Modern and Theoretical Physics

Heisenberg Uncertainty Principle: The physicist Werner Heisenberg developed the Heisenberg Uncertainty Principle, which says that when measuring the physical state of a quantum system there's a fundamental limit to the amount of precision that can be achieved.For example, the more precisely you measure the momentum of a particle the less precise your measurement of its position. Again, in Heisenberg's interpretation this wasn't just a measurement error or technological limitation, but an actual physical limit.

Part 1: Kinetic energy is not ½mv². A 4kg object dropped 1m (meter) has the same amount of ½mv² as a 1kg object dropped 4m, because force times distance equals ½mv² for an accelerating mass. But a rocket accelerating the masses to those velocities requires twice as much energy as fuel for the large mass as for the small one. Therefore, both masses do not have the same energy; the rocket does not transform energy in proportion to ½mv²; ½mv² is not kinetic energy; and a gallon of fuel does not produce a consistent amount of ½mv². Part 2: Kinetic energy is mv. A 4kg object dropped for 1s (second) has the same amount of mv (momentum) as a 1kg object drop…

A fan of the LHC put together this excellent LHC portal, the announcement is in "news" forum. Its a volunteer effort--all this stuff is gathered and organized to make it accessible. I really like what he's done. Two things. There is a timelapse montage of webcam footage showing the assembly of the ATLAS detector compressed into 5 minutes. Real people and events, but flashing past extremely quickly and the whole thing gradually coalesces. But what is more educational is to first watch a couple of 6 or 7 minute computer animation tutorials, that peel off the ATLAS layers and say what each does. So how the various particles can be distinguished and tracked and t…

Hello! Sorry if this question is to basic but since I'm no physicist, this confuses me. I'm reading an article by Ned Block about consciousness ("Two neural correlates of consciousness"). In it, he tries to draw parallels to physics in how to find a criteria for consciousness. He writes: "...observed electrons can provide evidence about electrons that cannot in principle be observed, for example electrons that are too distant in space and time (e.g. outside our light cone) to be observed." I have pretty good understanding of high school physics but this I can't really understand. Can even something outside our light cone affect us? Could someone explain what p…

Hi! When quantum mechanics was established it allowed us to do things that we could not do before. What would string theory allow us to do? Lets say that string theory was confirmed -- tests showed the projections string theory made were correct and now string theory was accepted. What would it allow us to do that we can't do now? What good would it do us? Thanks, Rusty

It is Universally accepted that time is the manifestation of the fourth dimension. Even so Have you ever seen a 4-dimensional figure? Can a 3-dimensional figure move without time? Can a 2-dimensional figure move without time? I am proposing that time is not the fourth dimension, but a binding law that all dimensions must obey. Tell me what you think.

Hi, On many of the videos I've watched they show waving sheets hanging next to each other or, slices of bread, or spheres to represent branes. They also show different people or worlds or universes on each 'slice of bread' or 'wavy sheet' brane. In and around all of this there is talk of 'higher dimensions'. Also 'wavy sheets' branes clash together and bingo, big bang. I have come away with certain assumptions about brane theory I wish to confirm and some confusion I wish to clarify. I hate to do a post with multiple questions, just quote this and confirm or refute what you know or believe. * All the things we can detect or interact with are on the same br…

This is a collection of links to physics video lectures on the Standard Model from CERN - introduction to the Standard Model, Standard Model physics and beyond the Standard Model. http://www.infocobuild.com/education/audio-video-courses/physics/standard-model-cern.html

....a particle's caught. The situation: two black holes passed near each other, like so... Their event horizons slightly overlap, with a particle caught exactly in the middle of this overlap. Now the black holes continue on their merry way. The particle must leave with one black hole, yet at the same time it must leave the other black hole. Thus does it violate a scientific principle? For now there would be something able to escape an event horizon. A side question...if a photon were caught instead of a particle, does anything interesting/unusual happen to its movement?

In discussion between L. B. Okun, G. Veneziano and M. J. Duff, concerning the number of fundamental dimensionful constants in physics (physics/0110060). They advocated correspondingly 3, 2 and 0 fundamental constants. Why they not considering case,where only 1 constant Planck-Dirac's constant; h/2pi=1,054x10^-27ergxsec? This will be convincingly, because c- not contain mass dimension for triumvir and G overloading.and breaks 1/3 metasymmetry principle. Pay attention to dimension L=01 T=11 (L- discrete,T- continue) c ; L T^-1 G ; L^3 M^-1 T^-2 ; (1/3)^-2*M^-1 h ; L^2 M T^-1 ; 1/3*M …

Unified Field Theory - by Nassim Haramein i want to share the most interesting thing i have learned in life so far ... it is a unified feild theory which i believe is correct and soon to be published there is much more involved and the vid is 4 hours so be prepared here is the link http://video.google.com/videoplay?docid=6151699791256390335&ei=z_jrSq3qE4ygqQPD-dw5&q=Nassim+Haramein&hl=en&client=firefox-a#

Hi! Has anyone put forward the thought that closed loop zero-mass strings (gravitons) not on our brane might leave their influence either as they passed through our brane, or from beyond this brane thereby accounting for gravity that we cannot find matter for (i.e. Dark Matter)? Or, put another way, that Dark Matter is the apparent missing strength of gravity? Thanks, Rusty

