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Activity for Logan R. Kearsley‭

Type On... Excerpt Status Date
Question Treating Postpartum Depression when Reproductive Mortality is ~100%?
Postpartum depression among humans is a thing that is "normal" insofar as it happens a lot, but it is not "normal" in the sense of "a thing that we don't worry about"; it doesn't happen to absolutely everyone, and we do in fact put (varying amounts of) effort into educating people about it and treati...
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over 4 years ago
Question Sensors for a clockwork/fluidic robot?
So, mechanical computers are a thing, as are pneumatic and hydraulic actuators. Combining those ideas, it's not that hard to design simple purely-pneumatic/hydraulic robots--provide them with a source of compressed fluid, and they just go (and that includes performing middling-complex mechanical cal...
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almost 5 years ago
Question Anatomically Correct Diggy Diggy Dwarfs
The song Diggy Diggy Hole makes some questionable assertions about dwarven anatomy. Specifically: Born underground Suckled from a teat of stone Raised in the dark The safety of our mountain home Skin made of iron Steel in our bones To dig and dig makes us free C...
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almost 5 years ago
Question Densest practical packing of protons vs. neutrons?
For background: I have some sci-fi technology based on sci-fi physics which depends on some fictional forces that interact differently with up quarks vs. down quarks. So, to get certain types of effects, you want to use materials with lots more down quarks than up quarks, and to get other types of ef...
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about 5 years ago
Question Doing chemistry under water?
Aquatic races are usually assumed to be stunted in technological development by the inability to create fire or forge metals. But what about doing chemistry at all? The development of chemistry in human history seems to hinge on being able to perform reactions in aqueous solution. That's convenient...
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about 5 years ago
Question Maximum scale for "bumblebee" flight?
Bumblebees famously cannot fly under fixed wing aerodynamics--and they don't. Rather, they "row" the air, moving their wings back and forth and varying the pitch to push air down like a reciprocating helicopter blade. Clearly, this style of hovering flight works at larger-than-insect scale, because ...
(more)
about 5 years ago
Question Anatomically Correct Dreel
The Dreel are a parasitic alien hive-mind from The Return of Nathan Brazil, book four in the Well of Souls series by Jack Chalker. Specifically, they are described as viruses which induce intelligence in their host, merging with the host's personality (it is unclear if they require already-intellige...
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over 5 years ago
Question Playing boules... IN SPACE!
Boules is a range of relative games played with small, heavy steel balls thrown on a court, such as the French Petanque and Italian Bocce. While there is variation between games in terms of how and why you thrown, and what the size of the court is, they all rely on the distinctly Earth-bound fact th...
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over 5 years ago
Question Sewer gas energy?
The Wikipedia page on sewer gas states that Sewer gas can be used as a power source, thus reducing the consumption of fossil fuels. However, no references or further details are provided. So, suppose that a typical modern house had its vent stack replaced by sewer gas burner system. Just how much...
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over 5 years ago
Question Biological refrigeration?
Technological approaches to refrigeration tend to involve either high compression ratios of fairly exotic (from a biochemical point of view, anyway) volatile substances, or high-power, low-efficiency solid state electronics. Neither of these seem particularly practical paths for a living organism to...
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over 5 years ago
Question Identifying minerals without sight
Properly ventilating a deep mine is a significant engineering challenge. Ergo, you don't want to be carrying around torches that use up some of your precious breathing oxygen if you don't absolutely have to. So, suppose we have a civilization of dwarves that have all learned to use echolocation (lik...
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over 5 years ago
Question How deep could dwarves actually delve?
Given an arbitrarily long time to do so, what is the maximum depth too which a dwarven civilization could practically extend their mines / cities? And what would be the final limiting factor preventing further expansion of the downwards frontier? I figure eventually they'll hit the Mohorovicic disco...
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over 5 years ago
Question What is the maximum equilibrium temperature that a mammal could evolve to tolerate?
Mammals live in some fairly extreme environments, but the most heat-tolerant ones all seem to cheat: e.g., they dig burrows to stay cool during the day and come out at night, avoiding the heat, or they drink tons of water to keep their body temperature down during the day and recover at night. A lit...
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over 5 years ago
Question Anatomically Correct Modular Body Plan Animals
The fixedness of body plans varies widely across different types of Earthling organisms. At one extreme, you have things like tardigrades, for which every individual of any given species has exactly the same number and arrangement of individual cells, differing only in size; at the other extreme, you...
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over 5 years ago
Question Anatomically Correct Slinky Worm
Despite the wide variety of movement strategies employed by Earthling animals, up to an including curling their bodies into circles and rolling, there is one mode of locomotion that is glaringly missing: nothing slinkies! What I have in mind here is more a whole class of creatures than one specific ...
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over 5 years ago
Question Anatomically Correct Hunter from Needle
Hal Clement's novel Needle was revolutionary in featuring a non-parasitic alien lifeform capable of inhabiting a human body. Specifically, the Hunter in its independent form is a gelatinous mass capable of amoeboid swimming and slow crawling like a slime mold. It is implied (though I do not recall i...
