Physics

I'm having a discussion with my roommate. His opinion is that only lead will block x-rays. I think anything will block x-rays, if it's dense enough or thick enough. So I'm sure that aluminum foil will block the x-rays used to x-ray packages going through the Post Office. So I guess the question is "is it possible to wrap unexposed film in enough layers of aluminum foil to prevent exposure of the film by the x-rays, and if so how many layers?" Thanks.

In the search for the proposed gravity waves, I have not come across anything to date of any repeatable evidence from any source to indicate their existence. What I am proposing here is an attempt to induce waves upon this gravity field. It has been demonstrated that the sensitivities of present gravimeters can detect the change of the gravity field when a person gets under the unit when it is mounted upon a stand. That being the case, what if: 1: A rotating eccentric mass is placed near a stationary mass in such a way so that their mass centers periodically "center", thereby creating a greater common mass at that instant. 2: A mass supported as a pe…

Just want clarification on a point of interest for me. Is it possible for the soul to travel faster than light? I kid, but thats not a million miles from my intended question. Ive read that two "objects" can exist in a "quantum entangled" state, in the same book it was theorised that this could provide faster than light communication. In a nutshell, if one of our quantum maguffins where on earth, and one was 30million light years away, a change to our earthbound maguffin results in an instant change to our distant maguffin, from which the state of the earth bound maguffin can be extrapolated. Voila faster than light internet! However, i also remember …

Hello everyone, Ok the definition of heat says it is the total kinetic energy due to random motion of molecules. My question is it really the total kinetic energy. For example I know in inelastic collision heat is released. So is thermal energy really heat released in inelastic collison of molecules. Also if there is a bunch of molecules in a container and they all had elastic collisions, would there be heat in the container. Thanks !! Merged post follows: Consecutive posts merged Edit: Oh I think I worked it out. Tell me if it is right. The total kinetic energy of individual particles in an object is thermal energy (This is what gives temperature). In inelast…

Using a dual plasma rocket where one uses mater and the other uses anti-matter which combine in a mixing chamber just before the nozzle would produce the higher thrust like a chemical rocket with the economy of a plasma rocket - or would it? I know it is not currently feasible due to cost and storage problems with anti-matter but as a concept is it doable?

http://www.suntimes.com/lifestyles/health/2299276,CST-NWS-muons21.article

I know there is a theoretical minimum possible temperature but is there a theoretical maximum possible temperature as well?

Hello I really like the forum here, and apologies for any redundancy in previous threads. I didn't find any answers in recently posted threads and didn't want to bump a thread that was too old. I'm looking for a simple way to make a small electrostatic precipitator for use in a small enclosed box by giving a plate or interior of the box an electrostatic charge strong enough to hold on to dust-like particles of a relatively large size as far as particles go, about the size as some of the larger particles in household dust but with a little more density. From what I perhaps incorrectly understand, metals aren't suitable for this purpose because of their conductivity…

Hello everyone, If some test tubes are placed in a centrifuge to separate the liquid in them, does the separation occur after the spinning is finished. I can't see how the centrifugal force can act when the tubes are spinning, does it act after it finishes. Thanks

We can't reach it, correct? If we could then time would stop inside an object moving that fast, which is just weird. However, we can't reach 99.999....% of it either because 99.99999.... = 100 for the same reason 0.999... = 1. So how close can we get? Some of the many proofs 0.999... = 1 http://en.wikipedia.org/wiki/0.999... If you need more I can send them..... It is time people just accepted it and moved on.

Infinity has a lot of odd, or amazing, or impenetrable, properties. Infinity can increase or decrease, but still be itself. Except that, even though infinity plus n (or plus infinity) is still infinite, infinity minus infinity is zero, but infinity minus n (some “ordinary” number that our brains can deal with) is still infinite. Infinity can be multiplied and divided and still be infinite. But infinity divided by infinity is 1. Infinity squared is infinite, as is infinity to any power. So infinity to the power of infinity is still infinity (to the power of 1). It's a really big huge meta-number that can't be transformed like other numbers. It's outside the normal beh…

I would greatly appreciate if someone could provide advice or sources of information regarding design and construction of small turbines. I will be attempting to build one and would like it to be as efficient as possible. I have reviewed the basic formulas involved but cannot seem to find information regarding variables such as what gauge of wire to use, determining diameter of loops, viability of linking several small turbines in series, and other design criteria that must be addressed before materials can be purchased. Thank you in advance for any advice.

