Why do the pedals on my bike scew on opposite from each other?

Because they are on opposite sides of the bike

b/c its lefty lucy and righty tighty as your lookin at it.thats the way my shop teach told me moons ago.it works.but the trick is,as your looking at it

Because otherwise one would screw off while you were riding it. Think about it.

The pedal on the drive side of the bike should is called reverse thread. This is because if you continue to pedal, you will eventually loosen the pedal on that side of the bike. When you pedal you are actual tightening your pedals into the crank with each turn.

you bottom bracket on that side of the bike is also reverse thread in case you are curious.

It's done this way so pedals don't screw themselves off when riding.

Please ignore all the folks who are trying to tell you it has something to do with the side of the bike you are standing on, righty-tighty, lefty-loosey, etc. They have no idea of what they are talking about.

The non-drive side pedal has a reverse thread. As folks with a clue stated, this is to keep the pedal from loosening itself while pedaling. A regular threading on the non-drive side pedal would have a tendancy to work itself loose as you pedal. If a pedal ever does come loose it tends to completely booger up the threads of the crankarm, so you want to avoid any possibility of this happening.

Hope this helps you out.

uh, r u okay to be riding that bike???