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For questions about the universal accelerative force between all objects.

2
votes
3answers
131 views

Making a 180 degree turn around a star

For a book under construction, I need a starship to make a 180 degree turn rather quickly. Give him sub-light speed in a star system (no relativistic effects) and on a path to the system primary. I ...
3
votes
3answers
71 views

Gravity being weaponized for its time altering properties

Physics isn't my strong suite, but I'm trying to understand if something could be theoretically possible in some highly advanced future: Would it be possible for an advanced civilization to invent a ...
13
votes
22answers
4k views

Plausible hypothesis on why gravity might fail on earth

I've been grappling with a story for a while, involving a scenario where gravity starts to fail. The goal of the story is mostly how people react to the knowledge that the world will end. But, I also ...
1
vote
4answers
268 views

Alternative to gravity inside a Dyson Sphere?

On the inside of a Dyson sphere there is effectively no gravity. Is there an alternative method to keep people on the inside surface from floating around? I know it could spin and that would keep ...
12
votes
4answers
2k views

Simulating gravity in a gravity-less universe

In my fantasy universe, there is a disc-shaped world that has a flat surface that has roughly the same atmosphere as Earth (see this); the atmosphere moves along with the world. There is no gravity in ...
0
votes
3answers
82 views

Conditional deniability of a natural asteroid belt with an atmosphere?

Is it unreasonable to suspend one's disbelief that an asteroid belt naturally formed with enough mass distributed through the belt to justify the formation of a belt-wide atmosphere given the ...
2
votes
3answers
226 views

Is it possible for humanoid life to develop on a 1.4 G planet?

I'm writing a JRPG-inspired novel set on a planet with 1.7 Earth masses and 1.4 Gs, but is it possible for life to even develop on such a high-gravity planet in the first place? I tried scouring the ...
2
votes
3answers
105 views

What should the size of my moons be?

(Not entirely sure if this is the right place to ask this but hopefully I'm right!) I'm writing a novel and the planet this novel takes place on has two, twin moons of approximately the same size. ...
0
votes
2answers
127 views

Effect of 1.5g (Induced hypertension health effects?)

On this planet, gravity faces many fluctuations, but humans spend most of the time in 1.4-1.5 gravity. During these periods (usually lasting about 5-7 days) I was thinking I'd have them increase salt ...
6
votes
6answers
301 views

Would lower gravity lead to earlier spaceflight?

This is in regards to the Tyranny of Rocket Fuel. Summed up: Heavier ships need more fuel which makes them heavier, etc. You end up with diminishing returns. This is compounded by higher gravity - ...
6
votes
6answers
439 views

What would happen to the Moon if it was lowered onto the Earth?

An absolute madman of a scientist tractors the Moon from it's orbit, and carefully lowers it through the Earth's atmosphere and gently brings it to rest upon the Earth's surface. There is no reentry, ...
37
votes
9answers
11k views

What are the effects of slicing the Earth in half with a particle beam?

Scenario: An exact copy of our world is sliced in half by a particle beam. The beam has a diameter of 40 meters and moves at a speed of 0.999c. The beam slices the earth from top to bottom in 600 ...
4
votes
2answers
186 views

Magic: Reality check of effects of mass-altering magic

I'm looking into magic systems for my fantasy world, and among other things, I want to make sure that I have the effects right. One such magic system allows the user to create a small 'bubble' of ...
5
votes
2answers
122 views

Reality Check: Planet with low gravity and water vapour

Using Artefaxian's excellent spreadsheet I have created a basic idea for my planet, but in the 'Stability Checker' part my low gravity planet is unable to hold H2O. I am wondering if it is possible ...
28
votes
6answers
7k views

5km artificial planet, with same gravity as on Earth

So, the idea in a story is that in far far future there’s a trend that rich people, they are able to buy themselves planets. Tiny little planets with sizes 4-6 km (3-4 miles) in diameter. The company ...
6
votes
2answers
130 views

Multiple moons but only one of them is tidally locked to its planet?

