Marshall Brain's Blog

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The Brain's Memory Capacity

In this article, entitled "Brain beats all computers", is the following quote:

For the first time, researchers have calculated that the power of a single brain in terms of memory capacity and discovered that it is greater than all the computers ever made.

While even the biggest computer has a capacity of around 10,000,000,000,000 bytes (10 to the power of 12), the human brain has a colossal 10 followed by 8,432 noughts, say the scientists who made the calculations in the journal Brain and Mind.

"10 followed by 8,432 noughts" is a rather substantial amount of memory. In fact, it is impossible to get a handle on that much memory. But here's an example to help understand how much memory the brain has.

There are thought to be something like 10 to the power of 80 atoms in the entire universe as we know it. Let's round that up to 10 to the power of 100 to make things simple.

It is believed that the universe has been around for 15 billion years or so. So, since the Big Bang, there have been something like 10 to the power of 26 nanoseconds that have elapsed.

Now let's say that you wanted to record the position of one atom in the universe with nanometer precision in three dimensions. If the universe is 30 billion light years across, then there are 10 to the power of 35 or so nanometers from one side of the universe to the other. So to record the position of a single atom with nanometer precision in three dimensions, you need an array with 10 to the power of 105 locations in it.

In other words, if you had a storage device with something on the order of 10 to the power of 230 bytes of memory in it, you could store the location of every atom in the universe with nanometer precision in three dimensions for every nanosecond since the Big Bang. That's a lot of memory. If you want to bump it up to picosecond and picometer precision, it is nearly inconsequential. If you want to store the position of every quark instead of every atom, you could do that too. It could all easily fit into 10 to the power of 300 bytes of memory.

If the scientists in the article are correct, and the human brain has 10 to the power of 8,432 bytes of memory, then the human brain has enough memory to store the complete picometer/picosecond/quark history of our universe, along with 10 to the power of 8,000 or so other universes. In other words, one human brain can remember everything.

Clearly that is nuts. If the human brain has all of that memory, then why can't I remember my wife's cell phone number? Why can't I remember where I left my keys?? Why can't I remember the name of my next door neighbor??? These guys need to check their calculations...