The Scales of The Universe

What are the largest scales of the universe? What if the universe itself could be considered ‘small’ to another observer? What even is small and large? It all really depends on the conscious observer that you ask. For humans, we could for example, consider large to be a building, and we might say that the Earth is massive. However, the Earth in comparison to the sun is pretty small, in fact, you would need about 1.3 million Earths to fill the volume of the sun. The number itself of 1.3 million Earths is pretty much incomprehensible for the human mind, we can imagine 5 apples, but increase the quantity to even something like 20 and it becomes harder to imagine. We simply have an idea of what 1.3 million means.

The Smallest Scales

So, what are the smallest and largest scales that we humans perceive? Let’s start from the smallest and work up to the largest scales of the universe, this post will be a basic overview, so we won’t go into as much detail here to any specific thing. Keep in mind that this is our current understanding of both quantum physics and cosmology, we may eventually find that there are ‘smaller’ scales and even larger scales.

The Quantum Scale

Atoms were believed to be ‘uncuttable’ and the smallest unit of matter, but we now know that it isn’t exactly true. Atoms are made up of protons, neutrons, and electrons. Protons have a positive charge, neutrons are neutral in charge, and electrons have a negative charge. We can still keep going further down the scale and find that protons and neutrons are made up of quarks, which are divided into 6 ‘flavours’ (yes, we call them ‘flavours’). These flavours are up and down, charm and strange, and top and bottom.

The Scale We Exist in

We as humans see things everyday that without an understanding of the smaller scales, we would not quite understand. Plants and animals for example are living things that without the use of instruments like a microscope, would not be able to understand them as deeply as we do now. Computers and phones would not exist without an understanding of quantum physics. The things that we see all work because of the smaller scales, and thus an understanding of them is crucial for scientific development.

The Astronomical Scale

The moon, the planets, the sun, the galaxy, these are scales that we can’t even begin to imagine how large they actually are, and just as we use instruments to observe the smaller scales, we also use them to observe the largest of celestial bodies. An understanding of the largest scales is important to grasp our place in the cosmos. The Earth is located in our solar system, which contains our star, the sun. Which is one of 100 - 400 billion stars that are part of our galaxy, the Milky Way. We are simply just another planet that happens to contain life that is located approximately 27,000 light years away from the centre of the galaxy. The number of 100 - 400 billion stars is already a massive amount, yet we are still not considering another important fact. That is, that there are potentially about 200 billion - 2 trillion galaxies in the universe. We are talking about trillions here, and that is galaxies, not stars… Although not part of the topic at hand, the question naturally arises if there is life out there, considering how massive the universe is, and how many galaxies and stars there are. We will revisit this topic in another post so keep that in mind!

Last Thoughts

Different scales may seem and act very different from one another, but everything is part of a single thing, which we call the universe. It is important to think of these scales as one as well, understanding that quantum physics will still have an effect on the astronomical scales. Everything plays a role in everything else.

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