An example is the B612 Foundation proposing to use a gravity pull to deflect a near Earth asteroid in a controlled manner. While they do not say anything much about the technological aspects of such a solution - the proposed solution is to place this machine at a constant alignment on either of the poles and attract the asteroid.
Gravity is an interesting thing and is not something I easily understand. Electromagnetic waves are a tad easier. Waves are nice. Me like water.
