# Q & A: tides, gravity, round earth

Q:
How would you best describe how the world's highest tides work to someone who believes the world is flat and have theories of electromagnetism/levitation controlling these tides? I have lived here most of my life and have just realized that the flat earth society is real, if we live on a flat plain how would this be possible? The tides on the Bay of Fundy are a force on their own and to me prove gravity. This is a comment I posted on youtube. The ocean can rise and fall up to 50 feet over the course of about a 6 hour period (tide). This happens on the Bay of Fundy (fact). All bodies of water have tides even lakes. And I included 2 links and maybe some other words not worth mentioning here.http://www.tides.gc.ca/eng/data)http://www.nrcan.gc.ca/energy/funding/current-funding-programs/cef/4955 The 2nd link was provided to show why put a tidal turbine in the ocean why not put funding towards harnessing this amount of energy required to move the ocean. I think I lost respect when I mentioned hanging something from the "dome". Any feedback would be helpful and please put it in SIMPLE terms so I can understand.I live on the Bay of Fundy And grew up with this fact So tell me I'm crazy Or tell me gravity exists Or go huddle up in a ball And try to forget I told you this.�
- kelly Daley (age 40)
Bay of Fundy
A:

Although not all your links came through in the question, I like your general idea that tides are an excellent way to demonstrate Newtonian gravity on the round earth.  I guess for starters, you could make the point that Newton's gravity and the round spinning earth together predict not only the basics of the solar system: days, years, omonths, etc. , but predict the tides as well. They directly give that there should be lunar and solar tides, and that the lunar ones should be bigger. They say why the tides should be biggest when the sun and moon and earth are nearly in a line. The explain why there are two tides a day. And so on. When a very simple theory predicts lots of different phenomena accurately, that's strong evidence for the theory.

So then the question gets thrown back to your Flat Earth friends. What's their explanation? Is it self consistent? Is it some special claim made up just for this phenomenon? Etc.

My prediction: you'll win the argument and change no one's mind. Those Flat Earthers are really crazy.

Mike W.

(published on 12/14/2016)