Assertion: black hole | /r/HasProperty | seen with sophisticated equipment
Facets:
value: in use
type: OTHER
value: directly
type: MANNER
Source sentences:
text: Neither wormholes or black holes have actually ever been seen directly, even with the sophisticated equipment in use today, but both follow inevitably from Albert Einstein’s General Theory of Relativity, and plenty of indirect evidence has been obtained (at least for black holes).