Physics

My astronomy book says: "When light reflects off a flat, horizontal surface like the ground or a lake, the surface tends to reflect light in which electric field is vibrating along (parallel) to the surface and to transmit or absorb light with electric fields vibrating in other directions. As a result, the reflected light becomes polarized, with its electric field vibrating horizontally." What do they mean by flat "horizontal" surface with regards to the "ground" or "lake"? Is the book saying that the lake and ground has a horizontal surface relative to your positional stance, in that you are standing perpendicular to the ground, such that the ground is horizontal…

Can you have EM radiation at any frequency or only those present in atoms?

World premiere from the Observatory of Lisbon: The star of Bethlehem has returned Year 7 BC the star of Bethlehem . Yesterday http://www.msnbc.msn...e/#.T2HCzPLYExA Sky chart year 7 Bc Although the planets are different these two conjunctions have similar apparent magnitude being the brightest in history. More data soon. http://thirdsecret.o...em-has-returned http://www.scienceforums.net/topic/61462-star-of-bethlehem-really-pointed-from-babylon-to-jerusalem/

Hello experts, please help me to solve following questions for my review (master thesis). Feel also free to state the literature correlated to the answers, if u now it. The minimum range limits of common MRI is approximately not lower as 3 micro meter. Why (setup, IT or mathematical background)? Correlated to a Review it´s dependent on the pickup coil. Can the resolution be magnified by changing parts, how would the improved future Version look like? Have a good day, Chris

The lowest achieve able at any technology temperature achievable on Earth recorded in Kelvin is 1.0 × 10-10 K That relates to Quantum Speed/Area to move Quantum speed is measured in meters / seconds area meters^3 m / sec / m ^3 = 1/sec/m^2 or m^2/sec (m^2/sec)/C <m/s> = m K can be substituted for m^2/s 1.0 x 10^-10 K / 299,792,458 m/s = Comes up with 3,335,640,951,981.52 m/s Math looks good End result doesn't Amazing and the speed of light still appears to be travelling at 300,000,000 m/s I think there's a constant!

does anyone know (or have an educated guess) what frequency electric shock pens operate at?

According to this: If the moon got too close to the earth, some mass would fall off into the earth. Iv'e been thinking about orbits as being somewhat to do with chance, things in non less stable orbits fell into or away from the things they were orbiting long ago and every orbit today is just a spiral. However does this mean that there is some relationship reguarding distance and orbit appart from the obvious? I'm thinking that if the moon gradually got closer and lost some of it's rocks to earth then it would become lighter it's orbit size would then increase again.

How do we know that time exists? As far as I know, it has no physical properties, no weight, no width, length or depth, yet we seem to think we can measure it and some even think we can alter it, so how would you define time?

Why are planets all oblate spheroids instead of say cubes? Is it because a sphere is less ordered than a cube? But why is a sphere less ordered than a cube?

The planet earth is differentiated through time zones GMT, so suppose if i travel from india to europe...when i reach i need to adjust my time. Or is it time travel when i traverse back and forth in time? Like in the movies 'around the world in 80 days' , 'back to the future' and 'time machine!' which time traversing is really a possibility not just adjusting time!

Are the lectures available anywhere online in video or audio form?

Ok, im a starwars fanatic, and as i was playing a game, i notised that the players could apply a shield field and be protected from bullets:eyebrow:. Now i have been doing some research on it and found this fourm, then i search for 'reverce magnet' and found this: Can a magnet be made to PUSH metal? So here i am wondering if you strip pyrolytic carbon to about 2 mm, would it lose any force from the orginal, i don't know, 1 sq. dm block, and, would it have the power to stop a bullet before it hit you? Thanks, -Iruka

I am not expert in physics. When I was reading a physics book, author explained that why the discovery of neutron delayed and how it was confirmed. Author’s writing is followed. Assume a invisible ball is on the billiards table. One visible ball moving on green surface of the table and suddenly, without any reason the ball goes in another direction. Scientists do not accept the, moving of anything or changing direction of anything without any reason. Therefore they decided that visible ball dashed with invisible ball. That invisible ball is the neutron. Is giving this example for discovery of neutron correct ? Is there any other examples, for perfect underst…

Hello! First post here, and I have a few questions. 1. Is it possible to completely destroy physical matter so that absolutely no scientifically measurable trace of it remains? If this is possible, what is the scientific term for it? For a long time I used the term vaporized, but looking up the word I'm sure that's incorrect. If it's not possible to destroy physical matter, what's the smallest form it can be reduced to and is there a scientific term for that? 2. How much energy would it take to completely destroy, (or reduce to smallest possible form if that's not possible) ordinary rock?

