All Questions
18
questions
60
votes
4
answers
142k
views
How does gravity work underground?
Would the effect of gravity on me change if I were to dig a very deep hole and stand in it? If so, how would it change? Am I more likely to be pulled downwards, or pulled towards the edges of the hole?...
- 703
39
votes
5
answers
34k
views
Would you be weightless at the center of the Earth?
If you could travel to the center of the Earth (or any planet), would you be weightless there?
- 543
20
votes
5
answers
136k
views
Why is Earth's gravity stronger at the poles?
Many sources state that the Earth's gravity is stronger at the poles than the equator for two reasons:
The centrifugal "force" cancels out the gravitational force minimally, more so at the equator ...
- 517
14
votes
4
answers
2k
views
What is the general relativity explanation for why objects at the center of the Earth are weightless?
The idea that as you move through the earth you get a symmetric cancelling of gravitational acceleration which approaches zero acceleration due to gravity at the center of the earth makes a lot of ...
- 1,039
4
votes
2
answers
2k
views
Does the Earth emit gravitational waves?
We know about Bohr's model and his vague postulate challenging Rutherford regarding discrete orbits and not emitting electromagnetic waves during this.
Extending this idea to our solar system, does ...
- 2,091
28
votes
2
answers
10k
views
How long until we fall into the Sun?
As a planet moves through the solar system, a bow shock is formed as the solar wind is decelerated by the magnetic field of the planet. Presumably the creation of this shock wave would cause drag on ...
- 16.6k
24
votes
11
answers
12k
views
Backyard experiments to falsify the Flat Earth theory [duplicate]
I recently became aware that the flat Earth theory still exists in the 21st century, and has colored the views of a friend of mine. Roughly speaking, the tenets are:
The Earth is a flat disk, with ...
- 371
5
votes
2
answers
9k
views
How would gravity change on a planet rotating around itself very fast?
Let's take a planet identical to Earth, but with rotation speed multiplied by ten thousand. What would happen with the gravity if it was spinning madly around itself? Would the centrifugal force make ...
- 1,281
5
votes
3
answers
931
views
Gravitational force of the Earth [duplicate]
Why does gravitational force of the Earth decrease as we move towards the centre of the Earth? Where as inverse square rule says that distance is less than gravitational force is more.
- 51
2
votes
2
answers
10k
views
Gravity beneath sea level [duplicate]
This is a very simple question, but I can't find an answer anywhere.
Earth's gravity at sea level is 1 (approximately 9.8m/s^2)
What happens being under sea level in a cavern/chasm/ravine, how much ...
- 121
3
votes
2
answers
273
views
Why is the inside of the Earth hot?
How does the Earth's internal heat exist? Is it available from its creation as collision heat? Or is there any other source feeding the heat to the core?
- 694
2
votes
2
answers
81k
views
Why does gravity decrease as we go down into the Earth? [duplicate]
We all know that gravity decreases as the distance between the two increases. Hence
$$ F = G \frac{Mm}{r^2}. $$
Hence the acceleration due to gravity
$$ g =\frac{F}{m}= G \frac{M}{r^2} $$
...
- 53
43
votes
8
answers
85k
views
If the gravity at the center of the Earth is zero, why are heavy elements like iron there?
If gravity is zero at the center of the earth, why is there a core of heavy elements, such as iron?
Alternate question for the opposite hypothesis:
If gravity is greatest at the center of the earth,...
- 449
10
votes
4
answers
3k
views
How do we know that Earth is not perfect sphere?
I've just read here that:
Equatorial radius = 6378.16 kilometers. Polar radius = 6356.78
kilometers, so the difference in circumference is 71.1 kilometers. It
is not a perfect sphere, but kind ...
- 213
6
votes
1
answer
429
views
Axial tilt and precession rate of exoplanets
The Earth's axis is 23.5 degrees away from othogonality to the ecliptic, and it takes about 26 000 years for it to precess fully. I have neither an intuitive sense nor the formula for precession ...
- 9,547