# Tag Info

44

The metal can be either very reactive, as you stated, or it can have a very high melting point, making it unpractical to use smelting based refinement techniques. Think for example of tungsten which melts at 3422 °C, most crucible and furnace materials will melt or decompose before it does, so how are you going to handle it in its liquid form? If your ...

27

Gliding doesn't burn much energy An albatross can fly non stop for days simply by gliding. For something as large as a dragon, powered flight would use massive amounts of energy, which means gliding is vitally important to avoid becoming exhausted far too quickly. The dragon would still be gliding in combat. The dragon might have two to five minutes of ...

23

I'd like to answer this question with a real-world example: Lionel Messi. Stats have shown that Messi runs for roughly 5% of a given game. Despite this, this man is breaking records - he's 5-time Ballon d'Or champion! So how does he do it, and what are the advantages of just walking/slow-jogging around as opposed to running all the time? Energy conservation:...

21

As an alternative to "hard to refine", I'll propose "dangerous to refine". Your metal is found in more than one natural isotope, where at least one isotope is more or less stable and useful, but the other isotope is radioactive. Isotope separation is quite awkward, even with modern technology, though perhaps magic helps in this regard. This means that given ...

16

There's a fairly basic contradiction in your posing of the question, which is that the more inert a metal is, the easier it is to purify by definition. A metal that is abundant as oxides or salts but cannot easily be purified is a metal that is by definition highly reactive; it doesn't want to exist as its pure form because it is so much more stable as a ...

12

Rare earth elements might be a good example. Good ore sources are rare, they are hard to concentrate, hard to refine and even harder to separate into elemental form as they all tend to occur in the same ore and have very similar chemical properties. The rare earth elements are reactive metals, but separation difficulty applies to other metals as well such ...

11

Your metal is allotropic, meaning it exists in multiple distinct forms under the same set of conditions (like diamond and graphite). Unfortunately for you, the allotrope that's useful is extremely rare. Refining the material produces 99.99% allotrope A (which is brittle and generally useless) and only 0.01% allotrope B (a metastable state and the form that ...

11

Let's do some math to find out. Let's say each "panel" of the sphere is 0.01 m thick, at a distance of 1 AU (149597871000 m) we would need to cover $4\pi r^2=2.8 \cdot 10^{23} \ m^2$, resulting in a volume of $2.8 \cdot 10^{21} \ m^3$. Assuming a density equal to that of water, we get that we need $2.8 \cdot 10^{24} \ kg$ of matter to complete the Dyson ...

10

So I'm wondering is it possible to live as a skeleton normally? No, for a lot of reasons: bones alone won't hold together and the skeleton would crumble to pieces in the blink of an eye. Which based on your description is leads to the infinity. bones alone can't perform any metabolism: they can't exchange gases, they can't allow the flow of blood, they can'...

10

It must be distilled. This metal has a low melting point and a low boiling point. Heat adequate to smelt it from its salt is adequate to boil it into vapor, which then escapes with the hot gases produced by the forge. To capture the metal vapor one must use something like a distillation apparatus or fractionation column to capture and condense the hot ...

9

You can see fires from space, but even really, really big fires are usually kinda small by the standards of a planet. Moreover, blobs of fire like that won't last very long because the fuel in them will be exausted and what you'll get instead is a wall or front of fire that is blown downwind until it reaches somewhere that's too damp (like the sea) or has ...

9

To form a "ready-to-be-born" baby one needs to follow a series of steps starting from the fertilized eggs. Therefore in that sequence there is no room for variation, if you want to stay within a single species. What can influence the duration of the pregnancy would be the capability for the woman to put the development on idle under certain circumstances. ...

9

Titanium is relatively abundant in the form of titanium dioxide, not particularly reactive like the alkali metals, but still quite difficult to refine and even harder to forge. Why? Because even though it's not very reactive under normal conditions, it will still burn, reacting with atmospheric oxygen to turn back into titanium dioxide, at a lower ...

8

A good reason is that Mars has a weaker gravity than Earth. If you need to colonize a new world from outer space, you will likely need a lot of arriving/departing* spaceships, so a lower gravity will facilitate these shippings. Moreover, Mars is farther from the Sun than Earth, which means that also travels to/from Mars will require less energy. *Arriving ...

7

In the mare magnum of the Internet, one can find anything, literally anything. Well, it looks like someone created also a habitable zone calculator*! The calculator takes as input the luminosity of the star, which you don't give. However you give the estimated masses, thus we can estimate the luminosity of the star using the mass-luminosity relation \$L\...

