Questions tagged [escape-velocity]
Questions about the speed at which an object can go to a point at infinity while ending at rest.
26 questions
2
votes
1
answer
65
views
Ejected galaxies, dynamical friction and dark energy?
I have a question after reading this paper (https://arxiv.org/abs/1411.5860).
There the authors analyse the ejection of galaxies from their local groups in the presence of dark energy.
I had some ...
- 1,333
8
votes
5
answers
2k
views
Does the escape velocity formula take into account how a gravitationally bound object's distance to its primary increases before coming back down?
Confusing title, I know. Imagine a perfect, homogenous sphere with an exact radius of $1,000 \text{km}$ and an exact mass of $8 \times 10^{15} \text{kg} $.
If you use the formula for escape velocity $...
- 2,799
1
vote
1
answer
185
views
Could You Escape an Event Horizon by increasing a Black Hole's velocity?
I have an idea for trying to escape the black hole's event horizon that might make basically no sense and I want it double checked. Basically, I do know that you can't escape the event horizon unless ...
- 309
0
votes
1
answer
307
views
Space travel relative to solar system's movement through space
Assuming our entire system (stars, planets, etc) is moving through space at around 180,000 mph. Why can't we leave in a direction opposite our system's movement to achieve deepspace flight?
Part two
...
- 19
2
votes
1
answer
96
views
Escape velocity of leaving the solar system vertically and horizontally [duplicate]
Is there a difference in the escape velocity when leaving the solar system?
a) Vertically (out of planetary plane, in a perpendicular direction to it)
b) Horizontally (in the planetary plane)
- 139
9
votes
3
answers
612
views
escape velocity of leaving the Milky Way galaxy vertically and horizontally
Is there a difference in the escape velocity when leaving the Milky Way galaxy
vertically (out of galactic plane)
horizontally (in the galactic plane)?
- 139
1
vote
0
answers
54
views
escape velocity of the Milky Way galaxy [duplicate]
I have heard of the escape velocity of Earth to be 11 km/s.
Is there an escape velocity of the Milky Way galaxy? If yes, what number is it and how can it be computed? Is there a difference in leaving ...
- 139
1
vote
1
answer
339
views
What is the maximum speed in which a human jumping away from Deimos and towards Mars would actually fall back down rather than enter Mars' gravity?
Imagine a universe in which Deimos and a human are the only objects in the universe. It doesn't matter if the human jumped even 1 nanometer per second slower than escape velocity, they would still ...
- 2,799
20
votes
3
answers
5k
views
Can an object from a natural process escape earth gravitation?
I'm no expert, but I once studied basic from advanced physics and understand
gravity
action/reaction
escape velocity of 11.2 km/s from the earth surface
escape velocity changing as the object go far ...
- 303
3
votes
1
answer
170
views
Can Stellar Spaghetti ever escape?
Spaghettification is the deformation of a body into long, thin strips due to tidal forces as the body passes through a powerful gravitational field. Image from wikipedia:
Stellar spaghetti has been ...
- 16.7k
4
votes
3
answers
346
views
What escape velocity would quark stars have?
Quark stars are hypothetical compact stars that are denser than neutron stars and maybe the last stage of upholding matter before stars that collapse into a singularity. Neutron stars have escape ...
- 143
5
votes
1
answer
1k
views
Can a habitable planet be smaller than 0.58 Earth radii?
According to the below image, the lowest escape velocity a planet can have in order to still be able to retain water on its surface and have a temperature above freezing is 6.5 km/s minimum.
With ...
- 403
3
votes
2
answers
366
views
What should the mass of a planet be in-order for its escape velocity to be near the speed of light? [duplicate]
What should the mass of a planet be in-order for its escape velocity to be the speed of light? Is it even possible? What will it look like from an outside viewer? Will it even be visible in the human ...
5
votes
1
answer
480
views
Do Enceladus' geysers fall back to its surface or do they achieve escape velocity?
Enceladus, a moon of Saturn, has a very low surface gravity at 0.114 m/s² or 0.012 g. It has a subsurface ocean of liquid water and is ejecting plumes of it. Does the ejected water eventually fall/...
- 1,108
1
vote
2
answers
175
views
Largest body in the solar system that a baseball thrown by a professional pitcher could escape
What is the largest (most massive) known body in the solar system that a professional pitcher could throw a baseball off of, i.e. that has an escape velocity lower than ~102 MPH? (45.33 m/s)
- 111
0
votes
2
answers
231
views
Are exoplanets which are above escape velocity of particular interest?
I was perusing the exoplanet database and looking for some of the more extreme orbits, when I happened upon HD 20782 B:
http://exoplanets.org/detail/HD_20782_b
Which is also listed (in two sentences)...
0
votes
1
answer
121
views
Could an object, assuming possible, escape black hole by travelling above constant speed? [closed]
I am always hearing that after travelling inside a given BH's event horizon, the escape velocity is greater than c, which makes it impossible to escape.
Suppose an ship is inside a BH. Assume it is ...
- 1,882
6
votes
2
answers
1k
views
Does matter accelerate to the speed of light as it approaches the singularity?
$$v_\mathrm e=\sqrt{\frac{2GM}r}$$
If we understand the escape velocity to be the speed needed to escape from the 'surface' of a gravitational object described by the above equation.
It is equally ...
- 63
1
vote
3
answers
355
views
Black hole, escape velocity, going up?
I do know nothing can escape a black hole, and I understand popsci explanation of geodesics of space-time around and inside the event horizon.
I however have some trouble with following thought ...
- 1,837
5
votes
4
answers
7k
views
What is the escape velocity of our Galaxy relative to?
I've been thinking that everything has a relative escape velocity, if it has Mass, seemingly. You can escape orbit around the earth by accelerating enough. You can escape the orbit of the sun by ...
3
votes
1
answer
319
views
Is the radius used in the formula for the escape velocity the average radius of the celestial object or the radius at the starting location?
I learnt that the escape velocity is given by $$v_e = \sqrt{\frac{2GM}{r}}$$
Say I want to launch a rocket from the earth into space and want to calculate the escape velocity $v_e$ (I guess without ...
- 183
11
votes
2
answers
2k
views
Can I leave a planet without achieving escape velocity?
I know that if you exceed orbital velocity, you will never fall-back to the planet. My question is not about orbits. It's about brute-force propulsion to achieve altitude. I'm using an ...
- 213
1
vote
2
answers
1k
views
Can earth escape sun's gravity with the help of a black hole heading towards our solar system?
To escape the Sun's gravity, the Earth would need sufficient amount of energy. Let's say a stellar black hole has entered our solar system and at a certain distance from earth, the black hole exerts ...
0
votes
1
answer
451
views
How to get from the earth to another planet/ the moon? What happens on the way? [closed]
I have a problem explaining for my students how to get from the earth to the moon? Is there someone who can give a good explanation?
I Think these are words that might be included. Escape velocity, ...
- 11
2
votes
1
answer
293
views
Why are the high density regions in outer space black holes?
The escape velocity of an object is given by the following formula.
$$v_e=\sqrt{\frac{2GM}{r}}=\sqrt{\frac{2 \mu}{r}}= \sqrt{2gr}$$
As far as I am aware, the mass of the star which formed the black ...
5
votes
3
answers
4k
views
What happens if you fail to reach escape velocity for the galaxy?
I was listening to Skeptics Guide to the Universe the other day, and Steve Novella mentioned that the escape velocity for the galaxy is 544 km/s.
If an object fails to reach escape velocity on Earth, ...
- 2,042