Physics

Water molecule are composed of atoms H2O, what about fire? What property is fire composed of? Photon? Electrons? Neutrons? Protons?

What is the gravitational time dilation at a point midway between two equal spherically symmetric masses m? For one mass, the time dilation is given by the tt component g00 of the Schwarzschild metric, and is equal to sqrt(1-2m/r)dt, where m/r is the potential. For two masses, however, I see two intuitive possibilities. First, you could simply take the sum of the potentials to get sqrt(1-4m/r)dt. Second, you could calculate first the time dilation due to one mass, then apply to that dilated clock rate the time dilation due to the other mass. This would be equivalent to taking the product of the two g00 components, with the result (1-2m/r)dt. These two values for…

Hey guys I have 3 minutes max to make this presentation. How are the facts in this? It's about how black holes work. Also if anyone has any cool ideas on how I can visually do an experiment relating to black holes or anything in the video please tell me. Also should I get rid of the part about field equations and replace it with hawking radiation or the photon sphere? Thanks! (Black solid with text saying 40 billion M☉) 40 billion solar masses. (Cut to me) That’s the size of the S5 0014+81, the largest known black hole in the universe. But did you ever wonder how they work? It all begins with Stars. In their core, nuclear fusi…

Hey everyone, is anyone able to check the facts of this speech I wrote? It's about the Schwarzschild radius and Spaghettification. Thank you so much! Black holes are an extremely heavy region of space where all sorts of crazy things happen in physics. To make a black hole, you need a lot of mass crammed into a very small amount of space. Imagine cramming the entire Earth into a ball you could fit into your pocket. One of the essential ways a black hole can be formed, is by having an amount of mass, say a star, and compressing it until it reaches the tipping point, collapsing into a singularity, the center of a black hole. This is called the Schwarzschild ra…

As mentioned in linked post I would like to discuss pseudo-objects. I couldn't find a definition online that wasn't about grammar, linguistics or programming. Maybe they are referred to by another name in physics. They are definitely not quasi-partjcles like phonons or 'holes' in an electrical conductor. One example would be a shadow cast by an object. If the source of the shadow and the surface onto which the shadow is cast are sufficiently distant from eachother, it is possible for the shadow to break the speed of light (even though the information that the shadowcaster has moved only reaches the shadow with the speed of light). It's a rather well known pheno…

We all know the importance of electric field when involved with brain simulation for consciousness. The thing is, how can one simulate a positive or negative charge inside a computer? It might involve the simulation of three dimensional space time and having that structure built inside a computer. But could an electrical charge exists without it?

How do you remove the presence of an electromagnetic or gravitational field from a macroscopic or microscopic test environment, or rather how can you prove that the value of the charge or gravity is locally zero? Let's take electromagnetism. Any test on Earth or close by will be subject at the very least to the Earth's magnetic field. If you create a shielded volume, how do you measure and prove there is no charge inside? Must any device that measures electromagnetic field interact with the field itself and potentially change it? Let's take gravity. Any test involving mass-ive equipment will be subject to gravity. Can you actually observe an absolute certa…

To block a given laser wavelength, proper goggles are to be used. Is the color of the lenses an indication of their performance ? Seen identical color chinese cheap goggles differing in wavelength specifications from one vendor to another, like they have no remote clue they are to be selling safety. Is there any true relation with the color of a filter and its blocking of a particular wavelength ? From a chinese vendor:

Brace yourselves for this is going to be a long post. Forgive me if this is not the right forum. I did not find a dedicated Materials Science or Solid State Physics forum. ----------------------- TLDR: I am trying to figure out the reason for AlSi's lower than expected from atomic misfit solid solution hardening (compared to AlZn, AlMg and AlCu). After about two weeks of digging I couldn't come up with any other explanation than Si's different electronic structure/being a metalloid. This article (http://www.springerlink.com/content/80408u1202556086/?MUD=MP; for coloured images http://crm-eac.imr.a...98%E7%A3%8A.pdf) reinforced my assumptions. Fast forward se…

I know there's a limit to energy production full stop in matter-antimatter pair annihilation, but what is the limit for just chemical energy? If I have a box of one meter cubed, what's the maximum amount of energy extractable chemically by the laws of physics?

