How does my aliens' tractor beam work in space?

Researchers create a sonic tractor beam

By Hanae Armitage 27 October 2015 1:00 pm

Using a simple set of loudspeakers, scientists have figured out a way to levitate and rotate objects in midair. If perfected, this "sonic tractor beam" could find uses ranging from treating kidney stones to creating artificial gravity on the International Space Station.

That isn't going to work for my aliens when grabbing onto other spacecraft. There are no sound waves in space. How can they use electromagnetic or other physics to create their tractor beam?

posted over 8 years ago

chasly from UK‭

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