I was driving in my car to work the other day, and I work 50 miles away so I have about an hour to myself to think. I listen to this song, not really important which song but i'll tell you anyway. (Superstar - Lupe Fiasco) and he makes a metaphor of digging a hole in the ground all the way through the earth and ending up somewhere that is the exact polar opposite of where he is now. So I had this idea for a site for someone to enter where they are right now, whether it be America, India, or Antarctica, and then I can calculate the opposite of their location. I tried to on Google Maps, found my Longitude, Latitude, and then went to Google and typed in the exact opposite. Now this is not exact, but lets say my current location is 40, -70 (it was close to that, with a few decimal points after it.). If I were to find out what location is at -40, 70, the exact opposite of my location, is that the polar opposite of where I am right now? It was a point somewhere directly in the middle of the Indian Ocean, 1/2 way between South Africa and Australia. It seemed correct, but I don't have a globe to calculate the exact location. Basically, I want to create a little site that says, "Where are you?", then you enter and address or coordinate, and it tells you exactly what is the direct opposite of where you are. This is not a coding question, this is more of a theory question. Any assistance or insight would be great.
Basically, what I am asking is, if my polar coordinates for where I am right now are, say, -70.003, 40.056; If I were to dig a hole STRAIGHT through the Earth, my coordinates would now be, 70.003, -40.056?