I haven't had Calculus II since my junior year in high school. I'm pretty good at math, so I pick up math easily, and I'm not too worried about multivariable calculus as long as I review some calc beforehand. My question is that I want to take it because I'm taking Modern Physics next fall. I'm in Algebra-based Physics I now, and I will move to Algebra-based Physics II next spring. Do you think this would be a good idea or just a waste of time? Also, does Multivariable Calculus help for Physical Chemistry?

are we entering an age of magnetronics? http://www.london-nano.com/content/researchhighlights/magnetricity/ "The research, published today in Nature (1), proves the existence of atom-sized magnetic charges called ‘magnetic monopoles’ that behave and interact just like more familiar electric charges. It also demonstrates a perfect symmetry between electricity and magnetism – a phenomenon dubbed ‘magnetricity' by the authors from the LCN and STFC’s ISIS Neutron and Muon Source ." "The experiment allowed the team to detect magnetic charges in the spin ice (Dy2Ti2O7), to measure their currents, and to determine the elementary unit of the magnetic charge in the materi…

Hi there, got a question for anyone with some expertise in the Dirac equation. The angular momentum of a free electron is of course conserved, and is made up of the spin and orbital parts. These two are not conserved on their own (they don't commute with the Dirac Hamiltonian) If I work out the time derivative of the spin a.m. operator s (in the Heisenberg picture) I get (d/dt) s_i = epsilon_ijk p_j gamma^0 gamma^k where epsilon if the antisymmetric 3-tensor, gamma^mu is the usual gamma matrix, p is the momentum operator and indices i,j,k = 1, 2 or 3 label spatial coordinates. 0 is the index for the time coordinate. Einstein summation convention applies. …

unbounded,eternal, infinite ,illimitable,sempiternal,endless,boundless .... different?

Gravity pulls inward in ever direction in ever infinitely small point with an infinite amount of force with an infinite amount of points creating an infinitley large space that's counter balancing the force of each point with one another constantly for infinity. Gravity field theory an explanation of how the universe works using a concept of the explanation of the properties of gravity by explaining what gravity is and how it functions one can explain how the universe works in concept. Think of a theoretical space that is infinite and in this infinite space in ever infinitely small …

In pair production, the emergence of positrons and electrons from a photon striking an atom nucleus, it's calculated that mass-energy equivalence creates the e-e+ from the photon's energy if it's at least 1.022 MeV by applying E=MC^2. I understand the mass of e-e+ and the energy of the photon. But it's not clear to me from what or where C^2 is derived. Where from do we calculate the speed of light squared in the photon's interaction with an atom nucleus? Many thanks in advance for any help.

The diameter of the known universe is about 89 billion light years. That's about 44.5 billion light years in radius. However, the universe is only about 13 billion years old. This seems to negate the law that the speed of light can never be reached or exceeded, which means that the universe should be less than 13 billion light years in radius, not 44.5 billion. Scientists (notably, Albert Einstein and his Theory of Relativity) have supposedly solved this dilemna by suggesting that the universe (not the matter and energy inside it, but spacetime itself) is expanding, and the rate at which it expands has no intrinsic limit. This essentially means that the univ…

Hi! Just three questions (not 11): 1. One of the dimensions discussed in M-Theory (or perhaps pre-M-Theory String Theory?) is where every possible action that can take place, 'does' take place but in different dimensions. I think I have that right. Does this theory have a name? 2. Yet another dimension suggested or predicted in M-Theory relates to strings on different Branes... is this correct? 3. Also M-Theory predicts that instead of 10 dimensions that strings vibrate into, there are 11. Is it ever suggested that either of the dimensions in questions 1 and 2 are part of this 11 dimensions or, are we now looking at 13 dimensions (or more?)? As you…

i.e. what doesn't have energy?

http://arxiv.org/abs/0802.2991 WTF?

Given the assumptions that: 1) Black Holes, as described by general relativity, exist, even at small sizes. 2) Hawking Radiation exists and follows the formula even at small sizes. Source for equations: http://en.wikipedia.org/wiki/Hawking_radiation The schwarzschild radius of a black hole depends on its mass: [math]r_s = \frac{2GM}{c^2}[/math] The Hawking Radiation can be written as a relation between power and mass: [math]P = \frac{h c^6}{7680 G^2 M^2}[/math] The time it would take for a black hole to evaporate can also be written in terms of mass: [math]t_{ev} = \frac{2560 G^2 M^3}{h c^4}[/math] Therefore, if P is the power output of the Hawking Radiation: …

1. A new hypothetical experiment uses two pairs of double-slits. Electrons go through one pair of slits (red), and further down also go through a second pair. > ° ° ° ° ° ° ° ° ° °l ° ° ° ° ° ° ° ° ° ° l ) ) >° ° ° ° ° ° ° ° ° ° l ° ° ° ° ° ° ° ° ° ° l ) ) A wave doesn't form at the red pair. Only because: you're observing, which collapses the particle's wave --- but as it travels further to the second pair, does it become a wave again? 2. Another hypothetical experiment begins in more familiar territory, where if the electron is shot one at a time, it would enter both slits and interfere with itself. However, you run a divider in between…

In quantum mechanics spin can be described as that while rotating around the spin axis, the phase rotates "spin" times – in mathematics it’s called Conley (or Morse) index of topological singularity, it’s conservation can be also seen in argument principle in complex analysis. So particles are at least topological singularities. I'll try to convince that this underestimated property can lead to explanations from that fermions are extremely common particles up to the 'coincidence' that the number of lepton/quark generations is ... the number of spatial dimensions. I've made a simple demonstration which shows qualitative behavior of the phase while separation of topol…