So…..
Same question. How do you know he's right. Everything he says could not possibly be known.
"Theory" is another word for "speculation", which is another way of saying "maybe ", which is another way of saying: I'm just making this crap up.
Do you really think that I made all of that up? Do you really think that all that I reported is merely speculation, without basis?
Do you really think that I believe that I could hoodwink you with a load of unfounded B.S.?
I have more respect for you than that.
“Everything he says could not possibly be known.” You need to get out more. You need to do some research before you write things like that.
How is the data that I reported acquired? There have been, to date, 26 successful missions to Mars (50 were launched) sent to acquire data. Of the 26, 16 involved landers on the surface. Each of these was packed with instrumentation to measure things like soil composition and to search for organic compounds. Orbiters like the Exomars gas trace orbiter look over larger swatches of terrain. In the case of the gas trace orbiter, the goal is to search for indicators of biological and geological processes by looking for gases produced by those processes. Gas trace analysis has proven reliable and accurate on Earth.
Other deductions are based on photos taken from orbit which indicate the possibility of , for instance, liquid water. These photos are compared to photos of Earth conditions. (What does a dry river bed look like?) Note: what I have just written is accurate enough but is an oversimplification of the projects and data and technology that produced the info.
Theory…….you use the word as if a theory represents a quess, a maybe. The proper word for that is hypothesis. A theory, in fact, is not a guess, a maybe; it is not speculation. A proper theory is an explanation of why and how something happens. A proper theory has been tested and proven to be reproducible, predictive and correct.