So quark is the smallest particle available that can be seen. But how big is a quark and are they all the same in size? Can we have a big quark and a small quark? Please let me know, thanks

I wish I could ask these questions to Dr. Michio Kaku. But may be any body can answer. A dot is from zero dimension And the only that zero dimension contains. All possible projections of a dot at the same time on the next higher dimension create a line (1d). Same way all possible projections of a line at the same time on the next higher dimension create a circle (2d). And so on all possible projections of a circle at the same time on the next higher dimension create a sphere (3d). So do all possible projections of a sphere at the same time on the next higher dimension create another 4d object? And if so, is our universe is just one of the possible projectio…

Hey all, Just wanted to quickly mention that this is my first post on the forums so I'm not sure if this is in the right place, so please let me know if it's not. So basically, over the last couple of days I've been really fascinated by cold nuclear fusion and I can't understand why there hasn't been done more research into it. Why do we not research further into cold nuclear fusion? Also, when do y'all expect it to be a fully reliable source of energy? I can't understand why something that seems like it could be so helpful to the world isn't properly researched like it should be.

Fission is the opposite of fusion, what do you guys think, could it reverse the sun's energy?

Radon dosimeters work by 'sniffing' the air or by measuring its signature radiation ?

Sunlight after a prism, with several equal solar cells placed to receive each of the colors individually... Which color produces more energy ? Should depend on the spectral response/sensitivity of the cells; but is there a color yielding more energy ? Ultraviolet ?

I often hear that Rayleigh scattering is several orders of magnitude more common than Raman scattering; for instance here is one description. However, i have not come across any explanations as to why this is so. I presume it has something to do with Raman being an inelastic process. Does anyone know of any quantum or classical derivations showing why Rayleigh is so much more common than Raman scattering?

What I find utterly troubling is the multiplication of units. OK meters by meters makes sense (square meters) where the m^2 is something that you can represent easily. M^3 is volume, no problem. But in one of the tables posted above you encounter m^4. What is this? Similarly, square seconds (s^2), what is this? As if time (which is single-dimensional) could be squared. Also, if one looks at the Universal Law of Gravitation, one sees kg^2 in the formula. Mass multiplied by mass: mass squared, what is this? And so on, physics if full of these.

Miniature sustainable sun created by fusion? P.S "The power of the sun, in the palms of my hand" Spider Man

Hello, I have four questions. As it stands now, I don't have the necessary materials to test this myself, which is how I'd prefer to learn the answer. I still plan on doing this experiment for fun once I can acquire the necessary components. This deals with Lenz's Law. My goal is to maximize the time it takes for an object to fall through a tube. 1) Most folks demonstrate Lenz's Law by dropping a magnet down a copper pipe. From my understanding, the relative motion of the magnet, to the copper pipe, is responsible for creating Eddy currents, which, in turn, provide an opposing force on the magnet as it falls. My first question is this: Does spinning the copper tube crea…

I copied and pasted the following from Unexplained-mysteries.com: "Imagine an electromagnet, hooked up to some energy source. Attached to it by a frame is a piece of iron, at some distance from the magnet. The electromagnet is switched on for a fleeting instant, and then switched off again. Its magnetic field travels out in all directions as a wave, propagating through space at light speed, about 300,000 kilometers per second. When it reaches the piece of iron, the iron is pulled toward the electromagnet, and its own magnetic wave travels back to the electromagnet. But by the time the wave reaches it, the electromagnet has been switched off…so it is not attrac…

I have heard that we only have "time" as a result of motion (relative ,of course). But I have also heard ,(in contradiction) that there are events that occur which do not exhibit motion (eg spontaneous decay,random but statistically time ordered.). If we just address for now the areas where time and motion are seemingly directly linked (classical physics ,I guess) can I ask which of the two phenomena could be considered more fundamental ? Does Time cause motion or does motion cause our perception of time? Also ,in the cases** where we have time without motion,is it completely meaningless to talk about a frame of reference for the sy…

Why satellite frequency can't penetrate walls and radio can? knowing that the frequency (energy) of satellite is higher than the radio... Why ?!

Hello. The wave of a half submerged in water loudspeaker is received by a dry microphone as 1 Pascal sound pressure level SPL. Its diaphragm vibrates say 0.01mm in amplitude. The wet microphone diaphragm should vibrate a larger, same or smaller amplitude ? (Both microphones equal, equidistant and vented)

Did ancient people invent wood bike?