Adaptive activation question

Greetings

I am very new to arduino so I am reaching out for help from those far more knowedgeable than I. I want to creat something that will trigger an electric pulse from the arduino whenever 2 objects pass eachother. While not exactly what I want it for ; as an example, lets just assuming i have a wheel with a sensor on the outside. This wheel is free rotating within a slightly larger wheel with a sensor on the inside, also free rotating in the opposite direction. Could it be possible to program arduino to activate each time the sensors pass eachother? How fast could these be going before it surpasses the capabilities of the arduino? Are there any systems better suited for high accuracy and highly regulated pulses?

I appreciate any feedback

Could it be possible to program arduino to activate each time the sensors pass eachother?

If one of the sensors is a hall effect sensor and the other "sensor" is a magnet, yes.

How fast could these be going before it surpasses the capabilities of the arduino?

Depends on the type of sensors. Measuring shaft rotation speeds of thousands of RPM is not terribly difficult.

Are there any systems better suited for high accuracy and highly regulated pulses?

It would be better to end the tap dancing session, and explain exactly what you want to do.

Mmaibl2011:
While not exactly what I want it for

You will get much better advice and your questions will make more sense if you explain what you do want it for.

What about an optical detector - either a reflective optical detector or a slotted optical switch?

...R