Classical Physics

Since neutron stars contain only neutrons, which are electrically neutral, the large magnetic field strength cannot be due to moving electric charges. Instead, it must be caused by the large mass and large rotational velocity of the star. If rotating gravitational fields cause magnetic fields, that would be the link between gravity and electromagnetism. From B, m, and [math]\omega[/math], the magnetic field constant [math]k_B[/math] can be calculated. Here are the calculations: [math]\text{1 Tesla (SI unit T) = }10^4 \text{ Gauss (G)}[/math] [math]Mass=1.4 M_{sun}, Radius=10 \text{ km}, \text{Spin rate: up to 38000 rpm}[/math] [math]Density \sim 10^{14} g/cc, …

Some metals are not magnetic I had a hunch that they might use electromagnetic induction rate of change of flux linkage etc but does this work for gold etc

I understand owing to or at least partly owing to f = ma in a vacumn all object free fall at the same speed/ velocity. So a = f/m so a mass of 10kg and a mass of 1kg so a = 10 * 10 / 10 = 10m/s. and a = 1 * 10 / 1 = 10 m/s. Which confirms the same accelerstion for both masses. IF we take gravity to be a force like a spring and the same masses on frictionless wheels representing a vacumn. If we put the same tension in the spring for both masses. It feels as if the lighter weight acted up by the spring in a horizontal direction accross the floor will move much more quickly than the heavier weight. In the same way as if someone shove…

We know that light does bend around a mass under the General Theory of Relativity, but why does light also bend under Newton's Law? and how is it calculated?

Hi everyone, I have a question for you about the effect of air pressure on damping of water waves. Imagine a container full of water. By dropping sth into the water I create waves and measure the time it takes for these waves to damp out. Now if I repeat the same procedure but this time the container is in a pressure chamber in which air pressure is significantly increased wrt the ambient, would it take the same amount of time for the waves to damp? Looking forward to hearing your opinions. Thanks.

what is the energy of a photon coming out of a standard everyday bar magnet? what end of the electromagnetic spectrum will it be in?

Hi everyone, this Thursday I have my Physics test and doing some exercises to practice I've noticed that in "rotational exercises" even though External Forces and Torques are = 0 you loose kinetic energy, for example when you have a rotating disc and then you put another one on the top of it, you loose angular speed because you gain mass but I am not sure of is how to explain the lost of energy. I'm guessing it is about the internal forces but I'd like someone who really knows to tell me the why, I'm not sure if I made myself clear with the question thank you guys!

Dears, Few months ago I had chance to post topic here about a non stop engine model. Now it has been improved and works well, and I wold like to introduce my new model here. 1. Tools and facilities: - The main component of this model is a wooden toy with dragonfly shape. Its head is a rectangle which is curved upward, with long tail - A sharp pillar - A medium sizes magnet (In attached screenshot it is the round and black piece) - A tiny magnet 2. Model - Stick the tiny magnet under the tail of dragonfly shaped specimen. The gravity of magnet makes this specimen settles down toward the tail. - Then, touch the sharp peak of the rectangle head of the specimen ver…

The temperature in my kitchen is about 22 centigrade, in my refrigerator about 4 C. Sometimes I open the refrigerator and take somethng out, then close it and after some seconds I open it again. And then I must apply much more force to open the refrigerator door. It means that opening the door for the first time lowered considerably the pressure in the fridge compartment. Why is it so? As I understand, when I open the door for the first time the hotter air from the room enters the fridge compartment and the pressure should rise and not fall. Please explain somebody Thanks

I have a doubt Like O2 expands in space..... what happens when a liquid(water) is thrown in space ? please clarify thank you

I'm learning about electromagnetic fields. My question is this: If a current running through a wire produces a magnetic field, why does current in computer hardware not strip data from the HDD? Is the magnetic field produced simply not strong enough? I'm not too sure of standard amperage in computer parts.

