What you seem to not understand is that what the Miller/Ulrey experiment was trying to do. They were trying to show that complex organic chemicals can occur naturally, without life being present.Not only did they succeed, but we have refined the experiments for 50 years after their initial experiment. You are acting as if the Miller/Ulrey experiment was the beinging and ending of that line of inquiry.. it isn't.
Indeed , not only do we have loads of expermental data from other experiments that have refined the results, but we also have objective evidence about the natural environment being able to form rich organic
chemicals in the presence of the atmosphere that is believed to be similar to the old earth. The moon Titan has an atmosphere that approximates those conditions. When the cassini probe recently skimmed saturns moon Titan, it found that it was rich in organic chemicals. So , not only do we have expermental data, but we have those results and conclusions confirmed with the sampling of another atmosphere.
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