Physics

we know the speed they travel at. we know how much mass they have (none). but how Big are they? they must have Some sort of Size in order to collide with things.

http://http://www.youtube.com/watch?v=trUfqGW5EHQ Have a look at the video. To his left of the guy, there's this small liquid tank. It's blue, and upon tilting, one of the immiscible liquid moves like a slow wave inside. Could you tell me what is it made of? And how could I create one myself? I just need the liquid ingredients, the mechanism isn't a problem. How is it possible to keep only one of the two liquids blue? The other seems like it's water or clear vegetable oil or something. Thanks a lot guys! <3 PS: I'd try mixing water and oil, but then either of the liquids can't be a different color. Plus, the oil would stay on top and water definitely do…

I currently have to do a project for grade 12 science were I have to create A person who can generate lightning. I have been reading alot about lightning but i need to way to explain how it could be generated on comand by a human. I is aloud to be far fettched as long as it envoles some science. I have also been reading about doornob shocks wich i thought could be used as a suttle version of it. if anyone has any ideas or links for me to read that would be reat Thank You PS hope this is in the right section

I've been learning about radioactive decay recently, and was wondering about some of the particles given off in beta decay. Do the neutrino or antineutrino, given off in positron emission and electron emission respectively, cause any noticable effects to surrounding matter? Do the presence of these particles result in other forms of radiation being given off?

I need help about Pt thin film or nano wire electric resistance. Because the thickness is in nanometer (~30nm), I think the resistance formula (R = p*l/s) is unusable. Please help me. If any material about that is available, please share with me. Thanks alot

Hi everyone, I'd be really appreciative if someone could clarify a few things for me. 1) If voltage is the potential difference, surely the 'difference' necessitates at least 2 different values, so there is something to differ. So, is the voltage the potential difference from one end of a circuit to the other? 2) Is the energy actually from the voltage? Or is it caused (transfered) when the voltage causes the charge to move through the circuit? thanks

Help, please. I read somewhere recently (I've forgotten, unfortunately) that light was actually invisible. The reasoning was a thought-experiment. Imagine that you're on a spacecraft in deep space. You're in the cock-pit, looking out. There's a powerful search-light on top of the craft, currently off, pointing in the direction you're looking, You look out at the scene, and then you turn on the light. Does the scene change ? The book suggested that it wouldn't. The beam of light itself would be invisible, you wouldn't be able to see it, and in fact you wouldn't be able tell whether the light was actually operating. Is this correct ? If so, what do…

Hi everyone, I've come accross this on the bitesize revision pages and it doesn't make sense to me, I was hoping someone would be able to explain it, the link is : http://www.bbc.co.uk/school... my problem with is is that the formula for working out the relationship between the voltages on a transformer and the number of turns on a coil is that they seem to change the formula round. First of all it is: Vp/Vs = Np/Ns then they write it as: Vs/Vp = Ns/Np which obviously isn't the same thing unless I'm missing something! They then add in a multiplication when there isn't even one in the formula!!! This is what the question is: "A transformer h…

Some gases, such as oxygen, helium, and nitrous oxide, for example, are stored, transported, and used from high-strength cylinders having very high internal pressure, perhaps several thousand pounds per square inch (psi). The witches' tale about such cylinders is that if one is tipped over and the valve broken off, the "jet propulsion" action of the released gas will drive the tank forward at dangerous speed. Can anyone confirm/deny the truth in this old tale? Imp.

I am looking for equations which would describe sound that a speaker produces. If I understood the principle how a speaker works correctly, there are a permanent magnet and an electromagnet. As alternate current flows trough a wire, the poles of electromagent constantly swich places. When current flows in one direction, the magnet repels the electromagnet, when the current flows in another direction, the magnet atttracts the electromagnet, so the electromagnet oscillates. The frequency at which it oscillates probably depends only on the frequency of the signal, but what the amplitude of the sound (loudness) depends on? Does anyone know any equations with expla…

First of all, sorry for my absence lately. With all this spare time I have at the moment (no school, no work) I think I've been directing too much of it to gaming rather than something constructive... say, science. Luckily, there was something that sparked my interest again. This has been bothering me for quite a while actually. While I'm not the kind of person that warms everything he can in the microwave, I sometimes warm sausages or meatballs or such. Well, today I had some meatballs in the microwave and after a few seconds of warming a sudden spark occurred between two meatballs that were right next to each other. This was clearly an electric arc, and the distinct…

Hello! I'm a guy who always needs to know how/why things work. If there are any members who are also members of the "gun culture", as I am, there are quite a few questions which have troubled me for years. One is the gas dynamics of small arms propellant (powder). Does anyone have knowledge of about when the gas pressure peaks when, say, a typical rifle is fired? Is it after the projectile (bullet) leaves the shell casing within the arm's chamber? Certainly, it must be before the bullet travels any appreciable part of the barrel's length. Another question: Smokeless powder "burns" at a rate dependant on the pressure surrounding it. But, the constituents, typically…

i was wondering if there was a type of metal that could be a 1mm cube inside of a 2cm cube and be able to have an visible effect on the big cube when it is on top of an electric magnet. The metal should not be attracted to regular magnets, atleast not enough where a person could feel a regular magnet attract to the 1mm cube inside the 2cm cube. any help or ideas?

