Wrong
You've attributed way too much "facts" to the Dogon tribe. Sirius is the brightest star and fairly noticeable. They thought it had TWO not 1 (male and female) companions. The fact you decided to omit this fact is telling. They also mention that one of these stars (the one you are no doubt referring too) makes Sirius brighter and dimmer as it orbits, and that it's orbit lasts 60 years. Both are false.
No diagram on any cave 700 years ago either.
The sphinx is not the largest structure, the quran makes no mention of the age of the Earth (any age interpreted from it gives an age of many hundreds of thousands of years), it is the creationist interpretation of the Christian bible that gives an age of 6000 years. Muslims do not believe that, and no muslim archaeologist retrofits their evidence to fit your bogus claim.
All evidence suggests the sphinx was built around 2500BC.
And no, the Earth's axis never points towards the centre of the galaxy, the galaxy has no conciseness, nothing will happen on 21/12/12.
The only people getting dumber are the ones who actually believe this shit. Just go and look at the evidence for yourselves instead of buying into the conspiracy bullshit because you're not smart enough to advance real answers or solutions.