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Hello universe!

Should “universe” be singular or plural? Maybe there is a multiverse and our universe is just one of its constituent parts. That subject is at the bleeding edge of cosmological physics and can’t be answered right now — may never be — but some prominent cosmologists think it might be true.

It is natural for us to wonder about what the stuff around us is. In fact, we should wonder about it.  Continue reading

The past

Here is the history part, without any promises of brevity. It goes from the beginning — at least as far back as we can go with any degree of certainty — to the present day.

So it starts with what cosmology and astronomy tell us.

Then we jump from interstellar space to the earth for what geology tells us.

And then the history of life as revealed by fossils, finding out what paleontology and evolution tell us.

And now we are in the present.

 

What atomic physics and chemistry tell us

I am, reluctantly, a self-confessed carbon chauvinist. Carbon is abundant in the Cosmos. It makes marvelously complex molecules, good for life. I am also a water chauvinist. Water makes an ideal solvent system for organic chemistry to work in and stays liquid over a wide range of temperatures. But sometimes I wonder. Could my fondness for materials have something to do with the fact that I am made chiefly of them?

– Carl Sagan, Cosmos

The early stages of the universe and the lives of stars are the matter of physics and astronomy and their offspring, astrophysics and cosmology. By the time the first living things showed up on Earth, processes were occurring which require our knowing about the phenomena described by the science of chemistry. QM is the basis of atomic physics and that is the basis of chemistry, so we are ready for it.

To do even begin a comprehensive survey of chemistry is well beyond the scope of this document. We will illustrate its usefulness and some of its fruits by considering two subjects of great importance not only to Carl Sagan but to all of us – carbon and water.

In order to do that, it is necessary to know about several sujects:

Then we move on to consider, first, the past, starting almost 14 Gya.

Science comes marching in — basic theories

 

Four theories of science are essential to our understanding of what our “environment” is and how it and we got that way. These are theories in the scientific sense, bodies of accepted knowledge – not at all the same thing as hypotheses. All have been tested by innumerable experiments which have found them to be true to nature. This does not mean that they will never be improved upon, but whatever other theory or extension does so must also explain why they are true in current applications.

We generally consider physics to be the most “basic” of sciences, because it is self-contained and explained by no other science. It in turn explains chemistry – and therefore geology – and parts of biology. Thermodynamics, quantum mechanics and relativity lie within the domain of physics. They are explained here, because they are necessary to an understanding of the first subject, cosmology. Evolution through natural selection is also explained here. Plate tectonics fits well into the chapter on geology. Chemistry is a fairly vast subject, more than a theory, and will be discussed with physics and also with biology.

The result of it all is that we live in a world where matter sometimes behaves like a particle and sometimes like a wave and where on the atomic scale only probabilities can be calculated. All this is taking place in a curved four-dimensional space-time in which space is expanding at an accelerating rate! And this space is not an empty vacuum, it is something. Got that? If not, you might want to read it again. But above all, do not give up. It takes some getting used to, that’s all.

And that is not all. Since mutation is random, both evolution and quantum mechanics inject the theme of randomness into our understanding of the workings of the universe.1)In spite of this, some scientists think the laws of nature are deterministic. I will not discuss this subject, as it tends to make my mind seize up. Relativity brings in the vastness of the universe and the puniness of man’s place therein.

It is clear that the universe was not created for us. A much better proposition could be defended that it was made for bacteria, which greatly outnumber us and are essential for our lives. In fact, the universe was not created for us or for bacteria or for any other creature. We get along, anyway.

The bottom line is that the real, physical world is not at all as we imagine it. We really should not be surprised at this.

Now that you have the basic stuff down pat, you can go on to read about what atomic physics and chemistry tell us.

Notes   [ + ]

1. In spite of this, some scientists think the laws of nature are deterministic. I will not discuss this subject, as it tends to make my mind seize up.

The natural universe

The chapters are arranged in some introduction and three parts.

Introduction — what this is all about

Part I — the past

Part II — the present

Part III — the future (the shortest part)

  • What happens next … and last

Introduction

How scientists view the universe, and you should too

NASA's Blue Marble, western hemisphere

NASA’s Blue Marble, western hemisphere, NASA via Wikimedia Commons

In order to understand the what and the where, we start with the wherefrom and work our way up to the “Pale Blue Dot”1)A photograph of Earth taken by Voyager I from a record distance of about 6 billion km inspired Carl Sagan to use this term. See it on Youtube. we call Earth. We will go through ideas from the following subjects:

  • cosmology and astronomy – the formation of matter; the birth, life and death of stars, and the subsequent formation of other stars and of solar systems and planets;
  • geology – the evolution of the Earth itself, its surface and atmosphere, what is below the surface and beyond the atmosphere, climate and the evolution of fauna and flora;
  • biology and molecular biology, paleontology – the study of life and its development, to learn about the evolution of living organisms, including man;
  • physiology – the study of cells and organs and organisms;
  • neuroscience – the nervous system and the body’s control center, the brain.

Our path will go by way of certain landmarks, theories without which we would never find our way to the understanding which we have today: quantum mechanics, relativity, plate tectonics and evolution through natural selection. And we will follow the thread of energy and how it is transformed and used.

There will be few, if any, explanations of how we came to “know” it, nor detailed analysis of the gaps in our knowledge, although some of these will be mentioned in order to keep things “fair and balanced”. Names of scientists will be avoided. We will just look at the prevalent current world-view of science as understood by this writer. As such, it is certain to be somewhat out-of-date and subject to change – and maybe soon.

Obviously, all errors or oversights are the complete responsibility of the author.

But now you are tired of promises of what we will do. So let’s get about it! Don’t be afraid, go on to read about basic theories of modern science.

Notes   [ + ]

1. A photograph of Earth taken by Voyager I from a record distance of about 6 billion km inspired Carl Sagan to use this term. See it on Youtube.

About

John started out his career as a physicist (particle physics, for five years — remember bubble chambers?), thinking he would make a better living that way than with his other main interest, music. But doing physics is not nearly as exciting as reading about it. And then there was the job situation at the time (early 1970s). So after five years, he switched to l’informatique (IT, system programmer, etc.) with the French Centre National de Recherche Scientifique. Since retirement in 2005, he has spent most of his time reading, traveling, eating and drinking well, and being with his cats (two now) and dog and Siv.

John has often observed that when men (and perhaps women too) get older — reaching what is sometimes called the third age — their interests often change. Some become interested in world religions, one he has heard of went throught the writings of the great philosophers, some may decide to read all of Shakespeare or some other Great Author, some become engaged in a particular field or form of politics, and so on. Some of these are really great ideas and some are quite silly and that does not really matter, does it?.

John has become fascinated by things he has been reading about science, especially physics and cosmology, neuroscience and evolutionary biology. He would like to have some at-least approximate notion of current ideas of the relation between the “real” world of physics (and geology and …) and our internal mental model of it (including of ourselves). Whatever winds up on this site is the result of his attempts to structure or order his reading and his thoughts on these subjects.

He is also astonished at the lack of scientific knowledge of much of the general public. So he would also like to do a survey of how science sees things.

Like lots of people, he is occasionally seized by the need to assemble his thoughts by writing them down. Or, he may just feel like discussing something that no one available is much interested in. John does not really expect anyone else to read this. Well, maybe Siv. Sometimes. Hopefully, he will have fun anyway.

Which does not really matter in the long run… because you all know what Keynes said about that.1)If not, then do a search it.

Notes   [ + ]

1. If not, then do a search it.