The earth tag has no wiki summary.
11
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1answer
115 views
Mars just collided with Earth! A question of eccentricity
One of the standard theories behind the formation of our Moon is the giant impact hypothesis, according to which Earth was struck by a Mars-sized body (about $10\%$ the mass of Earth) early in its ...
1
vote
2answers
47 views
Triple-right triangle experiment: what's the minimum distance?
Among the other ways, one way to prove the Earth is round is the triple-right triangle.
The idea is simple:
Starting from point A you move in a straight line for a certain distance.
At point B, ...
2
votes
1answer
58 views
Calculating the length of day at any time of the year? [duplicate]
Is it possible to calculate the length of the day at various location (distances) from the sun? I hear agricultural scientists are able to do that. To make calculations easier assume there is no axis ...
2
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2answers
66 views
Does spin of the earth vary at different locations?
Does the spin of the earth around its axis vary at different distance from the sun?,if so how does it correspond to the length of day and night,?
-2
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1answer
42 views
All of the deep earthquakes in the world are associated with? [closed]
Question:-All of the deep earthquakes in the world are associated with:
(a) Spreading centers
(b) Mantle plumes
(c) Ocean trenches
(d) Plate triple junctions
(e) Continental shelves
(f) None of these ...
0
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0answers
61 views
Does gravity change the closer you are to the Earth's core? [duplicate]
Very simple question that has bugged me for some time, does the acceleration produced by gravitation (e.g. $9.8\: \mathrm{m/s^2}$) would change if we placed an observer closer to the planet's core? I ...
0
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2answers
67 views
Could we use the coriolis effect to travel
Given a platform that is floating independent of Earth's gravity, would it be possible to put a platform over the equator and over the day, would the Earth rotate from under it allowing you to travel ...
45
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8answers
5k 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 ...
6
votes
3answers
348 views
How is it that the Earth's atmosphere is not “blown away”?
The Earth moves at a high rate of speed around the Sun, and the solar system is moving quickly around the Milky Way. How is it that the Earth's atmosphere is not “blown away”?
7
votes
2answers
225 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?
4
votes
1answer
89 views
How much negative charge do I accumulate by touching the earth?
The Earth carries a negative electric charge of roughly 500 thousand Coulombs (according to different sources I've seen). If I touch the Earth I should therefore pick up some of this electric charge ...
3
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1answer
118 views
Can Earth's Magnetic Field Create Electricity?
If the earth has a magnetic field, can it, in theory, be run through a conductive metal coil to create electricity?
4
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1answer
68 views
How would gravity change on a planet rotating around itself very fast?
Let's take a planet identical to Earth, but with rotation speed multiplied by ten thousand. What would happen with the gravity if it was spinning madly around itself? Would the centrifugal force make ...
3
votes
2answers
72 views
Orbits within a $-\vec{r}$ field
Let's say that we have a cold dark matter theory, so we imagine weakly interacting particles. Now, let's say that one of those dark-matter particles has a rare interaction while traveling through the ...
2
votes
1answer
57 views
What is the Earth's magnetic field in space?
I have looked around a bit, but haven't found a simple answer. At an altitude between 100-1000 km,
Is the magnetic field B still around $\sim 10^{-5}\ T$? Is there a simple equation that would provide ...
1
vote
1answer
53 views
What is the most optimal earth's axial tilt in terms of variation of seasons?
What is the most optimal earth's axial tilt in terms of variation of seasons?
What would be optimal axial tilt for earth that life would exist and change of seasons would be at minimal level?
0
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3answers
126 views
How to create frame of reference?
Is this possible to create a inertial frame of reference in the earth?
How it is possible?
4
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2answers
143 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.
6
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4answers
254 views
Why is the water on the surface of the Earth?
What makes the water stay on the surface? Why the earth does not absorb the water in it?
4
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2answers
64 views
Attenuation mass-thickness for sunset light
We are able to look directly at the sun near sunset and sunrise, which clearly demonstrates the fact that our atmosphere attenuates visible light. Let's imagine it follows the typical attenuation ...
0
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3answers
141 views
What would happen to the Moon if Earth is turned into a black hole?
Assume that all of sudden the Earth is turned into a black hole. And the moon revolves around the Earth (before turning into a black hole). What would happen to the Moon after earth changes to black ...
1
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1answer
67 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?
-2
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1answer
103 views
Based on what does Hawking give 1000 years of time for humans to escape the planet earth? [closed]
I read it news that:
Hawking Gives Humans 1,000 Years to Escape Earth
How did he arrive at this figure? Whats gonna make human race extinct in 1,000 years?
-6
votes
1answer
57 views
Energy flows in the core also responsible for another of the planet’s unique [closed]
Energy flows in the core also responsible for
another of the planet’s unique features: a
strong magnetic field. Scientists believe that
the earth has had a magnetic field for at
least 3.5 billion ...
1
vote
2answers
160 views
3
votes
1answer
89 views
Under what practical conditions would Earth's atmosphere be a dilatant?
