# Tag Info

7

You ask, science answers! Enjoy the wonder of the pentaprism A pentaprism is a five-sided reflecting prism used to deviate a beam of light by a constant 90°, even if the entry beam is not at 90° to the prism. The beam reflects inside the prism twice, allowing the transmission of an image through a right angle without inverting it (that is, without ...

13

Sure. It's just a periscope. You'd probably make it shorter both for wearability and durability, but if you have good mirrors, it'd work fine. (The major problem would be if it were a medieval setting or something, where good, silvered mirrors would be hard to come by.)

0

Metal Iris Umbrella, or Slatted Umbrella Since your design always points the hub towards the Sun, the primary heat source, it makes designing a light shield really easy. Build a tower directly outward from the hub (it can have an offset if you want landings there). Build a sun-blocking structure that can be fine-tuned. There are many good shapes. The ...

0

Rearrange, and increase the size of, your solar panels so that they almost completely shade your entire cylinder from the sun. The only openings you need are an entrance to your mirror system for internal lighting. Arrange any needed radiators on the external hull, which will still be shadowed, allowing for excellent cooling efficiency. Note that a ...

5

those habitats are part of a Dyson swarm in my design. Therefore, any radiation from this outer lateral area would be absorbed by the other habitats and not radiated to space. A perfect circle 1AU in radius has a circumference of nearly a billion kilometres. A McKendree cylinder is about 1000km across. If separated from each other by 1000km, you'd be able ...

3

Heat pipes are the answer: These were used for the McKenzie Valley pipeline to keep the permafrost cold under the supports. Thought experiment: Take a 30 foot long steel pipe, and put a few gallons of liquid propane in it. Let it boil, pushing the air out. Cap it. Propane liquifies at -40 under normal atmospheric pressure and temperature, and is a ...

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Your Tidal Locking Dilema You are already pointing tidally locked solar panels at the sun, simply place the panels between the sun and your habitat. This puts your whole living space in their shadow. Then you just need to evenly distribute things inside of your habitat that generate heat (lighting, computer systems etc.) such that they are evenly ...

-1

Can we not just do what someone said earlier. Huge solar arrays that super heat seawater then use silver particles to induce rain. Kill two birds with one stone. Drop the sea levels. Get more water on land. Even just topping up water levels would be useful. There always seems to be this massive con. Huge problem with these ideas. Oh it costs money. Yeah so ...

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You don't need a huge canal, just a little one. Once the water starts moving, it's going to dig the canal it wants! So you'll want to build a full-design-size system of headgates at the ocean side, so you can shut the darn thing off when it starts misbehaving. After that, you only need to cut a channel wide and deep enough that 100% of the water doesn'...

7

I would depend to a great extent on the nature of the rocky soil. If it’s fragments of rock that can be shovelled then that’s one thing but if it’s solid granite that’s something else entirely. It would also depend on the required depth and width not only the length. Assuming that its loose material and not solid rock one technique that might be used would ...

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Fun trivia: the word canal, and related words like cane, are most likely the only words in modern English derived from the ancient Sumerian language (from 𒄀𒈾, "qi.na") - spoken by a culture that has not just been extinct for four thousand years, but it was completely forgotten until they dug them up again in the late 1800's. Then it took another half ...

4

It depends on the size of your labour force how hard you want to work them. Using the figures from https://en.m.wikipedia.org/wiki/White_Sea%E2%80%93Baltic_Canal I reckon that you could build a 10km canal using hand tools in about a month with 100000 labourers, if you don't mind killing about 1000 of them.

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After his wife died due to poor access to medical care in his village, Dashrath Manjhi spent 22 years single-handedly carving a road through a hill 110m long, 9.1m wide, and up to 7.7m deep, using only a hammer, chisel, and other simple tools, such as fires and cold water to crack the stone via thermal shock. So, one man, 110m x 9m x 3.5m*, 22 years. Now ...

0

In a peacefull society/setting mining is still done every day. However millitary equipment has not been actually battle-tested for tens/hundreds/thousands of years and might therefore not actually work (well).

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The best answers can be found in the basic differences between mining and military endeavors. Mining is a for-profit venture; war is an economic black hole. Mining is a venture whose financial backers expect to see a return on investment. That investment can be significant, but a high rate of return can very easily justify higher cost of entry into a market....

