physics

I'm about two thirds through Anathem, by Neal Stephenson. It is a well-written story that attempts to cover many of the issues of science, philosophy and religion dealt with in threads on this forum. If you enjoy stories where people have obscure arguments for page after page (I do) then it's...

Things faster than light, but they aren't really "things". :eek: Faster-Than-Light Polarization Currents Space Daily I'm not quite getting what it is. Can someone please explain? Thanks.

Right now I'm involved in a discussion on the Freethought and Rationalism Discussion Board (FRDB) under the username Leon Belmont. The thread, if anyone is interested in actually reading it, is in the Evolution/Creation subforum, and is titled "How Lucky Are We To Have Evolved?" I'm currently...

Link to blog post... I’m a bad, bad person. No kidding, I’m bad – really, really bad. I say this because in my physics classes today, I killed Santa Claus. Well, to be more accurate, what I did was use our knowledge of physics to kill the fantasy of Santa Claus (because it’s pretty damn hard...

I've noticed that the trail left by a boat consists of sea far smoother than the sea outside the wake. I reckon this is because the propellers/hull etc churn up so many waves that they have a greater chance of canceling out. But interestingly enough the trail lasts quite a long time, longer...

Had a quick read of this article: http://news.bbc.co.uk/2/hi/science/nature/8363934.stm And have a question about just this: How small do the slits have to be in order to let only one photon through??

I just loved the Lawrence Krauss lecture, but you have to watch the other one first to have a good laugh. http://scienceblogs.com/pharyngula/2009/10/physics.php

Well, you just have to see the Kaye Effect in action. It's an interesting feature of fluid dynamics and can be demonstrated using a dropping stream of shampoo. Demonstration and explanation of Kaye Effect - YouTube More Kaye Effect - YouTube Still more - "lanyard of shampoo" Leaping...

Journeys in The Country of The Blind: Entanglement Theory and The Effects of Blinding on Trials of Homeopathy and Homeopathic Provings Lionel R. Milgrom Department of Chemistry, Imperial College London SW7 2AZ, UK...

The full video of Feynman's messenger lectures is available now at: http://research.microsoft.com/apps/tools/tuva/ And it's pretty freaking awesome.

Could a long rotating cylindrical space station keep rotating around its lengthwise axis without active stabilisation? Last semester a teacher briefly mentioned a cylindrical satellite which unexpectedly began wobbling after a while, and eventually switched to rotating around an axis going...

Here they view the electron cloud of an atom in unprecedented detail, including the first two orbital types: sphere and butt Xerox. So far so good. But I thought these were "probability clouds", i.e. just a mathematical definition of the satistical probability an electron would be at each...

I've created this thread because I disagree with these last two statements completely (and didn't want to derail the thread they were posted in). While it may be impossible to prove, given our current understanding of physics, whether or not the universe is deterministic or not, there are no...

...from say a propane leak. You can't exit the house prior to the explosion but you do have a bathtub full of water and a bunch of mattresses on the other side of the building. Would it be better to seek refuge in the tub of water or behind the mattresses? This question comes from a long debate...

Or not... http://www.guardian.co.uk/science/blog/2009/aug/26/entropy-time-arrow-quantum-mechanics Paper here. Thoughts? The quote above seems a little simplistic.

Some years ago I read The Elegant Universe by Brian Greene, and in that book he laid out a way of thinking about relativity that made things click for me like no other explanation had before. Professor Greene wrote that any object, particle, or photon, is always moving at the speed of light...

It seems to be a common claim among truthers that the collapses of WTC 1 & 2 "followed the path of greatest resistance", and this board is no exception. Example: My request for an explanation was ignored. I think perhaps the truthers are having trouble understanding the physics principle...

If two black holes were orbiting each other at a very close distance, would they still be spherical, or would the event horizons become more drop-shaped, just like ordinary binary stars do?

This thought was thanks to the "Space Expanding? Einstein Proof?" title, although the actual thread appears to be barking mad. As far as I know, we can tell that something is moving away from us by measuring the red shift. However, from that how do we infer that space itself is expanding...

Anyone else going to the summer meeting of The American Association of Physics Teachers in Ann Arbor 7/25-7/29? It's my other annual GeekFest (the first being TAM). Less pink hair, more bermuda shorts, black socks and wingtips. Michigan is my alma mater, so that adds to the grooviness.

I remembered this while reading the Toy Science thread: In a Driver Education class I took way back in High School, there was a lot of effort made to scare us into being good drivers, including such extreme measures as showing us pictures of terrible accidents with lots of blood. One of the...

Water is, as far as I know, a very pale blue. So why do clouds, consisting of fine water drops, appear white? Is it that water only filters out the blue fraction of light passing through, but affects reflected light differently, or are clouds actually blue, but the much deeper blue of the...

According to wiki: http://en.wikipedia.org/wiki/Microwave_oven#Hazards, putting a pointed metal object—like a fork—in a microwave oven is likely to produce arcing, but smooth metal should not have the same effect. However, I remember once microwaving a plastic container, which turned out to be...

18BL7MKjtZM Physics Rocks!

There have been many strange physics claims made by "single topic", obsessive, fight-picking, drive-by posters in the time I have been observing here, and most seem to be quickly dispatched by the many knowledgeable members here. Recently, there were two that I am not sure were directly...

Question from a patron: Looking in the back of a physics text book of some sort and it lists some constants. the speed of light is: 2.998 x 108 ms-1 What does the -1 do? Oh and is 'ms' meters per second, or miliseconds? Goggle wasn't much help here except that it gave me an answer in hertz...

A while back I was playing with a collection of small, ordinary magnets and marveling at how they attract and repel each other, and I began to wonder about something: With those magnets and some ordinary building materials, such as glue, wooden sticks, and so on, would it be possible to build...

(One thread inspires another. ;) ) If a large spherical hollow chamber, perhaps 1000 miles in diameter, was created with its center exactly at the center of the Earth, what gravitational force would be felt at various points within the sphere?

If an astronaut, equipped with a flashlight, was floating inside a sphere with a perfectly reflective surface, what would he see? Is there any software which could render his view approximately, or can it be figured out just with pen and paper?

Lots of fantasy worlds, like those in Warhammer Fantasy or Elfquest depict planets with two moons, both appearing to be about the same size—or bigger—as our moon. Would that be possible in the real world, without either of the moons being flung into deep space or crashed into the nearby planet...