7

It's not difficult to refine; magic makes the process unpredictable Several other answer mention the dichotomy between being inert and being difficult to refine. So, turns out it IS really easy to refine, it's just that part of it's inert nature is absorption of magic. When the metal is refined, the magic is released in a very uncontrolled manner. So the ...

6

I think that this topic is one that's likely to generate a lot of misconceptions when people answer it, since it's a complicated topic and analogies/explanations that are given by pop science are often not super accurate. So, in an effort to be more accurate I'm gonna try to walk you through some of the actual math. Don't worry if you don't know what ...

6

Yes. An awful lot of evolution is possible in 100 million years. Consider your question in the context of it being asked slightly differently by an intelligent alien visiting Earth 100 million years ago. At that time there existed a family of small, unintelligent, timid pre-rodents called multituberculata, the last common ancestor of mice and humans. Your ...

6

Rare earths already being suggested, I suggest something similar - Zirconiunm + Hafnium. They are very similar in chemical properties, found together in nature and rather hard to separate, zirconium is used in nuclear technology for being transparent to neutrons, hafnium is a neutron poison. If you need zirconium in a nuclear reactor, you need zirconium at ...

5

These kinds of weapons have been envisioned since the American Civil War, and likely before that Demonstrations of these weapons showed they had a very high rate of fire and were extremely inaccurate. This is because the projectiles have no stabilizing spin orthogonal to the velocity vector. Once the round leaves the centrifuge, it doesn't accelerate ...

5

Not really an option the way you want it, where it is always on fire. Fire takes a LOT of energy that the tree needs to build up over time. Let's build a situation where it might make sense to exist with limited time: On the continent of Worse Than Australia, funghi and various insects are a huge threat for plant life. They infest trees and kill them over ...

5

You raise legitimate concerns. Even if there was simply enough mass, it may not be the right atoms (we don't build anything out of helium for instance). Which is why some people already came up with the dyson swarm, as well as other variants. A Dyson swarm is a swarm of smaller constructs which gather and send back the energy they collect. It is more "...

5

Suggesting a Reframe... Not and Be Science Based The "molecular acid" (meaningless sci-babble) that ate through bulkheads couldn't reasonably have run through the veins of the alien in Alien, but Alien wasn't really meant to be hard sci-fi. That no one could hear you scream was a nice touch, but there's lots about the series that's definitely not science-...

5

The answer lies in the thriving world. The Martian environment is remarkably stable. Whereas after thousands of years while Earth might habitable, almost everything associated with a technological civilization will be unworkable, corroded into useless lumps of matter, or entirely gone. The aliens would either have to import large amounts of tech or build ...

5

Why would such a creature evolve to essentially never stop eating For half of an entire year? The energetic content that the animal can extract from the food is very low, thus it has to constantly feed to get the right amount of supply. Once I read that "eating celery costs more energy than what you get from it". Apart from the accuracy of the claim, ...

4

No. An intelligent, mushroom-looking creature: sure. But I don't think we'd consider it a fungus. If you start with a fungus and start adding features until it meets your requirements, it will start to break the rules of our definition of fungus. The primary characteristic of fungus is they have chitin in their cell walls. That's not incompatible with ...

4

Aqua Regia The human stomach uses a combination of different acids to form gastric acid, otherwise known as stomach acid, which has a pH of between 1.5-3.5. Admittedly, pretty effective by itself when it comes to destroying stuff. But it's composed of a mixture of two salts and an acid, sodium chloride (NaCl), potassium chloride (KCl) and hydrochloric acid (...

4

Gliding flight would be useful in combat by keeping them stable in flight and therefore more accurate with their breath weapon. Expending less energy would also be good in of itself, as the dragon would want to conserve its strength for when it has to dogfight or escape

4

Cant you obtain a starting supply of oxygen from water itself via electrolisis? I dont know if its the best way to obtain it, but its a way. And you still have to get the rest of the gases to get the atmosphere. Once there, you can get oxygen and food from hidroponic farms (I guess they are not consuming ONLY local fauna)

4

It seems very likely that Europa has a vast subsurface salt water ocean. Such an ocean would in all likelihood contain some nitrogen as dissolved gas, nitrate or ammonium salts or other more complex amides and amines. Such chemicals could be processed to release the nitrogen for use in a habitat. The exact method would depend on the form that nitrogen takes ...

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