Time and again, discussions with people who do not think COVID-19 is so bad or who do not believe that the undeniable climate change is man-made, say that they have a right to their own opinion and do not let science dictate anything.

Sometimes they justify this by saying that scientists change their minds time and again. The latter is true. But there is a difference.

There are opinions based on the consideration of all known facts. Anyone who has never seen the earth from above cannot know that it is round, but must believe this. Up to the moment when you realize that the sun is at the same time in the north at a different angle in the sky than further south. Measuring this phenomenon allows only one conclusion: the earth is round and has a circumference of about 40,000 km.

Erathostenes‘ method for determining the circumference of the earth

Anyone who, despite knowing this fact, still thinks that the earth is flat has a right to this opinion. Nobody can take this away from them. But in our Western, Enlightened society he has no right to be taken seriously or even to demand political and other decisions based on this opinion.

Even the deniers of the theory that the current climate change is man-made deliberately ignore relevant facts – for example, that fluctuations in solar radiation simply cannot explain climate change because they are too weak.

The same applies to opinions based on conspiracy myths (QAnon etc.) and opinions that contradict laws of physics (on the subject of 5G, for example).

If you want to be taken seriously with your opinion, you have to be able to justify it well. To do this, you need facts on the one hand and on the other hand you must not ignore any facts.