The Pale Blue Dot

Wikipedia. Do go have a look at that image.

If you have time, I’ll once again recommend Khan Academy’s Cosmology and Astronomy section – if you have never read about this kind of stuff, the first 5 or 6 videos will blow your mind.

Cosmology revisited

So first of all, I know a handful readers or two came by after I commented over at William’s blog – if one or more of you decided to come back to read this: Welcome!

If you didn’t read this post (that is: looked closely at the images) back when I posted that, I suggest you start there. Now Salman Khan has made a series of videos where he starts at Earth, then moves on outwards. I notice in one of the videos he mistakenly uses light year as a measure of time, not distance, but he was pretty excited at that point, for good reason. I’ve posted the first video in the series below – when I watched it on youtube, it automatically started the next video once the previous one had finished, which was both good and bad as I probably sat there for over an hour watching that stuff, but I don’t know if it’ll do the same when embedded here. If not, you should really watch the series on youtube if you think the first part was ok – it gets even better and far more mind boggling as he proceeds.

I love what Sal is doing. If you felt the need to follow the link to Salman Khan’s wikipedia article because you don’t know who he is or what he’s doing, here’s another good video you should watch:

And here’s the link to the site.

…

In other news, here’s a chess game I played earlier this evening (I was white and it was a 5 minute game so presumably lots of mistakes if you let the silicon monster have a look at it). I haven’t run it through a computer, but I still think my decision to exchange on g7 and move 20.f5 instead of taking on e6 was the right one. I really liked that 20.f5 move when I played it. If black wants to survive, he can’t defend that e6 pawn anyway, i.e. 20…Nf8, 21.f6+ Kg8, 22.Qd2 Nbd7, 23.Qh6 Nf6 (…Ne6, 24.dxe6 Nxf6(□), 25.Nxf6+ Qxf6(□), 26.Rxf6 and white has the same win as in the game with the Nf3 and Ng5-manoeuvre), 24.Nxf6+ Kg8, 25.Nh5! Ne6 (…gxh5 and after 26.Rxf7 black is mated), 26.dxe6 Rg8(□), 27.exf7 and game over). I think 20.f6 was a better defence than Ne5, Ne5 was a bad move. Black needs all the support he can get of the black squares around his king after he’s allowed the exchange of the g7-bishop. That said, the position after f6 is still losing for black.

“My life matters!” yelled the moskito

(Click to watch in a higher resolution. Link.)

(again, click to watch in a higher resolution. Link. Most of it is speculation and you can always quibble about the details, but the main point stands.)

(-ll-, link)

It is estimated that there are more than three times as many neurons in an adult human cerebral cortex alone than there are humans on Earth. The total number of neurons in the human brain is estimated at appr. 14 times the number of humans.

Between 50 and 70 billion cells die each day due to apoptosis in the average human adult (link). There are approximately ten times as many bacterial cells in the human flora of bacteria as there are human cells in the body (link). One might say ‘humans are complex creatures’ or one might say ‘humans are nothing special’. One might also be tempted to say something about the importance of any given individual alive here. Now combine the above with this (click to view in a higher res. – warning, it’s a very big file but you should open it anyway):

Stuff like this (once you start to think about it, you can come up with a lot of similar arguments) is part of the reason why I have great difficulty taking seriously any religious concept ‘explaining the universe’ that even mentions humans. Hell, it’s very hard to take seriously a God(TM) that’d even care about the Milky Way – there are more than 100 billion galaxies out there to choose from, and the Milky Way alone contains 400 billion stars. We don’t matter, a God that would care about what we do is too improbable for us to care about and a God like that raises way more questions than he/she/it answers. To use a God(TM) like that to answer any of the ‘fundamental questions’ is intellectually dishonest, because it’s the same thing as evading the questions entirely and just make up stuff that make us feel important. One of the first thoughts that crosses my mind when thinking about a God that actually cares about humans is ‘stamp collector’. One of the others is, as I’m sure you know, ‘evil bastard’.

Space colonization

Via MR, I found this blog. It looks very interesting. The post Tyler linked to, about the habitability of Earth, was fun to read, especially as I’ve often been thinking the same thing (far most of Earth is really, really deadly to humans, and in a historical context, most of the time this planet would just with almost 100 percent certainty have killed you dead, good and hard, no questions asked). But this post, about space colonization, is even better. Stross states in the beginning of the post that those of a sensitive (or optimistic) disposition might want to stop reading right now – I say: Read it, no matter what you think right now. I have for a long time, for many of the same reasons as the ones Stross outlines in his post, been a member of the: ‘human space-travel to exoplanets outside of the solar system…’, and especially ‘the succesful establishment of a human settlement on an exoplanet’…, ‘is just never gonna happen/work/succeed’-camp.

Interesting

In astrophysics and physical cosmology, Olbers’ paradox, is the argument that the darkness of the night sky conflicts with the assumption of an infinite and eternal static universe. It is one of the pieces of evidence for a non-static universe such as the current Big Bang model. The argument is also referred to as the “dark night sky paradox” (see physical paradox).

Much more here. I love wikipedia!

I remember that this really puzzled me when I was a kid, that is, why the night sky looked the way it did (Olbers’ paradox actually isn’t a good place to start if you want to know that, but anyway…). I didn’t get why, if there was a lot of stars around in the sky, lighting up everything, then even if the universe was very large and the stars were far away, why was everything so dark at night? If there was a star in almost every direction I could see, then why wasn’t the sky much brigther? Also, if the universe was infinitely large (I had a really difficult time accepting that statement), then there would be an infinite number of stars too, rigth (no, that’s not right, see point a in the link. But I didn’t get that back then of course)? And if there was an infinite number of stars, they would light up the whole sky, not just bits and pieces here and there, rigth? Asking my parents didn’t really help… (I’m pretty sure it was during my “asking age” I wondered about this, that period of your life where you drive your parents insane by asking them so many questions that no human being can possibly answer all of them, but I’m also quite sure it took me a long time to pass that age, so that doesn’t really help me pinpoint the exact time).

Btw: If you were wondering, the number of stars visible with the naked eye at night-time at any given location on earth, given ideal viewing conditions, is in the neighbourhood of 3.000, as Asimov expressed it in his book Facts and Fancy (recommended): The faintest star that can be seen with the naked eye, under the best conditions, is of magnitude 6.5 and the number of stars that exist in the entire circuit of the skies that bright or brighter is just about 6000. That’s all. That’s the hard fact of it. Six thousand.

For comparison, it is estimated that the total number of stars in the observable universe is 7×10^22.