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over 5 years ago
Question Electricity without electrons
The universe so far: If charged lepton fields are eliminated from the universe, charged pions become stable (having no decay path that preserves charge), replacing electrons to form bound "atomic" states with protons, as do free neutrons. Protium, however, is not stable, as it is energetically favor...
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over 5 years ago
Question Anatomically Correct "Stranger Things" Mindflayer's Monster
Background, with potential spoilers: In the Netflix show Stranger Things... ...there is an otherworldly creature known as the Mindflayer, which can telepathically control creatures in our world as long as the portal to its world is open. Once it has a creature from our world under control, one o...
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over 5 years ago
Question Blood for hydrogen breathers
Some follow-up thoughts on this question... Hydrogen isn't very soluble in water. Oxygen is more so, but still sufficiently insoluble that most oxygen-breathing Earth creatures use special oxygen carrying proteins (most famously, haemoglobin) to move oxygen through their blood rather than just relyi...
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over 5 years ago
Question A universe without light?
In the story Wang's Carpets (and part of the novel Diaspora), Greg Egan sketchily describes a high-dimensional universe which contains no analog for light, such that the aliens who inhabit this universe can only gain information about their surroundings through touch. (One could also imagine gaining ...
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over 5 years ago
Question Designing (a specific kind of) dark matter
There are exactly 2 force laws that can produce stable closed orbits: proportional (spring force) and inverse-square. The inverse square law occurs naturally for monopole central forces in 3 dimensions, while there isn't any space which naturally produces distance-proportional force fields, which is ...
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over 5 years ago
Question Body plan of a 4D human-analog?
I am attempting to design aliens that live in a universe with a 4+1 space-time--i.e., a universe with four orthogonal spatial dimensions, rather than three, in addition to a fifth time dimension. In this universe, gravity follows an inverse cube law rather than an inverse square law, but it still res...
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over 5 years ago
Question How much does the ecosphere weigh?
So, we've gone off to another star system and decided to build a Dyson bubble--a continuous statite, supported by radiation pressure, surrounding a star--with a surface gravity of 1g to live on. Now, clearly, the bubble has a total surface area of hundreds of thousands of Earths--plenty of space! Ex...
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about 6 years ago
Question What else changes with magnetic matter?
Consider a universe in which leptons & quarks (every fundamental particle that possesses electric charge) all have twins with magnetic monopole charge instead, resulting in two parallel kinds of baryonic matter--electro-matter, and magno-matter. This has all kinds of weird and interesting implication...
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over 6 years ago
Question Supercritical nitrogen as biosolvent?
Supercritical CO2 has been suggested as a potential alternative bio-solvent, replacing water, at high pressures and modestly elevated temperatures. But what about supercritical N2? ScCO2 is an industrially-useful solvent for organic chemistry, so a good bit of research has been done relevant to its ...
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about 7 years ago
Question Flying or swimming in supercritical CO2?
Suppose you have a planet covered in a deep layer of supercritical CO2, and animals evolved to live in it. Discounting the ones who crawl along the bottom, would their method of locomotion be more accurately described as swimming, or flying? Or in other terms, is this layer better described as an oc...
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about 7 years ago
Question Compressed air lighting?
So I've got this civilization that doesn't have electricity, but does have municipal power distribution via compressed air lines. Now, you can do a lot of useful things with compressed air. Even in the real world, compressed-air tools are fairly common. You can even use it for heating, via vortex tu...
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about 7 years ago
Question Biological transfer on a non-contact Rocheworld
I've been pondering for some time an alternate-history story where the Earth as we know it is replaced by a Rocheworld, of the canonical variety introduced in the eponymous Robert Forward novel where the two lobes share a common atmosphere but the solid and liquid surfaces do not touch, and in which ...
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about 7 years ago
Question White Dwarf mining?
This is a follow-up to Neutron Star mining. Assuming that problem can be solved, it would eventually degenerate to something similar to this case. And if it can't, white dwarfs seem like the next best source of stellar-mass quantities of elements heavier than helium. (And maybe thinking up solutions ...
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over 7 years ago
Question Neutron star mining?
Suppose you want to mine material from, and eventually completely disassemble, a neutron star. Presumably, you would be extracting heavy elements from the crust, and expecting the neutron-degenerate matter underneath to decompress and undergo beta-decay, turning back into more normal heavy elements a...
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over 7 years ago
Question Geological Processes Without Internal Heat?
Suppose you have a planet large enough to support life, with water and air all that, but old enough that it has exhausted its internal heat supply, the core is frozen solid, and there is little to no volcanic or plate tectonic activity. What sorts of geological / tectonic processes would still occur...
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over 7 years ago
Question Transporting water in liquid methane
I'm trying to work out some really basic biochemical details for cold-world aliens whose bodily fluids are based on liquid methane rather than water. I figure they have to be hydrogen breathers, because you won't get free oxygen on a world with methane oceans! But that means that their metabolism wou...
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over 8 years ago