I asked my physics teacher whether refractive index can be negative and he said that it can't be. But a group of scientist have made a meta material which has a negative R.I and it has made possible to make perfect lens which can focus at an area less than wavelenght of light. Do the laws in physics change often for example General relativity says it is imposible to travel faster than the speed of light but according to quantum mechanics it is possible for a photon to travel faster than the speed of light. LINK:- http://www.physicstoday.org/vol-57/iss-6/p37.html

Hi all, This morning, my glass stove top exploded into a million pieces. It was on at the time. Luckily, these things are made with safety glass, so the actual spray of glass was minimal. I'm thinking it may be some kind of build up of gas under the surface. I am curious to know what everyone may think! Thanks & regards, J

OK, I recently read an article on the internet about a bunch of scientist on based in Geneva who has created a machine which can, in theory, could re-create the big bang. The experiment will begin on the 27th of November 2007. The machine that will create this miniature bug bang is known as a Relativistic Heavy Ion Collider or RHIC. Inside the collider, atoms of gold will be stripped of their outer electrons and pumped into one of two 2.4-mile circular tubes where several of the most powerful magnets in existence will accelerate them to 99.9% of the speed of light. The ions in the two tubes will travel in opposite directions to increase the power of the collisions. …

Ok, the way I get it is this: One can work out Maxwell's equations in conductive or nonconductive media, and find a slower characteristic wave speed for electromagnetic waves, than the value for this speed in vacuum. I'm having trouble however to see past these equations; how does this work on a subatomic scale? What does this picture look like? Is there constant absorbtion/reemission going on, slowing down the passage of the photon, or does the photon interfere somehow with the electrons wizzing around in the medium, or...? Any advise is welcome. (First time poster, please be gentle )

Can space move relative to other space (or matter)? Since spacetime is influenced by the presence of matter, one might wonder if it could be influenced in other ways that either haven't been observed or have been and we're misinterpreting what we are seeing or... require highly advanced intelligence to cause. Could the inherent properties of space be manipulated, such as absolute zero, vacuums, causation, the existence of time in conjunction with it, the removal of one or more spacial dimensions from reality (or the creation of others, for that matter). What do we really know about space itself, rather than just what occupies it (the rest of science)?

I've read a bit about these standard theories, and quantum theories, and string theories, and this is what I have initially come up with regarding light. It has its own little section in the electromagnetic spectrum. Put all of the colors together and you get white light, kind of like broadband light. Is the light that comes out of a lightbulb considered to consist of photons or is the term "photon" really just a name for an imaginary elementary particle that meets the conditions required to be classified as an elementary particle according to proven laws of physics? If that is the case, are there other particles that stream out of the sun that cover other sections of…

Is there a substance or solution that can be put on paper or an object that would not be visible no matter how much you added on there. But you would be able to use filters to see the solution or substance. Anyone know anything that would work like this?

How do NPN and PNP transistors work. I understand n-type materials and p-type materials as well as the workings of a p-n junction in terms of doping and electrons and electron holes working as charge carriers. Jack

Hi. friends i want to know that what is hamiltonion(h).

I read an articly in the 28 April edition of New Scientist which sparked my interest. A particle physicist called Philip Mannheim put forward an interesting theory concerning the cosmological and gravitational constants. In essence, he seems to be suggesting that insted of trying to find an ever smaller cosmological constant (CC), it might be a better idea idea to use two different gravitational constants called Gnewton and Gcosmo. The former is used on small scales whilst the latter is derived from particle physics and is used on large, cosmological scales. Click here for the link: Particle physicist takes on Newton and Einstein A better and more detailed descrip…

Okay, a question has popped into my head and my teacher couldn't answer it. I hope it makes sense. The things I know A perfectly polished surface is one which is completely smooth. A white suface is one which emits all the light frequencies it absorbs. What I don't get What's the difference between a polished white surface and a polished silver suface eg. mirror? A mirror reflects any frequency that hits it but only at an angle of reflection whereas a polished white surface would absorb the light and emit in all directions thereby displaying white. My attempt at explaining Perhaps somehow the mirror doesn't absorb the light and then emit it. Maybe the light…

Will enough energy in a an appropriate environment, such as pressure, break apart any bonds matter may take, say for instance carbon dioxide. Also, if that’s true or not, is there a point in that regard in which elements themselves will begin to break apart, such as just carbon, giving enough energy in an appropriate environment again.