Questions tagged [earth]
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.
105
questions with no upvoted or accepted answers
3
votes
0
answers
64
views
What if you ejected a cone of material from the Earth out into space?
For calculation purposes, let's say it's a cone with cone angle (at Earth's center) of 30 degrees, that extends down to the outer surface of Earth's solid inner core, and the entire mass is ejected ...
3
votes
1
answer
95
views
Can a pendulum at resting equilibrium position still demonstrate the Earth's rotation?
I conducted an experiment in my youth, creating a 'sand pendulum' hanging from the bedroom ceiling to a bowl of flour. I did not set the pendulum into motion, but rather wanted to see if the force of ...
3
votes
0
answers
630
views
Estimating the Pressure of Earth's Center
The pressure of a medium of density $\rho$ and in a graviational field with strength $g$ at a depth of $z+dz$ is equal to the pressure at $z$ plus the pressure caused by the weight of a slab of volume ...
2
votes
1
answer
72
views
Will a man acquire orbit if we suppose Earth is rotating fast enough?
if we consider that the rotation of earth is mush faster (30000km/h), so if a man standing on earth jumps 1 meter above will it acquire orbit if we ignore atmospheric friction
2
votes
1
answer
96
views
Are there any types of winds or waves that are produced just by Earth's rotation?
Are there any types of wind or waves caused/produced only and exclusively by Earth's rotation? Not influenced by Earth rotation, but produced solely by it?
In the case of waves, are Rossby waves 1 and ...
2
votes
0
answers
105
views
Why do seismic P waves convert to S waves at an interface?
Why does a P wave refract and become an S wave when it hits an interface? What is the mechanism behind this? If P waves are longitudinal and S waves are transverse, how can this change occur?
2
votes
0
answers
890
views
Building orientation - how come both summer and winter solstice used for a facade?
I am planning to build a shed atop my terrace. I was analyzing the sun path to determine the overhang length, facade height etc, but got stuck with a conflict as below.
The summer sun's location peaks ...
2
votes
0
answers
47
views
How can we feel Earth magnetic field if we are rotating with it?
I know Earth have molten iron core and we should feel a magnetic force if we are stationary while Earth is spinning. But I'm curious how it is we can feel north and south poles so distinctly while we ...
2
votes
1
answer
110
views
Which location on Earth has the strongest deviation from the vertical due to gravity?
So, I've recently learned about the Schiehallion experiment, performed in 1774, where scientists detected the deviation from the vertical of a plumb due to the gravitational attraction of a single ...
2
votes
0
answers
156
views
Can Earth's Magnetic Field Be as Less as -85μT and as Much as +70.46μT?
What did create the question?
I was analyzing a data set where the researchers have used objective data. They have calculated earth's magnetic field through sensors and that research was conducted in ...
2
votes
0
answers
56
views
Ocean warming by induced electric current for wandering magnetic poles?
In a post on the co-rotation of Earth and its magnetic field (Does the geomagnetic field rotate?), John Rennie raised the point that, if Earth's magnetic field were rotating about its dipole axis, it ...
2
votes
0
answers
20
views
Being the Earth modelized as a big magnet (or solenoid), which would be the field intensity of such a model inside the solenoid or magnet axis?
This question has arisen from the Carl Friedrich Gauss’ statement that the Earth could be modeled, concerning his calculations about the earth’s magnetic potential, as a big magnet, himself having ...
2
votes
1
answer
256
views
How has the Earth's air pressure varied over geological time scales?
It is estimated that the Earth is losing about $5 \times 10^7 kg$ per year. Most of it due to hydrogen loss. I suppose this has an impact on the pressure of the atmosphere in general.
Thus, I am ...
2
votes
0
answers
65
views
How long would rising hot air from a 15,000 meter (49,000 ft) hole in the earth's surface stay warm for?
The deepest hole drilled in the earth is the Kora Borehole. At 15,000 meters (49,000 ft), the temperature was projected to reach 570 degrees F (299°C), so drilling was abandoned.
My question is, if ...
2
votes
0
answers
77
views
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 ...
2
votes
0
answers
237
views
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 ...
