# Tag Info

79

Let's look at the world of shipping here on Earth for inspiration I have a suspicion that if you look at the history of shipping, you'll discover that whether it's a cart or a bullet train, the basic limitations for being an independent owner/operator of a shipping company remain the same. I own a pickup truck and that lets me do a great many things, ...

51

The traditional answer to this question is "FTL drives don't work within gravity wells", which is sometimes justified by saying that they require a region of "flat" spacetime to operate reliably. If you're within a gravity well (i.e., spacetime is significantly perturbed), then they become dangerously unreliable and can self-destruct, shoot you off in ...

37

It depends (but probably not). Some forms will be achievable, with more or less difficulty. Any form? No. There are several limitations you did not take away (some of them are discussed in the Sight of Proteus (Behrooz Wolf) series by Charles Sheffield, where an intentional transformation machine, the "form-change vat", is a plot device): conservation of ...

26

If the water is already in microgravity and isn't mostly constrained by structures, the vapor pressure inside will tend to blow the mass apart into smaller masses, which will in turn blow apart more. At some point in this process, evaporative cooling will freeze the water, ending the cycle (ice has plenty of structural strength to contain water's vapor ...

26

SHORT ANSWER: There are several obvious reasons why using a warp drive near a planet might be a bad idea in your story. LONG ANSWER: And here are some of the reasons: The concept of the Kzinti Lesson first appeared in Larry Niven's novel Ringworld (1970) and refers to his story "The Warriors" in If magazine in 1966. It is phrased as: A reaction ...

16

Drives are cheap and light. Assume a technology that makes interstellar craft affordable. Instead of expensive, disposable rocket boosters to get into orbit, there is a sublight/maneuver drive that takes only a small fraction of the ship's total weight, leaving plenty for cargo and for a hull constructed out of normal steel, not titanium or expensive alloys....

13

I like JBH's answer and I agree with him. But just as a mental exercise, I'll defend the opposite point of view. Plastics. Because Wikipedia says: There is much more carbon than iron or any other metals around, and most of the carbon is in interstellar clouds where you don't need to fight against a gravity well to land. If you've got spare time and you ...

12

Metal William of Ockham, an English Franciscan friar (1287–1347), is credited with formulating the Law of Parsimony that we know better today as Occam's Razor, which can be simplistically stated: "All things being equal, the simplest answer is usually correct." Plastic requires the stuff of life to manufacture. If our own solar system is any basis for ...

12

Short version : No. Would they be able to transform to another creature, and regress at will if they wanted to? Say this person transforms from human to a bulldog or something twice as big as a human Your problem are essentially two key things : Physics Physics doesn't let you just suddenly generate energy (or equivalently mass). So let's say you want ...

11

Frame challenge If a person had control of every single cell of their body ... There's your problem right there: (1) Estimates put the number of cells making up the human body at around 30 trillion. No 'person' could hope to control (or even comprehend) that number of cells. (2) Humans contain a similar amount of bacteria - perhaps 40 trillion - mostly ...

10

The obvious answer is "use airguns" (something another poster already mentioned, so I'll probably pop it out of this answer if they end up using it). They scale up OK, are moderately powerful and so on, but you'd need to be pretty tricky with them in order to make things that were man portable and could penetrate modern infantry armour. Combat ranges might ...

10

Lazy answer: don't do anything. If everyone can create bots, let them, and then no-one will have the upper hand. Less lazy answer: Processing power and storage space ain't free. In fact, depending on the nature of the substrate your virtual reality runs on (how about a colony ship in deep space?), it may even have a strict upper limit that cannot be ...

10

I think the main factor that would simplify the ship production and cheapen the ships significantly would be this: most of the ships in the setting are not expected to enter or leave a gravity well of a planet with atmosphere. It may be that people in your setting live mostly in space habitats. Could be that all the planets have space elevator stations you ...

9

If you have a bottomless heatsink you can generate free electricity by using the difference between ambient temperature on Earth and voids of subspace. Basically an inverse refrigerator that generates electricity by cooling things. As it was pointed out in comments, a Stirling engine will suffice. Doing this will probably also affect global warming ...

9

Compared to the other races humans are psychotic. The other races (with the possible exception of the martians) would - literally - die before taking another life, humans can have lots of coping mechanisms for squaring away murder (self defense, first strike, the greater good). The martians are few in number, and see life as very precious given the harsh ...

