# Tag Info

17

I can think of at least four power sources: 1) Solar Power, which is used in the International Space Station. Solar panels are, however, vulnerable to micrometeorites and fast ionized particles in the solar wind, but it would be possible to have microrobotic repair systems. 2) Catching He3 from the solar wind for fusion power. Since this He3 is ionized, it ...

17

You can use the relativistic Doppler effect The relativistic Doppler effect is the change in frequency (and wavelength) of light, caused by the relative motion of the source and the observer (as in the classical Doppler effect), when taking into account effects described by the special theory of relativity. The relativistic Doppler effect is ...

16

If the spaceship was decelerating at one g, meaning a comfortable 9.8 $m/s^{2}$, then deceleration will take roughly one year shiptime. No need for special counter-acceleration measures. Plus, it provides convenient environment for astronauts to work and play in, while decelerating. Also, time to survey their destination prior to their arrival. However, the ...

14

It is important to note that travelling very near the speed of light is no different from being at rest - it all depends on the chosen frame of reference. Travelling at .999 c in one frame of reference = being totally still in another. You can only measure your speed relative to other objects in space. There is no absolute speed. If you are heading towards ...

11

There is only one orbit for a space-ring consistent with space-elevators - that is an equatorial orbit at an altitude above the earth's surface of approximately 35,800 km. At that altitude the ring will be in geo-stationary orbit - i.e. the ring will rotate at the same angular velocity as the earth-s surface so tethers stretching from the earths surface to ...

11

How close you pass to the black hole is almost completely irrelevant. The galaxy is only 100,000 ly across, and the Earth is only about 25,000 ly from the center. If the aliens are coming from a direction diametrically opposite the Earth across the galactic core, only 75,000 ly of their 66 million ly journey will even be within our galaxy, let alone near the ...

10

In terms of energy, solar is the way to go. All the energy stored chemically and kinectically in all the planets, comets and asteroids together pales in comparison with the energy stored and provided by the sun. If you haven't already familiarized yourself with the Kardashev scale, now is a good time. This is a paper from 1964, widely popular in science ...

10

As said many times here and in many other places, the problem with going to space is not about going high enough (a flight from Amsterdam to Tokyo travels more linear distance than a flight from Cape Canaveral to ISS, you could cover the distance to space in 1 day with a bike and a bit of exercise), but it's more about going fast enough. Orbital velocity is ...

8

TL;DR: you can't make a space-shuttle sized thing fly like a bumblebee, because engineering isn't scale-independent. In addition to the obvious issues (eg. you'll save very little over a conventional rocket launch) the other major problem is that bees are small and light, whereas things that are considered to be surface-to-orbit cargo vehicles are very much ...

5

No. It's not about being able to have enough energy. There would simply not be enough resources available for a closed system like a space station to sustain itself. They would need to recycle their air, water and waste perfectly to ensure the system could sustain itself. They would not be able to support a large number of additional life, like children due ...

4

Carbonite. https://www.reddit.com/r/StarWars/comments/1tcact/the_original_han_solo_in_carbonite_prop_on/ "Freeze" your spacefarers in carbonite. How does carbonite work, you may ask? Carbonite was a liquid substance that was made from carbon gas and could change into a solid through rapid freezing. Goods could be encased in carbonite for ...

4

Use a coordinate system. If I want to tell you to go to a place, I need to be able to describe the place to you. I can tell you "that place we hid the weed" and you will know. But if we are strangers, or are talking about a place neither of us have ever been, we need some objective way of describing that place. You need a coordinate system. There are ...

4

A1: 9.81 m/s² = v²/R = omega² * R = 4 * pi² *frequency ² * R so frequency = 1/(2pi) * SQRT(9.81 / R) = 1/(2pi) *SQRT( 9.81 m/s² / (240 feet*0.3 meter/feet)) = 0.0587 hertz = 3.52 RPM EDIT: Extra information, the outside of the hamster wheel will be moving at 26.5 meters per second (velocity = omega * R = 2*pi*frequency * R). This means that realistically,...

3

If the space station is designed and built 150 years in the future there is a strong probability that fusion power will be perfected by then. Presumably the water supply on the station will be extra large and will have more water than is needed for other purposes, so that from time to time some of the water will be broken down into hydrogen and oxygen and ...