Could Neutrinos be used as a form of communication to send messages through space to other 'Earth - like' planets for faster than radio transmissions?? Sincerely, Adam

Hello all. If a very long bridge was built, say from England to Australia, it would be correct to say that the bridge would follow the earths curve and therefore not be level. If, however, a bridge that was this long was built and was perfectly level, would I be correct in thinking that it would seem to gradually slope 'upwards' up to a point where it would be impossible to climb? Regards Ricky

I am just completing an entry for a lab experiment for my physics class and I'm just wondering if anyone can link some good examples of a professional lab report? I know design documents, when I was in game design, were an important topic and we were given some very interesting links to examples. So I'm just wondering if the same exists for physics lab reports. Thanks!

How does Faraday Cage effect to communication? If the cage can take up an external charge on its own, will it hinder in transmitting signals from inside? Can it hinder a 1-20GHz communication band if designed to resist few hundred GHz communication? Thanks in Advance! Chinmay

I was just pondering about pressure and it's effects on the body when a thought struck me: Would it be possible to very gradually increase the atmospheric pressure on a human so that they could survive in an extreme pressure environment. I imagined a situation like this: A deep sea laboratory where the pressure started at normal atmospheric levels and increased over time (weeks, months, years?) until the air pressure inside was equivalent to the water pressure outside and the subject would be able to swim in the water without a bulky dive suit. Would this be possible or does the human body have a limit to the pressure it can withstand no matter the rate of pres…

I am doing an engineering course at college and got some information on what I wanted to learn, I saw a question regarding D'Alembert's priciple and didnt know what it was about, for example it was a question that looked like this: mass x accelerates uniformly from rest to celocity of x in x seconds while ascending a 1 in x gradient, resistence is xKN making use of D'Alberts principle determine the tracktive force between wheels/road, the work done ascending the slops, the average power developed by the enginer. I am interested in how the principle works and how it would answer this sort of question, does anybody know of any good websites I could use to learn this pri…

I've been thinking, we have so many means of power, but all of which begin with the use of a potential/normal energy. However I believe that a chain of energy can be started with a force, a force such as a vacuum. (I don't think as gravity as a force that could start an energy chain because gravitational potential energy is basically gravity.) Nothing is all around our little blue planet right? So doesn't that mean we should utilize it? We could create something that would transform kinetic energy into a usable electrical potential energy. I was thinking a wheel or something that had a constant flow of air fed to it through a tube, and after which is rushed out of the tub…

if a moving object, such as a planet, has more gravity than an object not moving? Or, since isnt everything supposed to be moving??, does an object like a planet with more velocity?? have more gravitational attraction than an object the same size with less velocity? I'm trying to develop an explanation on what is causing gravity and the answer to this question may help me depending on what it is. Thank you. You guys are great!

Hi 1st Post I am trying something with an small electro-magnet. I was hoping it would attract steel but it doesnt, if it comes in contact with the steel it will hold it so hard I could swing from it ,but it doesnt attract? Do attracting electro-magnets exist on a small scale, is there anything I can do to make the one I have attract strongly from around 2 inches away? Is there another magnet available, I just need it to attract, and release when current is cut. Thanks in advance for any help!

Just out of curiosity, how do you go about calculating how much electric power is consumed by an electromagnet made of superconducting material? Since the resistance is zero, it would suggest that the current can be (nearly?) infinite. Wikipedia tells me that the only power consumed in a DC electromagnet is due to the ohmic resistance. Another wikipedia site tells me that superconducting magnets can maintain a current with no voltage applied whatsoever, a property which is used in MRI machines. But what if a magnet does work? What if a charged particle comes near, and the magnetic force acts on it? Shouldn't that alter the current in the superconducting magnet…

I wasn't sure where to ask such a simple question - so please accept my apology first for my complete lack of knowledge. So... This one simple thought threw me off completely. And I knew it sounded stupid, but I just couldn't get over it! My physic's teacher is out of reach, so I had to turn to the internet for some solid answers. If high level cosmic background waves from the big bang stretched over time to form longer waves (which can be recorded and thus, we can calculate the age of the universe (?)), why hasn't the visible light waves from the very distance galaxies stretched? What is the difference between the visible light of the EM spectrum and the …