Earth Definition and 1000 Threads

If a strong gravitational wave hit Earth would clocks record it? as if i understand it it is space time that is oscillating so the time component must be changing.

I want to find the ricci tensor and ricci scalar for the space-time curvature at the Earth surface. Ignoring the moon and the sun. I have used the scwharzschilds metric, but then the ricci tensor and the scalar where equal to zero.

Is there a Metric for the Sun and Earth other than the Schwarzschild Metric who has the Schwarzschild Radius on the interior of the body? What are the assumptions that turn that from GR to Newtonian? Rs(Earth)=8.87*10^-3m Rs(Sun)=2954m

First of all, I want to say that I am totally ignorant about physics. And I do not understand the general concepts of physics at all. Now coming to the question. Suppose, you drop a green tennis ball from above. Now It usually lands on Earth and stop there ( ignore the bounces for...

When i am standing on the surface of earth, there are two forces acting on me 1)the gravitational force towards the center of the earth 2)normal force radially oppt to gravity as the normal force equals gravity, (that is why i don't sink into the ground or start floating in air), so they...

From previous threads I have understood that crossing the event horizon of a supermassive black hole is nothing very unusual for the falling observer locally. Usually in these considerations the falling observer has been thought as a "point" without much dimension. How about if Earth (and...

Homework Statement "The Michelson-Morley experiment was conducted using an interferometer with L1 = L2 = 40m, lambda = 632nm, and maximum fringe separation d = 0.0022 fringes. Find the upper bound on the relative speed of the Earth and the ether, and clearly state the significance of the...

I original posted this in GD. It may be more appreciated here. It is a lot more than just pictures. It is long so get a drink and a some snacks before starting to watch.

How can the function for distance over time be found for an object which is thrown away from Earth? Acceleration as a function of distance is g = GM/r^2, where GM is constant, so let c = GM, then g = c/r^2. Then I wondered, maybe the formula for distance can be found by solving the...

that can be detected.

lets say a rogue star or black hole pass by our solar system and disrupt the orbits of the planets and pull the Earth away from the sun, can it regain or get back to its original orbit if the black hole is gone? some people say the chances of a black hole passing by our solar system is slim but...

I found that Earth rotates with a speed of 465.1 m/s.So if i take a jetpack and stand floating in air why can't i see the Earth rotating below me??

Hello, Suppose we pass a horizontal plane through the Earth's equator. Over a period of a year how is the variation of the Earth up and down the plane affected by the moon's motion and other planet's at closest approach to Earth and is it really possible if the moon had the same mass of the...

I am writing a screenplay that hinges around the imminent destruction of the earth. Can somebody describe a scientifically plausible cosmic event that could obliterate the earth. The only criteria I need to fill is that it can be identified four years before it reaches us. My first thinking was...

A fantastic Nova documentary. It is 2 hours long. It may be on YouTube in shorter segments. http://video.pbs.org/video/2334144059/

This is a basic question regarding Lorentz transformations. Let's say we have two observers - S on Earth and S' which we put on a rocket headed for Alpha Centauri (A.C) =). If i choose 2 events like this: rocket leaves Earth rocket arrives on A.C These two events clearly do not...

Homework Statement An unlikely weapon was once proposed which had all of the people in China to jump up and down simultaneously. Let us say there are 2 billion people (2.0 x 10^9) with an average mass of 50 kg. They all climb ladders which are 1 meter tall. At a particular instant they all...

Earth scientists of PF, why did you choose this field? When did you realize you wanted to study the earth? It seems that many people don't find an interest in the Earth sciences until later in their academic careers. I'd like to hear your stories!

So we know that for every action force there is an equal and opposite reaction force, but these forces act on different objects. And we know that the gravitational force acting on the Moon by Earth and the gravitational force acting on Earth by the Moon is equal. But what amount is this equal...

Hello guys, I really need your help. I have a homework in physics, i know this questions is easy for others but i don't know how to solve this, i tried googling:( So here's the question: ( i need solutions too) 1. If Earth's quadrant is 10 000 000m, what is the circumference of earth? 2...

Okay, so, this is not really a homework question but it is still related to coursework. I wonder why we don't feel that we are moving. Our velocity is constantly changing since we are going around the Earth's center. My research tells me that we can compare this situation to a car. But, in...

To blow up earth... ...what mass would I need to covert to pure energy (roughly)? Like, they say a paper clip converted into pure energy is the equivalent of the atomic bomb that was dropped on Hiroshima. Is that true? If so, would a van converted into pure energy be enough to blow up Earth...

Solids tend to expand when heated or when they transition to a liquid. Is this thermal expansion a factor in the earth? If the diameter/volume increases, this would cause the surface area to increase also. This would lead to cracks, rifts or faults in the crust of the earth. Could this be a...

Homework Statement gravitational potential at surface of the Earth = -63MJkg-1 gravitational potential at surface of the moon = -2MJkg-1The attempt at a solution I thought gravitational potential was a scalar, so in which case, you would surely just add up the potential due from both masses...

A 13.2Billion year old star just 186 Lyrs from earth I thought that these really old stars would have only been observed at super high red shifts because of a shorter life but apparently not. http://www.salon.com/2013/01/12/astronomers_may_have_found_the_oldest_star_in_the_universe/...

I have always wondered why the moon doesn't look blurred to us if Earth is spinning so fast, or are we spinning so fast that the image of the moon or everything else in the cosmos for that matter, looks clear? Like when a picture is taken of the Earth it looks still, is it because the thing used...

