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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Origin of the magnetic field of Earth

The Dynamo theory gives a good explanation of the magnetic field of the Earth: the Coriolis force focus inner currents into current spirals generating magnetic(s) field(s). What I'm trying to ...
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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?...
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Could Earth being multipolar 600 million years ago might have caused Cambrian radiation? [on hold]

According to some of the latest research Earth might have been multi polar instead of being bipolar 650 million year's ago (http://phys.org/news/2016-06-earth-ancient-magnetic-field.html) Do you think ...
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Relationship between Mars and Earth rotation

Is it by pure random chance that Mars and the Earth have nearly the same day duration (Mars day is barely 40 minutes longer, which is just 3% difference), or there is some causal relationship between ...
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What does the phrase “limb of the earth” or “atmospheric limb” mean?

What does the term limb of the earth (see this question, for example) or atmospheric limb mean? The phrase strikes me as very odd, since earth is nearly spherical. Do other planets with atmospheres ...
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How much mass must Earth lose to lose its Moon?

Maybe I am wrong about the basic concept here, but for my curiosity: how much mass would need to leave the Earth (like satellites and rockets) to create an imbalance between the Earth and Moon so that ...
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Question about Global Warming [closed]

Is it possible that a cause of global warming being shrinkage the Milky Way and be closer to the sun? Regards
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Air flight and Earth's rotation

I read a response asking why flights of equal distance east and west take roughly the same time (disregarding wind actions). I have trouble visualizing part of the answer; "the speed of the rotation ...
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What is the longitudinal difference between the sub­solar point and the magnetic poles at time $t$ (hours)?

I'm trying to convert geomagnetic coordinate to geographic, but there are some steps in the paper which I'm reading, that I don't understand. I have the geomagnetic latitude centered around the ...
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Why does the Sun “shine brighter” some days?

Today, the Sun seems extremely bright; more dazzling than usual, and even the roads seem to be brighter so it's not just when you look up in the sky. Is more light actually getting through (perhaps ...
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Will the day/night cycle change when the poles melt?

I want to know what will happen to day and night if poles melt i think it will change but I don't know why? ^_^
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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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If two pieces of the same type of metal touch in space, will they bond and be permanently stuck together? [duplicate]

Yesterday I was watching discovery channel, on a program they said that 'if two pieces of the same type of metal touch in space, they will be permanently stuck to each other.' Is it true..? If yes... ...
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differences of Aurora Borealis (North) vs. Aurora Australis (South)

I was wondering about the differences between the Northern vs. Southern lights: will one pole collect the positive charges, and the other the negatives? I know that the solar wind is composed mainly ...
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What will happen if we establish a physical connection between ground and ionosphere?

https://en.wikipedia.org/wiki/Ionosphere The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about 50 km (31 mi) ...
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Deviation of free falling objects (Coriolis effect) using conservation of angular momentum

I read this pdf on non inertial frame, in particular I have a question on the deviation of free falling object due to Coriolis effect. Consider a ball let go from a tower at height $h$. The ...
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Does the thickness of earth's crust accurately correspond with the current proposed age of the earth?

The current model is that earth started as a molten ball of liquid around 4.5 billion years ago. Today, the earth's crust ranges from about 5-50KM in thickness. This is just a layman's opinion, but to ...
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If water is essentially incompressible, why are there tides?

So recently we were taught in school that tides are formed because the moon 'cancels out' some of the earth's gravity, and so the water rises because of the weaker force. But if water is not ...
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Proportional acceleration due to changing density of the Earth

My question has to to do with a recent video Minutephysics posted about the time it takes for a person to fall through the earth, found here http://www.youtube.com/watch?v=urQCmMiHKQk At around 4:05,...
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What type of instrument can I use to determine my current distance from the center point of Earth?

Immediately, I think of a scale, but is there better way? I can only imagine weighing an object of known mass with an extremely precise scale. I am asking because I would like to be able to address ...
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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 (...
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How does one measure Earth's speed of revolution around the sun?

