# Tag Info

11

The devices are the controllers not the engines Through relatively low energy communication they control a vast array of machinery scattered throughout the solar system, cold and thus yet to be detected.

9

Probably nothing at all as a "dense" cloud of matter in space is still not nearly as dense as planetary atmospheres surrounding an earth like planet. Those pretty pictures of nebulas that you see are spanning areas of multiple stars, each likely to have some planetary orbits. In fact, any video game in which space is colored in some way to show it's in a ...

9

Maybe. It all depends. Trees rely on soil for a lot of things, and the alien soil would need to supply it and also refrain from being harmful. Not poison the tree: Some extraterrestrial soils are actively poisonous. (Mars' soil, for example, is highly oxidizing and would, untreated, almost certainly kill anything planted in it.) Retain water: Soil holds ...

8

Batteries and liquid hydrogen. Your ship uses as its engines a quartet of electric ion thrusters which fire hydrogen plasma (ionized hydrogen) at a significant fraction of the speed of light. Each thruster can rotate 360 degrees, though will not fire when pointing at the ship (that is bad for the ship and occupants). Combinations of thrusters confer ...

7

A lot of people assume that the magnetosphere of a planet is the main factor determining whether it can retain an atmosphere. Long ago it was calculated that the escape velocity (not the surface gravity, the escape velocity) of a object was vital to how long it could retain an atmosphere. As I remember, if a planet, moon, or other astronomical body has an ...

7

The PLSS had silver-zinc batteries, yet I believe that the batteries were exchanged rather than recharged. Are there reasons not to recharge them on Luna? Or am I mixing battery technologies? I'm reasonably certain that these were the non-rechargeable type, and rechargeable variants didn't exist back then. There weren't many rechargeable battery ...

7

I have some professional interest in the subject in a general way, not specifically to pressure suits. I'm a nuclear safety analyst. Knowing the reliability of equipment depends, in part, on a long service life with reports of failures, and analysis of the failure mechanism. That is, it needs statistics. The longest anybody spent on the moon was, what, ...

7

There won't be any humans to have a society. The single Chicxulub Impactor, which caused a mass extinction that included dinosaurs among many others, was about the size of a small city (not a big city). It's devastation was phenomenal - our estimates of a Nuclear Winter are like a day at the spa by comparison. Shattering the moon, which is the only case ...

7

The aspect of these items which projects into our 3d space is small. The items are not. Multidimensional space is a favorite of mine. Additional spatial dimensions beyond our familiar 3 spatial and 1 temporal is not wacky magic; mathematics easily describes additional spatial dimensions although physics struggles. https://en.wikipedia.org/wiki/Dimension#...

7

You are better off using lichens. A lichen (/ˈlaɪkən/, LEYE-ken or (USA) /ˈlɪtʃən/, LICH-en) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship. The combined lichen has properties different from those of its component organisms. They are the first organism to ...

7

Your planet will either be incredibly cold, or have no heavy elements. Krypton is a fairly light noble gas, it boils at 119K, and it's fairly rare. Naturally, such an element would never form the core of a planet. Even for planets where krypton occurs as a solid, heavier, denser materials will sink and form the core of the planet, especially when the ...

5

Your plants will most likely die as they don't have the supporting ecosystem in the soil. If you look at the evolutionary timescales, land based (read as soil inhabiting) plants are first thought to have evolved on Earth around 700 million years ago, but life first formed on the planet a lot earlier; around 3.5 billion years old, probably around 1 billion ...

5

Beamed power might be of interest: since these fighters remain close to the mothership, the mothership could supply them with energy via laser or microwave beams that they converted back into electricity for use in weapons and propulsion. This would allow your fighters to be smaller and lighter because they didn't have to lug around a power source, but it ...

4

1G for an hour is an astonishing amount of fuel for a space vehicle. It doesn't sound like much for an air breather, but space vehicles have to hold onto their own reaction mass. 9.8m/s^2 for 3600 seconds is 35km/s of delta-V, which is how rockets measure these capabilities. 35km/s is a lot. That's almost enough to escape Earth's gravity well and head ...

3

Any interstellar material would be redirected by the Heliopause in the Heliosphere (https://en.m.wikipedia.org/wiki/Heliosphere). The solar winds travel for a pretty long time and only get slowed down at the Heliopause (or mark the Heliopause by slowing down there, if you want to look at it that way). Besides creating a strong magnetic field, which deflects ...

