Because organisms based on RNA would not have ribosomes, which are usually used to detect living microorganisms, they would be difficult to find in normal circumstances.
The comic suggests that this hypothetical biosphere exists, and its study is funded by "shadow biotech" corporations. The field would be called "shadow biology", so people that study it would be "shadow biologists". However, this is reinterpreted to mean "shadow" biologist, meaning that anyone that studies it becomes undetectable. A "shadowy" figure, presumably a shadow biologist, is telling this to Megan and Cueball, but they are not shadow biologists and can't hear him.
Just spit-balling here, but here goes: This comic seems to be making a joke between the meaning of "shadow biosphere" and the more common meaning behind "shadow" being something unseen. I think "shadow biosphere" is currently pretty loosely defined and not widely accepted by academics, and it seems to refer simply to organisms that might exist but are not currently being studied widely. In fact to me, the use of the term "shadow" in the name is relatively misleading and simply refers to a possible case of something not understood and/or studied at length, not that it's invisible. Randall appears to be making fun of the name by suggesting it means invisible to normal life as we know it. The title text further pushes this pun by suggesting that a coating of "desert varnish" makes normally visible objects become invisible, as with the buildings where shadow biologists carry out their work. Desert varnish is in fact visible when it is found in appropriate locations on normal objects like rocks - it does not make the rocks invisible! Somehow, I think these ideas need to be incorporated into the explanation. Ianrbibtitlht (talk) 17:00, 3 July 2019 (UTC)
- "it seems to refer simply to organisms that might exist but are not currently being studied widely" - not that's not correct. It refers to hypothetical organisms that have a different biochemistry and as a result are not detectable using the techniques developed for studying organisms with 'normal' biochemistries. 188.8.131.52 05:29, 11 July 2019 (UTC)
The joke is that someone who studies the shadow biosphere would be called a 'shadow' biologist in the same way that a biologist who studies microbes is called a micro-biologist.184.108.40.206 11:25, 4 July 2019 (UTC)
The first paragraph of this comic explanation is a verbatim copy from the beginning of the Wikipedia article for shadow biosphere. It seems that we really should include citations when adding something like this. ---diGGdoug 220.127.116.11 (talk) (please sign your comments with ~~~~)
The desert varnish reference in the alt text is because desert varnish is the most likely example of the shadow biosphere. It seems to be doing something at least vaugely like metabolism, concentrating certain minerals far beyond expected by nature. -18.104.22.168 19:47, 3 July 2019 (UTC)
This needs an SCP classification. 22.214.171.124 03:45, 4 July 2019 (UTC)
Do you have a citation for that? Wikipedia article doesn't mention any metabolism. 126.96.36.199 22:31, 3 July 2019 (UTC)bk
Could "Shadow" be a Babylon 5 reference? -188.8.131.52 01:03, 4 July 2019 (UTC)
Could "Shadow" be referring to "Shadow Internet"? https://www.extremetech.com/extreme/191742-esnet-the-100-gigabit-shadow-internet-that-only-the-us-government-has-access-to 184.108.40.206 10:49, 4 July 2019 (UTC)
The joke feels more like a "The X Zone exists, but if you interact with it you become a X Denizen" ploy. E.g. "The Wraith Realm exists, but if you enter it you become a Wraith" or something like that. Randall might have gotten it from the Animorphs "if you are an animal for too long you stay as one" idea. From there, it goes into the "micro-biologist/microbiology" and the "shadow:unseen" joke area. 220.127.116.11 (talk) 00:01, July 5, 2019 (please sign your comments with ~~~~)
It might be unrelated, but in D&D there's a Shadow Weave... and there were in-game rumors that once you casted a "shadow spell", you'd become a shadow caster for life. 18.104.22.168 16:09, 5 July 2019 (UTC)
For me the shadow biotech companies are evil instead of being invisible and as a biologist you can either choose to listen to them (hey! they are financed and convert to the dark side - or you can decide to pretend they didn't tell anything important for you... 22.214.171.124 (talk) 13:30, July 5, 2019 (please sign your comments with ~~~~)
http://www.icamsr.org/docs/spie_4495-13_rock_varnish.pdf 126.96.36.199 21:44, 5 July 2019 (UTC)