Greetings everyone! I've decided recently to build a fortran code that integrates the newtonian two-body problem, just to have some fun, and I was wondering, do you know of any software, maybe similar to gnuplot, that could read the output file but instead of simply drawing a plot, creating an actual animation of the motion? I know Mathematica had some facilities similar to this but: 1. I don't really like canned software. 2. The Kepler equation doesn't have (at least to my knowledge) an analytical solution so it's not as easy as just inserting the law of motion as a function of time in mathematica and let it make the movie. So what I'd like would be a te…

Hello, I have an interesting question about water natural convection without an external heat source. Say we have a high tower filled with water. The tower walls don't allow any heat to escape or enter the system. There is a constant gravitational force present in a system (g-force). At the beginning the water is all at the same temperature. The water naturally contains faster and hotter atoms and slower and cooler atoms. Because of the buoyancy forces the hotter atoms will have a tendency to rise and cooler atoms will have a tendency to sink. Is it correct to say that after some time the water at the top of a tower will become hotter than the water at the botto…

Is the mechanics of swimming by fish more energy efficient than boat propellers ? Was it ever proved/disproved/calculated ? (As per comparative construction of artificial caudal fin propulsion)

Hi, I observed this form on thin aluminum foil in just under two seconds, any idea what could cause this or if not if the assumed energy (was not heat in the environment) would be safe to be around. Thanks any speculation welcome.

Hello all, i'd like to know if there is any way that once can counter EMF radaition? Cheers.

I am not too strong when it comes to optics / lenses, but I am trying to figure out a way to get a person to be able to focus on something substantially closer than his or her point of focus. I understand this technology has been around for centuries (eyeglasses), but I am looking for a way to be able to focus on an image at a distance of about 1-2 inches from the eye. I think it has something to do with focusing the image at infinity, so the viewer doesn't have to constantly break his or her focus on the things around them to focus on the image. I think I may be able to do this by collimating the light using a fresnel lens, but I am still not sure. Can anybody o…

I need answers: In 1D Motion; What is the Magnitude of Displacement? (Definition) Magnitude of Displacement <= Distance (True/False) (+Explanation) What is the Magnitude of average/instantaneous velocity? (Definition) Magnitude of Average/Instantaneous velocity <= Average/Instantaneous Speed (True/False) (+Explanation)

So is it an attraction between objects with mass or is it a distortion in space-time caused from objects with mass? I'm confused :/

Hello all, I am an aspiring hard science-fiction writer, and I am looking for a place where I can get some expert advice as to the scientific plausibility of several ideas. I hope that it's okay to ask these sorts of questions here. First off, I have a story idea that's been bouncing around in my head now for a while; heavier-than-air airships. Namely, the sort that are large and very heavy, with thick metal plates for armor, crews of several hundred, and large spaces for very heavy cargo. I want to avoid the usual trope of anti-gravity, and so i was thinking about using electromagnetism. I'm setting this story on another planet, one that has a unique mineral that is…

Hi. Is there a method of calculation for a magnetic field distant from the magnet itself ? Say: ================================================X <--- long iron bar N magnet S ================================================Y <--- long iron bar A magnet at left end, of known field strength, intimately attached to polished surfaces, between long iron bars, produces a magnetic flux between far right points X and Y. How are the bars length a factor in the value of the flux at the far end ? For sure iron purity, spacing, thickness... have an influence too; but let's discuss only the length. Would there be a zero flux at an infinite length ?

As you all know, as far as scientific breakthroughs go, it's all about replication. If you have something real, then it must be replicable in labs all over the world. Cold fusion gained attention after reports in 1989 by Stanley Pons and Martin Fleischmann, then one of the world's leading electrochemists, that their apparatus had produced anomalous heat ("excess heat"), of a magnitude they asserted would defy explanation except in terms of nuclear processes. One might think from the popular press, that all the attempted replications failed. Most did fail; but not all. Since there was little understanding of what the hell was going on at that time, and t…

(image not to scale) I'm interested in creating a pair of 15 meter diameter parabolic dishes facing each-other at an outdoor event taking place on a dry lake bed with a set of stairs leading up to a platform that would allow a group of people to talk or sing in the focal point, allowing long-range transmission of audio between the two points over a relatively large range, preferably more than 200 meters. First off, is this even feasible at this distance? Will there be too much noise pollution or loss of voice quality or amplitude? The temporary structure will need to be assembled on-site. I believe sectional panels could be cheaply built using cloth, chicken w…

Where would the readings between a manometer and a magnehelic gauge give the least error, low or high pressure, and why?

Hi, Two surfaces are at 5 mm, the dielectric is an iron piece of 4 mm and 0.5mm of air. I put 100 V at two surfaces (like a capacitor), when the capacitor is charged I cut voltage source. Now, I would like to calculate the fields at surface iron piece and the charge in it. How can I do ?