These are the top eight things I have been sharing with my granddaughter – who is all of one-year old today – about the wonders of the universe that we live in. In time, I hope that she will read this blog and know that this was my gift to her for her first birthday. Such are the stuff that our bedtime stories are made of.
1. Space is mostly, well, just that – empty space. If the Earth were the size of a marble, the sun would be a 40-inch beach ball and they would be at opposite ends of the length of four basketball courts. Pluto would be a pinhead about 5 kms away.
Proxima Centauri, the next nearest star to our own star, the Sun, would be about 32,000 kms away. In between all of that – emptiness.
2. When you look at the stars, you are travelling back in time. Light travels in a vacuum at close to 300,000 kms per second. Space is too big however that even at that speed, the light from the sun will take 8 minutes to get to Earth, 4 years to get to Proxima Centauri, and 2 ½ million years to get to the next big galaxy beyond the Milky Way. That makes telescopes like time machines. The largest ones show how the cosmos looked even before the earth was born.
3. We are all made of star stuff. Atoms inside stars combine to form other elements whose atoms then combine to form other elements and so on. This is what makes stars shine and is called fusion. This is also what made the carbon, oxygen, silicon and other heavy atoms in the universe. This stuff went on to form solar systems, planets, moons and – in at least one case that we know of for certain – grandpas, granddaughters, and golden retrievers.
4. Planets are smaller than stars. Stars are smaller that solar systems. Solar systems are much, much smaller than galaxies. Another scale model, this time galactic. If the sun is a marble, Proxima Centauri is a pea more than 300 kms away. Our own Milky Way galaxy has about 400 billion stars and it is shaped like a pancake with a thick spot in the middle. In this scale, the Milky Way pancake is about 6 million kms from edge to edge.
5. Extra terrestrials remain elusive creatures, but we’ve found out that planets other than our own eight (or nine) are everywhere. In the last few years, we’ve found hundreds of other planets orbiting hundreds of other nearby stars. In fact, it’s now pretty clear that half of all stars come with planets of their own. We can’t take pictures of them yet and we haven’t found a twin of the Earth, but that’s only a matter of time.
6. Science is about making mistakes – and learning from them – so we can uncover the truth. So is life. Asking questions is what makes a scientist a good one. So is trying things out and making mistakes, that’s what you call doing an experiment. The point of science is to find mistakes and to learn from them. In fact, we learn the most from scientists who disprove theories and ideas – restless skeptics who uncover mistakes.
7. Having a telescope does not make one an astronomer. Sure, there are some sights, like Saturn’s rings, that require a telescope. But with just your eyes, you can spot a moon, several planets, stars of many kinds, star clusters, a few glowing nebulae, and a distant galaxy or two. Simple binoculars can bring even more fascinating sights within reach.
8. No one owns the stars. They belong to everyone. The sky puts on the greatest show on earth, whether by night or by day. The best part is, admission is totally free. Learn some constellations and they will be your nighttime companions for life. You just got to learn to look up and find out more about what you see.