3

The force of gravity on a spherical body like a planet or moon is governed by Newton's laws. If a moon had the same surface gravity as Earth: $$F_{gravity} = \frac{G*M_{earth}*m_{object}}{r_{earth}^2} = \frac{G*M_{moon}*m_{object}}{r_{moon}^2}$$ Solving for the relative density of the moon and subbing in the info for Earth and ...

2

When you consider The Kzinti Lesson (the more efficient a reaction drive is, the better a weapon it makes). Any civilization that can produce the energy to travel between worlds can also produce a weapon that can turn pretty much any solid matter into plasma making armor irrelevant. This means the quality of your ship's defence is exactly proportional to ...

2

Nuclear Rocket is the only solution within ~100 years... Chemical rockets do not work Chemical rockets do not work because of the rocket equation. You have to carry your own fuel, so you need a very high effective exhaust velocity. See this table, here. Thrust is based on conservation of momentum ($mv$) between you and your fuel. If your $v$ is low, you ...

2

Not trees, trees are delicate sensitive things, though they may not seem it at first glance. You want weeds, dandelions, horsetail, bindweed, knotweed, grass. Plants that will grow out of a crack in concrete and call it a good home. Plants that your every effort to annihilate has knocked 6 weeks growth out of and look who's back. It'll take you a while to ...

2

With 1960 era technology, you are probably looking at the cutting edge as far as space suits and moon suits are concerned. Rechargeable battery technology was in its infancy, materials science had no previous experience with regolith when designing seals and material for the outer shell, and most of the other issues were being solved essentially from scratch....

2

There's a whole lot of answers based on what you may or may not believe about the differences between the sexes. However, there's one that is glaringly obvious: there's a mighty gap which cannot be filled by both sexes! If we consider our current command structure, 100 individuals are typically controlled by a lieutenant, captain, or major. Ten times that,...

2

When Edward Lorentz first described chaos theory, it was heavily misunderstood. Von Neumann famously admitted that he thought what Lorentz was describing would permit global climate control within a decade. It was only much later that realized that such attempts to adjust the climate would be like giving a well shuffled deck of cards an extra shuffle. You ...

2

Well, if the military here works like the current American military (voluntary sign-up, no draft), you're probably looking at a society extremely stratified by gender. Almost insanely so. [Okay, full disclosure, this post is based on things I've read and soldiers and ex-soldiers I personally have spoken to. Considering I have everything second-hand, I admit ...

1

Matriarchal society is not a "gender-bender" patriarchal one. It has a very special social structure. For matriarchal society the main focus is on raising children, not on war of any kind. This is exactly why it apperas and develops: if child surviving (not birth!) rates drops far bellow of what is needed to sustain population, mothers needs became ...

1

Here are my 2 cents... Fighting space battles is one thing. Owning the land is another. So the question is what role would men play in your world? It seems plausible to me that in a world where woman dominate the field their social status will greatly improve. But to make this a matriarchal world it will eventually also require social engineering to let ...

1

From this link we know that Tidal force is defined like so: In celestial mechanics, the expression tidal force can refer to a situation in which a body or material (for example, tidal water) is mainly under the gravitational influence of a second body (for example, the Earth), but is also perturbed by the gravitational effects of a third body (for example,...

1

As discussed on this projectrho.com page, for near-future rocket technologies there tends to be a tradeoff between thrust (which gives the force on the rocket, so you can divide by the rocket's mass at any given moment to get its acceleration) and specific impulse (which is just the effective exhaust velocity divided by an acceleration of 1 G, as mentioned ...

1

I am assuming you are not proposing some unknown method of thrust. Are you sure you need to thrust at 1 g for an hour? The rocket equation has something to say about this. The rocket equation tells you how much change in velocity you can get from a given rocket for a given change in mass. The rocket design gives you the specific impulse (that's the $I_{sp}$...

1

Here's a solution involving traversable wormholes, which Ash already mentioned as a possibility, but I'll give a little more detail to show how it can be done without violating causality (no one can do anything to exert a causal influence on their own past self). One key thing to understand about traversable wormholes is that time hooks up differently ...

1

You might be able to do some interesting things with a swarm of satellites a few thousand AU out, using the local star as a gravitational lens. This is a long way out, but not as far as going all the way back to Sol. A mission called FOCAL has been proposed that would send a single telescope out to the Sun's gravitational focus. There's been various ...

Only top voted, non community-wiki answers of a minimum length are eligible