Fair play
@Duke of Marmalade , you have provided an interesting summary of some of the technological workings of bitcoin that certainly give pause for thought. As previously stated, I'm in the novice arena when it comes to the technological side. I suspect that perhaps this area has been trashed out elsewhere in other bitcoin threads, if so, it would be interesting to re-read through previous thread (which one?) once more rather than repeat ad nauseum.
In the meantime, trying to break down your summary in purest lay-person's language, I will set out my stall.
My understanding of your post is that the levels of difficulty in the chain are unwarranted as by the 3rd block, the mathematical equations were complex enough to ensure it was impossible to alter the block at this point as to do so would require a period of time and processing power that would be useless by virture that, over that same period of time another block (the 4th block) would have been added to the chain? And as this is now the longest version, then it was the valid chain. And any attempt to corrupt the chain would have to recommence on that chain? By which time, another longer chain would have developed and this is the valid chain? Or something like that?
And, in turn, as we are at block 630,000 or so, meaning it is impossible today, by any reasonable understanding to alter and corrupt the blockchain, so adding additional blocks is actually a waste of time and, significantly, energy?
Certainly, the electricity consumption has always been a red-flag in my patch of the woods.
However, it is the conceptual side that I consider I have a reasonable grasp with bitcoin.
It all goes back to the beginning of the concept of money in the first instance. This, however, I know has been trashed out on other threads so I wont start those wheels turning again, but the claim is bitcoin is 'digital gold'
Instead I shall, which should please you, revert to reknowned political and economic historian Niall Ferguson (not of Nobel calibre, but if I understand correct, he schmoozes in those circles).
His 6 part documentary series "The Ascent of Money" is worth a watch if you havent seen it already. Episode one is provides good insight into how money is nothing more than a human concept derived from trust. Over the ages as we know, all sorts of things were used as money in one manner or another, seashells, paper, clay tablets, God, metal.
The critical point is that gold became the globally accepted measure of money, because it was the hardest form of money.
If you are not inclined to watch the whole series, or even a full episode, I would recommend episode one from 8mins 30sec to 11mins 40sec's.
Ascent of Money episode 1
In Fergusons words "
money is not metal, it is trust inscribed. It doesn't matter what it is inscribed in, paper, clay, a screen, provided the recipient believes in it"
So money is not metal, but if the price of gold rises high enough, there are miners willing to invest inordinate amounts of time, energy and resources to extract it out of the ground - it having become increasingly difficult to do by virtue of all the mining that has already gone before. And the only way to ensure that one piece of gold is new gold, and not a piece being double-spent, is to establish a vast network of vaults, registrations, custody orders etc on a global scale.
So all in all, there are technological elements of bitcoin that I am not comfortable with, however on a conceptual side it is a brilliant idea.
But what of the technological elements need resolving/improving?
So who do I listen to when trying to grasp a sense of progress in this area, economists? Nope, I listen to the technologists and innovators and entrepreneurs. And if you spend sometime listening to their side (not including price projections), then from my perspective, bitcoin is only at its infant stage of its life cycle. It hasn't even learned to walk yet.
It may not survive into adulthood, but it is growing fast and very robust. And, as it is being claimed, it is the hardest form of money, inscribed in digital form. That has value.