Oh no, you have been reading that Erich van Däniken crap? To take just one thing that is plain false:
oh, and a photo of the side of the sphinx was taken to numerous geologists who were asked to identify the type of erosion they were seeing in the pic. 100% of them said it was "obviously water erosion".
Even Wikipedia will teach you
that the erosion of the Sphinx is a highly controversial issue, both regarding its causes and (among those who support the water erosion hypothesis) regarding the climate of ancient Egypt. The outcome of this debate could change the dating of the sphinx from anywhere to as old as the great pyramids (the majority opinion among Egyptologists) to the beginning of the Old Kingdom -- either way, there is little doubt that it was built by Egyptians.
To come back to the point of plain falsity, it is not true that 100% of scientists believe that the Sphinx has been eroded by water. Furthermore, such a story about a photograph taken to "numerous geologists", who were then "stunned stupid", has all the marks of myth. Who took the photographs to which scientists, when? We get no details that would allow us to check the story because it never happened; it never happened, because this is not how science works. This is the kind of rhetorical story though up by crackpots who need to believe that there is some mythic "scientific consensus" out there which is protected by scientists not "looking at the evidence" until some clever freethinker "tricks" them into it. It makes me mad to see such nonsense spread, because it turns our legitimate wonder, doubt and curiosity into some kind of anti-intellectual conspiracy theory. Blegh.
Here is a fun fact, which I only recently realised: the Sahara became a desert only between 4000 and 6000 years ago (we are not sure). Before that, it was a savannah -- not lushly forested or anything, but still the kind of place where lots of animals could live, men could hunt, and so on. The earliest Egyptian dynasty is from a little before 5000 years ago: they or their not that distant ancestors have actually experienced this
. Have experience the greatest part of north Africa turning into a a desert. (And it is still going on: the north African coastal region was an important grain-growing centre for the Romans. Hard to believe now.)
Anyway, if you are interested in ancient Egypt -- and I encourage anyone to be interested in ancient Egypt, it is fascinating -- get a good book about ancient Egypt instead of reading the pseudo-science stuff. You will learn lots of things that you don't know, you will learn that there are many other things nobody yet knows (because all scientific books I have ever seen are very upfront about acknowledging this, and reading science is the best way to realise how little we know), and you will satisfy your curiosity by the kind of knowledge that only excites further curiosity. That is a lot more fun than getting a false feeling of I-am-smarter-than-those-scientists by reading nonsensical arguments about the Egyptians covering every inch they built with inscriptions (wrong; no one is going to inscribe the outside of buildings, and certainly not buildings meant to stand among sand storms for millennia), or about it being so surprising that they didn't paint the building of the pyramids (which, given that most of their paintings are meant to depict the afterworld, is the most unsurprising thing ever).
That was a bit of a rant, but none of it was meant aggressively, of course. I just... yeah, it really boils down to what I said. I hate how these people turn what is good (curiosity, the desire to know and understand) into what is bad (a false feeling of superiority and an antagonism towards even honest science, and most science is honest science) while that same good can lead people to wonderful discoveries.