Gravitational Definition and 1000 Threads

Can gravitational force have influence at objects at infinitely long distance? Is gravitational force in the form quantum packets?

Sir, heat is proportional to the vibration of atoms. If the vibration of atom is restricted to large extent due to intense gravitational field but has high quantity of total energy in the atom then does it mean it has high tempearture like the stars?

Wak a ball with a bat and the ball accelerates. Now under gravity, hold the ball out horizontally, let go and the ball accelerates ... without a wak. Given that gravity arises from curved space-time, I suggest further that the acceleration of the ball arises when sub-atomic particles (in the...

Why the area of the thin rings are ##2πasin\theta \, ds##? (a is the radius of the hollow sphere) If we look from a little bit different way, the ring can be viewed as a thin trapezoid that has the same base length ( ##2πa sin\theta##), and the legs are ## ds##. The angle between the leg and...

hello I'm korean high school student and sorry for my poor English. I saw ## t_0=t_f\sqrt{1 -\frac{ 2GM}{rc^2}} ## in wikipedia. does ## \sqrt{1 -\frac{ 2GM}{rc^2}} ## of this equation have name like lorentz factor ## \frac{1}{\sqrt{1 -\frac{v^2}{c^2}}} ##of ## t=\frac{t_0}{\sqrt{1...

If I start with two, otherwise isolated, masses M and m initially together and do work to separate them then the work done, I assume, goes into the gravitational binding energy between them. Will the system of mass M and m have increased in mass due to this in accordance with e=mc^2? I...

It's been more than 60 years since I attended high school, and I am trying to learn and understand concepts in Newton's physics that were not taught and were not part of the school curriculum during the 1950's. It is my understanding that the current mathematics taught and used in our...

We can derive the constancy of the speed of light from Maxwell equations. My questions are: 1. Why it is then need to postulate it when we can obtain it from Maxwell equations? 2. It is stated in many books that gravity wave also propagates with the same speed, c. How do we conclude that? Is...

hello guys, sims back again with another question.. I don't understand what is up with question (b) cuz like.. to get ##v_esc## we assume that at ##r_0=\inf## ##v=0## but now if I assume at ##r=1.5E8## that ##v=0##. And then find ##v_esc## from the following: ##\frac12*mv_{esc}^2 -...

Electrons flowing through a resistor are dissipating electrical energy. The electrical energy is transported from the battery to the electrons along the curved field lines of the Poynting vector. It seems like a meaningful idea that electrical energy necessarily travels from the source to the...

I've been thinking about gravity. If mass contracts spacetime, can the warping effects be measured in time as well as spatial distance? For example -- say you had some matter that suddenly disappeared (please ignore the "how"). Measured in a fixed position, would the gravitational effect drop...

Mentors’ note: this thread is forked from https://www.physicsforums.com/threads/free-fall-in-curved-spacetime.1016510/ But what if the gravity field is homogeneous? Like that of an infinite massive plane? The objects in the ship will stay where they are. An infinite massive plane is quite...

Hello everyone! I noticed in the derivation of potential energy, Mr Lewin defined the gravitational potential energy of a mass m at point P relative to a much larger mass M. He says the potential energy of m at point P is equal to the work he would have to do to move the mass m from infinity to...

We know that gravitational forces are nullified near the center of the Earth, so the gravitational field's influence is not felt. Is it because of the Moon's gravitational field that the area of zero gravity has shifted away from the center of the Earth? If this is the case, this eccentric area...

this paper postulating a minimum gravitational field strength postulating a minimum gravitational field strength (minimum curvature) and a minimum acceleration but otherwise leaving Gr could reproduce MOND [Submitted on 25 May 2022] MONG: An extension to galaxy...

I ran into another article demonstrating the Casimir effect and it hit me that zero-point energy is real mass and therefore would have a gravitational influence on our universe. Is there something wrong with this idea, am I missing something?

Hi! Isn't gravity just a smaller object moving toward the lower energy state created by a larger object (time slows down the closer you are to a massive object)? Why do we need a force carrying particle for gravity?

This is my first post so I apologize if i am in error anywhere. I recently had a thought that I have had trouble confirming. Based on the following assumptions. 1.) As you accelerate an object near the speed of light it’s mass increases exponentially. 2.) Mass warps space time. 3.) Spacetime...

How many time does a galaxy (same size as our milkyway) magnified the background ?

Does a body accelerating at 1g in outer space create a gravitational field around it ?

since the cosmological constant observed is that there is a small amount of energy in empty space, and in general relativity anytime there is energy there is curvature and therefore gravity, how to calculate gravitational field with dark energy and does it have any observable effects on matter...

in a nutshell what are the differences between gravitational and electromagnetic waves?

A question elsewhere got me thinking about the frequencies/wavelengths of gravitational waves. The most obvious source of gravitational waves we are finding is from merging black holes, so presumably the orbital period will directly determine the frequency of those waves, yes? So the...

Hi guys, I have a question that is simple but I do not know how to answer that. It is the following, where does the acceleration of 9,8 meters per second squared go when We're dealing with uniform circular motion? I know that We have the centripetal acceleration that is a vector change, but the...

That may seem like a silly question, but suppose the crew of an interstellar vessel wanted to measure the mass of their ship, perhaps to estimate remaining resources. Unless they have very well calibrated thrust and a very well calibrated accelerometer, the only option is to do so...

Are gravitational waves purely temporal? An object with no spatial velocity experiences gravity due to temporal velocity?

