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.

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1answer
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If earth stopped spinning how much heavier would 1kg feel

My girlfriend seems to think if the earth stops spinning we will all fall off However, she did spark my imagination, due to centripetal force things must feel lighter then they otherwise would on an ...
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1answer
32 views

Physics Riddle - Know Plant Earth [on hold]

I hope it's OK to ask here, because it's pretty much as basic as physics can get. So here it is: I have a hot air balloon that can rise to any altitude I'd like, a precise watch, a sandbag, a weigh ...
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3answers
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I was told that if the Moon had a retrograde orbit, tides would have a faster rhythm. Why is that?

Would this be because tidal deceleration causing the Earth to spin faster or are there other actions in play that I haven't considered? Would the Earth even spin faster because of the tidal ...
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0answers
38 views

What is it exactly Earth's shape? [on hold]

What is it exactly Earth's shape? If Earth is 90% water, with so many oceans on Earth. Shouldn't Earth be not round in shape? shouldn't it be something really different?
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1answer
53 views

Electromagnetic radiation bending on Earth

Most articles say that a radiowave is able to propagate itself beyond the horizon because it is reflected off by the ionosphere (and the Earth itself). But do radio waves also get bent according to ...
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0answers
14 views

Direction of CMB and magnetic fields?

Measurements show the CMB is warmer to the North. Could more photons coming from that direction of the sky, cause metals in the Earth to move in that particular direction? As the Earth orbits the ...
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2answers
171 views

Where did the energy released due to gravitational binding energy of the Earth go?

The gravitational binding energy of the Earth is $2×10^{32} J $, so the same amount of energy must have been released during the Earth's history. According to this and this, the current internal ...
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0answers
24 views

Relativity question [duplicate]

If a rocket is traveling away from earth, why does time pass slower for the rocket if from the rocket's perspective, earth is going away from it?
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1answer
26 views

Why is there a rainbow after the rain?

Usually rainbows are present after the rain. But if a rainbow is caused by diffraction of rain droplets, shouldn't rainbows be present during the rain, not after?
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8answers
3k views

Why does the Sun always rise in the East?

Why does the Sun always rise in the East? Earth is rotating on its own axis & also revolves around the Sun, then how come the Sun always rises in the East?
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1answer
29 views

How the earth's internal heat exists

How the earth's internal heat exists? Is it available from it's creation as collation heat? Or is there any other source feeding the heat to the core?
2
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1answer
76 views

How many hours will there be in a day 5,000,000,000 years from now?

It is known that the moon is moving away from Earth 2cm a year, and in doing so makes the days longer. I want to know how many hours will have one day, when our planet is near its end.
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0answers
20 views

Effect of Earth's rotation on apparent weight (acceleration due to gravity) [duplicate]

What would be reason for change in weight due to rotation of Earth? How can the direction of $g'$ (The value of $g$ at any point on Earth) be the apparent vertical direction? Why isn't $g$ the ...
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5answers
6k views

Build a ring around Earth, then remove the supports

What would happen if we decided to build a giant ring that managed to wrap around the whole world, end to end that was supported with pillars all along the ring and then the supports all suddenly ...
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1answer
44 views

Why do we have to use an integral in this scenario to figure out $v_{max}$? [duplicate]

$$\int_0^R mg\frac{r}{2}dr=\frac{m}{2}v_{max}$$ and can't write $$\frac{m}{2}v_{max}=mgR$$ don't we usually equal potential energy to kinetic energy? A stone is falling through a tunnel towards the ...
4
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2answers
89 views

Why is the current atmosphere made of nitrogen (75.5%)?

As I read a book on meteorology, 4 billion years ago, atmosphere was made by steam, carbon dioxide, carbon dioxide and a few nitrogen. Then photosynthesis came, run by underwater organisms, which led ...
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1answer
89 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)?
5
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1answer
90 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 ...
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0answers
24 views

how to find whether molecules will absorb radiation of a particular wavelength or not?

I am trying to understand vertical temperature profile of Earth's atmosphere. We know that different frequencies get absorbed by molecules at certain heights. I want to show this mathematically. For ...
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2answers
115 views

Why does the Earth rotate on its axis?

I know that the earth moves around the sun because of the gravity force, because the spacetime around the sun is curved. But why does the earth rotate on its axis, and which parameters can affect ...
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2answers
82 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?
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3answers
662 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!
4
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3answers
193 views

Why is Earth's gravity stronger at the poles?

Lots of places 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 ...
7
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2answers
689 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 ...
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1answer
25 views

Correcting for oblateness of the Earth [duplicate]

I'm trying to model numerically the effects of the Earth's oblateness on satellite orbits. I'm seeing precession of the orbit, but not in the plane that I'm expecting. Here's my corrected grav. ...
5
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1answer
176 views

How much power would be needed to make a substitute for natural Earth magnetic field?

Imagine the Earth's magnetic field will take a "maintainance pause" for 1000 years and there is gigant 10 years "doomsday countdown timer" ticking in the sky. The magnetic field will be just normal ...
4
votes
3answers
105 views

Why does the sea horizon line always seems to be at the same height as one's eyes?

