# What observation(s)--if any--confirm that the types & concentrations of energy, which are influenced by gravity, are the same ones that cause gravity?

General relativity allows various forms of energy to participate in the gravitational force.

What observation(s)--if any--confirm general relativity's notion that the various types & concentrations of energy which are influenced by gravity (i.e. feel the effect of spacetime curves...sometimes referred to as "passive") are all the same types & concentrations that cause gravity (i.e. create spacetime curves...sometimes referred to as "active")?

I now provide links to a couple Physics StackExchange questions which arguably come close to answering the above, but don't quite answer it...with one answerer readily admitting he's unaware of any such observation(s), when it comes to light.