Astronomers measured the power of jets erupting from Cygnus X-1 (the first confirmed black hole, 7,200 light-years away) and found they travel at half light speed while carrying energy equivalent to 10,000 suns—about 10% of all energy released as matter falls into the black hole. This is the first direct measurement of black hole jet power, done by combining 20 years of radio telescope data showing how the jets bend when hit by stellar winds from the nearby star. The result matters because black hole jets shape entire galaxies by either igniting star formation or blasting away the gas needed to make stars, so measuring their actual power helps astrophysicists understand how galaxies evolved across cosmic history.