Modern and Theoretical Physics

Planck units like the mass and length come up all over the place in modern physics---they are not the only system, there are other convenient special purpose units, but they are worth getting familiar with. Using the google calculator we can take a kind of almost experimental approach to planck units, explore, build up our concepts, try them out. It is easy---a few posts will show what I mean. So here's a brief tutorial. 1. get to know hbar (Planck's constant) Think of hbar as being the product of amounts of energy and time. Check that by typing things like this into google hbar/minute hbar/year It will give you answers in energy terms----small amounts …

Hello friends! I have a question about light. We all know that we see objects because they reflect light into our eyes. But we never see the actual light. So my question is why can't we see light. Or can we in fact see light. If so, how?

A friend and I were having a debate as to wether this theory holds true: Please try to imagine that you were motionless in free space (relative to whatever....) and you were standing on one end of a plank with your feet firmly secured to the plank, and at the other end of the plank there was a board much like a basketball back board firmly secured to the plank facing you. Please Imagine you had pockets full of good sized rocks, if you were to throw a rock at the back board, you and the plank along with the back board would move in the opposite direction to the rock until the rock hit the back board, then at that point the rock hitting the backboard would cancel out t…

I have been looking at the structure of the atom lately and wondered what makes the electron orbit? You would think if a proton is positively charged and a electron is negatively charged that the two would eventually stick together. I realize in theory that the orbiting electron like a planet never lets this happen. But what makes an electron orbit in the first place and when an electron goes from one atom to another how does it automatically orbit in a way that it does not collide with the proton or neutron? I am not interested in theories (there are way to many of them flying around), but in proof + experiments on what is going on. Thanks.

Is it possible to CREATE a wormhole, even in theory in any way?

Think of a body moving as in Newton's first law - in a straight line at a fixed speed say. I have been wondering where is the information for the body to "know" how to move? One could argue that the motion itself is the "information", but that is somewhat unsatisfactory from an information theory point of view. I understand that information theory is being suggested as a possible way of looking at fundamental physics, so my question might be relevant, even though I am only a novice student of theoretical physics.

Does the magnetic field of a wire carrying a current have mass?

this is a pretty simple concept, look it up on google if u dont know it: basically my question was: if u built a metal suit, wore it, and got hit by thunder, would you be fine? assumin the metal can withstand the current. also are there any conditions, e.g. the metal suit has to be earthed? or does it have to be perfectl smooth, or can there be lumps, bumps, for your head, or where it joins together? and does a car work as faraday's cage if it is hit by ligthening, are the ppl inside fine, would they know about it? would they be electrocuted!?!

and before anyone complains about this post, I have express permission to post it! here`s how to build your own atomic reactor exploiting the decay principals and it`s physical effects. ALL radioactive isotopes with a high enough decay rate exhibit the physical effect of being several degrees warmer than their ambient temperature, Radium will always be 1 degree C above it`s ambient temp. the principal is simple, put enough radium into a thermos vacuum flask and fill it with boiling water, the water will gradualy get hotter and create steam. that steam may them be used to drive a small fan (turbine) and in turn a that rotation will turn a small generator ( a l…

I have read several threads stating time doesn't exist. I want to see how many think it does and how many don't think that it exists.

Time. We waste it, save it, kill it, make it. The world runs on it. Yet ask physicists what time actually is, and the answer might shock you: They have no idea. Even more surprising, the deep sense we have of time passing from present to past may be nothing more than an illusion. How can our understanding of something so familiar be so wrong? In search of answers,this video maybe help a bit This gives a very proper idea of how time works, very interesting topic and quite a good documentary. http://www.youtube.com/watch?v=yqzgYRBlslw So the real question is....: How do we run out of something that doesn't exist? please leave some comments and tell us your o…

gravity by muhammad owais pdf_2602242145004.pdf

The only way I can think of to describe the present time is this: The instant position of your thought and body of awareness. How does science describe the present time.

Quantum information isn't massless...

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.

