hi I'm dr. Johnson Hoss and welcome to earth parts another useful rule of thumb for thinking critically and thinking skeptically is to try on more than one explanation for a problem a more scientific unknown try to seek alternate solutions that fit the available evidence and it's really important to look for holes in your own explanation this is one of the core ethics of science is that when someone's pursuing a project often the emphasis is not so much on proving an idea as is disproving the idea finding the holes or the vulnerabilities in the argument and trying to pursue those doing experiments to try to prove yourself wrong this is essentially how a lot of scientific research goes on and it's a healthy thing to try to look at a problem from multiple directions if you can try to see it from different perspectives not just your favorite answer this is how science works science essentially lets the different ideas fight and the surviving idea wins if there are multiple competing explanations for some problem for some scientific mystery science examines each of them and discards the ones that can be discarded the ones that can be disproven I can test this and I can show you that it doesn't work okay that alternative explanation is now off the table until there's only a few and ophélie only eventually one idea remaining the correct one or at least as close to correct as we can get another good rule of thumb is to not assume you're right don't necessarily assume that your first take on interpreting something is the correct one and that's a healthy perspective right everyone likes to be right and we treat being wrong as a terrible embarrassing thing when it's it didn't have to be being wrong simply gives you an opportunity to correct a mistake and never be wrong about that again don't get too attached to your favorite assumptions you're more than that an opinion is what you might have as a provisional conclusion to some issue or some problem but always think of it as provisional and you can adjust if you get new information that shows you that you should that's a healthy perspective be quantitative when you can at least try to know a ballpark estimate of something that is important to you something that you're talking about or have an opinion about it helps to put numbers around things to try to clarify issues that sometimes are difficult to imagine I'm a geologist I work routinely in talking about things that happen over millions or hundreds of millions of years a span of time I'm getting I'm incapable of experiencing but I'm able to abstract that enough that the biological inability to deal with gulfs of time like that doesn't hinder me from examining the geologic history of our planet and evolution of life geologic processes and how long they take the history of our planet and our universe I can deal with all that if I can quantify everything and remove it from the realm of an emotional gut response or what I think my intuition should tell me once we begin to quantify quantum mechanics the interactions of particles at a subatomic scale once quantum mechanics became a thing it became almost a cliche to say with it that it's weird and non-intuitive and strange and it is and the numbers allow us to abstract ourselves from that and look at it cleanly the hard numbers are always better than fuzzy thinking based upon imprecise or touchy-feely language by quantifying things you put a room around it and you see how big the room is and you can measure other things in relative to that it makes sense then and it objectively will then be the same quantity no matter who measures it a useful rule of thumb to keep in mind also is that a valid argument rests on a valid premise and it's built up logical steps one at a time every link in that chain of argument must be valid every link with one link in the chain is broken then so is the entire chain just like in real life if one link breaks the chain breaks in a logical argument you can't ever have a place where you come to a point and say a miracle happens at the next step or the next step is completely blank but then I'm gonna go on to another step where I've come to a conclusion on that blank it's not how it works this rule of thumb is famous by the name Occam's razor it's well known but most people actually know it incorrectly to be honest you may have heard the idea when faced with two or more competing explanations for something choose the simplest one but that's not really what Occam's razor says if you look at it in detail what it actually says is when faced with two or more competing explanations for something choose the explanation that makes the fewest unnecessary assumptions don't add assumptions that you don't need to add to an argument for example at one time there were people who promoted the idea that on Mars one of the buttes one of the mesas on Mars if you look at it from just the right angle vaguely resembles part of a face we see faces in clouds we see them in rock formations that's what humans do it's called visual pareidolia there were people who looked at that and said no that's actually a face that's actually a car of the monument on Mars it was carved by apparently Martians who had a civilization on Mars at one time so the problem with that argument is that it rests on a lot of unnecessary assumptions that have no supporting evidence for them of any kind to have a carved face on Mars you have to have had Carver's if you're proposing it's actually a piece of sculpture then there were Martians and they had a civilization and they had to evolve there with other species on Mars as part of the Martian biosphere where is it there's no evidence of any kind that Mars has ever supported a biosphere water yes on the surface rivers seas sure but life widespread life widespread enough to support a biosphere that could evolve a sentient species that could carve things no evidence for that at all where are the other carvings let's say they aren't from Mars but came here from somewhere else and carved things is that the only one cuz it's a pretty bad carving what about the roads aqueducts other buildings other carvings where's the quarry work if we went down there would we see tool marks these are actually rational questions that you'd have to propose if someone was proposing honestly that the face on Mars is actually a face Occam's razor says all those are necessary assumptions about Martians you're just piling in there for no reason scrape those all out what do you have left a funny-looking rock finally at least for this lecture is the idea testable at all if something is an interesting concept but it hasn't a way of being tested we don't necessarily discard it but we can't treat it as a scientific research project we can't pursue it if it can't be pursued a nice example is the subject of string theory in physics string theory posits that all subatomic particles or objects at that scale are actually vibrating strings of fundamental material we are incapable of testing string theory right now we don't have any machines that generate the energies that will be necessary to conduct experiments directly interrogating the universe about string theory that doesn't make it a pseudoscience but it does make it a concept that right now is not testable and therefore we can't pursue it we can't go down to the next steps in researching string theory and make progress because we can't test it that's the nature of science if you can test it then you can examine it if you can't test it it may be that you can't ever test it in which case it's not a scientific concept that has any value if it is something that you can test but we haven't built machines big enough yet well well then people are working on it be patient you