Stephen Hawking has been one of the brightest scientists of the last fifty years, and one of the most exceptional human beings our planet has ever seen. Forty years ago he posed an enigma that still perplexes us: is absolute oblivion possible in our universe? Black holes - where time is distorted to reach its end - seem to tell us yes. However, the quantum denies this possibility. This paradox between the two main pillars of physics: gravity - the science of the very great - and quantum - the science of the very small - has been the main scientific contribution of who refused to accept a tragic destiny and never stopped looking at the stars.