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.

learn more… | top users | synonyms

23
votes
4answers
91k 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?...
35
votes
5answers
19k 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?
44
votes
8answers
88k views

Why doesn't the Moon fall upon Earth?

Why doesn't the Moon, or for that matter anything rotating another larger body, ever fall into the larger body?
16
votes
3answers
2k views

Do mankind and manmade activities/constructions have any effect on the rotation of the Earth?

We walk or ride on our vehicles to our destinations daily. Does our movement have any effect on the rotation of the earth according to Newton's law? What will be the effect if we move all the peoples ...
9
votes
4answers
22k views

Can the Earth's magnetic field be used to generate electricity?

Since the Earth has a magnetic field, can it, in theory, be run through a conductive metal coil to create electricity?
42
votes
5answers
11k views

Why has Earth's core not become solid?

The Earth is billions of years old, yet its core has not yet cooled down and become solid. Will this happen in the foreseeable future?
36
votes
12answers
66k views

What is the simplest way to prove the Earth is round?

Assume you've come in contact with a tribe of people cut off from the rest of the world, or you've gone back in time several thousand years, or (more likely) you've got a numbskull cousin. How would ...
6
votes
4answers
31k 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 gravity minimally, more so at the equator than at the ...
20
votes
2answers
10k views

What is the net charge of the Earth?

This question arose in a seminar today about the solar wind... This is my vagueish understanding of the problem - please correct if you see errors! The 'classical' picture of atmospheric electricity ...
6
votes
4answers
416 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 ...
18
votes
5answers
7k views

Can Helium Disappear from Earth?

Can Helium disappear? As we know Helium is lighter than air, so basically Helium fly off from Earth. Is it possible that in the future we will run out Helium?
6
votes
3answers
3k views

If there was a black hole on earth, what would it look like?

If an answer does exist, I'd love to hear it. I'm trying to incorporate a doomed earth story in something I'm writing, and the end of the world I'm going for is a black hole. Let's say the black hole ...
6
votes
4answers
2k views

If you could ride an elevator through the earth [duplicate]

What if it was possible to ride an elevator straight through earth. If we take all the heat and pressure problems away, and assume it would be possible: What would happen with gravity? Would gravity ...
1
vote
2answers
317 views

7 Billion people jumping at once

What would happen if every person in the world gathered at a minimum possible area and jumped all at once? Would that have any effect on Earth?
33
votes
8answers
13k views

Would it matter if the Earth rotated clockwise?

In the Futurama episode "That Darn Katz!" they save the world by rotating the Earth backwards saying it shouldn't matter (which direction Earth rotates). If Earth rotated clockwise and remained in it'...
8
votes
6answers
19k views

How fast is Earth moving through the universe?

As the galaxy is moving and the solar system orbiting the galaxy and the Earth orbiting the sun. So how fast is each object moving and what is the fastest we move at? Do we even know how fast the ...
8
votes
2answers
1k views

Huge buildings affect Earth's rotation?

Does constructing huge buildings affect the rotation of the Earth, similar to skater whose angular rotation increases when her arms are closed comparatively than open?
6
votes
1answer
214 views

How much effort would be required to fix the Earth's rotation?

Given that the earth's rotation has been slowing down by very slight amounts over time, forcing us to introduce leap seconds and so forth into our clocks and calendars, I would like to ask if this ...
5
votes
3answers
10k views

Does Earth's Rotation Affect Its Shape?

The question I am working on is, "Consider the following. (a) Find the angular speed of Earth's rotation about its axis. rad/s (b) How does this rotation affect the shape of Earth?" I am ...
6
votes
4answers
3k views

Effect on length of day as the polar ice caps melt

If the polar ice caps of the Earth melt, how will the length of the day be affected?
4
votes
1answer
1k views

Why is the geomagnetic north pole at a different location from the magnetic north pole?

According to this site Magnetic North, Geomagnetic and Magnetic Poles The Geomagnetic poles (dipole poles) are the intersections of the Earth's surface and the axis of a bar magnet hypothetically ...
3
votes
7answers
7k views

The Earth is spinning, so why don't we jump and land on a different location?

I know there are similar questions in stackexchange but i think it's different and detailed. The earth is spinning 465 meters/second so why don't we jump and land on a different location ? I have ...
35
votes
4answers
15k views

Why is a new moon not the same as a solar eclipse?

Forgive the elementary nature of this question: Because a new moon occurs when the moon is positioned between the earth and sun, doesn't this also mean that somewhere on the Earth, a solar eclipse (...
22
votes
2answers
5k 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 ...
4
votes
2answers
2k views

What would the effect be of a small black hole colliding with the earth?

If a small black hole (say about .1 mm radius or 1% of Earth's mass) came flying along at the speed of a comet or higher and impacted the earth, what would happen? Would it pass through the earth (and ...
4
votes
2answers
1k views

Cancel out Earth's Magnetic field

Is there any tools except helmholtz coil to cancel out earth's magnetic field to calibrate magnetometers in practice.
4
votes
3answers
5k views

If the earth would stop spinning, what would happen?

What would happen if the earth would stop spinning? How much heavier would we be? I mean absolutely stop spinning. How much does the centrifugal force affect us? If you give technical answers (please ...
4
votes
2answers
176 views

Can a Storm make the day longer/shorter?

