🪐FMS 7: Cosmos all around

And I don’t mean the cocktail.

I have always been interested in outer-space. It is vast, unknown, and maybe a little bit scary. It holds so much awe inspiring beauty and is always changing. Kevin Pretorius has been interested in space and astronomy since he was a boy. He is giving us some knowledge on how to pursue your space curiosities.

I grew up in London, England during the 1960s. When I was perhaps 9 years old, I owned a small, cheap, wobbly telescope that I used to look at the moon and Jupiter. I devoured astronomy and science-fiction books from the local library, I avidly followed the space race, and I was glued to the TV watching astronauts walk on the moon.

I remember being very excited to read that there would be a total solar eclipse in the UK, but was then crestfallen to realise that it wouldn’t happen until 1999 - by which time I’d be really, really old.

My childhood interest was supplanted in my teenage years by an interest in electronics and computing. I studied those subjects at university, and I pursued a successful career in the IT sector.

It was the arrival of the spectacular comet Hale-Bopp in 1997 that rekindled my interest in astronomy. I bought a small telescope to watch it, and then another, larger telescope soon after. I watched the 1999 eclipse with my family and I was hooked again. This time I took up the hobby more seriously.

When my children left home for university themselves, I became nostalgic for my own university days and longed to get back into the learning habit. I found a distance-learning course with the University of Central Lancashire that I could study whilst working full-time. Last year, at the age of 65 – I graduated top of my class, with a Bachelor’s degree in Astronomy.

Astronomy attempts to tackle some of the biggest and most profound questions of existence — How big is the universe? How did it all begin? Where did we come from? Are we alone in the universe? Are there other places we might one day call home?

So much goes into earning an astronomy degree and understanding astronomy. My program taught me about astrophysics, planetary science, stellar evolution, galaxy dynamics, cosmology and much more. To the curious mind, astronomy is a cornucopia of stimulating topics, unsolved questions, and bold ideas. The pace of discovery in the last 25 years has been simply phenomenal.

I enjoy knowing about such things, and I enjoy sharing such knowledge with others. I’ve run evening classes on astronomy, given many public and private lectures on a wide variety of astronomical topics, and I’m heavily involved with my local astronomy society.

But away from the science, there’s also a simple pleasure to be had from being out under the stars, away from the bright lights, and trying to capture the beauty of some distant nebula or galaxy with a telescope and a camera. This can be a technically challenging thing to do, so it’s satisfying when it goes well and everyone can enjoy the beauty of the result.

The universe provides a natural laboratory for studying extreme physics operating at unimaginable scales, and for looking back in time to understand how it all began.

Astronomers can observe massive stars exploding at the ends of their lives; objects with magnetic fields strong enough to wipe every credit card on Earth from the distance of the moon. We can also observe the dance of a pair of black holes spiralling inwards and merging with each other in an event so violent that it shakes the fabric of spacetime, enough that we can still detect this from hundreds of millions (even billions) of light years away.

The Rose Nebula: Image by Kevin Pretorius

Telescopes like WMAP and Planck have enabled us to study the big bang through the patterns written into the cosmic microwave background, much like archaeologists reconstruct the lives of ancient peoples from the remains of their buildings and artifacts.

The James Webb Space Telescope will look back in time billions of years to study the emergence of first stars and galaxies, and will analyse the atmospheres of planets orbiting around other stars. The discovery of methane and oxygen might indicate the presence of life, but even that would not be as paradigm shifting as the discovery of industrial pollutants.

I think anything that inspires a sense of wonder and curiosity in science can only be a good thing. My youthful exposure to astronomy and the space race motivated me to pursue a STEM career, and I’m certain that I’m not alone. We face many global challenges in the 21st century, and the world needs a lot of engineers and scientists to help us solve them.

There’s a lot of confusion about cosmology and the big bang, and in part that’s down to complexity of the subject matter, some overly simplified communications, and how rapidly our knowledge about this is deepening and changing.

For example, it’s not unusual to hear people describe the big bang theory as the whole universe popping into existence and exploding outwards from an infinitely tiny point at the centre, sending galaxies rushing through space at speeds faster than the speed of light.

Most of that is completely wrong or at least highly misleading.

Firstly, the big bang theory has never been about the initial moment the universe ‘popped’ into existence. It has always been a theory about the evolution of the universe from the earliest moments after ‘whatever happened’ at the beginning.

Secondly, the usage of the term ‘big bang’ has changed in recent decades, as evidence has grown of there being a phase of rapid, exponential expansion that took place before the ‘traditional’ big bang started, that set up the conditions for the traditional big bang to take place.

This inflationary phase may be something that happens infinitely often in some precursor state of the universe that produces essentially infinite numbers of universes eternally. Or something different. We don’t know, and perhaps we never will.

Thirdly, we don’t know for a fact that the entire universe originated from a point, only that our observable universe was once contained within a very, very small volume. The entire modern universe might be infinitely large, and if it is infinitely large now, then it always has been, and at the time of the big bang it would have been hotter and denser, but nevertheless still infinite.

Fourthly, the big bang isn’t an explosion of matter within a pre-existing space. It’s the expansion of space itself that is carrying matter (stars, galaxies, etc) with it as it expands. Space is much more than ‘nothing’ – it has properties and behaviours that we understand and model through general relativity. It also only exists within our universe, which is why you may hear astronomers advise that there is no outside and there is no centre.

When thinking of everyday applications for this knowledge, I’m not immediately sure there are any. To quote Richard Feynman, “Physics is like sex. Sure it may give some practical results, but that’s not why we do it.” Astronomy is much the same.

Kevin’s song choice

Kevin said he loves this rendition of Aladdin’s A Whole New World, but more importantly, it is scientifically and historically accurate!

Follow your curiosity

Phil Plait offers a wonderful educational YouTube series that has well over 30 installments. Your Crash Course in Astronomy starts here.

If you know a bit more, or want to challenge your brainpower (always recommended), more advanced topics in Astrophysics are covered on PBS SpaceTime.

Ethan Siegel is a prolific blogger who writes currently for BigThink. In addition to his writings, Ethan produces a monthly podcast called Starts With A Bang.

There are many things we have left to discover within our world and what is out of this world as well. We observe to learn and we learn to adapt. Look up.

Take it all in,

Skyler