Mantle geologists study that part of the planet that's below the top "crust" of the planet. The top layer of the planet, which is several dozen miles thick, is the only layer we've been able to explore, by digging tunnels, spelunking, etc. The only way to study the mantle and other inner layers of the earth are through non-visual, non-tactile, indirect methods, and by analyzing old samples of the mantle that have made their way to the surface.
In this comic, Ponytail, talking to Megan, is describing her job as a mantle geologist as that of living on one side of a thick wall that is, and likely always will be, impossible to get around, but she has to study what is on the other side of the wall. In this case the wall is horizontal rather than vertical, the wall being the earth's crust, and makes a complete sphere, so the only way to get past the wall would be to go through. It is theoretically possible to go through, but as of the comic's posting, humanity is far from doing so. (The deepest hole dug as of at that time, as measured by true vertical depth, is the Kola Borehole, which only goes down to 12,262 meters out of the estimated 35,000 meters needed to get through at that location.)
In the title text Randall states that he doesn't trust mantle/core geologists. Because if they got the chance he believes they would not hesitate (even the duration of a heartbeat) to strip away Earth's crust to study the mantle or even worse the core directly. Of course if they only did this locally to look at the mantle it would not shatter the Earth although that local area may become a volcano. But if they actually peeled the entire outer layer away, we humans would have no place to live, as the mantle is really hot and would melt easily (producing magmas and therefore lavas when magma’s exposed to surface, see title text of 1405: Meteor to be more confused). However, after a while all these erupted lavas would solidify and become a new crust. Humanity needs to withstand just some millennia of active worldwide volcanism.
But Randall is afraid that their craving to get around that 20 mile wall would prevent the researchers from even hesitating if they did get that chance. Fortunately, we can study planetary cores in the solar system without stripping Earth's surface by visiting an asteroid which is thought to be the exposed iron core of a protoplanet. The Psyche mission is scheduled to launch in 2023 and arrive at 16 Psyche in 2029.
This comics seems to be a spin-off from the previous comic 2057: Internal Monologues, where Randall tried to find some interesting monologues from scientist from different research fields. Maybe he did not find an internal monologue he liked for geologists, but ended up with this idea instead. Thinking about the core or mantle, lava and magma seems to be something Randall does a lot, and thus he must have some ideas about how a geologist would think, as in 913: Core.
The situation of peeling off the outer layers of the Earth has been addressed in more detail in the "Lose Weight the Slow and Incredibly Difficult Way" chapter of What If? 2.
- [Ponytail is gesturing towards Megan with her hand, while talking to her.]
- Ponytail: I live next to a wall of rock 20 miles thick. There's no way around or over it. I'm trapped on this side forever.
- Ponytail: I study the stuff on the other side.
- [Caption below the frame:]
- Mantle geology seems like the most frustrating field.
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There doesn't seem to be a link from the previous (#2057/Internal Monologues) comic to this one yet. I tried in another browser just in case my cache was messing up. -boB (talk) 14:21, 12 October 2018 (UTC)
- Thanks for your note. It's maybe the proxy in the background so I will wait a little bit for further actions. Nonetheless this shouldn't happen and I will figure out the reason. --Dgbrt (talk) 14:58, 12 October 2018 (UTC)
- The link is now shown and this means the problem is definitely caused by the proxy cache. If this happens again on Monday the BOT will handle this in the future. --Dgbrt (talk) 15:54, 12 October 2018 (UTC)
- The link showed up when I purged it and completely forgot to comment here (sorry). So that might give a good hint for why it was happening. --NeatNit (talk) 18:15, 12 October 2018 (UTC)
- Thanks, that's exactly what the BOT will do at the than former latest comic if really needed. This expires all caches, hopefully. But the BOT action is only a workaround I don't like. It did work in the past when the site template provided a new link and it should do so now without a BOT. --Dgbrt (talk) 18:41, 12 October 2018 (UTC)
I am not a mantle geologist, but I've always thought that if the core of Mars has really cooled & solidified, blasting the whole surface off could let us get at that sweet nickel-iron core. I mean it's a giant wad of semi-refined metals with some rock caked on top of it, right? If there's no magma to deal with, we could actually get at the good stuff much more easily. Mine Mars' core!
ProphetZarquon (talk) 17:20, 12 October 2018 (UTC)
- That would make terraforming Mars lot harder. -- Hkmaly (talk) 22:11, 12 October 2018 (UTC)
- It's already sitting out there in the asteroid belt... why deal with the Mars gravity well? Just mine the space rocks, so much easier. 184.108.40.206 02:49, 17 October 2018 (UTC)
Wouldn't the part of astronomy which studies black holes be even more frustrating? Also, peeling away the event horizon, even locally, might destroy whole universe ... -- Hkmaly (talk) 22:11, 12 October 2018 (UTC)
- I think, perhaps, that theology might top even that. Perhaps a really enterprising (hah!) astronomer could find a way to the other side of the event horizon (though transmitting her findings back might be hard) and perhaps someday the Kola Superdeep Borehole project will be, ah, re-opened. But getting anything truly verifiable back from beyond the dead is probably ... a bit out of reach. 220.127.116.11 02:03, 14 October 2018 (UTC)
- Good point, theology is even more hard to reach AND likely more dangerous when peeling away ... (note: for why peeling away the event horizon from singularity might be possible, just not good idea, see Naked singularity) -- Hkmaly (talk) 00:02, 16 October 2018 (UTC)
Something Weird Would Happen - may refer to this expedition to find out what weird thing happens at mantle exposure. https://www.livescience.com/1317-mission-study-earth-gaping-open-wound.html -- FT FreeTim (talk) 09:01, 14 October 2018 (UTC)
Why isn't there a geology category? I mean... we have so many useless categories with only 2 or 3 entries, and from the top of my head there are at least 5 geology comics... (this one, the one where cueball sits on his chair and looks down to the core and gets scared, the one with the geology sex puns, the one with the real time plate tectonics game, the one where a trophy hunter takes a piece of a rock and hangs it on the wall labeled "earth")... and with some actual searching I guess one could find more...
Anybody remember the Dr. who episode where the third doctor had to deal with people trying to break through the crust on an alternate Earth? -- Keybounce (talk) (please sign your comments with ~~~~)
- Oh, THERE Liu Cixin stole the basic idea for his short "Mountain" :-) 18.104.22.168 20:25, 16 October 2018 (UTC)
I distinctly remember a previous comic along the same lines (something about studying the thing we're on), but don't have the time to track it down. 22.214.171.124 (talk) (please sign your comments with ~~~~)