Effects Definition and 1000 Threads

Hello All I'm new to the forum and have a question. I was looking at the time dilation function and noticed that negative time would be described with imaginary numbers and be a kind of anti-time, albeit that rest mass can not be pushed faster than the speed of light but for the sake of...

Hey guys, I understand that 'ballistic re-entry' is usually used in the context of drag only with 0 lift, but if I were to look into the effects of lift how would I go about resolving the forces acting on a body at each instant to determine the instantaneous body acceleration ? My initial...

If we put two identical quarter-wave plates together what will be the resulting plate? How would it be different from one of the quarter-wave plates?

As I was lying awake staring at the ceiling last night, I wondered what the effects of sleep deprivation were. Would you experience decreased coordination, memory loss, ect? A timeline would be useful, i.e. Day 1-lalalalala, like that. I have heard that the CIA once used sleep deprivation as a...

How does radiation (e.g. x-ray) affect the flow of electrons in an electric field? More specifically how does this affect for instance the resistance of a resistor. Thanks in advance. :smile:

Hey @ all, when windowing in DSP in time domain one multiplies all recorded time samples with a weighting factor (hanning, hamming, etc.), followed by a Fourier transform (FFT) to reduce sidelobes in the spectral domain. But now when thinking about starting up in frequency domain where I...

When pressurized heated air is released does the temperature drop down below ambient temperature, or simply finds temperature equilibrium with ambient air?

Hi PF I was wondering about the problem of quantum gravity, and maybe the reason why we struggle so much with a formulation of quantum gravity is, that spacetime itself is the source to all quantum phenomena. The evidence is, that with the standard model, we describe the quantum phenomena...

How does the angular velocity change with increase in the mass? For example : if there is a shaft rotating at 1500 Rpm , then if a disc of 5 kg is fastened , does the angular velocity of the disc will be same as 1500 RPM , and what happens to the RPM if the disc mass is 50Kg.

Hi all, If one were to consider a classical particle in a box of length L in Minkowski space then clearly the time taken to go between the walls of the box is L/v with v velocity. In the GR case with some metric coefficients A(r) and B(r) (spherically symmetric system, say) it's clear that...

I saw this video on a car cleaning product. In it he talks about the improtance of pH balance and how it effects metals. I'm not a chemist, and it's been a long time since I took undergrad chemistry. You can see he does a little lab experiment with the metals in the various pH cleaning solutions...

if i consider space time to b a fabric as considered by einstein then expansion of this fabric leads in two direction 1-if the fabric has high elasticity then the curvature of space caused by the a massive object will keep on increasing,thus the flow of time will be faster...

Hi all, I've just been thinking about something today which I freely admit I've not got the knowledge to actually comprehend at this time (my physics studies don't start until September!) and so it might actually belong in engineering or it might just be a load of nonsense that I've gotten...

Hello all, I feel somewhat strange posting on this forum because I'm majoring in biology and we're supposed to be the enemies of physics, but I've come across a question that I can't seem to find an answer to; this is actually in regards to independent research. Does instantaneous or prolonged...

If dark matter really does exist everywhere, and is constantly passing through our bodies, why doesn't this extremely dense matter affect regular matter? How are the atoms of our body not pulled by dark matter's gradational field? Also, if dark matter is thought to exist because stars in...

Can/do relativistic effects explain select quantum "phenomena" Can/do relativistic effects explain select quantum "phenomena"? A photon (a mass less "particle" that travels at the speed of light) experiences space-time in a different manner. A photon does not experience time. Would the sun...

I'm an amateur, but was wondering if you experts can help me wrap my head around gravity velocity and time; and the universe. If as gravity increases time slows down, isn't time faster on Earth than on the sun? And faster, still in interstellar and intergalactic space? Also, if the...

Hi everyone, I'm working on random materials which are coincidencely oxides and showing semiconductor behaviour... Some of these are metals and i suddenly realize MOS (which are practically everywhere). I know them, i know how they work and behave still i can't get to understand the effect of...

How does lightning cause a voltage spike? Is it the changing magnetic field caused by the lightning current that induces an emf in the power lines, or are electric charges deposited on the actual lines (like a battery pushing charges). Is it possible for the emf of the lightning to cancel the...

According to Einstein's General relativity, gravity is known as a curvature of space-time fabric. I watched a video clip on youtube and it said that gravity is not really a force but a shape of space and time. Then here comes a question-if gravity is not a force and just a curvature of fabric of...

My Achilles Heel has always been motivation. I was wondering if taking nootropics is a viable solution. Are there any (general) side effects?

Homework Statement A sound goes up one octave, from 256 Hz to 512 Hz. What happens to the, period, frequency, amplitude, pitch, and speed? (choices are increase decrease or stay same) Why? Homework Equations N/A The Attempt at a Solution N/A

1. Suppose that Cepheids did not exist and there were no other standard candle technique that worked at the same distances. Which statement would be true? a. We would not be able to measure the distances of distant galaxies. b. We would still be able to measure the distances of distant...

Considering that most of the planets are opposite to us, excluding Saturn and Pluto, could that have anything to do with major earthqauke in the last couple of years? Just a thought.

I was wondering how waves of the non-ionizing part of the electromagnetic spectrum differ from each other besides mere frequency and more specifically with respect to possible biological effects. How does exposure of a human or other organism to for example radiation from visible light differ to...

