Modern and Theoretical Physics

Thought some of you here might be interested in this article: Impulse Gravity Generator ? This the same person that did the work with rotating superconductor disks that he said appeared to shield gravity to a small extent. There is a PDF link at the bottom of the page in link I provided that will give you his full paper on this. This work looks much better done than the last time. He was widely ridiculed for his “Gravity Shield” and looks as though he is attempting to answer any potential problems that could have effected the results of this work. Scott

I just found out about this from the recent news article about black holes. Is this something that is hypothesized or is it considered a pretty solid notion? I thought photons could not escape black holes. If this were true, how could photons exert enough pressure in the opposite direction to keep matter from falling in?

do you guys know anything about string theory? how would i explain it to a bunch of 13 year olds. i am doing an oral and handing in a written report on it for class, but i'm a little unsure of what exactly to say. any comments would be helpful regards, bunnies4ever.

Hi everyone I have a few questions for anyone or anybody so here they are: Is time travel possible or not possible? Will time travel be in our near future? Was einstein right or wrong that time travel will be possible or not? Are time travelers real or fake? I have heard that nothing can travel faster than the speed of light is this true? The speed of light is faster than humans, objects, and animals but what would happen if all three of these subjects you know humans, objects, and animals were faster than the speed of light and one more what would it look like to us?

I was reading up a bit about string theory, and the author (Brian Greene) mentioned that the strings are "2-dimensional". How can something be 2-dimensional without being infinitely thin? Given the technology was available, wouldn't it have some width?

when an electron and positron (or any particle/antiparticle) collide, you just end up left with energy, in essence, mass has disappeared, since both have positive mass. this is a bit confusing really, since all the other quantum numbers are conserved, such as charge, spin, lepton number etc... so why does, in the case of mass 1 + 1 = 0 ?

dear frinds i have some questions in electromagnetism and want ur help in answering them 1) in RL circuits as u close the switch the back or induced emf is a maximum value then it starts to decrease why theis happens? from the physical point of view 2)what is the physical explanation of faradays law of induction 3)what is the physical explanation of lenzs law

Today I went to a colloquium on neutrinos, with a lecture by the same guy who discovered supersymmetry. Here's some thoughts I had: Neutrino oscillations: tau, electron, and muon neutrinos all have different masses; so why isn't neutrino oscillation a violation of mass conservation; since electron neutrinos would gain mass? Dimension Five calculations in the Standard Model allow for violations of lepton conservation (related to our past argument involving their conservation if an electron was split) The Cosmic Neutrino Background, similar to the CMB... anyone have thoughts on how we might detect it? What exactly is happening besides neutrino production wit…

If an observer in a ship entered our solar system towards the Sun at .9999C it would still take quite a while to pass by. Would an observer in the ship even see the Sun or would its radiation be so blue shifted that it would be in the range of x-rays or gamma rays relative to the observer? As things were passed would they switch to red shifting where they could only be detected by radio or microwave antennas? Just curious. Just aman

What does everybody think of time travel? Regarding the possibilities and impossibilities?

Have you guys come upon this article or anything similar? If so, [or not], what are your thoughts? http://www.thestar.com/NASApp/cs/ContentServer?pagename=thestar/Layout/Article_Type1&c=Article&cid=1035777849035&call_page=TS_Canada&call_pageid=968332188774&call_pagepath=News/Canada

This is pretty cool: looks like a team of scientists created a substantial amount of antihydrogen: about 50,000 atoms.(link) I don't think I fully understand antimatter. What is the difference between antimatter and matter? If I had a box of each, how would I know the difference?

this is comedy: "Just as electrons are not a single particle, but composed of some 387 particles, light is likewise not composed of a single particle, as hundreds of particles are involved in the phenomenon called light." and this displays absolutely no knowledge of what red shift is: This should be obvious to man, as light spreads into the colors of the rainbow, and as his scientists describe the behavior of red light as Red Shift, where no such behavior is ascribed to other colors in the light spectrum. see what else you can find on this site, a treasuretrove of bollocks.

Okay this is a question... What is the minimum required power of a laser (in standard wavelength ~650nm) to cut through steel quickly? In addition how much power would be required to run this laser? Which kind of laser would be best? (ie HeNe, CO2, etc) I'm kind of interested in building a "poor man's laser" but as with everything "if it's worth doing it's worth overdoing.":D Thanks.

I know that operator product expansions exist in Quantum Field Theory (Wilson-Kadanoff expansion) and in conformal field theory. I'd like to know if anyone knows a reference (or anything) about operator product expansion in many body quantum mechanics? Hopefiully my question is not too naive....

Very nice chart here.

I have a problem i just can't get my head around and wondered if anyone here had any ideas. We have a set of LEDs and are required to find out what the composition of them is. They are made up of a mixture of Aluminium, Gallium and Indium but we don't know in what proportion. There are 3 different LEDs that give three different colours; red, yellow and green. These 3 all have a different mixture of Aluminium, Gallium and Indium. Is there any way that anyone could suggest to determine the exact composition. So far we've found the band gap energies via several methods. Spectroscopy and IV characteristics have both given us values for the energy gap …

Whats the scientific position on gravitrons?? I thought gravity was like a curve in spacetime...or does it CURVE spacetime? If there are gravitrons, do they ahve an effect on each other?

In a statistically mechanical intergalactic space with (noninteracting) hydrogen atoms of average density 10^-5 atom/cm^3, with age 10^17 seconds, radius 10^28 cm, and temperature 3 K, what is the maximum radius void of matter to have existed given those spacetime parameters? That is, create a random walk model to describe the maximal absolute void volume that classical intergalactic spacetime has ever allowed.

Has anyone heard of this? I remember reading something recently postulating that the speed of light is actually slowing down over time. Anyone know if there is actually any physical evidence for this? Also, if in fact, it were; what would be the implications?

Whats the difference between individual and group velocity? This question comes in response to faf's news article "According to the latest research published in Applied Physical Letters, MTSU scientists used a setup that cost about $500 to set up a system that brteaks the speed of light (group velocity, not individual particles). " So...is this a big thing or not?

A Nobel Prize was awarded in 1996 because a scientist cooled a gas to millionths of a degree above 0 Kelvin. The atomic structure of the elemental gas collapsed into a super molecule. They never said if it returned to normal upon adding energy. They theorized it would have collapsed farther if they could have cooled it more. If I cooled a desk to 0 Kelvin and it collapsed into a point. Then I reheated it would I have a desk? Just for thought. Just aman

Faf and I had this discussion quite some time ago, just want you guys input. e=mc^2 photons have energy, and energy = mc^2. So if the mass is 0, wouldn't the energy be 0?

http://www.mkaku.org/tt.html This article shows several perspectives on time travel. Very nice and worth reading!

Australian University research group have teleported a messge in laser beam. They have maanged to take apart an encrypted laser beam and simulatenously rebuiild a replica one meter away using the process called " Quantum Entaglement" Basically they can take billioms pf photons , destroy them and recreate them in another place. DEF: PHOTON: a particle of electro-magneitc radiation energy. Personally i believe another 100 years it will take, and we shall eb able to teleport people from point a to point b, sci-fiction is becoming sci-reality, or perhaps sci-nightmare? End of post.