I learned from my physics class that it is the strong gravity of earth that not only binds us to it but also keeps the moon in orbit... in a similar fashion that the sun by its extremely strong gravity keeps all the rest of the planets (that we know of) in orbit. Ofcourse, centripetal forces are also involved here but what I wanted to know is the energy source for this gravity.. more specifically, the source of energy of earth's gravity. Is it located at the central core of the earth, as some would predict?? what does it look like?? at what rate is the energy being used up (the power, i.e) and, if it goes at this rate, at approx. what point in time will it be totally …

First of all, I think it's wonderful that people focus their efforts on creating theories regarding various subjects and spend time discussing about them with other people . Nevertheless, I have a qustion to pose: every day we produce several theories during our effort to understand the universe that surrounds us. Depending on our studies and our interests we elaborate on specific topics, trying to reveal some of the mysteries that "provoke"our mind. But does anyone know (and can tell the rest of us) HOW are theories produced? Many philosophers have tried to answer this question, but the answers that they have given have left me unsatisfied. Production of theories has …

Hello, There is a lot of discussion about whether photons are energy or matter. What do you think??? Pomlom

Can optical tweezers move a atom and could a optical tweezers be made as small as a cell or smaller? And if the optical tweezers can move a atom can it like move one by one to put them together? Because then this would achieve the "build one and it builds more and they multiply objective, and they all can move atoms to make anything, and if they use magnetic power it would look like smoke coming together, and could move anything around too)

Amazon has this "general physics" bestseller list that has things like Brief History of Time, and Brian Greene Elegant Universe etc. And Kaku books etc. I just checked it out around 6 PM pacific today Wednesday 30 August and SMOLIN WAS NUMBER ONE http://www.amazon.com/gp/bestsellers/books/14560/ref=pd_ts_b_nav/102-4540543-7840144 and this is people advance ordering the book because it isnt even available for shipping until 15 Septemberl Amazing. Really. I am totally amazed at the popularity of this book. the list changes hourly so it might not be #1 when you look. It has been in the top 10 or so for over a week, but I didnt expect it to actua…

I don't understand how any theoretical physicist can credibly argue that the arrow of time is entirely a product of human perception and that it doesn't really exist when we have such things as the fossil record that clearly demonstrates that time has proceeded long before there were humans around to perceive it. Just been watching the documentary Through the Wormhole - Does Time Really Exist?

I started this thread for general stringy questions, if anyone is interested. Discussion is carried over from http://www.scienceforums.net/forum/showthread.php?t=28281 Wormwood--- Good question. This is actually one of the great successes of string theory---the fact that it predicts a number of dimensions is a success that no other approach to quantum gravity can claim, yet. The dimensions are predicted from the theory, by the requirement that the theory be consistent with quantum mechanics. In order to quantize a theory consistently, we have to introduce an idea called gauge invariance. This basically says that physics cannot depend on the way tha…

I know it's bull, but there's still no other explanation for it that I found. Essentially on the history channel they were exploring possibilities that aliens were involved in the past, and a lot of evidence was subject to interpretation, but there was a particular one that got me, which is that in India, there is a field of glass that nearly perfectly matches the type of glass that was produced in deserts in the US where nuclear bomb testing was done, in fact atomic bombs specifically melt rock as to have formed that type glass, so my question is: is it plausible that a meteor with high uranium content struck the Earth and become compressed enough to cause an explosion? …

I am seeking some clarification ref quantum fluctuations in space. What could they caused by? The quantum effects are probabilistic, not deterministic. Therefore, a quantum fluctuation has no "cause." Quantum fluctuations are a point change in the energy of a volume of space due to the Heisenberg Uncertainty Principle. Can they be viewed as a result of interference waves moving at light speed in various directions, (similar to the double slit experiment), creating an apparent probabilistic and not deterministic effect. If they are viewed in this way they have a cause but it is not possible to calculate there appearance other than via probability theory. ht…

Time being the most experienced thing in this universe but can we really describe what time is? Are we in a state of describing time? Ask this question to yourself and then say that can we scientifically define what time is? The motive of this discussion must be to scientifically define that what time is? And ill tell my own theory to describe what time is?