When diving Tubbataha Reef, a World Heritage atoll located in the Sulu Sea, divers are suspended in space above countless schools of iridescent fish darting amongst a kaleidoscope of corals, both soft and hard, making up one of the most beautiful wonders of our world.
This is how it is when I look at two incredible images on my computer screen on the morning of July 14th, 2022. It’s like I’m suspended above a coral reef teeming with cosmic life, where galaxies of iridescent stars glow from amongst a kaleidoscope of interstellar dust, where zooming in closer and closer reveals more and more of the intricate dance of the cosmos.
The first image covers a tiny portion of the night sky, the size of a sandgrain held out at arm’s length according to NASA. The scene is extraordinary in a number of ways. First, it shows the enormity of our universe. This single tiny speck of space contains hundreds of galaxies, hundreds of billions of stars and trillions of planets. It holds more winning tickets in the lottery of life than a lifetime of Lotto draws, yet we can never communicate with aliens located so far away that what we see today is the fossilized light from billions of years ago.
Modern physics says it is impossible to know what these galaxies look like today. This is because light takes billions of years to travel to us and nothing can go faster than light. We would need some kind of exotic wormhole in spacetime, currently the stuff of science fiction. This snapshot of fossilized galaxies is a treasure trove for cosmologists as it shows what our universe looked like near the very beginning, allowing us to deduce a likely history after the Big Bang, just like looking at the fossil record on earth allows us to deduce a likely history of our own planet and life upon it.
Another extraordinary thing about this image, is that we can see galaxies tucked away behind other galaxies, where they should be hidden from view. That we can see them, is due to gravitational lensing, where the gravity of the galaxy closest to us warps the light coming from behind, bending the light so that we can see the galaxy behind appear not only once but multiple times. We are truly like children looking up into a kaleidoscope of the cosmos.
The second image on my screen is jaw-droppingly beautiful. It is part of the Carina Nebula and shows billowing banks of interstellar dust pin-pricked with thousands of glittering stars. Whereas the first image shows the beginnings and lifecycle of our universe, this image shows the beginnings and lifecycles of stars, the outpourings of energy that create all the stuff we are made of and make life itself possible.
These two mindblowing images are courtesy of the James Webb telescope, a meticulously assembled machine and a masterpiece of human ingenuity weighing more than six tons located more than a million kilometres from Earth, having been shot up in a rocket and projected into space, unfurling its huge umbrella to shield it from the Sun about which it orbits.
The James Webb telescope will teach us more about the history of stars and of our universe than we have learnt in the entirety of our species so far. We may even discover that we are not alone by looking through the atmosphere of planets orbiting nearby stars.
Humans have a long history of learning by looking up. Nowadays, everyone has heard of helium, the gas used to fill party balloons. What not many people know, is that helium was first discovered not on Earth but on the Sun. A French astronomer found this lighter-than-air element by examining the spectrum captured during a solar eclipse back in the year 1868, the name helium being derived from helios, the Greek word for the sun. Weirdly enough, it took another twenty years or so before helium was first identified here on Earth, hidden inside a chunk of uranium ore.
Early natural philosophers could not work out how the sun could shine for so long. If it was powered by burning coal, it would only last for a few thousand years. It was only upon the discovery of nuclear energy in the twentieth century that this puzzle was finally cleared up, nuclear power being so much more energetic than coal power.
I go outside and lie on my back beneath the night sky. Everything I can see, all the thousands upon thousands of stars visible to the naked eye under dark skies, are part of our own Milky Way galaxy. All the other hundreds of billions of galaxies in the universe are too faint for us to see without the aid of binoculars or a telescope. All except just three, neighbouring galaxies that happen to be luminescent and close enough to be seen, the two misty clouds to the south making up the two Magellenic galaxies and the Andromeda galaxy to the north.
It is Winter as I lie there in my backyard and showtime for Scorpius, which is (apart, of course, from the Southern Cross) here in our southern skies the most iconic and, with its magnificently coiled tail, most easily recognisable constellation during these colder months. In the Summer months, Orion the hunter takes centre stage, with Scorpius having shifted to being hidden in the glare of daylight, at least from the perspective of our planet.
I go into the house and return with a pair of binoculars. I point them upwards towards a bright blob on the ecliptic and the planet Jupiter swims into view together with its four Galilean moons all in a straight line. Jupiter has more than seventy moons but these are its largest. They are named after the Galileo of Pisa Italy, the father of observational astronomy. By watching how the four moons orbited the huge planet and observing the moon-like phases of the inner planet Venus, Galileo became convinced the motion of the Earth could be explained if it was orbiting the Sun rather than the Sun going around the Earth – and of course got into a lot of trouble with the Church on that account.
A flood of observational astronomy followed in the footprints of Galileo. Saturn and its rings, the structure of which James Clark Maxwell explained in mathematical terms. Neptune’s orbit not conforming to Newtonian physics and only explained after the formulation of Einstein’s general theory of relativity. Star explosions like Eta Carinae seeding the local neighbourhood with star dust forming new stars in turn and creating the heavier elements in our bodies. Neutron stars merging together in cataclysmic collisions generating the even heavier elements like uranium. Comets. Black holes where physical entities like space and time cease to exist.
And now the James Webb telescope, possible harbinger of extra-terrestrial life.