Effects Definition and 963 Threads

First of all, I'm having a difficulty in defining what a static spacetime is. Does it presume that the objects with mass in the system are just sitting around and doing nothing, with no motion, relative to our frame, so there can be no motion and change in curvature of spacetime through time...

I have limited physics knowledge, but I have always been interested in the physics and I am an industrial radiation safety officer with an engineering background.Have there been any experiments in respect to measuring half life with large variance in gravitational fields? Although half life may...

I would like to show the details of the situation before asking the specific question so: Conditions:The attached sketch shows a situation that is slightly after the start, since the balloon is shown with air already inside. The question that I will ask is about a situation where the balloon...

This is a pretty hot and rarely understood topic in the automotive / racing industry. Sure, everyone knows spinning mass on a car is worse than mass sitting in a car. its effects are greater, but by how much? Besides the benefits of the unsprung weight having less gyroscopic forces...

What is means by transverse and longitudinal effects in lasers. It is mentioned in some material I am reading, but I was unable to find what is meant by this. Like here for instance...

Lets assume we have a starship which is flying from Earth to star XY which is in distance for example 100 lightyears. The computer of that ship is programmed that way, that it maintains acceleration 1 g. After some time the speed of ship reaches some significant part of speed of light and to...

Can anyone tell me how significant are entrance effects for a fluid entering a circular pipe? Like the fully developed region, laminar region etc. comparison between these regions...

Homework Statement A forklift truck of weight W has dimensions shown in the figure below. Its centre of gravity G is mid-way between the front and the rear axles. When a uniform block of weight w (w < W) is placed on the front forks as shown, how the load on the rear axle will change...

Hello- I am running a simulation of a simple brazed copper assembly; brazed at 1050°C. I believe the Young's Modulus will drastically change after brazing at this temperature since the annealed state is "dead soft". My analyst colleague is using an annealed value for E of 15E-6 psi, which...

How does friction affect the type of rolling motion of an object. For instance, does having more friction than the required friction for rolling cause the object to spin?

I have two questions related to inflation, and wonder if there is an answer to any of them: 1- If there was inflation occurring faster than light at any time, so that the universe's radius is larger than aprox. 14 billion light years, then shouldn´t we be seeing some galaxies more than once...

On the ISS, special relativity dictates the station's clocks run slower than clocks on Earth because of the high velocity, but general relativity dictates that the station's clocks run faster than clocks on Earth because of the lesser gravity. Which effect is predominant, and do the station's...

I can fairly understand the concept of gravity as a curvature in space time in general relativity, but so far I could not understand completely the tidal forces explained by the curvature of spacetime. When the moon is on one side of the earth, the oceans on this side come closer to the moon...

Ever since Einstein showed us that time is relative, and that there is no such thing as independent time but a space-time fabric, and since we’ve got experimental results about the dilatation effect that speed and gravity/acceleration have on time: Is it OK to say that the universe started 13,79...

1.What would be the effect of the following factor on the maximum power that can be transmitted. (give reasons for your answers) Increasing the included angle of the pulley groove. 2. What would be the effect on the following if the load torque is increased and the speed maintains constant? The...

Hello The textbooks about nuclear physics I have read don't explain too much about the Yukawa's model. For example, the textbook Structure of the Nucleus -by Preston and Bhaduri- finish the Yukawa's model with open questions about the "mesonic effects" by virtual pions. And my doubt: are the...

I'd like to know some specifics about the biological effects of X-rays on living tissue. I am aware that X-rays, along with other forms of ionizing radiation, have stochastic effects of DNA but what is the data regarding the non-stochastic effects of intense X-rays? In particular, can sufficient...

I understand obviously that the image and light will be kept but it will become a little bit green. But what happen in a very specific way especially about absorption??

Hi Everyone, i was wondering about how graphite flakes formed in Grey cast iron, and how Nodular or Spheroidal graphite formed in Ductile iron, and also how magnesium enhanced the spheroidal formation of graphite in Ductile iron, please elaborate your explanation (you may answer it in terms of...

Explain the effects of AC power supply parameters-voltage and frequency?

Questions about how useful surge protectors are. 1) Why is the circuit breaker not effective in acting as surge protection? 2) At home if for example I have my computer connected to surge protector, and surge protector connected to wall outlet. Then there is a sudden voltage spike in the...

Hello, I am curious regarding the forces other than the pressure created by combustion process in IC engine.Whether inertia and friction affect worth considering or not, I want to know magnitude and nature of these forces and their effects On efficiency and performance.Thank you...

I had a chance to go through a lecture on general NVH issues in Automobile engineering. The faculty used to say "first harmonic", "second harmonic" etc. during the course. I found in wikipedia to know that harmonics are multiples of frequency of vibration. What has harmonics got to do in NVH...

I'm building a linear actuator and I don't have much experience with magnetic circuits... A rough sketch of what I'm building is attached. I'm trying to determine if the materials I'm using for the shaft and shaft collar will have a detrimental effect on overall force output. Right now, my...

Ok small bit of a problem which I have been experiencing. I am using an industrial size plasma oven by advance plasma sytems. This plasma oven operates at an RF of 1600 watts for approx 8 minutes for the duration of the plasma cycle. It pulls down to a vacuum of 450mTorr and use oygen as a...

If, when the universe was young, and you had all of today's universe worth of matter compacted into a space only a few thousand/ million light years in diameter the gravitational effect on time would be much stronger than it is today. Does this affect our calculations on how old the universe is...