It has occurred to me from the statements in various threads that I may be misunderstanding the effects of dark matter, so I'd like someone to either verify that I DO in fact have it right, or that I am mistaken. MY understanding is that dark matter: (1) has a gravitational effect on...

how does salt turned into an engine affect?

1. why does gas expand to fill a container when there is no increase in temperature or any force applied to it? ( I am confused with the rising effect of gas in air and the expanding effect. how can we distinguis it?) 2. how can we determine the limitation of gas expansion when there is no...

Hello, In the design of electromagnets, why does the length of the solenoid matter? The magnetic field inside a solenoid, given by B = \mu n I , depends only on n, the number of turns per unit length, and not on the length itself. I know that the equation above applies only to the case...

I have 2 gyroscopes that are aligned on a common plane. The first one is larger than the second and the second resides inside the first. The first one is proportionately less dense to account for it's size and therefore, both discs have the same kinetic energy. Also both gyroscopes are attached...

Not long ago I was arguing with someone on the Internet (where everyone is wrong) about impact of quantum effects on macro scale objects. Imagine ice-hockey table (one with almost no friction) with number of pucks on it. If you'll hit one of them it is safe to say that pucks' paths are very...

Sorry if I sound amateur, but I am. I've recently been wondering about the effects of speed on time dilation. I have read that the closer you get to the speed of light, the greater the effects are. I know that movement is relative, and speed is defined by the observer (I think). So I was...

I was wondering why it is when you use the electricity from an electrical generator, it bogs the generator down? Shouldn't the draw off of electricity negate any sort of back flow there by making it easier on the generator to function?

I have a question about of light waves. Moving at high speeds toward or away from visible light could be the difference of experiencing that light as violet or red. Of course this experience is due to the photoreceptors in the eye seemingly experiencing a shorter or longer wavelength. My...

Hey, my first post on here, just wanted to ask how to calculate the effect of a motor, and a switching current in the wires supplying the power on the surrounding electronics. The two motors will be supplied a PWM signal of 20Khz frequency, 5amp, 7v2 at 80% duty cycle. This is part of a...

i saw in car batteries in electric vehicles one can get more cycles (discharging them and recharging them) if one does not discharge it all the way. ie, its better to charge often even when it does not need them. but i had heard that for my phone battery it was better leave it charge all the way...

I have a question about using NA (naturally aspirated) intake plenums on turbo charged cars and the detrimental effects it may have. Here is a standard NA plenum for an rb30 engine Here is a turbo plenum for an rb30 engine The difference is with the turbo one the plenum (large...

if the Earth stops rotating , what will happen to the apparent value of g on its surface ?

FYI - Consolidated Guidance: 10 CFR Part 20 — Standards for Protection Against Radiation (NUREG-1736) http://www.nrc.gov/reading-rm/doc-collections/nuregs/staff/sr1736/ I expect there are lots of questions about radiation effects and radation protection. So please post questions or...

More specifically, on acetylsalicylic acid (both crude/made in class, and commercial/store-bought), and salicylic acid. Please hang with me, I'll get to my question in a second. I did these tests: Crude aspirin w/ iron (III): Translucent, light peach in colour Crude aspirin w/ iodine...

What do grad school acceptance committees think about withdraws on a transcript? I'm taking elementary linear algebra just for fun (not required at all) but I find that my physics coursework has a near monopoly on my time. I would really like to withdraw and focus on E&M, modern physics...

Homework Statement Homework Equations What happens if you take into consideration the mass of the pulley, the mass of the string, and the force of friction between the string and the pulley when you are doing a Fletcher's trolley question? The Attempt at a Solution i know that by taking...

I have an assignment on movie magic in which I have to pick a scene from a movie and analyse the physics (including calculations of physics in movie, description and calculations of correct physics etc.) Problem is, I haven't picked a movie yet :frown: I was going to pick 2 different scenes...

When we connect a wire to a negative side of the battery, electrons flow from the negative terminal to the wire in order to make the electric potential same. That only happens for a short period.(the other side of the wire is loose) Having said that, what would happen if we connect just one...

arXiv:1101.4890 (cross-list from gr-qc) [pdf, ps, other] Title: On the quantitative interpretation of dark energy by quantum effect of gravity and experimental scheme with atom interferometer II: the inclusion of general relativity Authors: Hongwei Xiong Comments: 18 pages, 3 figures...

Can anyone tell me the physical law which is behind certain physical effects? 1. Resonance 2. Adhesion 3. Heat strain 4. Lever effect 5. Surface tension 6. Cutting/Bending 7. Evaporation 8. sublimation 9. Weissenburg effect 10. Torsion It would be really helpful for my research...

1. A tire of an automobile has a gauge pressure of 30 psi at the top of a mountain, and the air temperature inside the tire is 300K. The atmospheric pressure at the top of the mountain is 1.7 atm. The car is driven down to sea level, where the atmospheric pressure is 1.0 atm and the air inside...

First let me apologize for asking these questions. So much has been devoted to discussing the expansion of space both on the internet in general and this forum that the answers to my question are probably out there, but there is a lot to wade through. A lot. I found this forum and thought...

I'm only talking about galaxies far enough away where the only significant motion between us and them is caused by the expansion of space itself. When we look at a faraway galaxy, does it appear to be as far away to us as it was at the time it emitted the light that we're seeing? Or does it...

Homework Statement The experiment we did was pretty basic, it was a copper box with five different metal rods (unlagged and of equal lengths and diameter) welded onto the bottom, on the bottom of each were pins stuck with petroleum jelly. Hot water was then added to the box and the order at...