Hello. Why wouldn't the Earth gravitate towards the Sun? I have done some online research on this question and it appears that the reason is due to the Earth's rotation. I am not convinced and see no reason why that should be the reason. According to the Rutherford's model of the atom, an...

Why are hydroxides of Earth alkaline metals so insoluble in water? They are polar compounds and have an OH group, so they should do hydrogen bounds with water, as well as permanent dipole interactions, which in my conception are strong forces. Even Mg(OH)2, witch do not have a big mass, has a...

so i wanted to know for my own GK about Earth's daily axial tilt.So far i have found only axial tilt on solstice and equinox. there is one way but it is cumbersome and that is to manually find it

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 (through conduction) and become negative charged. Assuming the Earth can modeled as a conducting...

I'm having a debate with a good friend and we haven't come to agreed yet. I'm very sure, yes, we will jump higher. I summarized this from several sources which explained my view: http://i.imgur.com/nTsqVnc.jpg But we come to the point where he states: Is he correct or is it wrong...

[SIZE="3"] [SIZE="2"]I'm a writer, damn it, not a physicist! My imagination takes me to a world where a moon can be a habitable planet that orbits the largest planet possible that could be completely engulfed by liquid water.

Homework Statement On a clear night the Earth loses heat according the equation \frac{dQ}{dt} = \sigmaAT4 If the average temperature of the ground is 10°C, calculate the rate of heat loss, per square metre, by the Earth and the total heat lost, per square metre, in one hour. Homework...

big G = G = 6.674E-11 N(m/Kg)^2 Mass of Earth = Me = 5.972E24 Kg Radius of Earth = Rsurface = Rs = 6.371E6 metres THIS IS NOT HOMEWORK Okay so I was interested to know how you would work out the distance you'd need drop an object from (above the Earth's surface), for it to reach a given...

How can I plot the tidal force vectors on the surface the Earth in Mathematica or Python? The potential energy of the tidal force on the poles are $$ U = -GM_{moon}m_{water}\left(\frac{1}{d}+\frac{x}{d_0^2}\right) $$ where ##d_0## is the distance between the moon and the Earth 384400 km. The...

Homework Statement The intensity of sunlight reaching the Earth is 1360 \frac{W}{m^2}. a.) Assuming all sunlight is absorbed, what is the radiation pressure force on the earth? Give your answer in Newtons. F_r= b.) Give your answer as a fraction of the suns gravitational force on the earth...

Hypothetically, if the Earth were a cube, would walking to the corners(vertices etc.) feel like you were going uphill or would it feel flat?

Hi! I am trying to solve this triple integral for computing the potential: G*ρ*∫∫∫-atan((x*y)/(z*sqrt(x^2+y^2+z^2)))dxdydz with the limits x = 0 to 1000 z = 0 to 1000 and z = 0 to 1. The G is tha gravitational constant and ρ is the density of rock/earth. I have tried to use multiple...

EDIT: I apologize for not noticing this earlier, but I realize this should be in the HW/Coursework section of the forum. If possible, would someone be able to move it over for me? Again, sorry for my error and any trouble/confusion. I would like some help calculating the flux of neutrinos...

Wow, a bit scary! http://www.weather.com/sports-rec/weather-ventures/postcards-from-google-earth-20130412

Homework Statement Postal workers on planet Vashtup want to drill a straight tube through the planet, starting at Post Office 1, passing through the center of the planet, and ending on the other side at Post Office 2. They plan to release small packages containing mail into the tube from P.O...

So I'm just studying for my final on Saturday and I realized that I'm missing the answer to a question in my notes( probably missed that day). So I was that hoping someone could look over my attempt. Thanks :smile:! Homework Statement The muon is an unstable elementary particle with charge...

Remembering 10 years ago ish, hearing about a plan in Norway using a mirror in space to reflects light into the North Pole. I am not if they have done it or not but here is the deal, Earth is in space (which is at around Absolute zero) how long it takes for the Earth to freeze if light of sun...

So I just watched this documentary (or whatever you want to call it) called Evacuate Earth. It talks about a hypothetical doomsday scenario where a rogue Neutron Star is headed towards the Solar System, and scientist figure this out 70+ years in advanced. It is a NatGeo documentary, and I...

There is something I don't fully comprehend. When I throw a ball into the air while I'm sitting in a train, I won't accelerate past the ball because the ball carries the momentum of the train just as well as I do. Furthermore, the ball, the train and I carry the momentum of the Earth, which is...

so i was thinking in the future all our resources would be depleted but we would harvest other planets for metals such as chrome aluminium titanium and so forth and maybe even iron. And we all know the more mass the planet has the higher the gravitational pull. so how much mass/resources can...

Homework Statement A traveller with mass m = 66,5 kg travels with a velocity of 0,82 c to the Andromeda galaxy which is a distance of 2,55·106 lightyears away. Light with the wavelength 459,4 nm is emitted from the galaxy. assume the galaxy doesn't move and use the exact speed of light. How...

While the mean speed of the Earth on its solar orbit is about 30km/sec, what is its approximate speed during the both equinoxes and the both solstices ?

I was just reading in "Spin physics in semiconductors" by Dyaknonov section 1.2.4, page 4 in the footnote, how the Earth's spin is expected to precess around its orbital angular momentum. Does anyone know if this has been considered as a possible cause for Geomagnetic reversal...