Why is the sky – An introduction to science

I was asked by a child “why is the sky?” and I couldn’t answer it, because this is a partial question. A full question includes both a subject and a specific testable item. “Why is the sky blue?” or “Why is the sky made of air?” or “Why is the sky so tall?”. Each testable item can be investigated and proven to be false, or evidence gathered to become closer to support the test criteria.

Take the first real question – “Why is the sky blue?” The first part to test is this: “Is the sky blue?” If the sky is green, then the question is faulty.

If the sky is blue, then the second part is to differentiate between “how” and “why”. How explains the process that gives the sky a blue colour. Why implies a reason, which in itself implies a will that creates that outcome.

“How” is something that can be discovered.

“Why” cannot if “why” includes a non-human intelligence. If we are looking to understand “why” without the will, then the answer is always entropy. Briefly, entropy is the system loosing energy, thus all things take the path to the least amount of energy. This can sometimes be confusing because the least path of energy may seem locally more energetic, yet overall have less. One can then ask “why entropy” and that is not answerable without suggesting a will or stating “because it is”. This is a side issue though, mostly we aren’t interested in “why” in science, but rather “how”.

First though, why science? The scientific method was created as a subset of philosophy to slow down the roundabout ride of philosophies about the world and to start testing the claims of “how things worked” to rule out the ones that didn’t.

For example “When did you stop beating your wife?” A great deal of resources could go into researching how violent I am, when my violence stopped, or even if it did. I could spend ages talking about my wife, about her life and so forth. None of this actually answers the question. So lets go back to the question itself. The first question should be, “do I have a wife”, followed by “did I ever beat her”? If the answer to either of these questions is no, then the original statement is a faulty statement and we can stop there. That is, let’s test the object and event of the statement first, and if either are false, stop investigating that line. In this case, not only do I not have a wife, I don’t beat this currently non-existent person either. So, end of line of philosophy.

Previous to the sub-school of philosophy, debates would last for centuries about what is, how it is and so on because no one stopped to test if it really is or isn’t. Here is an example of a continuing one – is there an ultimate god? If there is, what is it? Does this ultimate god care about humans? Who would win in a battle – the ultimate god or superman?

Here is the scientific take on it: Find the object, test the event. The object – Is there any evidence for a god? Here are the components to that question – evidence is the result of a test, and the test must have a result that either supports the questions, or proves the question false. In this case, there is no test for a god, because there is no result that proves the question false. Many tests can be done to support the claim “if there is an ultimate god, it must have created the universe, the universe exists, therefore the god exists”, but if it isn’t possible to have a result that indicates the claim is false, then the test is not valid “if there is no ultimate god, then it may not have created the universe, or the universe was not created at all, we are in the universe… so no solution”. If you do come up with a good test, please, let me know. This does not mean that there is no god – just that there is no test for it, thus no evidence for it. Since there is no evidence, don’t pursue this line any further.

Is the sky blue? This can be tested using a number of tools. Test the object and the event. Is there a sky? Yes, it is part of the atmosphere we live in, and exists between the Earth and space. Next the testable item – is the sky blue? Blue light is defined as a specific range of the light spectrum. If the tool that measures the part of the light spectrum coming from the sky is outside of that light spectrum, then the claim is false – that is, the sky is not blue. If the result is within the claim, then there is supportive evidence for that claim. It is not proven to be true. In this case, the light from the sky is within the light spectrum called blue.

Science does not prove things to be true. That is not in the nature of science. If you don’t believe me in this example, wait until night time and check your tools again.

A good question is to ask why science doesn’t prove things to be true? Well, truth is considered to be an objective immutable fact. That is, it can’t change. Our perception of the universe, even with the best tools we have, is only a fraction of what is really there in the universe. We can’t really define what we cannot observer or interpolate (worked out likelihoods between the bits we can observe), yet as our tools get better, we can observe more. To assume that what we have tested gives us truth is to rule out the ability to learn more about something. This is pretty arrogant and very limiting.

To go back to an earlier example: even though there is no current evidence (that is test with a useful result) for the existence of an ultimate god, if we did someday find this test and gain supportive evidence for the existence of god and it was verified, then science would accept that investigating god is worth spending time on. This is true for anything in the realm of science – without some basic evidence, no further investigation is worth doing. With some evidence, further investigation is worth doing. This doesn’t mean that a god exists, it just means their is some evidence.

