The Farthest Galaxy
The Rho Oph nebula, a star-forming region in our Milky Way photographed by the Spitzer Space Telescope. The oldest stars here are over 12 billion years old. Our galaxy must be extremely old. Using the Spitzer and Hubble Space Telescopes, astronomers have photographed one of the most distant galaxies ever. A1689-zD1 is about 13 billion light-years away, and must have formed when the Universe was about 700 million years old. Those numbers are approximations, for the speed of light has not always been the same.
Every galaxy ever observed contains at its centre a massive Black Hole. Galaxies have been found dating from barely half a billion years after the Big Bang. Their supermassive Black Holes are far too young to have formed from star collpase or mergers of smaller objects. They are very likely primordial, formed from quantum fluctuations shortly after the Big Bang. These tiny fluctuations grew large because of the Universe's rapid expansion. Size of a primordial Black Hole is limited by a horizon distance related to the speed of light. Supermassive primordial Black Holes are one more indication of a "c change" in physics.
Even with the evidence, it may take a while for physicists to accept the simple idea of a changing c. A physics education forces students to treat c as fixed, just like the Earth. This is a reasonable assumption to make if one's mind is small. When careers and dollars have been wagered on "dark energy," escaping the epicycles is dificult. To comprehend the wonder that is our Universe, we must accept change.
More exciting discoveries at the new Carnival of Space!