The earth tag has no wiki summary.
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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?
0
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1answer
59 views
Geodetic model for numerical weather prediction
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 ...
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1answer
59 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 ...
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4answers
240 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?
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2answers
65 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
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1answer
54 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 ...
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4answers
118 views
How to create frame of reference?
Is this possible to create a inertial frame of reference in the earth?
How it is possible?
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1answer
45 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?
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2answers
218 views
What is geostationary orbit radius?
I'm asking this apparently "general reference" question for the simple reason: I was unable to find whether the quoted everywhere "35,786 kilometers (22,236 mi) above the Earth's equator" means ...
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2answers
113 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.
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4answers
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Would you be weightless at the center of the Earth?
If you could travel to the center of the Earth (or any planet), would you be weightless there?
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5answers
556 views
Where on Earth can you find plasma?
Ok, so not that 'where on earth', like literally - 'Where on Earth'.
Where on Earth, can you find matter in the 4th state, i.e. the plasma state?
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4answers
677 views
Is the earth expanding?
I recently saw this video on youtube:
http://www.youtube.com/watch?v=oJfBSc6e7QQ
and I don't know what to make of it. It seems as if the theory has enough evidence to be correct but where would all ...
4
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2answers
56 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 ...
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1answer
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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?
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3answers
115 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 ...
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1answer
99 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?
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2answers
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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 ...
3
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1answer
81 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 ...
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3answers
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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 ...
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8answers
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Would it matter if the Earth rotated clockwise?
In the Futurama episode "That Darn Katz!" they save the world by rotating the Earth backwards saying it shouldn't matter (which direction Earth rotates). If Earth rotated clockwise and remained in ...
3
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1answer
96 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 ...
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4answers
206 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?
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3answers
262 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?
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3answers
1k views
How long until the sun cannot sustain human life on earth?
The sun will last, at its current brightness for 9 billion more years. How long until the sun gets burned down to the point where it cannot sustain life on Earth anymore?
Updated: I am more concerned ...
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2answers
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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 ...
3
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1answer
236 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 ...
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0answers
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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?
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2answers
219 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 ...
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1answer
50 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
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1answer
32 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
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1answer
144 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?
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8answers
13k views
Why doesn't the Moon fall upon Earth?
Why doesn't the Moon, or for that matter anything rotating another larger body, ever fall into the larger body?
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2answers
126 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 ...
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2answers
138 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 ...
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1answer
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What is the extent of Earth's gravitational pull?
Where the gravitational pull of Earth exist up to?
What distance from Earth it will be zero?
How do the skydivers fly at a same altitude?
Won't they feel gravitational pull?
What is the Earth's ...
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1answer
33 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 ...
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4answers
2k views
Earth's Magnetic Field, Human Brain and Sleep
I remember reading somewhere:
when you sleep in a way subjecting your body to cut the geomagnetic
field at right angles, you become highly emotional whereas when it
is Parallel, it cools your ...
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2answers
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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 ...
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1answer
111 views
How can the properties of the Earth be determined?
How can the properties of the Earth be determined? And how is the gravitational constant then determined from them?
A satellite can determine the G.M.. But, how they are individually determined ...
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2answers
83 views
Assuming that the Sun wouldn't evolve into a red giant, how long would the Earth's atmosphere last?
It's not going to last forever - Jeans Escape is going to eventually act on the atmosphere after trillions of trillions of years: see http://faculty.washington.edu/dcatling/Catling2009_SciAm.pdf
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Imagining to speed up the Earth's revolution around the Sun until we feel its motion
If the Earth were revolving around the Sun much faster than it does, let's say 100 or 1000 times faster or whatever big-enough multiple of its actual speed, would we feel it? What sensation would we ...
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1answer
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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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1answer
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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?
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0answers
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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 ...
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2answers
660 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
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1answer
112 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 ...
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1answer
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Why did the june 2011 lunar eclipse last so long?
It was kind of hard to miss the lunar eclipse this week, although I didn't see it in person (Sod's law means that on every relatively major astronomical event clouds cover where I am). From what I ...
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4answers
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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 ...
