Here's a pretty decent, but brief and high level, discussion of the structure of a water molecule. The first image gives a pretty good structural idea of what's going on, which is mostly that certain electron pairs are arranging themselves in a roughly tetrahedral pattern, two of the points of which correspond to the positions of the hydrogen atoms. It's more complex than that, of course (especially in liquid state, where the hydrogen atoms are actually breaking off and joining other molecules all the time), and some of the finer details are indeed measured rather than determined from first principles. However, the overall basic structure arises nicely from the electron interactions, so the fact that water makes nice hexagonal structures with open space when it freezes (responsible not only for the fact that ice floats, but also for all those pretty snowflakes) can be shown to arise simply from the fact that it's a molecule formed from an oxygen atom and two hydrogen atoms* and from the principles of quantum mechanics. Which is really pretty cool, if you think about it.

* And of course the fact that this combination forms a stable molecule at all is pretty easy to show from basic quantum physics, too!

[-X Those accuracies are very easily achieved with today's technology. What we have some problems with is deciding how they did it with their technology (same with Stonehenge and so on).

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Knowledge is a curse, but ignorance is worse

How do you know they were drilled accurately? all you see is the hole and not how it was done.

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'The eye can only see what the mind is prepared to accept'

I'm thinking Black Sea myself--or seeing the big Med spill over the pillars. I can't imagine what that would have looked like. That's enough to mark one's collective unconscious if anything could do so.

I think a lot of people thought the ancients didn't have good sense.

That doesn't mean they saw a flying dragon in mid-air--but it doesn't mean they were just making it up either.

Most likely a fireball.

smoothness. generally speaking, drilling/cutting methods from thousands of years ago left very discernable grooves.

@fram: yes, i suppose i should have said "barely acheivable with recent technology." laser drilling and cutting, as well as water-jet technology (which i did work with in the early 90s at UMR), offer extremely smooth cuts. however, only a couple decades ago, this was difficult even for us.

either way, yes, it is really tough to fathom a civilization capable of such things several thousand years prior to our own capability.

taks

That's funny. Stonecutters have been producing smooth and flat surfaces on marble and granite blocks for centuries. Visit an old graveyard in New England some time and check out the near Grade B surface plate faces on some of the stones from the 1600s.

Re the smoothness (i.e., surface finish) and flatness of the Egyptian blocks, this was discussed in detail in this thread. There's nothing extraordinary about the Egyptian blocks, except as examples of some of the first large-scale applications of technology to materials by human beings.

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My understanding, and I'm no expert here, is that one of the major issues is the fact that the Egyptians had not developed iron, and so were doing this all with copper tools. It allegedly is very difficult and time consuming to drill into granite using copper. Of course, I've never tried it, so I can only repeat what I've heard.

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As above, so below

Yes, that's why I said that there can be discussion about how the Egyptians did it with their technology. There is no question that e.g. the Romans could do it quite easily, and that that technology has not been lost again afterwards (look at the cathedrals and so on). And of course with current technology we can go far beyond what the Egyptians have done, but there's no real need for that when building something except in extreme circumstances (for scientific experiments or so).

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Knowledge is a curse, but ignorance is worse

Check the thread I linked to. No need to drill, just to cut. Plus if one finds the right kind of materials, fracture lines play a role. Egyptian equivalents of diamond-tipped cutting tools were a factor too. All the matrix (or toolholder) has to do is support the insert, the insert tool produces the chips.

Finally, the general assumption re the Egyptian blocks always seems to be that what the quarry produced by cutting/fracturing/etc. was the finished product. Not necessarily. Once you have the general shape there are many processes that date back to ancient times for refining the rough-cut surfaces. Among these are grinding and polishing.

As an old telescope maker, give me a couple blocks of granite or marble with rough cut surfaces, some sacks of sand or other appropriate materials, from coarse to fine, and some water, and I'll produce a surface that's like a mirror.

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@jens: yes. actually, i believe they did their drilling with harder stones.

@mksutov: smooth, yes, but not nearly as smooth as the cuts and bores in the egyptian pyramids, FWIU.

taks

true again. i don't discount that. however, to call it amazing for several thousand years ago is an understatement. written languages were in their infancy, yet the egyptians were able to figure out some seemingly very advanced technologies.

taks

btw, the water jets we used at UMR (University of Missouri-Rolla) were capable of cutting 18 inches into granite. there's a balance between the material used in the water (steel shot, silica, etc.), nozzle size and water pressure that must be adjusted rather precisely for various materials. i think they've got it down to a science now, however.

i particularly worked underneath the st. louis arch cutting out the rock (dolomite) to make way for the IMAX theater. of course, in the end, we had a caterpillar lowered into the hole with a pneumatic jack hammer on the end breaking the rock up for us to haul out in a nifty hopper apparatus my buddy and i designed. yeah. we dug dirt.

the school also used the water jets to cut a mini-stonehenge, which is where dr. summers (the water jet researcher) earned his "fame".

taks