I've read that changes in jet streams can affect the speed that the Earth rotates on its axis, thus making the day longer or shorter?
2
votes
2answers
2k views

Earth-Centered Inertial (ECI) reference frame as approximate inertial frame of reference

In many practical applications, one can consider the Earth-Centered Inertial (ECI) reference frame approximately as an inertial reference system, though strictly speaking, it is non-inertial. Is ...
1
vote
2answers
2k views

Argument for proving Earth-Centered Earth-Fixed (ECEF) reference frame is non-inertial

Today I heard an argument to prove that the Earth-Centered Earth-Fixed (ECEF) reference frame is non-inertial. It seriously doesn't make any sense to me but I also heard that same argument was made by ...
-3
votes
1answer
751 views

Gravity anomaly in Lacnov, Slovakia: Gravity ashamed

http://www.youtube.com/watch?v=4qxwqNqL-Nc http://tvnoviny.sk/sekcia/spravy/technologie/v-lacnove-sa-predmety-kotulaju-do-kopca.html (Sorry: above links in Slovak.) Can someone explain this to me? ...
51
votes
8answers
26k views

Proof that the Earth rotates?

What is the proof, without leaving the Earth, and involving only basic physics, that the earth rotates around its axis? By basic physics I mean the physics that the early physicists must've used to ...
21
votes
1answer
2k views

How fast is the Earth-Sun distance changing

This is inspired by Evidence that the Solar System is expanding like the Universe?, which referenced an article by G. A. Krasinsky and V. A. Brumberg, "Secular Increase of Astronomical Unit from ...
14
votes
2answers
2k views

Why is there a temperature gradient on Earth?

I was thinking about why the poles are colder and I came out with three possible explanations. 1. The atmosphere blocks light beams coming to poles The Sun is seen only slightly over the horizon ...
12
votes
6answers
2k views

Are metals more heavy due to the Earth's magnetic field?

Non-metal objects are attracted to the Earth due to gravity. So the weight of non-metal objects can be only dependent on their mass. On the other hand metals can be attracted to the Earth's magnetic ...
10
votes
5answers
7k views

Does the moon affect the Earth's climate?

So, this morning I was talking to a friend about astronomical observations, and he told me that lately there has only been good weather when there was a full moon in the sky, which was a shame. I ...
4
votes
3answers
2k views

How can we see the moon while it's between the Earth and the Sun? [duplicate]

I know this sounds like (and probably is) a stupid question, but I can't figure it out. As far as I know, the crescent shape of the moon is when the moon is on the sunny side of the Earth, but that ...
3
votes
3answers
398 views

Would a sea level rise (on the other side of the Earth) if you would dip your finger into the ocean?

(I'm not a physicist & I hope this question isn't too basic/lame) The question says it all & assuming: No atmosphere No Earth rotation Not a single object in the ocean(s) Ignore all other ...
3
votes
3answers
1k views

If the Earth left the solar system for interstellar space. How long would it take for atmosphere to freeze?

If the Earth left the solar system for some reason. Assuming its moving at the same velocity it's currently exhibiting. How long would it take for the atmosphere to freeze. Would we get methane clouds ...
2
votes
2answers
3k views

Why does Earth behave like Natural Bar Magnet?

What is the reason for the Earth to behave like a bar magnet and have poles (North and South poles)?
2
votes
3answers
760 views

While finding escape velocity, does human mass counts as the mass of Earth?

Escape velocity depends upon the mass of earth. my doubt is whether human mass adds into it or not? If it add then Earth's escape velocity would be increasing!
1
vote
3answers
172 views

Why geologist do not consider molten iron in the magma to be the source of Earth's magnetic field?

This was a question that came in a exam. How come is this possible? Actually, a question on the source of Earth's magnetic field was asked here on physics SE, which matches my opinion. The ...
0
votes
4answers
114 views

Does not the mass of those living on the Earth add on to the mass of the Earth or is it too negligible to be cared for?

Source: Earth weighs about 13,170,000,000,000,000,000,000,000 pounds (or 5,974,000,000,000,000,000,000,000 kilograms). Since Earth is too big to be placed on a scale, scientists use mathematics ...
12
votes
2answers
385 views

How are the northern lights produced?

Although I've never seen it myself, I hear the northern lights are a sight to be seen! I know they're related to the Earth's magnetic field but I don't know much more about them. What is the physical ...
10
votes
2answers
268 views

Does the geomagnetic field rotate?

The Earth rotates about it's own axis. Do the geomagnetic field lines rotate due to this rotation or not?
5
votes
3answers
743 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.
5
votes
2answers
2k views

Why does the Sun turn red near sunset?

At daytime the Sun's light is yellowish if not near white. Why when the Sun starts to go down that it's light turn more red. I don't think the earth's rotation is so rapid to cause a red shift. Why ...
4
votes
2answers
623 views

Deviation from Earth's orbit

How much orbital deviation is required for the Earth to get knocked out from current orbit so it either moves away from Sun or towards the Sun?
2
votes
2answers
359 views

How far would I have to go to see a fully rounded Earth? [duplicate]

How far would I have to go to see a fully rounded Earth? Recently, I saw a video on Youtube in which a sky diver called Felix Baumgartner ascends to $120,000$ feet (= $39$ miles) in a stratospheric ...
2
votes
1answer
402 views

How small the earth should be for it to become a black hole

How small would the earth have to be squashed so that it would become a black hole?