So, you've got a computer geek's
1989 paper as your prime source, and then Wiki entries, not directly on the subject. Your original source is where you picked up your awful "roughly" habit of guessing withing a range of 2 orders of magnitude:
You should also have noted that your original source gave two very different figures for the size of the brain. This alone should have stopped you stating brain size here unequivocally.
At least you have acknowledged your cock up. That's a step forward. It may encourage you to be more careful with your claims in future. What it hasn't done, though, is get you to use Wiki properly. Go to the noted source for the figure, in this case:
You'll find that
here.
Read it, to find out if it says what Wiki claims it says. You see,
with people like you editing Wiki, there can easily be inaccuracies.
Finally, just put "number of synapses in human brain" into your favourite search engine, and you might come up with some interesting stuff. For instance, did you know that males have a much larger number of synapses than females? And that the number of synapses declines with age?
Here. Thus any one single figure for the number of synapses in a brain is inevitably wrong for most cases. That undergraduate paper, by the way, gives the total number of synapses in the neo-cortex alone (ie only about 75% of the brain) as between 0.85 x 10^14 and 1.7 x 10^14, with the first figure being of young males, and the latter figure being for 90 year old females.
It also seems that you build and lose synapses all the time, and by that I mean on a daily basis. There are, it seems, variations of between 35 and 50% in the number of synapses in the brain when you are asleep compared with when you are awake.
Here is a paper on that subject, but not the source of the above figure.
I don't have the time to do this more thoroughly now, but what this shows is that any simplistic figure for brain size (in synapse terms) is wrong. It is much more accurate to describe the total number of neurons in the brain, rather than the temporary and transient synapses, which are constantly making and remaking themselves (you've hear of "brain plasticity" no doubt).