I know that there are several formulae that one can plug numbers into to arrive an estimate of Earth's speed around the sun (Kepler's third law for instance), but I'm wondering how these things are ...
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Possible Safe Areas In a Solar Flare

Which part of the earth would be the safest in case of the major solar flare? Will it be near equator or something like that?
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Are the Schwarzschild metric and the Geodesic Equation relevant in the context of the Earth? [closed]

The geodesic equation used in general relativity is the following: $$ {\mathrm d^2 x^\mu \over \mathrm ds^2} =- \Gamma^\mu {}_{\alpha \beta}{\mathrm d x^\alpha \over\mathrm ds}{\mathrm d x^\beta \...
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Velocity Profile of the Upper Atmosphere

Consider an Earth-Centered Inertial (ECI) frame in which the tangential (to Earth's surface) velocity is measured. Now consider obtaining constant average velocity profiles of the atmosphere as a ...
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Gravity change as a function of time only [duplicate]

Is it possible to find how gravity changes with time? That is, height is not part of the equation. For example, $g$ can be expressed as a function of height that does not involve time with this ...
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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 ...
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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 ...
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Gravity Sun Earth Moon [duplicate]

The gravitational pull the Sun has on the Moon is roughly two times greater than the pull the Earth has on the Moon. If this is the case, why does the Sun's gravity not pull the Moon away from the ...
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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?
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Why doesn't sunlight flicker like candle or flame torch?

Why sunlight appears constant and stable like sun is a bulb? If the surface of the sun and processes going in it are not completely uniform why don't we notice any flickering or non- uniformity in ...
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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 ...
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How fast could you suck up the atmosphere [closed]

So kind of a strange question, but if i had a 1000 foot wide hose with endless storage space, whats the quickest possible time it could be used to suck up the entirety of the Earth's atmosphere. Edit:...
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Calculating the Velocity of an object far far away

I saw a satellite the other day, it moved very fast through the night sky. Now I know it took around 110 seconds for it to fully travel out of the night sky(out of my visual bounds assuming, that I'...
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Why doesn't the earth collide with the sun in 64 years?

According to another answer on this site, the time it takes for two bodies in space to collide can be computed with the following formula: $$\frac{\pi}{2\sqrt{2}}\frac{r_0^{3/2}}{\sqrt{G(M+m)}}$$ ...
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What factors will make Earth re-rotate again if it stopped? [closed]

"What will happen if Earth stopped rotating?" have been answered multiple times with a lot of informative and interesting answers. Continuing this hypothetical question, I have another one in mind. ...
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Sun's tidal force on Earth

My question is regarding effect of Sun's gravity on earth. I want to know that if Sun's gravity can change Earth's landscape in long duration (i.e. billion of years) or not? Means if earth is dead ...
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Maximum temperature possible on earth

What is maximum temperature that can we have on earth on a single day? Lets say an air mass is static over an area and there is no way for air mass to move, sun warming it up would increase ...
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How much does the Earth's rotation affect a golf ball?

When launching rockets into space, they start straight but begin to lean, I assume due to the Earth's rotation. For something on a much smaller scale, such as a golf tee, is there a measurable ...
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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 ...
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Direction of deflection of Coriolis force on Earth

I'm a bit confused about Coriolis force direction on Earth. The observed deflection is to the right in the northern emisphere and to the left in the southern one. But what about an observer in the ...
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How far has Earth moved from its birth orbit?

It says earth is almost as old as 1/3 of the universe's age which would mean 4.5 billion years . So how far has earth moved towards or away from the sun in these 4.5 billion years? Now perfect ...
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Why is earth on an axial tilt of 23.4 degrees?

What were the influences for this to occur? Did some things play a bigger part that others?
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What exactly will happen if a small planet collides with earth

This is a video of a simulation of Ceres (a dwarf planet) hitting Earth at 2000km/s. What strikes me the most, is how fast the shockwave is moving. It takes about 6 minutes for the shockwave to pass ...
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Is the length of the day increasing?

In Frontiers of Astronomy, Fred Hoyle advanced an idea from E.E.R.Holmberg that although the Earth's day was originally much shorter than it is now, and has lengthened owing to tidal friction, that ...
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D2O distribution in water [duplicate]

I just learned that about 1/1000 of hydrogen is deuterium. Does that mean 1/1000 of water is D2O, which is heavier and sinks to the bottom in a glass of water? And consequently is there a layer of D2O ...
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Coriolis object deflection and conservation of angular momenutum

I'm trying to understan kinematic inertial explanation of the apparent deviation of objects due to fictitious forces in rotating Earth. Take an object moving from the equator northwards, or ...
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Why can't we detect the Earth's orbital motion when looking at the sky and stars?

After I read that speed of earth orbit around the sun is 30 km/s, I looked at sky and I didn't notice any change when compared to the start location. 30 km/s can be converted to (30 * 60 ) km/minute =...
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If Earth's atmosphere would be cooled, how would its pressure change relative to its temperature?

I have a feeling it would not behave like an ideal gas? For example, if the atmosphere were to cool down at a constant 1 atm to 90 K, oxygen would liquefy. If changing of pressure would be considered,...
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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 ...