our history, when you think about history
- on a grander scale that most of us have some, uh, relation to
- or we have kind of have heard it,uh,uh, talked about it, a little bit,
- and the whole point of this is to try to understand, or try to begin to understand how long 13.7 billion years is.
- So just to start off, I have here, this is the best depiction
- I could find where I, it didn't have copyrights, this is from NASA,
- of the Big Bang, and I've talked about it several times,
- the Big Bang occured 13.7 billion years ago.
- And then if we go a little bit forward, actually a lot forward,
- we get to the formation of our actual Solar System and the Earth.
- This is kind of the proto-planetary disc, or a depiction
- of the proto-planetary disc forming around our young sun,
- and so this right here is 4.5 bilion years ago. Now this over here,
- once again, these aren't pictures of them,
- these are just depictions, cause no one was there
- with a camera. This is what we think the asteroid
- that killed the dinosaurs looked like when it was impacting
- the Earth. And it killed the dinosaurs 65 million years ago.
- 65 million. 65 million year ago. Years ago. so until then,
- we had land dinosaurs, and then this, as far as the current
- theories go, got rid of them. Now we'll fast forward
- a little bit more, at about 3 million years ago.
- 3 million. Let me do this in a color that you can see.
- About 3 million. So 3 million years ago. Years ago.
- Our ancestors looked like this. This is Australopithecus afarensis.
- This, she's, uh, this is, I think is a depiction, uh
- This is Lucy. uh, this is one of our, uh, probably
- many of us share, uh, I, i believe the theory is that all of us
- have some of, some DNA from her. But this was 3 million years ago.
- And you fast forward some more and you actually have the
- first modern humans appearing on the planet. People
- that looked and thought like you and me. This is 200,
- 200,000 years ago. That's right over here. Obviously
- this drawing was done much later, but this is a depiction
- of a modern human, so 200,000 years ago. And then
- you fast forward even more , and I don't want to keep
- picking on Jesus. I, I did that when him getting on the jetliner,
- and I, I genuinely don't mean any offense to anyone,
- I just keep picking Jesus because frankly our calendar
- is, uh, is, is, uh, kind of, he, he was a good person that
- most people, most people know about 2000 years ago,
- It's when we associate, you know, kind of a lot of modern history occuring
- after his birth, so i'll put this right here as, obviously
- a painting of the birth of Jesus, and this is 2000
- years ago. 2000 years. And then this might be a little
- bit, uh, a little bit, uh, uh, american centric, but
- you know, the Declaration of Independence, it was a
- major event, actually, even on a world-wide basis
- it was the first, uh, secular democracy, that, based on kind of a
- constitutional democracy that, that, showed up on the
- planet, they had gotten rid of, uh, they said we don't
- want the King of England anymore, and, uh, this was
- about 234 years ago. 234, and I always remembered cause
- I was born almost on the 200th anniversary, so you just
- have to add my age to 200. So this is 234 years ago.
- So these are all, these are all events or periods of time
- that, that we've heard about and we've talked about and
- people throw around these types of years, but what I want to do
- in this video is relate it to time scales that we can
- comprehend, so instead of the Big Bang occuring 13.7 billion
- years ago, let's pretend like it occured 10 years ago,
- cause we can, most of us, especially if you are over the
- age of 10, can kind of understand what 10 years is. It's
- a very, very long period of time, but something that's well
- within our lifetimes, well within our experience. So let's say,
- let's say that 13.7 billion, instead of saying the Big Bang
- occured 13.7 billion years ago, let's pretend like it occured
- 10 years ago. 10 years ago. And if we pretend that it occured
- 10 years ago, let's think about how many years or minutes or hours
- ago each of these events would've occured. So the Big
- Bang, which is really 13.7 billion years ago, if it really had
- occured 10 years ago, and we scaled everything down,
- if we had scaled everything down, then the Earth, the
- Earth, would have been created about 3.3 years ago. So
- this would have been 3.3 years ago. So still, nothing, you know nothing
- kind of amazing about this. This is a significant fraction of the
- age of the universe, so not that, not that
- mind-blowing just yet. But if we go all the way to
- when the dinosaurs were extinct, the last land dinosaurs.
- Now the 65 million years, this will give you an appreciation
- of the difference between million and billion, if the universe
- was only ten years old, then the dinosaurs would have been
- extinct 17 DAYS ago! Not even a month ago, the dinosaurs would
- have been extinct! So, if the universe was created when I was,
- you know,uh, you know, just graduated, well, i'm in my thirties
- now, so when I was 24, Just last month, the dinosaurs
- would have gone extinct! And it gets even crazier!
- 17 days ago, the dinosaurs would have been extinct.
- Australopithecus afarensis would have walked on Earth
- 19 hours ago! Yesterday! 19 hours ago. 19 hours ago,
- she would have been walking around on the planet. And
- modern humans, modern humans, wouldn't have showed
- up until eighty minutes ago. Eighty, eighty minutes.
- A little over an hour, there wasn't even a modern human.
- Then, you know, the universe was ten years, It didn't take until just very
- recently, last hour, for we, us to see someone that looks something
- like us. Looks and thinks something like us. Fast forward
- even more, the birth of Jesus, if the Universe
- was 10 years old instead of 13.7 and, billion, and if we scaled
- everything down, then the birth of Jesus would have been
- 46 seconds ago. 46 seconds ago. And then if we fast forward
- all the way to the Declaration of Independence, this would
- have occured, this would have occured 5 seconds ago. 5 seconds
- ago. So this isn't quite, quite as mind,as mind-blowing as the scale
- of the universe, but in my mind, this is pretty, still pretty amazing,
- I mean all that has happened since 1776, on a global basis,
- could have been encapsulated in 5 seconds if the Universe was,
- if the age of the universe was 10 years. So hopefully,
- that gives you a, a little bit of perspective. In the next video,
- i'm going to compare, instead of, instead of condensing things
- in time, i'm going to compare this scale to kind of a distance scale,
- so we can kind of say "Hey, if the age, if the universe was the,
- the number of pixels on my screen,how big will each of these things be".
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At 5:31, how is the moon large enough to block the sun? Isn't the sun way larger?
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When naming a variable, it is okay to use most letters, but some are reserved, like 'e', which represents the value 2.7831...
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