2
votes
0
answers
59
views
Different time between equinoxes
I calculated from here that there are 16 104 096 seconds between the vernal and autumnal equinox, if I made no mistake, this is some 650 592 s longer than the other half orbit.
I imagine this is due ...
2
votes
0
answers
88
views
Is there a resonance within the earth, separate from the Schuman resonance?
In a very recent biography of Nikola Tesla by Bernard Carlson, the author explains that Tesla measured the resonant frequency of the earth using his invention - the amplifying transmitter. Tesla came ...
2
votes
1
answer
113
views
How did the Moon survive next to the Earth since earth and Moon came into existence?
What mechanism(s) prevented the gravitational effect of the earth on the moon from shattering the moon when it was closer to the earth than the Roche Limit some 4.5 billion years ago?
2
votes
0
answers
96
views
Terrestrial Space Elevator Construction - Plausability
Framework
If there was a cable constructed at the equator about the circumference of the Earth, and if this cable had sufficient strength to remain intact while erect, call this tensile strength T.
...
2
votes
0
answers
82
views
Could there be a planet just as the Earth, but bigger?
Could there be a planet twice or thrice the size of Earth but while being the same? and by the same I mean, hosting the same life as Earth, having a day last 24 hours and a year 365 days.
Basically, ...
2
votes
0
answers
123
views
Could water physically makeup the core of a planet or otherwise large celestial mass?
Knowing very little about the nature of water, wondering how it might behave at the centre of a planet or centre of an another massive gravitational body.
Could water take such pressures or might it ...
2
votes
0
answers
73
views
Computing Latitude Given Quiescent Gyroscope Data
Suppose I place a gyroscope in a theoretically perfectly quiescent, closed room. Let its output be given as a vector ${\bf v} = (v_x, v_y, v_z)$ indicating rate of rotation around three orthogonal ...
1
vote
1
answer
27
views
Do frame dragging affects falling object?
Imagine there is a tall tower erected at the equator, a pulse of light is beamed from the top of the tower to the ground. Do I need to consider frame dragging? After all the spacetime is being tucked ...
1
vote
2
answers
173
views
Coriolis force relation to wind velocity
I'm learning coriolis effect on Winds moving from equator towards North pole. This is for geography.
Question:
Why is coriolis force stronger for winds having larger speed(larger component of ...
1
vote
0
answers
34
views
Orbital obliquity of the Earth
Consider that we have all the orbital parameters that characterize the Earth. How would one calculate the orbital obliquity of Earth?
One could argue that since the rotation of Earth doesn't change ...
1
vote
1
answer
68
views
When I see a rainbow in the sky, is the full EM spectrum included? does it form a disc and not just a circular arc?
If you could actually see every part of the EM spectrum from a rainbow, would the circle be completely filled in? and would it also extend further outwards from the visible spectrum?
1
vote
1
answer
125
views
Is there a distortion of Earth's electric field by high objects, especially man-made?
Recently I've read one of Dr. Feynman's lectures about storms and lightnings. This one to be exact: https://www.feynmanlectures.caltech.edu/II_09.html
There he said, that human has the same charge as ...
1
vote
0
answers
30
views
How do surface temperatures drop in response to optical depth?
I'm trying to come up with a super simple estimate for how atmospheric surface temperatures would be affected by a substance overhead with some optical depth $\tau$. I'll assume that the sun is always ...
1
vote
0
answers
46
views
Earth magnetic field, WMM/IGRF
I am studying about World Magnetic Model (WMM) and International Geomagnetic Reference Field (IGRF) models. It is well known that, to a first approximation, earth magnetic field is a field of dipole. ...
1
vote
0
answers
119
views
How did Al-Biruni know the height of a hill?
I knew of Eratosthenes famous experiment for determining the size of the Earth, but a recent question led me to read about another method by Al-Biruni. Like Eratosthenes' method, it required two ...
1
vote
0
answers
61
views
How much should I dig a hole to set a post?
I need your help to solve this problem
We suppose that we have a post pulled by
$N=4$ barbed wires separated a distance $dh = 30 \text cm$, and that each wire pulls with a force of
$F=300\text N$ . ...
1
vote
1
answer
112
views
Why does $g$ vary from a direct square relationship inside the earth to an inverse square relationship above the earth's surface?
