To answer your question Light is only a very small slice of the electromagnetic spectrum, they are not interchangeable but are varying degrees along a continuum. for reference [en.wikipedia.org]

I found him completely daft until the graviton commentary started. Up to that point all his inane babbling was bullshit.

Once he got into gravitons they started making some good points. The old classical theories are based in a 3D world ... not one recalculated mentally for "space-time". Space-time is reality now plus in the future all wrapped in a ball and divided by slivers of individual experience. As Dyson remarks individual temperature is a measurement only relevant in a given moment in space-time. In total, with all space-time together the energy balance would be zero. But in individual slivers it may be high or low. So as a measurement temperature means nothing in quantum terms.

Dyson proposes that the old theories describe gravity in a 3D world and it may not be an issue at all in a quantum world. Much like temperature gravity is a singular measurement in a sliver of space-time calculating spatial distortion due to an object's mass. Over all time that will be zero as well. I am thinking this is because that distortion is actually our big bang explosion trying to propel us forward to the front of the blast wave like other explosions. Time is the lag caused by that spatial distortion felt in individual slivers as gravity.

Sounds feasible.