4 ms·

Just out of curoisity, how many bits would it take to include all the people that have ever lived? Also, how many to realistically cover the the future?

napierzaza 15y ago
Though the bits (more like items and not actual BOOL) aren't defined, I imagine you don't need anymore. A DOB and DOD (date of death) would probably account for enough information to tell John Smith 1872 from John Smith 1905 even if they lived in the same place and had the same mustache.
chrisacky 15y ago
How can anyone possibly ever answer that question? People have been disputing how many people have ever lived on the earth for decades. Some anthropologists have thrown out numbers as high as 70billion-120billion, although other scientists have admittedly said the number is probably around 7-10B. How many people to calculate how many people have ever lived? That's just a log2( X ) number of bits would be needed. As the author of the blog says, 6000 billion people could be written in just 43 bits.
- fooandbarify 15y ago
  According to Wikipedia [1], numbers around 100 billion have been bandied about quite seriously, and much lower estimates have been "debunked as unscientific". An interesting debate, regardless. I had no idea it could be so hard to calculate. At any rate, as you say, 43 bits would have humanity covered for a long, long time. [1] http://en.wikipedia.org/wiki/World_population#Number_of_humans_who_have_ever_lived http://en.wikipedia.org/wiki/World_population#Number_of_huma...
andreasklinger 15y ago
Stop me if I am wrong but… According to… http://www.wolframalpha.com/input/?i=how+many+people+have+lived+on+earth http://www.wolframalpha.com/input/?i=how+many+people+have+li... http://www.wolframalpha.com/input/?i=106+billion+in+binary http://www.wolframalpha.com/input/?i=106+billion+in+binary 37 bits
- chris_dcosta 15y ago
  Isn't the answer always 42?
  - andreasklinger 15y ago
    If you take the timespan of HHGTTG into account yes. ;)
djbender 15y ago
A quick google search showed me that 107 Billion people have ever lived, so you would need at least 37 bits. 2^37 ≈ 137 Billion
peteretep 15y ago
37 for everyone who's ever lived (+30% more people)... and for the future? I dunno, how long do you want to go? 2x... However, 33 bits is a simplification. You can express 8.5 billion different values with 33 bits, but unless those 33 values map to well-distributed discriminators, the number is meaningless...
- kingatomic 15y ago
  It's not a simplification. It's information theory. It's not about one-to-one encodings (eg, bit 14 is whether you live in Arizona or not -- such a scheme would be ridiculous), but rather the amount of information that a discriminator reveals. For instance, knowing that a person lives in the US reveals a little under 5 bits of information (there are a little over 2^28 people living in the US, according to Google). The entropy is just a measure of the amount of information that gives us in narrowing down a population; not an exact encoding. *Edit - s/science/theory/i
khafra 15y ago
The Anthropic Doomsday Argument says that, since it would take 37 bits to include all the people that have lived so far, it takes about 38 bits to include all the people that will ever live. Many people find this somewhat disconcerting.

napierzaza 15y ago

Though the bits (more like items and not actual BOOL) aren't defined, I imagine you don't need anymore. A DOB and DOD (date of death) would probably account for enough information to tell John Smith 1872 from John Smith 1905 even if they lived in the same place and had the same mustache.

chrisacky 15y ago

How can anyone possibly ever answer that question? People have been disputing how many people have ever lived on the earth for decades. Some anthropologists have thrown out numbers as high as 70billion-120billion, although other scientists have admittedly said the number is probably around 7-10B. How many people to calculate how many people have ever lived? That's just a log2( X ) number of bits would be needed. As the author of the blog says, 6000 billion people could be written in just 43 bits.

fooandbarify 15y ago
According to Wikipedia [1], numbers around 100 billion have been bandied about quite seriously, and much lower estimates have been "debunked as unscientific". An interesting debate, regardless. I had no idea it could be so hard to calculate. At any rate, as you say, 43 bits would have humanity covered for a long, long time. [1] http://en.wikipedia.org/wiki/World_population#Number_of_humans_who_have_ever_lived http://en.wikipedia.org/wiki/World_population#Number_of_huma...

andreasklinger 15y ago

Stop me if I am wrong but… According to… http://www.wolframalpha.com/input/?i=how+many+people+have+lived+on+earth http://www.wolframalpha.com/input/?i=how+many+people+have+li... http://www.wolframalpha.com/input/?i=106+billion+in+binary http://www.wolframalpha.com/input/?i=106+billion+in+binary 37 bits

chris_dcosta 15y ago
Isn't the answer always 42?
- andreasklinger 15y ago
  If you take the timespan of HHGTTG into account yes. ;)

djbender 15y ago

A quick google search showed me that 107 Billion people have ever lived, so you would need at least 37 bits. 2^37 ≈ 137 Billion

peteretep 15y ago

37 for everyone who's ever lived (+30% more people)... and for the future? I dunno, how long do you want to go? 2x... However, 33 bits is a simplification. You can express 8.5 billion different values with 33 bits, but unless those 33 values map to well-distributed discriminators, the number is meaningless...

kingatomic 15y ago
It's not a simplification. It's information theory. It's not about one-to-one encodings (eg, bit 14 is whether you live in Arizona or not -- such a scheme would be ridiculous), but rather the amount of information that a discriminator reveals. For instance, knowing that a person lives in the US reveals a little under 5 bits of information (there are a little over 2^28 people living in the US, according to Google). The entropy is just a measure of the amount of information that gives us in narrowing down a population; not an exact encoding. *Edit - s/science/theory/i

khafra 15y ago

The Anthropic Doomsday Argument says that, since it would take 37 bits to include all the people that have lived so far, it takes about 38 bits to include all the people that will ever live. Many people find this somewhat disconcerting.