Did I understand?
What means understanding something? What means detecting a star? What is detecting a black hole? I understand, am aware, believe that a black hole cannot be seen with my own eyes as I can see a star in the sky. What is seeing a star in the sky? Just a spot of light. What use can I have of this observation? Is it necessary to have any use of it? Oh this science! It causes more questions tha it answers.
On the level of this text, it is impossible to see the practical usefulness of science, although our everyday life is completely dependent and lying on the basis of science!
Four stars for the glimpses of hints to our experiences and the chance of reconstructing an encyclopedy out of smoke and ashes after it having been burned.