Why does acceleration due to gravity $g$ vary with altitude, height, and depth from a direct square relationship inside the earth (below the earth's surface) to an inverse square relationship above ...
1
vote
0
answers
20
views
If the liquid internal parts of the Earth solidify, what will be the consequences?
Will the Earth's radius just decrease, the daytime decrease, and the magnetic field seize to exist?
1
vote
0
answers
36
views
Approximating the warmest time of day
I'm trying to find a very simple approximation of when the maximum air temperature will occur on a given day at a given location. By "air temperature," I just mean the air temperature at ...
1
vote
0
answers
39
views
Rate of neutrino generation in Earth's core?
I know that there are radioactive elements present in the Earth's core, but has anyone determined how much? That is, do we have an estimate of the number of neutrinos per second generated within the ...
1
vote
0
answers
41
views
Atmospheres and oceans on lower gravity planets
Using Earth as an example, how much less gravity could the planet exert and still retain its atmosphere and oceans? Or is it a matter of size, mass, magnetosphere, place in the solar system, all of ...
1
vote
0
answers
39
views
What path would it produce if someone kept on going after their shadow (on Earth)?
Imagine someone is standing on the surface of the Earth (let's assume it is completely flat) and they start going exactly in the direction their shadow is cast (that is, exactly opposite of where the ...
1
vote
0
answers
63
views
Would the Earth have weighed the same if no life had developed on it?
I was reading this question and talking about it with my flatmate when a question came up. Ignoring the effects of losing or gaining mass due to cosmic dust, meteorites, and atmospheric losses as ...
1
vote
0
answers
182
views
Difference between Critical and orbital velocity
What is the difference between orbital and critical velocity of satallite ?
I have read that critical velocity is constant value and it does not depend upon altitude. It only gives the velocity of ...
1
vote
0
answers
91
views
Earth's surface area
Here we are trying to calculate the earth's surface area via geodetic coordinates:
\begin{align}
x&=(R\,p(\lambda)+h)\sin\lambda\,\cos\phi\\
y&=(R\,p(\lambda)+h)\sin\lambda\,\sin\phi\\
z&...
1
vote
2
answers
91
views
Is the period a physical observable in General Relativity?
I am currently seeing the classical tests of GR. To justify the introduction of a test based on the Doppler effect, the professor says that the previous test ( Shapiro and echo-radar test ) is based ...
1
vote
0
answers
56
views
How much time does it take in Earth to generate the energy supply that the sun produces in one second?
According to this article which I ignore if it's correct The amount of energy the sun emits every second is , the amount of energy the sun emits by second is $4\times10^{33}$ ergs . And according to ...
1
vote
1
answer
386
views
How can I obtain the position of the Earth on the orbit for given date?
I would like to be able calculate (or at least download some time-series data of) the position of the Earth on it's orbit at given date. For my purposes, it would be sufficient to account for the ...
1
vote
1
answer
72
views
Does Earth's precession rate change with the seasons?
As Earth's precession is caused by the differential solar, etc., attraction to its 'spare tire', then does the rate go to ~zero at the equinoxes and ~twice the average at the solstices? (preferred ...
1
vote
0
answers
25
views
What are ShadowBands during SolarEclipse and how can it be reproduced?
I recently got to know about different phases of a solar eclipse and its impact on Earth and its living creatures.., but one of the most interesting and not well explained phenomenon is the ...
1
vote
0
answers
79
views
On the formation of Earth's moon
NASA states that :
The moon was formed ~4.5 billion years ago, about 30–50 million years
after the origin of the Solar System, out of debris thrown into orbit
by a massive collision between a ...
1
vote
2
answers
417
views
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,...
1
vote
0
answers
1k
views
What is this bright spot in the sky?
I took this picture a few minutes ago (35 minutes ago, currently 1828 here)
As you can see there's a VERY bright spot on the right that shows a spectrum on the one side.
I am pretty confident it's ...
1
vote
0
answers
86
views
To what altitudes does cosmic radiation penetrate?
How far does high energy (Cosmic) radiation penetrate(km above sea level) into the planet earth? And at what rate(/m^2/s)? (limited set of rates here)
(The Aurora is low energy protons that stop at 90 ...