We're certainly not going to resolve the
Demarcation Problem here.
The demarcation problem in the philosophy of science and epistemology is about how to distinguish between science and non-science,[1] including between science, pseudoscience, and other products of human activity, like art and literature, and beliefs.[2][3] The debate continues after over two millennia of dialogue among philosophers of science and scientists in various fields, and despite a broad agreement on the basics of the scientific method.[4][5]
However, the fact that this problem exists does not mean that we can cast doubt on the things that have been demonstrated by science to be true (allowing Stephen Jay Gould's caveat that
true can only mean
demonstrated to such an extent that it would be perverse to withhold provisional consent).
Take Newton's laws of motion. An object in motion will stay in motion in a uniform speed and direction unless acted upon by an outside force. This can be demonstrated, quantified, and on the macro scale, shown to be true. You can dispute this, in which case you will be invited to perform the experiment yourself, and if you do it correctly, you get the same results.
Astrology is often cited as being scientific, since the process of drawing up a natal horoscope involves carefully calculating the apparent positions of the planets in relation to the Earth, and as far as this process goes, it is as scientific as anything. But the astrologers do not stop there. They claim that the positions of the planets have
meaning in human lives, and this is where they go off the rails. You can give a single horoscope to two different astrologers and they will produce different predictions. This does not happen with a scientific experiment. If you and I have an identical experimental protocol, then we will get identical results. If we don't, then we have to reconsider our hypothesis.
That's one way in which science differs from pseudoscience, but as should be obvious from the fact that this thread is four pages long after only two days, the question does not lend itself to simple pithy answers.
It is a common tactic of believers in pseudoscience to challenge people to come up with a simple, pithy answer to an extremely complex and difficult problem, and then claim victory when such a simple answer is not immediately supplied. The creationists have known this for decades.
The OP has issued us with five such challenges, knowing full well that no-one in over two millennia has had the answers they seek. They somehow think that they are going to score points by doing this, but it is disingenuous. Not only are we as aware as they are that the Demarcation Problem exists, but we also don't think it's that big a deal. In the most part, it is clear what is scientific and what is not. If two groups using the same experimental protocol get the same results, then it's probably scientific. If they don't, then it probably isn't.
And let's get away from asking for CERTAINTY. Science doesn't deal in certainty. Science deals with describing objective reality in increasing accuracy and detail. Anyone demanding CERTAINTY from science has fundamentally misunderstood the method and purpose of science.