3

Once you have a single orbital ring, your best bet is to make it wider and thicker. The places you bean stalks (space elevators) have extensions anyway for the counter weight to balance the weight of the stalk. Usually this is a small asteroid at around 100K from the earth. For in system flights by matching speed with one of these exterior spoke (cable to ...

3

Any way you want. It depends on the energy you have available. To not tether them requires that you have thrusters of some kind to enable them to maintain position (ie. not crash into the planet). The most energy efficient way to orient them would seem to be in line with the ecliptic plane, because this will require little energy to maintain. Another ...

3

I am writing a short story about an overworked planet whose civilization has achieved space elevators and orbital rings. Note that there is no known material strong enough to build a space elevator. People will talk about carbon nanotubes, but even with the best manufacturing capabilities imaginable small imperfections in the material will reduce its ...

2

Using the orbital ring itself for habitation is a poor use of its potential on a utility/unit mass basis. To keep building up an orbital ring, you need to spin up the rotor even faster, or add mass to the rotor. Both are non-trivial requirements. A more elegant solution would be to have a band or orbital habitats, connected together by physical supports ...

2

I don't have a solution; what I do have is a possible path to a numerical solution. For the sake of simplicity and sanity, I will consider the special case of a non-rotating, chargeless, spherically symmetric black hole. This black hole causes space to take a shape described by the Schwarzschild metric. A small test particle - which in this case can be our ...

2

So you want a coordinate system for the universe... Let's assume that your teleportation system relies on a centralized information source which has some existing knowledge such as the constantly updated coordinates of the absolute center of mass of every inhabited planet that your species knows about. Now getting to anywhere in the inhabited universe ...

2

A strategy depends on the analysis of potential threats. Since nothing is specified in your question, I'll outline a few situations. If all the worlds in your spacefaring nation have no threats and are at no risk, then its immaterial where the Army is at any given time. A central location that permits travel to any given place in the nation's system ...

2

A skyhook may be a better answer than a space elevator. A skyhook is a cable suspended from a large space station (or, in this case, spaceship) that does not reach all the way down to the planet's surface. The cable rotates around the spaceship, and with the right combination of orbital speed and cable rotation, its end could have zero velocity compared to ...

2

Yes it's possible. It depends on how many sci-fi like elements you want to apply. Right now, there are huge issues in the production of carbon nano-tubes long enough and in large enough amounts to support the construction of a space elevator. Going through such an undertaking however would suggest you already have easy access to space as you are performing ...

2

Yes, but probably not on the scale you want. Time dilation exists on earth. According to a study from the National Institute of Standards and Technology, "if one twin spent 79 years living at an altitude 1 foot higher than her sister, the first twin would end up approximately 90 billionths of a second older." We can extrapolate from that that a person ...

1

Biology, Not Physics Although we can talk about situations involving speeding up or slowing time and hit an answer, there's a whole other scientific realm available to this answer: biology. And while we don't know how to stop aging exactly (or exactly what causes it), a biology-based answer requires no less handwavium than physics (where we can say what to ...

1

Time Travel Time travel, either back in time from the journey location to the return arrival time or farther along their own personal timeline. If the "traveler" twin is displaced in time as well as space, or goes somewhere where the passage of time differs from that on Earth (in this case it would have to go faster), then they may actually experience more ...

1

Keyword here is mobile. You see, a Space Elevator is nothing more than a really tall satellite: the sheer weight and centripetal force on the far ends keep the thing pointing upwards and downwards, it doesn't even need to be tethered to the ground with the correct weight balance and orbital speed, it will just float with it's mass pulling towards the planet ...

1

Since teleportation doesn't happen in our universe (let's avoid semantic arguments about entangled photons), you can posit whatever you wish. Remember that StarTrek:TOS used pads for their beaming, but they certainly weren't necessary. The back-story was that the reliability/safety was improved when pads were available. By comparison, any number of ...

1

How do you target regular transportation? Well, you move in a certain direction at a certain speed for a certain amount of time. With teleportation, you do the same thing, except the speed component is bigger, presumably you move through obstacles, and the time component is nearly zero. Done.

1

The question is flawed. Space wars should be fought by space navies, not by space armies. I think there is a scene in Heinlein's Starship Troopers where a recruit asks what is the use of ground troops in an age of atomic weapons and push button warfare, and the drill sergeant throws a knife and pins the recruit's hand against a wall and asks him how he is ...

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