How do we use bits? We can count. 00000, 00001, 00010, 00011, et cetera. So we can count, but we can also label things. And a good example of this is the barcode for things you buy in the supermarket. The barcode is a series of lines, the lines are a bunch of narrow lines, and then there's some thicker lines in between. And the idea is that each of these narrow lines is zero and each of these thicker lines is a one so this barcode that I actually drew for you right here is in fact a barcode that says 000 11 000 1. It's a number in binary but each item in the supermarket has its own specific barcode, that says, "Hey it's just a label that says this is an apple, a gala apple from Washington State." Or "This is a box of All-Bran Buds." So we can use these bits as labels, and now you see how the power of information comes in. Because with a relatively small number of bits, we can label a very very large number of things. To get a sense for how many things we can label with bits, let's note the following feature. So two to the tenth, which is equal to two times two times ... times two, ten times, this is two raised to the power of 10 which is equal to 10000000000 in binary. is actually equal to 1024 in digits. That is to say two to the tenth is approximately equal to ten to the third, a little more than a thousand thousand plus change. Actually in the old days with computers, when you bought a computer and you would say, "I bought a computer with a thousand bits of memory." That's how old computers have a very small amount of memory. It didn't mean a thousand, a kilobit, it meant a thousand twenty-four bits. A byte, by the way, is equal to eight bits. A megabyte was a computer with not just a million bits of memory, but an extra 2.4% for free. Sadly, a few years ago, the computer companies realized the error of their ways and they stopped giving you this extra bonus. It's terrible, you can call this progress, and progress, you know, information processing Microsoft Word 95 was significantly easier to use than Microsoft Word today, which shows you the perils of information processing. So if we have these 10 to the 90 particles, that's approximately equal to two to the 300 elementary particles in the universe and because there are two to the 300 particles, that means that a barcode for each particle. If we wanted to make a barcode to label every elementary particle in the universe, it's not really quite clear where we would put this barcode on the elementary particles, but if you could put a barcode on elementary particles, that means that 300 bits suffice to label every elementary particle in the universe. So say, well I want this microwave photon over here, and they take this microwave photon this got a 300 bit barcode, and they put it on the scanner, "Yes here's your microwave photon, sir. That will be 300 dollars." Well, inflation is also taking its toll over the last few decades. So, you see information can be measured independent of what it means. We can count things, and because we can count things, we can label them with digits or with bits. And with a very small number of bits, we can label a huge number of things. Three hundred bits suffice to label every elementary particle in the universe. By contrast, if you look at DNA, three billion base pairs of DNA, and there are four possibilities for each base pair and that means two bits per pair, which means that there are six billion bits in the human DNA. This is way way way... more amount of information than is required to label every single elementary particle in the universe. And what do these bits represent in DNA? They represent possibility, they represent the different possible genetic combinations which could program what we do. Now, of course, most of these bits, the vast majority of these bits are programming just elementary processes about chemical reactions on ourselves, we share most of these bits with yeast, and we share 99% of our bits with other primates like chimpanzees and 99.8% of our bits with other human beings but that extra little tiny bit makes that extra difference the difference that makes a difference.