It was hard to miss the very first picture of a black hole recently heralded in the media. The image of a blurry orange doughnut against a black background hardly made for compelling viewing, but it is the story behind the picture that triggers thoughts about our own place in the universe and the wonder of it all.
The story begins with Einstein, who proposed the existence of round black holes with his General Theory of Relativity, although even he had difficulty imagining how something could be so dense that light could not escape from it. Thus, finally getting an image of something that emits no light is a great tribute not only to the scientists who devised a clever method using multiple radio telescopes over a couple of years, but also to Einstein’s predictive genius.
Beyond the brilliance of our scientists to advance knowledge both in theory, and now in practice, is the captivating awesomeness of our cosmos. One way to capture this wondrous reality is with numbers. The recent image of the black hole comes from a galaxy called M87, which is about 55 million light-years away. This means that the light from that blurry image is what the black hole looked like eons ago not so long after our dinosaurs were wiped out by an asteroid, a mere 10 million years earlier. And of course, this was eons before our species, Homo sapiens, was even a twinkle in the eye of Mother Nature. We’ve been around for less than a couple hundred thousand years.
It is not just numbers involving incredible lengths of time that boggle the mind, but also numbers related to size and quantity. That black hole, for example is 6.5 billion times the mass of our sun. One commonly cited comparison is that there are as many stars in the universe as there are grains of sand on our planet’s deserts and beaches. This is surely a tough one to conceptualize. It is hard enough to imagine that there could even be as many stars as there are grains of sand on the beach at Repulse Bay, let alone every beach and desert in the world, especially when we consider our sun is large enough to hold over a million planets the size of our Earth. However, now when improved telescopes are pointed at dark patches of the sky, newly found distant galaxies are appearing. And these show that the grains-of-sand analogy may be of out of date. Some estimates now claim that there are ten times as many stars as there are grains of sand!
When thoughts about our place in the cosmos arise, one of the first questions that enters our mind is whether there is life beyond our planet. None has yet been found in our solar system, but given the numbers above, it seems improbable that out of the trillions of stars and even more planets that we would be the only one. There are likely billions of planets in the universe that revolve around their stars in the so-called Goldilocks Zone, where liquid water, necessary for life as we know it, exists.
And the number of planets is only one factor. Time is also in great abundance. Life may have come and gone on billions of those planets already, as it might have already done so on our close neighbour, Mars, which probably had running water billions of years ago.
But life comes in many forms, and the great likelihood is that if the universe is teeming with life, most of it will be microscopic, like bacteria or single-celled amoeba.
The disappointing reality is that the bar for intelligent life, even with perfect Goldilocks conditions, is very high. After all, the twisted path that led to our species, starting all the way from simple strands of DNA billions of years ago through to the dinosaurs, who fortunately for us, got wiped out 65 million years ago, was far from a certainty. Actually, the lack of intelligent life beyond Earth may not be disappointing at all. Any intelligent alien life arriving here would be so far in advance of us that they could easily take over.
Finally, let’s finish with a mind game. Imagine that intelligent life emerged on a planet circling a star in galaxy M87 that had managed to avoid getting sucked into that black hole. And further, let’s imagine that they were able to detect our dinosaurs based on light emitted from Earth that had taken 55 million years to reach them, piquing their interest. If they had sent a spaceship towards us at the speed of light at that time, it would be arriving right about now. Whether they would be disappointed to find us instead of the dinosaurs is a moot point.
Kong Tsung-gan‘s new collection of essays – narrative, journalistic, documentary, analytical, polemical, and philosophical – trace the fast-paced, often bewildering developments in Hong Kong since the 2014 Umbrella Movement. As Long As There Is Resistance, There Is Hope is available exclusively through HKFP with a min. HK$200 donation. Thanks to the kindness of the author, 100 per cent of your payment will go to HKFP’s critical 2019 #PressForFreedom Funding Drive.
