Reber had just one little problem. To explore the radio energy, he needed a radio telescope – a telescope that could detect invisible radio energy – but there was no such thing at the time. So he invented one. —A Black Hole Is NOT a Hole, Carolyn Cinami DeCristofano How does the information about Reber's invention connect to what you have learned about black holes? Black holes are also invisible. Black holes are seen in a telescope. Black holes were also invented. Black holes detect radio energy.