Questions tagged [earth]
Earth is the planet on which we live, the 3rd planet from the Sun. Questions using this tag should be about Earth the planet and not Earth-like planets nor earth, as in dirt or soil.
1,114
questions
9
votes
3
answers
2k
views
Why is aurora borealis circular in shape when viewed from space?
These are some false color images of the northern lights captured by NASA's satellite Dynamics Explorer-1.
Image credits: Dynamics Explorer - 1 (DE-1)
Spin-Scan Auroral Imaging (SAI)
Photo Gallery
It'...
- 12.5k
1
vote
0
answers
33
views
In Cyclical Cosmology (Big Bounce) is it possible the new universe will be different or the same? [closed]
Could it be a universe with similar laws to ours but a different configuration of matter, so there may be another earth like planet in this new universe?
- 11
1
vote
1
answer
66
views
When I see a rainbow in the sky, is the full EM spectrum included? does it form a disc and not just a circular arc?
If you could actually see every part of the EM spectrum from a rainbow, would the circle be completely filled in? and would it also extend further outwards from the visible spectrum?
8
votes
5
answers
283
views
What is the gravity in the center of Earth?
Let's suppose the earth is a perfect sphere and let's ignore its rotation and movement.
What would happen if I would be in the center of the earth? Would the gravity be zero in any direction so I ...
- 209
2
votes
1
answer
72
views
Will a man acquire orbit if we suppose Earth is rotating fast enough?
if we consider that the rotation of earth is mush faster (30000km/h), so if a man standing on earth jumps 1 meter above will it acquire orbit if we ignore atmospheric friction
- 21
7
votes
1
answer
3k
views
Why does the Earth's magnetic field have an angle of 11.5°?
Does anybody know why the magnetic field of the Earth have an angle of 11.5°? According to a theory by Prof. Blackett, Earth has magnetism due to the rotation of the the Earth about its own axis. (...
- 103
2
votes
1
answer
104
views
Measuring Earth's circumference in Genius documentary by Hawking
I was watching the first episode of the Genius documentary series by Dr. Hawking. At the beginning of the documentary, the people prove that the Earth is round and not flat by going to a lake, and ...
1
vote
2
answers
131
views
Will the moon ever proceed to lose its orbit and hit the earth?
Assume that the moon it orbiting the earth in a circular trajectory.
It will experience an acceleration directed towards the centre of the earth given by $\frac{GM}{R^2}$ where $G$ is the universal ...
- 335
16
votes
6
answers
4k
views
If another planet was opposite Earth, would we be able to observe it?
Imagine another Earth-sized planet, in the exact same orbit as Earth, but 180 degrees out-of-phase. In this arrangement, at all times, you would be able to draw a single straight line through space ...
- 461
0
votes
0
answers
35
views
So I've found out heavier objects technically do fall faster? [duplicate]
Given the Earth's mass to be $M_E$, I know that $F_G = -\frac{GM_Em}{d^2}$, so the gravitation acceleration of a mass towards Earth is $g = -\frac{GM_E}{d^2}$. But what about the force exerted by the ...
60
votes
4
answers
10k
views
Why does CNN's ‘gravity hole’ in the Indian Ocean dip the sea level instead of raising it?
Ref. There is a ‘gravity hole’ in the Indian Ocean, and scientists now think they know why
According to CNN, the 'gravity hole' is an area of decreased gravity, compared with the surroundings. This ...
- 725
0
votes
2
answers
139
views
Using earth as a conductor
"To use the earth as a conductor, you can't merely stick a little wire into the ground next to the tomato plants. You have to use something that maintains substantial contact with the earth, and ...
3
votes
1
answer
52
views
Does a planet's "equatorial bulge" induce any kind of motions or currents in the atmosphere?
Rotating planets, like the Earth, are not perfect spheres but are instead oblates. This affects both the crust and the atmosphere, creating a bulge in the equator 1.
I was wondering if there are ...
- 2,466
2
votes
1
answer
76
views
How large would the earth have to be to retain hydrogen?
How high would the earth's escape velocity have to be to retain hydrogen or helium over geological timescales?
- 2,888
1
vote
1
answer
56
views
What is the EM spectrum of the earth seen by a satellite?
I am asking because of the greenhouse effect. It is said that without the atmosphere, the average surface temperatur of the earth would be about -18 celcius. This number is obtained simply by assuming ...
- 1,947