In the electromagnetic spectrum, as frequency increases, at what point do photons start being detected? And further beyond the ultraviolet, are they still photons? Are photons detected in the microwave region for example? How is light being the defined without photon action? Bob.

According to Fermats principle of least time, light travelling from one transperent medium to another transperent medium takes a path that requires the least time. this explains Snells Law that refractive index of second medium with respect to the first is sin i by sin r. Now if light is travelling from a rearer medium such as air to a denser medium why is it that it does not travel along the normal in the denser medium? That path would require the least time right?

I was talking with my dad the other day who has a Masters degree in astrophysics. We got talking about light particles and gravitons. My dad said that it is interesting that as a light photon's wavelength gets shorter, it starts to resemble matter. So I thought that if you could possibly give a photon enough energy (like the big bang) could you transform it into matter? My second theory. If the concept of the graviton is correct, I thought of a gravitons as very tiny ropes that extend from a piece of matter, and as soon as a graviton found another piece of matter, then the "ropes" would pull them closer together. But my dad asked how would these "ropes" know whe…

what makes metal turn red and glow when it is hot?

Hello everyone, If we have 2 eyes how come we don't see 2 objects. Then I found the answer was binocular vision, and both eyes concentrate on the same spot. Now my question is does the brain make the 2 different angles into one object or it always happens? I mean does something have to be done from the brain to merge these 2 views? Also I would like to know more about how the different view merge. Thanks

Imagine a foot ball player enters an elevator holding the ball.The elevator chain breaks and at that same instant he drops the ball to the elevator floor.will the ball ever fall to the floor?

A block and tackle system of pulleys is used to raise a load of 500N through a height of 20m.the work done against friction is 2000J. what is the displacement of the effort and the mechanical advantage of the system?

Hi, Can anyone give me a link to a good valid PDF on quantum field theory...

Hello, I recently got informed of how 3D 'angles' work, e.g. in a sphere type 3D 'radius'. However, I was thinking of how one would even think of a 3D angle? Or is there already a measurement for one? If one took a sphere and made it 4D would a 4D angle look as if a sphere in a sphere or a torus? (ironic because this is how the universe is hypothesized to look like ) Aplogies if the last sentence is irreadable (unreadable?), I don't know how to describe something if I don't know what it is

how do you derive that the refractive index of water with respect to air is real depth of an object placed in water/apparent depth as see from air?is this an approximation?

We all know about the classic red laser pointers that you can buy at the dollar store. I've recently built a high powered Blu-Ray laser on my spare time. It can burn paper, pop balloons, write on glow in the dark objects, light matches and much more. Its of the 405nm *nano meters* so its violet, not actually blue which is around 473 nm's, thus having a lot of people being mislead into thinking blu-ray is actually blue. I built my laser from an Xbox HD DVD Drive which is the external one. It runs on 3 AAA's at around 5 volts. It's much stronger then the laser pointers that you get at the dollar store. Its power measured in Milli-watts is around 90-100mW. I'm runn…

:-)Hello everyone, First of all I have to say I never understood what voltage is? So this is my final hurrah at understanding this I'm hoping to understand this using pressure analogy. Pin= 120 mmHg -----res1-------res2---Pout= 0mmHg This is the circuit. Now lets think water is flowing. Now I want to know when water passes through the resistor 1 and resitor 2 why is the flow rate the same. I mean if res 1 slows down water, then res 2 should slow it down further.Why is it constant? The way I have come up with an answer is like this, please tell me if this is right. Water has 2 energies = Hydrostaic pressure energy + kinetic energy pressure. So each tim…

Hello everyone, If there is a pipe and it has a certain hydrostatic pressure and then goes through a region of high resistance. Why does the pressure drop? If hydrostatic pressure is due to gravity. Gravity is always there right? Momentum, So in the pipe when the molecules are moving. The hydrostatic pressure is converted to kinetic energy. Hydrostatic pressure molecule, hits another molecules and it goes flying, while reducing the pressure of the hydrostatic molecule. My question is can't the molecules that are moving (kinetic energy) collide and give back the lost hydrostatic energy? Thanks