Ekpyrotic

As long as you're stationary the beams will always travel towards each other at c, so they'd always meet at [math]\frac{x+y}{2}[/math]. The sources are like expanding circles.

Did you mean yes? Kinda' like that video but with only one observer.

First, let's say I'm stationary.

Just thinking here. If two moving, and opposite, sources emitted a radio signal from distances x and y. Would you always see the light beams meet at [math]\frac{x+y}{2}[/math]? If you were in-between the sources and nearer to one?

Hey guys. I'm interested in knowing how you get to: [math]t = \gamma t'[/math] ...from: [math]t' = \gamma (t - \frac{vx}{c^2})[/math]

Revising for Jan test; it's become apparent that my spec. rel. knowledge isn't watertight. I have a particular problem with questions in the following form. Anna is in a ship traveling at 0.8c; Bob is at relative rest. (At rest both the ships measure 100m). So, Anna whizzes past at 0.8c when the two ship's tails are next to each other the tail's clocks both read 0. Note: There is also a clock in Anna's ship's nose; Bob's ship has a camera next to Anna's ship's nose. (a) Where is Anna's nose relative to Bob's ship? This stuff is no problem. Lorentz factor = [math]\frac{1}{\sqrt{1-0.8^2}} = \frac {5}{3}[/math] So, [math]\frac{5}{3}*100=60m[/math] (b) What time does the camera record for Anna's clock that is in the nose. (I have problems here) I know that the clock should read an earlier time; but don't know how to calculate that time. Thanks. Ripiptickakee! Got it, ridiculous question on my part.

Here's where I am. The object has grav. potential at the start, then transfers that to kinetic energy. [math]gpe = \frac{1}{2} I \omega^2 + \frac{1}{2}mv_x^2 + \frac{1}{2}mv_y^2[/math] We can work out [math]I[/math], which is equal to [math]\frac{1}{3} mL^2[/math] Any advice? Hints?

I have a rod with a fixed base, a hinge. It starts to fall sideways (rotating). Using the conservation of energy, how is the angular speed related to the angle with the ground?

It depends on what you like, it's a pretty vigorous analysis of the world (particulary economics) from a mathmatical slant. Although it's very easy reading. Worth reading the blurb and seeing whether it piquets your interest, very well written. It's a matter of habit, I'll try and stop.

Thanks insane_alien. It's actually really interesting: Time to research. Thanks, Jordan (Ekpyrotic)

BenTheMan: This makes a lot of sense, I've been subject to the narrative fallacy. (have you read 'Black Swans' by Nassim?) Thanks for the clarification. Swansont: I must have worded my question badly. The problem was in having the top quark as massive as a gold nucleus, yet much smaller in size. However we couldn't say it was more dense. Hope that has cleared up the issue, thanks, Jordan (Ekpyrotic)

I'll respond to each commentor in turn. insane_alien: Thanks again for your response. I very much did, and it took a good 15 minutes too. The quoted references in your response seem rather vague, let us remember we want evidence that photons interact with each other. I can't see that anywhere in these quotes: This tells me the following: photons have 0 mass, they are the perpetrator of the electromagnetic force, they have no charge, and travel at c in a vacuum. Not that they interact with each other - which I don't doubt - I just like sturdy evidence. BenTheMan: You really know the art of writing well informed, insightful posts - if you don't mind the flattery. This particularly took my interest: And however geeky this might seem I'd love to see the maths behind it, it always seems clearer that way. This makes it a lot clearer, I'll need to spent some time reading up on the subject as of yet - but thanks again. Thanks, Jordan (Ekpyrotic) hehe, I got moved to the pseudoscience.

I read the Wikipedia entry through, and I couldn't find any implicit mention of massless particle interaction. The closest I get was the following: I know I'm being demanding, but I like to be throughout. Thanks, Jordan (Ekpyrotic)

Thanks for the fast response insane, I'd like to take the time to discuss your points, please excuse my ignorance. Can you quote a source that I can read up on. I thought this was the case but I couldn't find any description online for this behavior. All I could think of was Young's double slit, which would mean the particles are interacting with a 'Higgs wave', is this the case? This refute is dependent on the integrity of your argument against the first point. Thanks, Jordan (Ekpyrotic)

Warning: I'm kinda' crossing physics and philosophy here. I've constructed a logically proof for the inexistence of a Higgs particle, and I need some physicists to point out the logical fallacy in the argument because I can't see it myself, although I can see potential flaws. (1) Massless particles can't interact. (this is a major flaw, but I can't seem to find information for this either way) (2) In order for a massless particle to attain mass it must interact in a Higgs' field. Therefore the Higgs particle requires a mass. (3) For a Higgs particle to aquire mass it must interact with another Higgs that already has mass. (4) Step (3) repeat until we work back to the first Higgs particle. (5) The first Higgs couldn't have come into existence because it would have been massless, which makes it useless. I'm sure it will be shot down on the first point. Thanks for reading. Jordan (Ekpyrotic)

Hi swansont, I'd hate to question your scientific prowess, but isn't this equivalent to saying you can't compare the mass of a chair and a human because they are made of different materials.

Thanks everyone for your swift answers, BenTheMan that is a great answer/explanation. Thanks for taking the time to write it. I suppose the next question that the topic is begging for is why does a top quark interact so much more in the Higg's field than an of the other quarks/leptons. But I don't suppose particle physics has the answer to that yet.

Thanks for the answer w=f[z], Indeed that is what I meant, I'm prone to stupid-error-blindness when proof reading my posts. The problem came from my head, and the information quoted is accessible from a wide range of resources. [1]. I used mass in the previous post because it is the most logical solution. But, in any form it breaks down because density essentially boils down to: amount of stuff in a particular stuff. When we're talking about a top quark the former amount of stuff doesn't exist because it is pointlike. Hope I have articulated myself, Jordan (Ekpyrotic)

I have a certain problem that has been bugging me. I'll try to set up the problem at straightforward as possible. (1) It is accepted that a top quark has the mass of 174.3 +/- 5.1 GeV, which in analogical terms is about the mass of a gold nuclei. (2) A top quark is much smaller (in size) than a gold nuclei. (3) A top quark can't possibly be more dense than a gold nuclei because it is made of only itself. (disregarding any bizarre fringe physics) (4) So a top quark is the same mass as a gold nuclei, but it smaller, yet not more dense. How is this possible? Thanks, Jordan (Ekpyrotic)