This begs the question, how much evidence is needed for something to be considered proven, true or real? The answer is that science doesn’t prove things to be true or real. What it does is gathers evidence that moves the claim closer to objective truth. To move the claim requires refinement of the idea, as some parts are discounted due to evidence proving that aspect wrong, and other aspects are supported by the evidence.

Consider electricity. At first we knew that it was a object created by storms. Then humans created batteries around 2,500 years ago and harnessed certain properties of electricity (mostly electro plating). A few hundred years ago it was thought that tiny particles were travelling from one terminal to another, and later found to actually be the reverse direction. It was thought that electricity could only travel in one direction, then it was found that by using magnets to induce a current, the electricity could travel in two directions in alternating currents. Now electricity is split in all kinds of circuitry, recombined and forms the impulses that turn the text I’m writing into on/off switches that eventually make it to the thing you are reading.

If humans had looked at lightning and not learned about it by incremental steps, we would not have computers. To learn what we have, many ideas have been postulated, tested and discarded or furthered. The early ideas of electricity, when compared to what we know now, are quite ludicrous. Yet if we had dispensed with the testing because the first one showed the early idea about how electricity does what it does was false, we would not have developed computers today.

Lets compare this to unicorns. First of all, is there any evidence of unicorns? So far, no. Is it worth working out what they eat? No, because we haven’t passed the first step of finding evidence of the existence of unicorns. Is there any evidence of electricity? Yes, plenty. Is it worth working out what you can use it for? Yes, because we have evidence of its existence. Do unicorns exist? Probably not, but one unicorn turning up will certainly change opinions about their existence. Does electricity exist? Yes, see the earlier evidence. Should we act as if unicorns exist? Well, that is a personal choice, but scientifically we don’t until some evidence is provided that indicates the existence of unicorns.

So what is evidence? Evidence is not the result of a test, nor is it an observation. Always remember, an observation is an anecdote. To quote Dr Karl  Kruszelnicki, the plural for anecdote is anecdotes and has no weight beyond a single anecdote. Scientific evidence is a collection of results from a series of tests from a series of testers in carefully selected types of tests. Wow, that seems pretty loaded and stacked in someone’s favour. That is absolutely true – the favour is given towards weeding out inaccuracies, both individual human and poorly constructed tests – aka experiments. The goal is to further the confidence you have in an idea being closer to truth and more distant from error.

Here is the evolution of “scientific knowledge”. Of course, keep in mind, science doesn’t know things, it has confidence in ideas – the greater the evidence, the greater the confidence. Knowledge implies being aware of what the truth is, and as covered earlier, that is not possible. Okay, here we go from lowest confidence to highest:

– An idea (no results, no suggestion of how)

– A hypothesis (no results, a suggestion of how)

– An experiment (no results, a suggestion of how, a test that includes a way of distinguishing if the idea is false)

– Initial publication (If the results are useful, either for supporting or disproving an idea, the results are published in a systematic way, such that other people can replicate the experiment or indicate flaws in the experiment)

– More scientists perform the same experiment to see if the results are consistent (These too are published. If there is consensus, the idea is elevated to a concept, rule or law depending on the idea)

– Different experiments are performed to discover the limits of the idea (These too are published) All useful ideas have limits.

– With sufficient evidence from sufficient experiments and time, the idea is now elevated to the ultimate form – a Theory.

To disprove an idea that has been previously tested, the new results must equal or outweigh the previous results. Results are not measured just in quantity or quality, but rather a minimum quantity of quality.

Okay, so lets summarise.

* Science is a process of discovering the universe by testing ideas for validity. These evolve the ideas towards an objective truth, but will never actually get to this truth.

* Science is interested in discovering “how” things happen. “Why” is not scientific unless looking at the process of entropy.

* If there is no testable evidence for an idea, science does not explore that idea further.

* Science disproves an idea, or it supports an idea. It doesn’t prove an idea to be true.

* When science says “The Theory of X”, then the understanding of X is as close to truth as can be measured and tested, yet it still allows the understanding to evolve to a newer, more accurate version as more about the universe is discovered. This understanding of X is the one with the most confidence and is no longer disputed by reputable scientists.

– Examples of science undisputed by scientists

-> Gravity

-> Evolution

-> Climate Change and the role of humanity in the current climate change

-> Atomic theory

-> The existence of subatomic particles

-> Continental drift

-> The big bang