The film Amelie came on TV last night here in Paris, one of my favorite films, and at the end, something hit me. I’ve never really paid attention to what the narrator says at the end when he’s summarizing what is happening around Paris at one moment. There’s a guy sitting on the bench and the narrator says something along the lines of (rough translation from memory), “[So-an-so] just learned that there are more connections in the brain than there are atoms in the universe.”
Probably depends on what you mean by ‘connection’. If you’re using that to talk about every possible neuron pathway, then possibly yes. If you mean every neuron, or even ever pair of neurons that are in contact, then definitely no.
There are more possible combinations of pair-bondings among the staff on my floor than there are employees in the entire building.
The claim is not that there are more neurons in the brain (or atoms in the brain) than there are atoms in the universe, the claim is that there are more connections. A to B could be one connection and A to C another, and B to C yet a third.
It’s still highly doubtworthy but your logic isn’t compelling.
But they’re talking about connections not items. And he might have meant “possible combinations of connections.”
To make some uneducated guesses, we might say that any any one neutron might be englobed by fourteen other neutrons, and can receive a single input from and expel a single output to any two of these fourteen.
Neurons Connections
0 0
1 0
2 2 (on or off)
3 7
4 36 (perhaps?)
...
Looks like one heck of a curve to me. Of course it will be limitted by the two connections per neutron of a selection of fourteen rule, but I would still think it will be quite large.
okay, the hamsters almost ate this and other people have posted the same notion, but:
Not quite impossible, as long as what’s being counted inside are not discrete physical objects, but combinations or sequences of objects.
For instance, out of a hundred numbered pins, you put seven pins into a bag. Are the number of possible subsets of the pins in the bag greater than the original hundred??
The number of possible subsets of a group of seven items is… 127 or so, depending on whether or not you count the original set and the empty set.
So no, I don’t think the question is impossible on the face of it, it’s just totally ambiguous without defining the term ‘connection’ in this context.
Carnac’s answer did not involve a false assumption at all. He answered the OP’s question correctly, which made no mention of possible connections. The only assumption was the one by subsequent posters who assumed that the character (or OP) meant possible connections. Maybe they did, maybe they didn’t, but as it stands Carnac’s answer was right on the money.
In my mind, he did make an assumption, that a connection was something that could be pointed at, (composing one or more atoms,) and exclusive to the extent that you can say ‘that atom is connection #43539852 and no other connection.’
There’s more of the definition that I left out because it didn’t seem to have any possible relevance to brain connections, but there’s more than enough here for an ambiguity.
Carnac seems to be thinking in terms of 2a, connecting structures between neurons. In that case, yes, you need atoms to build a matter structure, so there couldn’t possible be more of them than the atoms in the universe.
I was thinking more in terms of definitions 1a or 1b, sequences, relationships and associations, which don’t need to be physical associations in the sense of having a little bit of matter for each association. For instance, if neuron A sends a signal to neuron B and then to neuron C, to me that’s a connection in the brain. Not a possible connection… (I wasn’t the one to introduce the term of ‘possible connection’) It’s a real connection, a valid combination. If neuron A sends a signat to neuron B and then to neuron D, that’s a different connection: A-B-C is different from A-B-D. Depending on how long a connection you consider valid, you can easily get to a point where the number of connections, the number of distinct circuits, is greater than 10^79.
That standard would make 100 billion (10[sup]11[/sup]) times 100 thousand (10[sup]5[/sup]) or 10[sup]16[/sup] connections.
For comparison, I estimate the number of atoms in a brain as 2 * 10[sup]26[/sup], give or take a factor of 4 or 5… I didn’t model the composition of the brain in terms of its component elements too closely.
“It seems, then, that the number of atoms in the Universe is at least about 4e78, but perhaps as many as 6e79. I would suggest 1e79 as a reasonable estimate. That is, 10 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 000 atoms.”
Ummm… I’m kinduv wondering why you quoted this into the thread, Carn. We already had this estimate of the number of atoms in the universe, courtesy Kimstu, though he didn’t mention the upper and lower bounds. Did you just want to spell it all out for us to drive home how big a number with 79 zeroes really is?? Rest assured, I’m about as aware of that as my human brain will allow.
What is a “possible connection”? Nerve cells reach out and almost touch each other, right? And for each possible connection, there’s a whole bunch of molecules that make up each side of the synapse. And for nerve cells that don’t reach out towards each other, there’s not even a possibility of connection, is there?
If the question is simply how many permutations are there to group nerve cells, I’m sure it’s more than 10^79, but that’s a meaningless question.