9

Partial Obsolescence of Space Drives A space drive (both the cross system FTL part and the in-system maneuvering engines) drop in power rapidly in the first few years of use, before leveling off. Within the first five years, a space drive drops from its maximum power rating to about half that. It then stays at that level a century or more. It's still ...

8

It takes a surprising amount of energy to form a gas bubble in water. As an example, consider a glass full with some soft drink at rest. Usually there will be bubbles of $CO_2$ going up continuously, but they will all originate from a certain number of points on the glass surface, not from within the liquid. These points are impurities in the glass' surface ...

8

Earth has a technological advantage over everyone else. That is why they are in charge. The martians are living on a dead world, so most of their resources go into just staying alive. The Dar circles are naturally cooperative, so their history is peaceful and mostly conflict free. Their technology is amazing, but it is non-aggressive and often shares ...

8

"basically superheated plasma held in place by a magnetic field" That's your reason right there. Do that in an atmosphere, and the plasma ring will be massively disrupted, leading to a uneven matter conversion. This, in turn, will ensure that the warp bubble is itself warped, the consequences of which can go from the inner volume being flooded in hard ...

7

The human they present as, is actually a hyper-dimensonal object. Consider: The diagonal of a square is 1.4...(square root of 2). So a 1.4 foot 1 dimensional line can fit in a 1 foot square. More applications allow a $\sqrt3$ line to fit or a 1 x $\sqrt2$ plane. So your human shape is the 3 dimensional cross section of a higher dimensional object.

7

Directed Energy Weapon Eater one could armor something we wish to protect with the bottomless heatsink to protect it against directed energy weapons. So long as we can absorb all of the incident energy and the heat transfer rate to the bottomless heatsink is high enough, we can prevent the armor from melting. For more fun, we can use said absorbed heat to ...

6

Metal (assuming you're in space.) In a space-faring civilization, there are a few assumptions we can feel entitled to make. The first is that metal is plentiful. Plentiful under these circumstances means that said civilization has entire asteroid belts of mine-able metals to work with. An army of replicating solar-powered drones should be able to burrow ...

6

I presumably misquoting this phrase, but anyway: Internet is not a democracy, but an loose federation of petty dictatorships and fiefdoms Right now already people are enthusiastically being engulfed in their own echo chambers. Instead of mass media that would lie in crude and uniform way, people right now prefer to hear much more personalised lie, ...

6

If (some of) the bots don't know they're not human, how do the humans know? I'm going to get to the government in just a moment, but this is important. I suppose the software could let the actual humans (and the software would need to know which are humans and which are bots) could let the humans see the bot avatars with a big honking sign that says "I'm a ...

6

Let's talk about fence posts Have you ever driven a fence post into the ground? You betcha! You get one of those cool tubes with handles and bang! pound that sucker right in. Now, I want you to keep that in mind as we talk about magnets. (Heh, you're going to love this. Trust me.) A big-ol' magnet is resting against a block of iron. The magnet is the ...

6

Don't land The most expensive operation in a typical mission from a planet is the takeoff. If your ship never lands on the surface of a planet, it never has to take off. It can just travel from space station to space station. How freight and passengers get to the planet's surface or how the space station gets freight and passengers to it aren't the space ...

5

Aethir. Known to the ancients of Greece, Aether (after a god of the same name): pure upper air that the gods breathe... According to Epiphanius, the world began as a cosmic egg, encircled by Time and Inevitability (most likely Chronos and Ananke) in serpent fashion. Together they constricted the egg, squeezing its matter with great force, ...

5

Stellar Exploration Literally meaning coat your ship and go take measurements of the insides of the sun. If you can do that then perhaps add a layer if to the sun to make it impossible to achieve helium fusion and stop the sun from expanding into a giant and swallow the Earth. Condense Jupiter so we can suck out Liquid Hydrogen with a simple hose. For ...

5

This is a very short answer, which basically boils down to this essay: https://what-if.xkcd.com/1/ Anything traveling at high speeds has to deal with air resistance. The faster you go, the more energy has to go into pushing air out of the way. In that article, Randall talks about the case of a baseball at sub FTL speeds. Imagine if it was an entire ...

5

Short version: Because very few people actually want one and there's a lot of shipyard space that could be used to build one, and occasional it even is. Long version: Most ships are huge and all ships are one of a kind, this situation only really makes sense where the limits of the drive systems being used are unknown and the economy is expanding. The ...

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