Expert snuggler wrote:All the OBS would need to do is notice diesel spoor somewhere, anywhere, and then power up a previously dormant module that throws rocks at mobile heat sources.
How does this handwavium of the OBS noticing the diesel exhaust actual occur?
The largest pollutant in exhaust from internal combustion engines of any type are the NOx components. The concentration of all the NOx pollutants in the exhaust is 500 to 1,000 ppm. in percentage terms that is 0.05% to 0.1%. A sensor with a spatial resolution of 10 square cm might possible be able to directly measure the exhaust gases. There is also the little problem that it has to search for the gases indirectly as there is a vacuum between the Safehold atmosphere and the OBS. The OBS has to be monitoring all the possible 10 square centimeter patches on Safehold looking for diesel pollutants. Oh yeah in case that's not difficult enough it has to do the monitoring in real time. If by some miracle of handwavium, this could actually be accomplished, you would then need to deploy a remote to confirm that the first measurement was not a false positive.
Given the difficulty of making this measurement the false positives would be in the order of thousands or millions of false positives for every true positive. From Merlin's perspective the existence of such a system would be good news as a remote could eavesdrop on the communications between the remotes and the OBS to decipher the communication protocols required to make a close approach to the OBS. The OBS problem would be solved. Even if no false positives had occurred since Merlin woke, another handwavium miracle, the entire system would have to be tested periodically to ensure all the components remained operational.
To put it simply the entire concept of an OBS sensor able to detect diesel exhaust from orbit in real time requires multiple levels of handwavium.
The problem of detecting the steam engines was absurdly simple in comparison. Simply detect heat sources and analyze the source over time to detect any peculiarities in the nature of the sources. it requires far less spatial resolution, computing power and the required sensor is much simpler any anything that is required to measure gas concentrations in the range of parts per million or lower.