I wonder why, when I look at a sea/ocean, the horizon line always seems to be at the same height as my eyes, no matter how many meters I am above the sea level. This is something I noticed when I ...
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2answers
95 views

Gravitational field strength inside the Earth [duplicate]

please could someone give me a relatively straight forward answer why the gravitational field strength follows a straight line (linear) relationship with distance from the center of the Earth but when ...
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2answers
81 views

Is Water the only Liquid of Life? [closed]

What makes scientists think that water is better at sustaining life than every other substance? every organism we know of needs water to survive. In fact, without water, life on Earth would have ...
33
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4answers
4k views

Why is Earth's climate so stable?

Earth wasn't always the only water-world in the solar system. Mars also appear to have started out wet but, as conditions changed, Mars lost its oceans. So, how has Earth managed to avoid a ...
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6answers
430 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 ...
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0answers
28 views

If earth generates magnetic field does it attract metal? [duplicate]

If earth generates magnetic field does it attract metal objects at the surface of the planet and make them heavier?
3
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1answer
148 views

Why is the Earth's moon so big?

It could just be me, but it seems like our Moon is WAY bigger than it should be for a planet of our size. If you look at satellite-to-planet mass ratios for the largest moons of Jupiter, Saturn, ...
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2answers
97 views

Does angular speed of the earth around the sun remain constant?

I presume that angular speed is nothing but angular velocity without direction. So, since the earth always takes nearly 365 days to complete one revolution around the sun, can't we conclude that it's ...
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0answers
20 views

Reason behind the rotation of Earth? [duplicate]

I want to know what is the reason that the Earth rotates on its own axis? What are the forces responsible for the Earth's rotation?
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0answers
19 views

Is the density of air in the mountains higher at the equator?

I have heard that at e.g. 5000 m altitude, the subjective feeling is better in the Himalayas than e.g. Tien Shan, because Himalayas are located near the equator, and due to Earth's rotation "air is ...
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1answer
88 views

How much energy is necessary to set a year to exactly 360 days

How much energy would be necessary to slow down Earth rotation such that a year was 360 days long? In the same spirit: how much energy would be necessary to make the Earth rotate faster around the ...
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6answers
1k views

If everything is relative to each other in this universe, why do we keep the Sun to be the reference point?

and study the solar system and universe relative to it and why not relative to the Earth?
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0answers
28 views

What if there was a hole between earth poles [duplicate]

Imagine if there was a hole between two earth poles, let's say 100 meters wide, as deep as the Earth's height between north and south poles - what would happen if we threw an object from the North ...
3
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3answers
315 views

How would normal matter behave under conditions found in the core of the sun?

Considering how low the power density is at the sun's core, I seem not to be able to expect what would happen to matter in case it was thrown inside the sun's core. For example, let's assume an ...
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2answers
164 views

Two expressions for potential energy in the gravitational field of the earth

Let $M$ be the mass of the earth, considered as a point mass, then the potential energy of a point with distance $r$ away from the center (assume $r > \textrm{radius of earth})$ is $$ U(r) = ...
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1answer
64 views

If you dig a deep tunnel, will the rock sublimate?

If a tunnel is dug deep inside the crust (but before reaching places where the rock is liquid), how will the enormous downwards pressure manifest itself? Will the difference in pressure ...
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1answer
77 views

Gravitational acceleration at half Earth's radius [duplicate]

What would be the gravitational acceleration at half at Earth's radius? Something tells me it should be proportional to the mass distributed in that part, but I am not sure. Of course, we assume we ...
3
votes
1answer
309 views

How to determine satellite position in J2000 from latitude, longitude and distance from Earth?

Due to my task of writing orbit prediction routines I am trying to understand the reference frames better and how to use them ( particularly for Earth orbits ). I think I get the idea of what ECI ...
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0answers
30 views

Cause and properties of northern lights [duplicate]

If outside on a dark night in the middle to high latitudes, one might be able to see an aurora. It may be several hundred kilometers high and several thousand kilometers long, stretching around Earth ...
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2answers
353 views

What if an asteroid the size of the moon hitting earth

Would we all parish due to excessive heat? Or would that be only limited to the area near the impact while as the people on rest of the earth would die from other phenomenons such as mega earthquakes, ...
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1answer
67 views

How powerful would an explosion have to be for its effects to be felt worldwide?

If an explosion were to occur at any point on earth, how powerful would that explosion have to be for it to be audible or otherwise detectable by every person on the planet? Detection could mean ...
1
vote
1answer
53 views

Why does absorption cause seismic pulses to increase in length over distance?

The specific question I'm trying to answer is "How does the progressive loss of higher frequencies in a propagating seismic pulse lead to an increase in pulse length?" I understand how the higher ...
2
votes
1answer
325 views

Why does earth cool? [duplicate]

This question is boggling me for some time. We know that heat can be transferred from matter to matter and heat is nothing more than tiny atoms vibration intensity (correct me if I'm wrong). But space ...
8
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2answers
116 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?