6

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 "...

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 ...

4

In the real world, I work for a company that uses both mining equipment, and "military spec" equipment. None of the fun stuff, unfortunately, just industrial equipment that's certified to meet the military's durability/ruggedness standards. I can say that there definitely is some truth to the trope, but it's not a straightforward comparison like trope ...

1

There are lots of good answers for 1, let me post some thoughts on 2. What could drive our sci-fi heroes to construction or mining equipment? Military equipment built by humans is designed to fight humans. If we suddenly run into an opponent that is decidedly not human-like, we will be scrambling. Rifles work great, but poking a 5.56mm hole in that ...

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Military equipment has to be light enough to be transported - often by human power - to the unpredictable locations where it will be used for an unpredictable but probably short length of time, after which it might well be abandoned rather than transported back to a military base. Assuming, of course, that it is not destroyed by enemy action. Mining ...

6

It's probably fair to say that most people aren't familiar with the realities of military or mining equipment, much less space military and space mining. They see on TV that tanks and humvees look bigger and bulkier than their Honda Civic, so they assume military=tougher. They see that earth moving equipment looks even bigger and bulkier, so they assume that ...

4

Since this is sci-fi, one such scenario would be where weapons are cheap, but warp drives are punishingly expensive. War requires mobility, and that mobility comes with a cost. Let's say for example that it costs 1-3 space bucks per kilo to build a laser, any laser, but a warp drive costs 1000 space bucks to be able to move that kilo of laser quickly. ...

0

Military equipment has an expiration date, for all intents and purposes. If a war is expected to last for 5 years, why mass-produce weaponry that will last for 20 years? Example 1: This is the sort of thing we see with German Panther tanks versus Russian T-34 tanks. Sure, an individual Panther was better, but the Russians better understood the temporary ...

6

I want to offer an alternative perspective. The military pays for the cheapest bid offered, sometimes there is corruption involved. The equipment might under preform(think of the M16 in Vietnam) and the cost is mostly in human lives, but grunts are not that expensive to replace (unless you are thinking of starship troopers type infantry where each soldier ...

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Is the idea that mining tools are designed to be very durable grounded in reality at all, and if so what's the reason for it?* Absolutely it is. I'm going to talk primarily about machinery here, and the key point is that in a working mine, the machinery works 24/7. The workers may trade shifts, but the trucks and the mining drills and everything else is ...

2

Money. If the mining equipment is more expensive than the military stuff, it will be better quality. This is not that unreasonable; mining is a multi-billion industry, vitally important to all infrastructure. A large, world spanning mining company easily has the profit to invest in the most cutting edge. It's not like the olden days when mining was just ...

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No, not really. Dead Space is a game about engineer stranded on a mining space-ship fighting off space-zombies. Primarily, mining and construction tools are what he has access to. Secondarily, space-zombies in DS are animated by space-magic emanated by space-artefacts, said space-magic makes them impossible to kill and keeps them going forever. Main ...

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is there a reason that mining tools would be made to specifically prioritize durability while military equipments may not be? Logistics costs. Mining is a commercial enterprise; if using tougher kit makes it easy to keep a site up and running with reduced repair and resupply costs, some spreadsheet wrangler is eventually going to point this out and things ...

9

Mining tools are made to crush, destroy, pullverize SPACE stuff. Things made in space scale temperatures mixed with space pressure. On Mohs Scale diamond is 10, the hardest mineral. Hardened steel is just 8. You design tools for that to be used days after day after day for 8-12 hours a day. While your military equipment is designed to "work" for minutes ...

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Combat equipment has to travel long and fast. Take for example the difference between Light, Medium and heavy tanks. Heavy tanks are far superior in armor and weapons to light and medium tanks, but due to the weight of its parts it becomes a nightmare to deploy to the battlefield because of its low speed and high fuel cost. Add to this the fact that their ...

1

Q1: In the case of cylinders, pressures acting radially do not one-to one correspond to hoop stresses. Basically, you have to counteract a radial force with a force almost perpendicular to it (the cohesion force between adjecent wall elements). So there is a "penalty", which grows proportionally with the cylinder radius, since the bigger the radius is, the ...

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