Next possibility is a massive blast of electromagnetic energy from a ground source.

Is heat produced by rubbing two rocks together electromagnetic energy too?

He believed this electromagnetic energy had an amazing effect on physical health, and that it could be transmitted from one person to another.

One solution was to use electromagnetic energy rather than a mechanical connection.

The total electromagnetic energy inside the box is thus given by:

This process requires interaction with high levels of electromagnetic energy.

Light is also made up of electromagnetic energy and has a frequency.

They cut off every kind of electromagnetic energy anywhere on the island.

To all other forms of electromagnetic energy, and to matter in any form, it was impervious.

This would explain why electromagnetic energy can travel both ways - it doesn't have to be converted.