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

31
votes
5answers
9k views

If the Earth is a good conductor of electricity, why don't people get electrocuted every time they touch the Earth?

Since the Earth is a good conductor of electricity, is it safe to assume that any charge that flows down to the Earth must be redistributed into the Earth in and along all directions? Does this also ...
0
votes
0answers
83 views

How general relativity shows that gravity decreases as we go inside the Earth [duplicate]

Why is it that gravity decreases as we go deeper inside Earth? Can anyone explain theoretically with reference to general relativity?
10
votes
2answers
1k views

Why heavy elements don't sink to the core?

If earth assembled out of space dust, how come we find heavy elements like gold, silver, uranium and bunch of others that are heavier than iron on the surface? I mean silicon (Si mass 28.084) being ...
1
vote
1answer
43 views

Will my data drives be safe in an emp event? [closed]

If there was an emp event (maybe because the rotation of magnetism of the earth or an atomic bomb) would the data on my hard drives, ssd, dvd, mini dvi tapes and cassette tapes be safe?
0
votes
0answers
29 views

Are these reasonings about tides correct?

This is a picture of the "M2 tidal constituent": The nodes corresponds to fixed points, for which the moon has no influence on the altitude. 1. Static VS Dynamic problem? I was first wondering if ...
0
votes
2answers
1k views

about angle between magnetic axis and geographical axis of earth

How the angle between the magnetic axis of earth and the geographic axis of earth can be calculated?
3
votes
1answer
61 views

Relativistic effects of an orbit around sun in a different direction than Earth

If I manage to orbit around the sun at the same speed but in a different direction than the earth, will I perceive the time on earth going faster or slower than my own time? And what about people on ...
4
votes
3answers
2k views

Are we increasing the gravity of Earth with our population?

I have these questions related to my question title: Do we, other species and things have our own gravity? How much Gs a human have? Are we effecting Earth, nearby moons and planets with our gravity?...
2
votes
0answers
21 views

The moon affects the motion of the oceans, but can the motion of the oceans affect the moon? [duplicate]

Obviously the earth's oceans have mass and therefore they have an attractive force upon the moon. However, let's say that we were to cover most of earth with tidal power generators that extract some ...
0
votes
0answers
50 views

Was Nikola Tesla right about the blast on earth? [duplicate]

It was said by Tesla that if we blast on earth at some specific coordinates then it can divide the earth into two parts .Is it really possible?
2
votes
2answers
484 views

Which will collide first, the moon and Earth, or Sun and Earth?

As time progresses, which scenario will happen first? The moon colliding with Earth, or the Earth colliding with the Sun? I figure the Moon and Earth will happen first, based on proximity, but the sun ...
2
votes
1answer
46 views

Earth precession

I got a bit confused while studying the tropical and sidereal years. I noticed that the Earth's precession is in the opposite direction than that of a top's precession, when their rotational direction ...
5
votes
5answers
17k views

What is the scientific reason for the inclination of earth's rotation axis?

This titled position of the earths axis is known as inclination of the earths axis. The earth's rotation axis makes an angle of about 66.5 degrees with the plane of its orbit around the sun, or about ...
4
votes
2answers
635 views

Rivers that flow “uphill” due to Earth's rotation

One of the fun tidbits that gets bandied around in physics departments is that the Mississippi River actually flows away from the center of the Earth. Due to the Earth's oblateness, the source of the ...
19
votes
3answers
6k views

How quickly was the Earth rotating 250 million years ago?

The Earth is slowing at a rate of $4.7\times10^{-4}$ miles per second every 100 years due to tidal forces of the moon. See: http://en.wikipedia.org/wiki/Earth%27s_rotation http://imagine.gsfc.nasa....
1
vote
0answers
167 views

What is this bright spot in the sky?

This is my first question here so please be gentle! I took this picutre a few minutes ago (35 minutes ago, currently 1828 here) As you can see there's a VERY bright spot on the right that shows a ...
1
vote
1answer
356 views

How does the Moon cause the tides?

I am considering the following question, but I can't quite figure it out... I have looked up differential gravity, but I cannot derive the equation for the effect on Earth, and I haven't found any ...
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?
1
vote
0answers
58 views

Why is gravity high at poles but lower inside the surface of Earth, as compared to $g$ on surface? [duplicate]

My high-school physics teacher recently displayed some formulae stating at when we dig deeper the gravity pull is lower but at poles (the flattened part) it is appreciably higher. Now, if we consider ...
1
vote
1answer
100 views

What is the outward force on the Moon that makes it go in orbit rather that falling straight to the Earth? [duplicate]

So, we know that the gravity is responsible for pulling the Moon towards the Earth. But because it moves in an orbit, it makes me think that there must be a force that is causing the moon to travel in ...
0
votes
0answers
52 views

Using an Earth magnetic or electric field to fly [duplicate]

Are there possibilities to use the magnetic or the electric field of earth to let a matter flow in space?
6
votes
2answers
3k views

How is the Earth heated by a Full Moon?

While the moon is certainly not a good reflector of solar radiation, surely the radiation it reflects back heats the Earth (even if it is a terribly small amount). How would one go about calculating (...
-1
votes
1answer
162 views

How much radiation does the Earth receive from the Sun's total radiation? [closed]

I was thinking how to solve this problem. $1\,\mathrm{AU}$ is roughly the distance from the Earth to the Sun, $1.4960 \times 10^{11}\,\mathrm{m}$. The radius of Earth is approximately $6.4 \times 10^{...
0
votes
1answer
67 views

Could a big enough straw stretching from Earth to space eject atmosphere into space? [duplicate]

Assuming the straw can be built out of any material, shape, size. Would the vacuum effect of space acting on the pressurized gas have enough force to lift the weight of the atmosphere contained in ...
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 ...
1
vote
2answers
184 views

Can we get energy from the Earth's rotation?