A habitable planet with multiple moons, only one of which is tidally locked to the planet: is this general scenario possible? I understand that tidal locking takes a very long time to happen. So ...
4
votes
5answers
381 views

How would gravity affect a structure that completely encircled the earth

If a circular structure could be built that would wrap around the entire earth, but was of a larger radius, would it 'float' above the earths surface or would it somehow fall onto the surface at some ...
2
votes
4answers
226 views

Hyperdense Object

If a planet has a core of super-dense material, how might that effect the geological composition of that planet? Specifically: imagine a lunar-sized planet, with earth-like geology and density. If ...
1
vote
6answers
166 views

Reasons People Wouldn't Weaponize These Gravity Machines

So when making my space stories I have put them in a technological time in history where gravity manipulators are available to the common creature and you can use it to go to other planets and live in ...
8
votes
3answers
598 views

How much artificial gravity could create a black hole?

In my world, people have powers based on the four fundamental forces. One of my characters can generate spontaneous gravity to crush his opponents. He's also resistant to his own power (so I ignore ...
42
votes
5answers
7k views

What are the safety margins for destroying a planet from space?

My empire's flagship, the Persecutor class UJBHE1 Abhorrent, rides into the home system of my greatest enemy, Baron Obsequious, levels its Death Ray2 at his beloved home, and pulls the trigger.3 ...
12
votes
3answers
264 views

Humanoids in Super Earth

So, I was reading this article about how difficult it would be for any alien race to escape an exoplanet with about 10 times the mass of Earth. It states they probably would even lack satellites. ...
14
votes
3answers
1k views

How large can surface gravity anomalies grow before the planet becomes uninhabitable?

Is a planet with varying fields of gravity possible? Yes. Earth has varying gravitational fields at various different times due to various factors, mainly location based. How extreme can I make these ...
5
votes
3answers
82 views

Solutions for sustainable living in reduced gravity environment

I am building an idea for a terraformed environment with 1/6 the gravity of Earth, with a permanent human colony that has been established and sustained for 40+ years. I have thrown around a few ideas ...
6
votes
2answers
129 views

Effects of gravity upon weather?

So there are loads of things that are taken into account with weather from geology to water currents to axial tilt etc. But i am wondering what the effects would be on weather on planets with varying ...
40
votes
7answers
6k views

Could a cave-in or avalanche in low gravity be dangerous?

I have a character on the surface of Enceladus, one of the moons of Saturn. It has an icy surface on top of what is believed to be a liquid ocean. There is no atmosphere, though near its south polar ...
0
votes
1answer
121 views

What happen to gravity if time is suddenly running backward? [closed]

From my naive understanding of Einstein theory of relativity: gravity is not a force but only a consequence of inertia in a world where mass deforms the space-time. Without time, no gravity is ...
3
votes
2answers
192 views

I want a layer out of frozen clouds floating around my planet. How could that work?

Beforehand: I must excuse my english. It's not my native language. Neither take this question too seriously. It's a stupid concept and I don't think that I will keep it by. It's just very "cool" to ...
5
votes
4answers
235 views

Valid justification for “GMO mech suit”

I'm writing a story about a group of humans (or humanoid people) that are living on a spaceship that's orbiting a planet with high gravity; the force is too much for direct human involvement. There ...
-1
votes
2answers
70 views

How big would be a planet with a fifth of Earth's gravity? [closed]

First of all, I want to make clear that I don´t know how to calculate the gravity of a planet in m / s². Starting from there, I don´t know any formula referring to this knowledge and that is why I am ...
15
votes
8answers
3k views

Would trams be workable on a low-gravity world?

After reading this thread from a bit under a year and a half ago about the most cost-effective means of travel on Mars, where one of the answers mentions rail as the best option, I started wondering: ...
6
votes
2answers
223 views

Einstein-Rosen Bridge Worldgate time-gravity travel issue

In this mostly hard-science universe I am using a theoretical "Hyperstable Gateway" to travel between planet X and Y; The wormhole has a ~5m diameter, The "Bridge" itself is negligible and a physical ...
14
votes
6answers
2k views

Junkyard planet trash distribution?