I have been thinking for the past couple months on how the expansion of the universe effects the matter and energy within it. Please read every line, skipping any part of this thread will lead to confusion. Hopefully someone can shed some light on this amazing new question of universal expansion...

I am not sure if this question even makes any sense, it just popped in my mind while reading a book on special relativity. Suppose an observer throws a ball upwards, now at the time of throwing, both the observer and the ball have a horizontal velocity same as the instantaneous velocity of...

I'm looking for an equation that can give me the the amount an explosions force dissipates based on varied gas densities. I've already posted this in r/AskPhysics, r/AskScience, and r/Physics, and thought posting it here might give it better exposure. Oh, and before someone asks, this isn't...

Homework Statement How do sterics affect basicity? Homework Equations Sterics has to do with kinetics. Basicity is a thermodynamic property. Nucleophilicity is a kinetic property. The Attempt at a Solution So is the answer "sterics don't affect basicity"? I can't see why sterics...

So I was thinking about the space time field and trying to wrap my head around how it is actually bent around a mass. Has anyone thought of thinking about the bending of space time around a mass like multiple orbits? Almost like in the way we describe the orbits of an electron around a...

I was wondering if somebody could let me know if wings inside of a closed environment (tube of sorts) with air flowing over them would generate lift, or if the air flowing over them would be directed downwards onto the bottom of the tube, canceling any lift generated by the wings? The first...

When a proton collides with a proton say at the LHC, is vacuum field theory used? It seems like you shouldn't have to include temperature effects since there are only two particles. But then again, all experiments take place at finite temperature, the ambient temperature of the room? When a...

Hi everyone, I just wanted to share this really cool game MIT Game Lab made, it's called A Slower Speed of Light: http://gamelab.mit.edu/games/a-slower-speed-of-light/ Sorry if this is already commonly known among people interested in SR (probably is- but maybe there's a few people who...

http://arxiv.org/abs/1407.0989 White hole anyone?..^^ "...intense gravity creates a horizon, but it is not an event horizon. It is locally like an horizon, but not globally. So, matter is trapped for a while, but not forever; it is called sometimes a “trapping” horizon."-CR

SR is a theory based on flat space-time, and all of its effects are there in a flat space-time framework.My question is, how is SR compatible with GR, since GR uses curved space-time? Or to say it better how are time dilation, length contraction and relative simultaneity manifested in curved...

I was just thinking about this, and from a perspective of an inertial frame, it's easy to see how distances contract, times dilate, simultaneity varies between observer and the speed of light is exactly c in each case. But what about non-inertial frames? In the presence of gravity almost...

I am looking for an equation that correlates material failure and collision speed; so that I can better understand the effects of size and speed on model airplane crashes. Is there an equation that correlates an object's length and speed to material failure, for one-dimensional elastic...

Homework Statement A small solid sphere of mass M0, of radius R0, and of uniform density ρ0 is placed in a large bowl containing water. It floats and the level of the water in the dish is L. Given the information below, determine the possible effects on the water level L, (R-Rises, F-Falls...

Hey all, Random question, but is there anyone in the microwave/radio frequency industry that also wonders the biological effects of constantly being exposed to it? From what I have been told, the effects are not scientifically sound, and as such, the majority of people I have met treat that...

A recent study of eighteen rhesus monkeys provides clues as to the effects of birth order on an individual's levels of stimulation. Could someone please explain the bold part?

Hello, My question is out of curiosity and pertains to transient currents and their possible effects on any electrical equipment. For example, The various electrical components(infotainment systems, headlights, radio etc) in a car are “grounded” on the chassis, If a live wire from a electricity...

Let's say there's a current going around in a superconducting loop in vacuum. Then the loop gets buried in huge amount of matter, which has the same magnetic susceptibility as vacuum. (when not affected by gravity the matter has the same magnetic susceptibility as vacuum) Will the magnetic...

Light of constant intensity is incident on a metal surface, causing electrons to be emitted. State and explain why the rate of emission of electrons changes as the frequency of the incident light is increased. My answer: As frequency increases, energy of photons also increases, so more energy...

Are there any other measurable danger other than the following Short term (short half life) I -131 Do not react with air Forms aqueous solution with water Long term (long half life) Cs -137 Forms cesium oxide with air, can be carried away by air Forms aqueous solution with...

So basically, my physics class has begun focusing on SR. And i just wanted to clarify something. I have been referencing: http://physics.mq.edu.au/~jcresser/Phys378/LectureNotes/SpecialRelativityNotes.pdf On page 23, it states "A clock will be observed to run at its fastest when it is...

Sorry, if this should have been in an homework section. Anyway, I was wondering what effects backstreaming has on the pumping speed of a diffusion-pumped system. I can see how you would not want backstreaming to maintain clean system, but would it also affect the net speed? Also, does anyone...

Greetings, Long time reader, first time poster, so try to go easy on me :redface: I'd love to get a sanity check on something my father discovered and I've been helping him refine. We're not professional physicists, so we've had to take to the Internet to discuss and collaborate. Before you...

I know that a smaller width of a gap would lead to "more diffraction", and diffraction effects are at their peak when the wavelength of the diffracted waves is equal to the gap width. But what if the gap were smaller than the wavelength? Can someone describe the diffraction pattern (if any) that...

I'm trying to understand inflation (in the cosmic sense). I know that ultimately that's a subject that involves both quantum field theory and General Relativity, but I'm wondering to what extent it can be understood from the point of view of classical (non-quantum) GR. If you have a classical...