PHOTONS travel light. They have been zinging around the cosmos largely unimpeded since around 380,000 years after the big bang, when atoms formed and the universe became transparent to them. Astronomy is essentially the act of capturing as many photons as possible; cosmology that of translating this act into a coherent picture of the universe.
News this week that we have made our best ever map of the cosmos, depicting some 11 billion years of its history, is a milestone on both counts (see “Biggest ever map of the universe reveals 11 billion years of history“). It is the result of two decades of light gathering by astronomers at the Apache Point Observatory in New Mexico involved in the . For cosmologists, the map is the best confirmation yet that their standard model of the universe is correct – albeit with one big caveat that suggests our understanding is far from complete.
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If you leaf through the you might think that, for such a grandiose view of the universe, it rather lacks in visual appeal. Not so for the image that is the centrepiece of our cover story this week. Rarely have photons been combined to such iconic effect than in the first direct picture of a black hole.
“Future generations will have the chance to look further, and sharper, into the universe than we can”
There is a tendency with such a momentous breakthrough as this – made by the Event Horizon Telescope in April last year and, again, one decades in the making – to walk away thinking “job done”. But the power and beauty of scientific discovery is that it builds on itself. As often as not, such events represent the closing of a chapter and the opening of many new ones.
In this case one new chapter is the mind-bending, yet simultaneously awe-inspiring, thought that the black hole’s orange glow hides infinite rings of photons that it captured at different times – a movie of the universe as seen from its perspective (see “Black holes are hiding movies of the universe in their glowing rings“).
Does it matter that we lack the capability to see much of that cosmic footage yet? Not really. We should see these insights, and those of SDSS, as investments for the future. They remind us that if we preserve ourselves, and the planet we live on, future generations will have the chance to look still further, and sharper, into the universe than we can.
