Building telescopes on the Moon could transform astronomy
I hate to say it (as someone formerly from this field), but --Astronomers can justify any amount of spending you ask them to, based on whatever incremental learning a telescope of a new type can be built for, based on:-- size of telescope-- new sensors-- background noise reduction, sensitivity-- frequency domain, spectroscopic resolution-- it goes on and onWho provides the external check of whether the latest improvement is worth spending the money?  Because astronomers will always say it's worth it on some dimension.  How do we decide whether that dimension is worth the money?Is pushing the discovery of some metal content in an early galaxy by one more unit of redshift worth $10B?  Study of dust obscuration of some nebula really pushing the boundaries of our understanding like it was 50 years ago?   (or similar esoteric questions)What $ / unit scientific discovery is worth it?Edit to add: and yes there are things like the decadal survey and the “industry” has to justify itself to Congress (in the US at least).  And yes, I generally do think the finding of this is (at these levels) probably going to bring some net positive multiplier benefit even if hard to quantify.  And is more value per money than sending it to war to use an extreme comparison.  But I wish there were a more defensible bar for knowing, other than public opinion or “at least we’re not as much a waste as ”.Just lucky for astronomy that at least they produce pet pictures for the public to support. But sad for other important fields that don’t have this luxury.