Modern and Theoretical Physics

a Bit like Red-shift but wider. a space craft is on a heading to pass in front of you from the left to the right mega fast. as it approaches it will be shifted to the blue/violet, when directly in front of you it will be it`s real color and as it passes it will shift to the Red end of the spectrum. at least that`s how I understand it. so will you get all the colors of the "rainbow" from UV to IR, or does it snap from one to the other the second it passes you?

Hello! I'm new here and I just wanted to ask one question. What do you guys think about creating plasma with a grape, a glass, and a microwave? You can find videos of this all around but I was curious regarding the safety of this experiment. You cut a grape into 4 section and place 2 sections side by side in a microwave with a glass over the top of it. After about 5 seconds the charge between the two, very water saturated, masses creates a plasma ball that is captured in the glass. Its a very neat idea but I was just mainly concerned with the overall safety. What do you all think? Could it really damage a microwave after only 10 seconds? I'd love to use this on …

One thing that I have been wondering about was, how are nuclear reactions in a nuclear power plant controlled? It seems to me that one really cannot control the neutrons that cause the chain reaction, and I know that the reaction cannot be stopped once it starts. I'm guessing that it is probably the speed of the reaction that is controlled, rather than the reaction itself. What is it that keeps a nuclear power plant from becoming a nuclear bomb?

How difficult is it to make a Farnsworth-Hirsch Fusor? I don't have any experience with reactors so i don't think i want to get into building one. I want to find a really interesting alternate energy project for school. I'm looking for something cooler then a solar hot dog cooker, a solar powered car or a wind turbine. any ideas welcomed. thanks

This isn't a speculation isn't merely that I am curious to hear how most people think of the future of "physics". It seem that different people think of the future of (theoretical) physics in different ways and have different visions, that are more or less abstract. For example chemistry is explained by the underlying physics, but will the future grand theory that explains physics as we know it still be physics, or will it give birth to a new field, or fit better into another field, relating to physics, a bit like chemistry relates to physics? Considering many of the current speculations... quantum foam relating to a collection of almost indistinguishable nei…

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…

The very matter that caused the big bang, the singularity that existed before this univserse came in existance. What exactly was this? Was it atoms completly squashed into eachother, to the point all particles were directly "Squeezed" together? Was it just random particles together (Gluons, neutrons, ions, muons, quarks, hell, even tachyons), just clusterf*cked together? Or was it 1 single atom of an infinite mass? (Infinite electrons / protons)

Hi everybody. I would like to share with you something I have been mulling over on and off for the past few months. I remember during lectures when discussing temperature, I was intrigued to ask my lecturer if there was relationship between temperature and disorder. He gave me an answer bt I would be interestedto know how ppl on this forum would answer this question. I now that our idea of temperature only has sensible meaning when applied to randomly disordered enviroments, such as the a volume of gas. I remember he mentioned such a thing as a "cold beam" of particles, with a considerable energy but very low temperature due to the "order" within the beam. Another u…

how far CAN space be Curved before it tears or rips? using the rubber sheet and heavy object in the middle of it analogy (like a bowling ball in the middle of a large trampoline). that sheet can only take SO much mass before one of 2 things happen, 1, the sheet rips under the weight (mass) the mass drops and the sheet returns to normal position again with a tear in it. 2, the sheet Doesn`t Rip, but it`s "anchors" do. so what Really happens in the Real "world"? a mass so great and dense that not even Light can escape, my guess is that this mass isn`t all THAT great if it can`t rip space.

Hello, I was just doing a bit of research on general relativity when I came across this about backwards travelling light. http://www.rochester.edu/news/show.php?id=2544 Is this legitimate because all other sites I have looked on all refer to this one page. Is it possible? And I also wasn’t aware they made light go slower and faster, is that true as well? What are the implications of it? Here are some of the other sites I looked at: http://www.physorg.com/news66582110.html http://www.livescience.com/technology/060518_light_backward.html

I just looked at the UK amazon physics bestseller list and Smolin "The Trouble with Physics...and What Comes Next" was number one. that is maybe not so surprising. It was the number one physics bestseller in the US for a couple of months or so in fall 2006 when it came out, and the UK edition just came out last month. But here is something unexpected: Smolin's book is currently the #23 UK amazon bestseller in ALL BOOKS. Here's the UK physics list http://www.amazon.co.uk/gp/bestsellers/books/278409/ref=pd_ts_b_nav/026-8303087-5718006 Here's the page for the book, that currently says the salesrank is #23 (might be different an hour from now.) http:/…

