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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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 ...
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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? [on hold]

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 ...
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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. ...
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1answer
38 views

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 ...
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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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1answer
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Deviation of free falling objects (Coriolis effect) using conservation of angular momentum

I read this pdf damtp.cam.ac.uk/user/stcs/courses/dynamics/lecturenotes/section4.pdf on non inertial frame, in particular I have a question on the deviation of free falling object due to Coriolis ...
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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 ...
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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 ...
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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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If we live on the surface of Earth then why Earth images shows maps around it? [closed]

If you visits google map and go to earth we see the image as attached below. My question is if the earth is round like sphere ball and if we live on the surface of this ball (point me if i am ...
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Can Earth be converted into a black hole? If so, how? [duplicate]

A black hole is a region of spacetime exhibiting such strong gravitational effects that nothing—including particles and electromagnetic radiation such as light—can escape from inside it. The theory of ...
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Could an asteroid land slowly on Earth's surface?

The concept in my mind is that an asteroid is on a vector similar to Earth's, but slightly slower (e.g., 50kmh slower). As Earth passes it, it enters the atmosphere at a sharp angle, and since Earth ...
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Could moving land mass alter Earths gravity?

This is potentially a very stupid question but I'm going to ask it anyway. With all these huge buildings such as the Abu Dhabi Mosque, where an unbelievable amount of materials such as marble was ...
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Can humans control rotation of the Earth?

I'm a class 12th student and this thought just struck me from nowhere. Assume a situation where every human on this planet turns towards west. All of them start walking simultaneously in west ...
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Do volcano blast changes earth's course?

Volcano blasts are one of the most powerful calamities on earth. When they blast they release large amount of mass in the air just like a jet does. Does such a blast have any effect on the course of ...
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1answer
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Is it possible to 'push' a path to the Earth's core?

This may very well be a question for Earth Science SE, but as it is very hypothetical, maybe pure physics is more appropriate... Question: Imagine we have have a wedge that tapers down into an ...
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Would running along Earth's Surface at escape velocity cause you to get out of the Earth's gravitational pull? [duplicate]

If one were to run/drive/fly along the earth's surface (by this I mean tangential to the Earth) at escape velocity (about 7 miles per second), would that person escape the gravitational pull? If not, ...
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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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What force is needed to turn the Earth Pole-over Pole. Eg. UK now on Equator? [closed]

Specifically, if someone could specify the Joules energy required to force the Earth to slowly rotate the poles end-to-end by say 1 degrees rotation, and by 5 degrees. To be clear I mean to literally ...
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1answer
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(Constant) Value Of Gravitational Pull $g$ Of Earth [closed]

I want to know How the value of $g$ was found and what experiments did Newton conduct to land upon the value that we use, which is 9.8 m/s^2. I tried to search for it but I couldn't find much ...
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1answer
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What's the distance between the center of mass and geometrical center of Earth? [closed]

With a good approach we can say that they are identical. But how accurate is this approach? Since Earth is not homogeneous there must be (can be) some difference. In other words I'm asking if Earth ...
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why the shape or size of Magnetosphere is different both side?

Two days ago, I watched a documentary about solar flares, and how Magnetosphere protect us from that to earth. I was able to understand most of it, but I'm still curious to know why the ...
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Would a non-rotating Earth collapse on the Sun?

If the earth stopped rotating on its axis, would this influence its revolution motion? In particular, could it collapse on the sun? I ask this because on the one hand I thought the two degrees of ...
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Current length of the solar day?

As can be seen in this diagram, the length of the solar day has varied Question considerably the last century. But the diagram is incomplete and doesn't show the very last years. Can anyone tell me ...
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Formula for getting time of sunrise at a particular location?

Is there a formula that can get sunrise at a particular latitude and longitude (and elevation from sea level)? If so, what it is? (Why does it work?)