I have read and heard in many places that when the astronauts of Apollo were coming back to Earth, they had to determine the best angle of attack to re-enter the atmosphere. This is usually indicated ...
-1
votes
3answers
134 views
What cosmic event would cause Sun rising from the west?
I'm wondering what kind of astronomical or geological events would cause the reversal of Earth's rotation. For instance, Is a meteorite passing very close to Earth able to reverse its rotation?
Can ...
3
votes
4answers
215 views
Why a day is divided by 12/24 hours? Why the number 12?
Why a day is divided by 12/24 hours? Why the number 12? Why not using 10 or 6 or 14, 16? Who invented this? Any physical reasons behind this?
2
votes
2answers
86 views
Spot of my light on the moon
This is a funny question, but worth answering. The distance between the moon and the Earth is 384,400 km. The speed of light is 299792.458 km/s. It will take 1.3 seconds (Approx.) for my laser beam to ...
-1
votes
1answer
63 views
Geodetic model for numerical weather prediction [closed]
What is the implicit geodetic model used by common numerical weather prediction products? WGS84? NAVD88?
For example, NOAA's Rapid Refresh (RAP), North America Mesoscale (NAM), and Global Forecast ...
3
votes
1answer
288 views
How much energy would it take to blow up the earth?
There is a common statement running around that we as a species has enough nuclear weapons to blow up the earth several times over. What I want to know is: by how many orders of magnitude is that a ...
0
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0answers
28 views
What is the formula for calculating the length of any given day (sunrise to sunset)? [duplicate]
In a specific date what law gives us perfect measurements and how will we measure if latitude is given?
5
votes
2answers
251 views
Do we have any effect on the rotation of he 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 ...
0
votes
1answer
55 views
How much energy is needed to curve the space so the Sun will come 1 meter closer to our planet? [closed]
How much energy/work will it take if our planet is:
5.9736×1024 kg
or
3.0×10−6 Suns
to move Sun and Earth 1 meter closer ...
0
votes
1answer
34 views
What role has our Moon played in creating a persistent geomagnetic field?
The question comes from a comment by Mark Rovetta on my earlier question about the Earth's core going cold.
3
votes
1answer
173 views
What if the earth's core goes cold?
What effects would occur if the earth's core goes cold? Would the planet stay liveable after this happens?
1
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3answers
274 views
Speed of the Moon
Why the motion of the Moon looks very slow in the sky? Doesn't it need the high speed in order to escape the earth's gravity?
3
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2answers
171 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 ...
0
votes
1answer
34 views
What is the Willmore energy of the Earth (or the geoid)?
Wikipedia defines the Willmore energy as:
$$e[{\mathcal{M}}]=\frac{1}{2} \int_{\mathcal{M}} H^2\, \mathrm{d}A,$$
where $H$ stands for the mean curvature of the manifold $\mathcal{M}$.
What is the ...
3
votes
1answer
99 views
Link between Earth and Mars
I am trying to the calculate the link budget for link between a ground station on Earth (with a particular latitude and longitude) and a rover at a particular location on the surface of Mars, either ...
2
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2answers
135 views
How does earth carry moon with it, if it can not force moon to touch it by gravitational force?
earth's gravitational force is acting on its moon in such a way that it forces moon to rotate round its orbit by centripetal force and carries it while rotating round the sun by gravitational force. I ...
41
votes
2answers
6k views
Was the 2013 meteor over Russia stronger than an atomic bomb?
Reports of the Russian meteor event (2013) say that it released more energy than 20 atomic bombs of the size dropped on Hiroshima, Japan:
Scientists estimated the meteor unleashed a force 20 times ...
11
votes
1answer
147 views
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 ...
2
votes
1answer
107 views
Does the Earth rotate the same encased in ice during the height of an Ice Age as it does when the bulk of it's water is liquid and always in motion?
Ice Age vs. Now.
Does the Earth rotate at the same rate when encased in ice during the height of an Ice Age as it does when the bulk of it's water is liquid and always in motion?
1
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0answers
34 views
Interaction of geomagnetism on free falling coil
Take the Earth, or a similarly large body with an Electromagnetic field. For now - expect atmosphere.
Then take a much smaller object - say the size of bus, containing a coil with many windings.
If ...
3
votes
1answer
115 views
Finding radius of Earth through observation of Sun's motion
The question I'm about to pose is from a physics book I had recently bought. Since I am very interested in physics I am quite keen in understanding how this question can be solved. Before I present ...
5
votes
2answers
766 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 ...
3
votes
1answer
71 views
Does the Earth have a semi-solid body at its core because of lower pressure at the center of the Earth?
I have read that the Earth has a semi-solid iron body at its core, even though that object is surrounded by liquid magma.... I'm wondering if this is because of a pressure (and resulting temperature) ...
1
vote
2answers
83 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 ...
4
votes
1answer
203 views
If the Moon had gravity as good as the Earth and a magnetic field could it have supported life?
If the Moon had gravity as good as Earth and a magnetic field could it have supported life? Because if the Moon had gravity, it could have retained water more than is present today on the surface.
...