The removed mass is ##\frac{1}{8}M## My idea is to find ##g## from large sphere then minus it with ##g## from small sphere (because of the removed mass): ##g## at A = $$\frac{GM}{R^3}\left(\frac{1}{2}R\right)-\frac{G\left(\frac{1}{8}M\right)}{R^2}$$ Is this correct? Thanks

Recently viewed video about wormholes that required negative energy to create it. Suppose hypothetical aliens have discovered this technology. Spaceship enters in first point and exit at second. To prevent spaceship destruction they might have technology to smooth gravitational waves on exit...

Electromagnetic or gravitational wave carries energy and momentum from place to place as,I understand.Does it imply that such waves only can carry information and if their energy gets dissipated as heat, the information contained is lost. Is this information content is to be decoded by human...

Hello everyone, I know that GR equations are complicated and beyond my scope. But does GR give a simple gravitational equation: Force (as we know it) as a function of distance? (without any complicated tensors). - If yes. What is the equation? Does it give us something similar to Newtons...

I was wondering what someone standing far away from a planet with mass would see if he drops a clock towards the mass. And then vice versa if I was standing on the planet, what would I see. would I see the clock tick fast and then slow as it approaches? Thanks!

How does the Earth's reference frame "know" to experience the gravitational pull of where the sun/Earth barycenter will be in 8 minutes, rather than orbit around the spot where the barycenter was 8 minutes ago? The latter case seems required by the finite speed of gravitation, but coplanar...

My attempt: Let ##M_e## be the mass of the Earth and ##M_m## be the mass of the person. Let ##D_{EM}## be the distance from Earth to Mars and let ##R_e## be the radius of the earth. Defining these constants (leaving off units for brevity): Masses in Kilograms (G is not a mass but I'll leave...

It's a well known fact that acceleration due to gravity is independent of the mass of the accelerating body, and only depends on the mass of the body it is accelerating towards and the distance from it. One can prove this mathematically very easily. F=GMm/r^2 (equation 1) but also F=ma...

An exact gravitational plane wave solution to Einstein's field equation has the line metric $$\mathrm{d}s^2=-2\mathrm{d}u\mathrm{d}v+a^2(u)\mathrm{d}^2x+b^2(u)\mathrm{d}^2y.$$ I have calculated the non-vanishing Christoffel symbols and Ricci curvature components and used the vacuum Einstein...

Density of the Sphere = 3M/4πR³ Mass of carved out sphere = density × 4π/3 × R³/8 = M/8 The position of center of mass of The Sphere {M(0) - M/8(R/2)}/M-M/8 -R/14 So total distance between centers of the two bodies is R/14 + 3R = 43R/14 So now I found force between the Mass 7M/8 (left out...

Without this test,using only math, would you prove that left ball will comes first?

Black holes form. An undeniable fact. Let's imagine a massive shell collapsing under its own weight (the exact composition of the mass is not important, so just imagine to be a continuous mass with zero thickness). What happens if the process of collapse evolves? The time on the inside will run...

I haven't gotten anywhere. I don't find it possible to calculate this since Fg varies based on the Mass of the meteroide and because of that it will change acceleration. I thought about trying to remove m1 by making F=m*a the same as 𝜸(m1*m2)/r^2 since I think they are the same force. m*a=...

A question to physicists: What sort of real world scenario / image would *best* depict the increase in gravitational potential energy in a radial field? Would a rocket traveling through the Earth's atmosphere suffice or are there better alternatives? This image would have to be relevant to the...

Book says that correct answer is d) but I can't understand why. If the result of gravitational and centrifugal force is 0N then there is no force that would keep those objects inside the spacecraft orbiting around the planet. Or am I just completely wrong? Thank you for your help.

Why are gravitational waves able to move at the speed of light?

It seems to me that gravitational waves are ignored when inflationary physics are described. I'm not very well read, and honestly do not know so much about most of the physics going on with inflation. Still, wave mechanics matter, harmonics matter, and it just seems intuitive to me that in order...

Hi if I understand it correctly, this is the process to find freefall acceleration of a falling body. S=ut+1/2at^2 Initial time and displacement is zero so, S=1/2at^2 find acceleration a=2(S/t^2) graph for change in displacement over time squared a= 2(yf-yi/xf-xi) (f=final i= initial) I...

How do gravitational waves in spacetime stretch and compress solid matter such as the LIGO experiment. I ask this because the expansion of spacetime of the Universe doesn't seem to have any effect on the small scale ie the solar system.

i spoke to my proffesor about it but all he said was to put 1 in m1 and m2... for r^2 since it says to quadruple to just put 4^2 I asked about the G in the equation but he said not to worry about iit and pretend its not there...

Hi ! It catches my attention that atomic particles such as protons, neutornes, electrons and their respective subparticles such as Quarks are theoretically formed by high-energy electromagnetic fields such as gamma rays and then the gravitational field that would generate the mass of these...

Hi, I would like to ask for some clarification about the physics involved in the gravitational waves detection using interferometers. Starting from this thread Light speed and the LIGO experiment I'm aware of the two ends of an arm of the interferometer (e.g. LIGO) can be taken as the...

A popular theory is that black holes gradually leak information because of black hole evaporation due to hawking radiation. When black holes merge, a significant portion of their mass is converted into gravitational waves. If it's true that black holes leak information due to hawking radiation...

Here is my solution, which is correct. The tilt of the water at the top can be described in terms of ##x## and ##y## as ##y = \frac{2y_0}{L}x##. The height of the water at any given x is then equal to ##h + \frac{2y_0}{L}x## where ##x \in [-\frac{L}{2}, \frac{L}{2}]##. So the potential...