Ahhh, more cult parroting. There is actually a simple experiment you can do to prove the equatorial bulge, and IF YOU WERE BEING SCIENTIFIC instead of just being a cult parrot, you'd know how we actually figured out there is an equatorial bulge with a simple, but damned clever experiment, that anyone can do.

Take two identical pendulum clocks and run them at the equator and at another latitude... then explain why one runs slower than the other if the earth is flat and stationary. Good luck proving that it's due to something else other than equatorial bulge... but , being a scientist, you can't just IGNORE this observable, repeatable, measurable, predictable observable reality... and you ARE a scientist... right? LMAO.

https://en.wikipedia.org/wiki/Equatorial_bulge

And how this experiment was confirmed.

https://books.google.com/books?id=qumVBAAAQBAJ&pg=PA124&lpg=PA124&dq=equatorial+bulge+newton+pendulum+different+lengths&source=bl&ots=7zjqrGj0QJ&sig=CvPXazyIy_HMGmz8lFHYWCaEIFg&hl=en&sa=X&ved=0ahUKEwjb1JjPmZHbAhUB-J8KHXZfAYAQ6AEIfTAM#v=onepage&q=equatorial%20bulge%20newton%20pendulum%20different%20lengths&f=false