I have a question for those on here have experience with dealing with publications. First there seems to be several uses for the various journals and archives. I assume the more important part is that anyone who is interested can find the papers. And in each papers sufficient information exists if the author needs to be contacted. The second is the research funding systems and so on. I have noticed that there is alot of journals and archives out there, some journals for some reason sell the articles. I don't know if the money is for paying the peer reviewers or if it is simply business? Anyway, there are both free and non-free journals. Reviewed and non-reviewed. …

hey I need a good way to detect alpha particles without using a gieger counter. i know that zinc sulfide will sparkle slightly when hit with alpha particles but does it need to be "activated" or can i use the zinc sulfide i get from burning zinc and sulfur together. thanks for your time.

Where can I find the schematics for a classical Stern Gerlach Magnet, or, even better, where can I get a pre-fab Stern Gerlach Magnet? Thanks. Adendum: Upon further reflection, I need any kind of an electron spin separation device, that can be practically built in a workshop envioronment, or be bought online.

found an amazing site for kids which helps them learn or refresh their basics .......science for kids those who are interested can refer the site ....... please ....no offense ...those who are really interested to build their basics refer the site . regards ramakrishna

Tachyons have imaginary rests mass and they do have real mass now does anyone know if they have positive or negative mass? Definitely. Thanks why06

Based on the theory of Big Bang, there once was singularity and because of it's incredibly large density it exploded creating our Universe. Should we consider that the start of the World and all its laws of nature or did they exist before Big Bang? I think so, because if there were no laws and time, nothing would exist in our understanding. But if time and the laws of nature existed before BigBang, then it would have to follow them. It would need space in order to expand, and a reason for it. (the reason why it expanded is because of laws of nature). So what was that staff around the singular point? Ordinary vacuum? Dark matter?

http://www.arxiv.org/abs/hep-ex/0702026 Charting the Course for Elementary Particle Physics Burton Richter AAAS National Meeting, San Francisco, 2007, Symposium, A New Frontier in Particle Physics, 15 pages, 8 figures SLAC-PUB-12345 "It was the best of times; it was the worst of times is the way Dickens begins the Tale of Two Cities. The line is appropriate to our time in particle physics. It is the best of times because we are in the midst of a revolution in understanding, the third to occur during my career. It is the worst of times because accelerator facilities are shutting down before new ones are opening, restricting the opportunity for experiments, and …

An excellent PBS NOVA video series I found explaining string theory!! http://www.pbs.org/wgbh/nova/elegant/program.html

As the title says I am a biology student, I want to understand string theory and all the controversy behind it. String theory is a model of fundamental physics whose building blocks are one-dimensional extended objects (strings) rather than the zero-dimensional points (particles), I understand what this says, but I don't understand how this would apply to real life or how would change the current understanding of our universe. Compared to our current understanding of the universe, what changes does string theory cause to our current understanding Please try to explain in general terms, with minimal use of complex terminology.

I saw my first fredrik post just now and it was something of a wake-up call. IMO this is an astute perceptive viewpoint. I am very glad you stated it so clearly and it DOES have relevance, indirectly, to understanding the current shift in the way various audiences perceive string research. I will try to answer.

I just went to Google and typed in sqrt(hbar*c^5/G)= and it gave me the natural unit of energy sqrt((hbar * (c^5)) / G) = 1.95627185 × 10^9 joules I typed in this sqrt(hbar*c/G)= and it gave me the natural unit of mass sqrt((hbar * c) / G) = 21.7664598 micrograms I'm impressed. the latter 21.7... micrograms would agree with what the NIST has for Planck mass in its list of fundamental constants. good for Google! and good for TurricaN for calling our attention to this Google feature.

I am proposing that the vacuum polarization field does not need to have spin or rotational characteristics to transmit magnetic forces. Locally, elements of moving charge can be analyzed in a frame of reference where electric field alone describes the field medium. If the vacuum manifestation Lorentz transforms so as to preserve this relation, then the hypothesis is valid. I have been talking with H.Puthoff on this and have some support.

Has anybody(besides me) heard of Steven Hawkings?

How does one isolate a single electron? For example, the double-slit experiment requires that a gun fire a single electron at the slits. How do you get just one electron?