In the modern world, as soon as you propose a new idea, the first argument that you will be faced with is that the idea is not scientific. Although, just being scientific does not really make the idea very useful or legitimate it does help a lot to gain respectability if you are able to prove that it really is scientific. So what is scientific? What does it mean to say that something is scientific?
Invariability in Space
Scientific ‘laws’ or equations or statements should be invariable in space. For example, when Newton says that action and reaction are equal and opposite, what he really means is that they are equal and opposite all over the universe – in Europe, in Asia, in America, on the Moon and even on Andromeda. And there is a slight extension to it. In case your statement actually has to do with measuring physical quantity then the scientific idea should be invariable with rotation too. For example, if a proton decays in t seconds when your apparatus points north, it should also decay in t seconds when it points west.
Invariability in Time
Invariability in time is perhaps even more important than in variability in space. It is this that makes scientific statements into ‘laws’. A law is something that always happens. It happens today, it happened yesterday and we have reason to believe that is also happened billions of years ago right back to the Big Bang. Scientific laws should be repeatable.
There is something more to be said about repeatability. Things are repeatable only when the ‘experiment’ is set up in the same way. One cannot expect gravity to act the same way on moon as it does on earth. The masses are different. One has to make sure that all the factors that significantly affect the phenomenon are similar. If you want the same amount of gravity on moon as on earth, you must put in the same amount of mass into the moon.
This condition is perhaps the trickiest of all. And the most difficult to understand, perhaps. But also the most crucial. Often you will be faced with unscientific claims that are invariable in space and time. But they also have to be deniable. Unless they are deniable they are not, by definition, scientific claims.
To state simple, deniability means that it should be possible to set up an experiment that can possibly refute the scientific claim. For example, taking Newton’s example, it should be possible to set up and experiment that can possibly prove that action and reaction are not always equal. One such simple ‘experiment’ would be putting your pen on the tabletop. If action-reaction were not equal-opposite, the pen would fall through the table. But is does not happen.
The idea here is that it should be possible to set up such experiment and not that the experiment would necessarily refute the above claim. In fact, if the claim indeed is a law then it cannot the experiment cannot refute it. However, such an experiment should be possible to set up.
Another thing to note is that merely having such an experiment does not make the claim scientific. You have to ensure invariability in space-time too.
Using these tools let us examine a spurious ‘scientific’ claim. A pundit claims that if you pray to Vishnu with full faith he will cure your cancer. And indeed, he cites many cases (possible concocted by himself) when this has happened. But he says, faith is important, if there is not faith it will not happen. This ‘scientific-ness’ of this claim is easily put to test. Is it possible to set up an experiment where someone prays with full faith and still does not escape from cancer? As soon as you say that, the priest is in trouble because then he will have to define exactly what faith is and what it is that you have to do during the prayer. I’m sure he will not do that.
Because if he does that, then you can immediately perform the experiment to see whether his claim holds or not. As it will turn out, I’m sure, the claim will not be scientific. It is valid as a claim of religion and faith but not of science.