Is there any way to harvest large amounts of energy from the Earth's rotation?
0
votes
1answer
85 views

Gravity Relative to Mass?

Why is it that, in basic physics, it is taught that the acceleration of gravity is the same for objects of any mass (at a constant distance from earth)? Why then is the acceleration of gravity ...
0
votes
1answer
151 views

Would a pipe from the surface to the Earth's exosphere suck all atmosphere to the space? [closed]

If I built a tube from Earth's surface to the exosphere, would all the air be sucked out to space? If this pipe reached to a big planet, like Jupiter, would its gravity through the pipe suck our ...
-2
votes
1answer
134 views

Why the moon doesn't fall down to earth? [duplicate]

Why the moon doesn’t fall down to the earth? We know that the moon travels in speed perpendicular to the gravity of the earth so that it doesn’t fall down to earth. But what if we supposed that the ...
1
vote
3answers
659 views

Was the early Earth radioactive?

I've been reading of the (surprising) fact we are uncertain on whether there is nuclear fission in the center of the Earth or not (yet we know so much detail on structures at the other end of the ...
2
votes
1answer
97 views

Why is it that not the entire surface of Earth is covered by water? [closed]

Isn't it a coincidence that our planet is mostly but not completely covered by water? Is there a reason why less water or more water is not compatible with intelligent life? Also, isn't it a ...
1
vote
2answers
157 views

How long will it take before the orbit of the earth is 365 days exactly?

I understand that the number of days per year has changed throughout the history of the Earth. Apparently there were once over 400 days per trip around the sun. How long will it take approximately ...
2
votes
1answer
95 views

Why does Moon always poses the same face towards Earth?

If both Earth and Moon are rotating as well as revolving around some focus, shouldn't they have drifted out of phase with each other long ago? So, why do we always see the same side always?
1
vote
0answers
59 views

To what altitudes does cosmic radiation penetrate?

How far does high energy (Cosmic) radiation penetrate(km above sea level) into the planet earth? And at what rate(/m^2/s)? (limited set of rates here) (The Aurora is low energy protons that stop at 90 ...
2
votes
1answer
53 views

Does the Earth's magnetic field sort cosmic rays by charge?

The Earth is struck by both negative and positively charged particles. As these particles interact with the Earth's magnetic field they become deflected. Do the magnetic poles of the Earth receive ...
0
votes
1answer
56 views

What will happen if all the population all over the world jumped together at the same time in sea? [duplicate]

What can happen if a magnitude of such huge force is applied over the sea water of earth? Force applied will be average mass of each person *7 billion *9.8 .
1
vote
2answers
79 views

Estimation of the age of Earth

By calculating the ratio of U-238 to Pb - 209 the age of the earth can be estimated. Is it not a possibility that non radioactive lead already there formed during the birth of earth it self alter the ...
1
vote
3answers
234 views

Is gravity actually missing or lower in certain spots on Earth?

I have heard and read about "missing gravity" in some regions of Earth. What I seemed to gather from this info is that if I go to a certain spot and jump, I can jump higher; or I could maybe lift more ...
1
vote
1answer
75 views

Earth density distribution from shooting neutrinos?

I am interested in possibility of inferring Earth interior structure from gravitational data. As classical calculus problem shows, it is impossible to understand non-uniform density distribution ...
6
votes
2answers
380 views

Earth's magnetic field shields us… from what threat?

This is a nice artistic picture of the magnet field of the earth, shielding us from the solar wind. (source) Wherever you look, it is stated that without our shield, life would not be possible on ...
1
vote
2answers
260 views

Could we be on the inside of a concave hollow universe?

Recently I was discussing this theory again (a little drunk, I admit) and then tried to find answers, but couldn't find anything satisfying. There is a theory (or several theories) that we could be ...
0
votes
2answers
93 views

Where do atoms of H and He go when they rise in the atmosphere? [duplicate]

What happens to atoms/molecules of H and He when we let them freely fly in atmosphere do they get into space? Is there any particular way to enumerate the 'force' that drives them upwards? Does ...
1
vote
3answers
183 views

Is the Earth round?

Imagine you are a common man and want to prove that the Earth is Round, how would you prove it without any mathematical derivation or without the theory of the ships.
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 ...
2
votes
2answers
92 views

Can a GPS system detect the decline in the rotational velocity of the Earth?

From Wikipedia: Rotation in Angular Velocity of Earth Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's ...
1
vote
1answer
225 views

What will be effects of harnessing lightning?

In Feynman's Lectures, volume 2, chapter 9, there is a mention of earth getting charged by thunderstorm lightning. It is the thunderstorms throughout the world that are charging the earth with an ...
2
votes
2answers
104 views

Reaction due to gravity

There is a reaction to the gravity of the earth on us but the earth does not move due to its huge mass. But what if I combine the weight of all humans and other things on Earth? Is it not enough to ...
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?
0
votes
0answers
54 views

Do I weigh less during high tide? [duplicate]

Given weight = mass * gravity do I weight less during high tide and more when tide recedes? My guess is weight = mass * gravity * gravitational pull of moon factor
0
votes
1answer
553 views

What happens when a compass is taken to the site of magnetic pole of earth?

We know that the direction of compass needle always points towards the magnetic north pole. If we take the compass to the site of magnetic north pole, which direction will the compass needle point?