So, I've got a planet that's basically a junkyard. It's just one big junkyard. People from various space-faring societies dump all the crap there that they don't want to deal with. Derelict spaceships,...
0
votes
0answers
67 views

Why would a world have a floating ocean [duplicate]

I'm imagining an expansive body of water that is suspended high above the ground. One that can sustain diverse ecosystems that take advantage of the water to air conditions. What natural or other ...
2
votes
2answers
226 views

Could soft matter infused with nano or pico sized magnets be used to clump together so that we could create environments with it?

I am trying to create a planet with low gravity that keeps an atmosphere and has an ocean that covers the whole planet. Basically I am developing beings (separately from this question) who can live in ...
1
vote
1answer
81 views

Stability of a really dense galaxy [closed]

How stable would a galaxy where everything is very close by be? Would solar systems be able to exist (long enough for humanoid organisms to evolve)? By close, I mean that the distance between two ...
8
votes
2answers
651 views

Life in extremely low gravity water

Let's assume the planet has only one half the mass of the moon and is covered by shallow ocean. To eliminate water pressure at extreme depths, assume the ocean is also quite shallow, with a maximum ...
0
votes
1answer
105 views

How would a planet sized monocellular organism behave [closed]

in many american comics such as dc and marvel they have living planets and even stars. If we could live in a world where cells have sizes that range from planet wide and still function under its own ...
0
votes
1answer
191 views

If you dug to the center of the earth would you get stuck in an infinite gravitational pull loop?

I was wondering what would happen if you dug to the center of the earth. Would you get stuck in an infinite gravitational pull loop, or would you just simply get torn in between the two pulls? Yes, I ...
54
votes
12answers
11k views

How would people conceivably escape a planet too large for chemical rockets?

I was reading this article from NASA about chemical rockets and they argue that, with a planet 50% larger than the Earth (assuming similar density, about 1.5G surface gravity), it would be impossible ...
22
votes
16answers
9k views

How to put a lake on the ceiling?

Another user's answer to a recent question, specifically the way it was worded, gave me a vision I cannot shake. Our intrepid adventurer, Joe A. Venture, is making his way through a subterranean ...
7
votes
6answers
2k views

How could it be possible to exert gravity without mass?

Some of what I read in How could a 4D organism influence events in our world made me think in a different direction about a question I asked before. I'm trying to create a large sphere shaped field ...
-1
votes
4answers
153 views

In a world 2x the size of earth would sentient aquatic life be more probable?

The idea is in a world with 2x the gravity (which follows from 2x the size), gravity would have less an impact in the oceans. Does that follow?
-3
votes
2answers
292 views

Can a Large Planet Orbit a Smaller Planet?

Let me clarify on the title, because this is important. In recent years, people have been feeling less comfortable calling the only natural satellite orbiting Earth a moon. It may not be the largest ...
1
vote
2answers
127 views

Can a smaller black hole orbit a larger black hole? [closed]

Let's face it. Black holes are confusing, scary and awesome. They have defied our understanding of physics and astronomy and we still have no idea of their true nature. So can a smaller black hole ...
0
votes
1answer
111 views

How would a civilization deal with Jupiter level gravity for colonization [duplicate]

Consider the planets of the solar system. Each one is unique with its own unique problems when it comes to colonization. This question is specifically about one aspect of living on Jupiter. Based on ...
-3
votes
3answers
127 views

Can gravity be controlled? [closed]

Humans might naturally be able to manipulate the gravity around us with our bodies and control it and focus it for propulsion uses. This is just a guess. So my question is, is it possible for a human ...
9
votes
3answers
272 views

What are the climatological effects to the surface of a planet where the atmosphere gives way to vaccum? (diagram included)

(Please see diagrams) This is a question regarding an area of a Rocheworld scenario that I haven't found anything on. It is suggested that the OUT side of a planet that is tidally locked with ...
10
votes
1answer
179 views

Flight within the shared atmosphere of a Rocheworld, and between the planets, with low gravity wrinkle?

In a Rocheworld scenario where two planets are tidally locked and share an atmosphere, but where both the planets are so small that their gravity is very little (as low as one of the dwarf planets in ...
1
vote
1answer
131 views

Falling in a micro-gravity scenario?

Let’s say we have a micro-gravity environment where people are staying afloat in the air because they have wings or some other means of resisting the low gravity, but then for some reason they find ...