rajama

Ah, thanks... I just tried to enter the site using the hyperlink in the notification email and got more scripting errors - nothing to do with the component then, it just happened to be the first bit of script to reference something not loaded. Looks like IE has problems... Regards

I just logged-in and downloaded a PDF... Adobe Reader then hung, so I closed the browser window. After ending the Adobe process that had left toolbars on the desktop, I returned to the site and began to get script errors relating to urchinTracker... clearing the cache cured this, but I wondered what it was???

Someone here will - no doubt - have a clearer understanding of this or be able to answer your question in a more meaningful way, but until then, as I was passing, try this: If we use a 'common sense' or 'day-to-day' view of speed, and imagine trying to attain an infinite speed (say, moving away from Earth) then you would expect this would take an infinite time, and an infinite amount of fuel, and you probably wouldn't see it as possible… All we need to add is that because of the nature of spacetime - for something with mass - infinite speed is pulled all the way back down to 'c'. In Relativity, that makes 'c' special. Obviously, the number itself is measured in whatever arbitrary measurement system we happen to be using... But does that explain why light travels at 'c' in the absence of matter (I’m sure you’ll find several threads on this topic)... well, the idea that light travels at (effectively) infinite speed for our spacetime kind of makes sense. What do you think? Also, if something moves with infinite speed, then our ‘common sense’ view would be that no time elapses between the beginning and end of a journey. In our spacetime this is still true, but only if you’re making the journey – that is, for light, or one of the other massless entities that carry forces around the universe. Hope this is useful…

Interesting… Isn’t there a gap here – actually, more a chasm…? I posted some diagrams, related equations and questions in ‘speculations’ a few months ago – didn’t realise it was for ‘crackpots’ only, but maybe the label fits in the context of the posting… I wasn’t that optimistic that anyone would look at them and point out the flaws in the thought processes or ideas presented, but I did hope that someone might explain where I had screwed-up. So, apart from a complaint about the lack of clarity of the posting – granted, I was more than a little hyper when I posted it – I got nothing back… Why? Well, reading around the forum, I assume it was just too much trouble... Firstly, maybe am I a ‘crackpot’ who should be treated with care? Hmmm (still pondering that one) … then, of course, most of the pro-scientist members just don’t seem to have the time. This is not unreasonable: I don’t, so why should they? Also, some synchronicity is involved if a posting is to be noticed: it has to peak the interest of the browser who happens to spot it, and that may not be the pro-scientist who might be able or willing to respond… Also, it’s in ‘speculations’, way down at the foot of the list… So, what is the speculations section for, if the only postings read are regarded as ‘crackpot’ and responding to anything at least attempting scientific rigour is too onerous a task, too chancy an activity, to be considered worthwhile… Any thoughts?

On your third topic: if time rate slows isn’t it reasonable for mass to also increase – to balance things out? And of course this would be a reciprocal arrangement: if your spaceship slams into Earth, it doesn’t matter whether you’re on the ship or standing on the ground, the bang should be equally energetic…

In the UK during the '70s 'O' level math - usually taken at age 16 - included differentiation : the limit / continuous curves, finding min / max / turning point of a curve etc., all the basic but useful stuff for applied math and physics... but not integration as I remember.

Also liked the old 'new posts' button...

Good point about security, but your script runs server side - so, after the post... Okay, this protects the database entry, but surely the only thing available at the client side is a series of caching instructions ('no cache' etc.) to the browser and an SSL (https) connection... ...unless you have other concerns / ideas???

It looks like herme3 has to work with a Lynux operating system running Apache, MySql, PHP etc. so the corporate Microsoft route probably isn't that useful in this instance...

I thought the article was fairly neutral, appearing almost entirely a statement of claims made by the originator. Kind of careful. It reminded me of an anti-gravity machine that appeared on national UK news some years ago - same storage of kinetic energy, but using a pair of gyroscopes. This device used EM radiation - new twist... Actually, more alarming than claims of a reactionless drive was the £1/4million funding from the DTI... Ouch! Question: the article claimed microwaves in the cavity were moving 'close to the speed of light' and had 'their own frame of reference', which I would imagine is just bull, but was this a reference to the group speed for EM in a cavity?

Sorry, Atheist, yes in trying to cut down the length of the post I totally lost its context... I found the Relativistic Radial Doppler Shift ‘k’ for a superluminal inertial frame differs from the sublight value - is this correct? If so, given that the LT can be written entirely in terms of ‘k’, substituting k for v > c we get a different LT than for v < c... I assume I made a mistake or two as I haven't seen anything like this in SR and it implies a real rest mass for a tachyon? Any expert input would be much appreciated... :-) :-) :-) :-) :-) And here's the long version: A little while ago, a post was made on the Relativity board by CPL.Luke in order to discuss the appearance of a superluminal object. In that thread, the model presented by Mowgli was, it seemed, non-relativistic: he maintained his theories would not work under special relativity (SR). It occurred to me that this was probably not so. As I have a text that derives the Relativistic Radial Doppler Shift without utilising the Lorentz Transforms (LT) in SR, I thought it possible to derive the Doppler shift without encountering any imaginary terms, so drew a thought experiment based on this, which produces a result different from the usual SR result… My post of the diagram in that thread was either ignored / misunderstood by Mowgli et al (maybe I should have explained it more fully) but this brief piece of work led me to look at the whole ‘classical’ tachyon hypothesis again and I found myself railing at the idea of imaginary mass as it comes an experiment that cannot be conducted for v > c. The textbook I mentioned derives the LT from this ‘k’ value… so in deriving a different value for ‘k’, do we get a different Lorentz Transform for inertial frames where v > c ? I put together a thought experiment (though you don’t actually need it) for v > c and I wrote the LT purely in terms of ‘k’. But when you put in the ‘k’ term you get a different LT… You’ll find a very brief attempt to discuss this in the thread tachyons. In that thread I decided it would be better to write a speculative post… So, a second LT? Sounds dodgy, doesn't it..? Any expert input would be much appreciated...

ah, sorry, no - not 'publish' in that sense - it's just a few notes sitting in the speculations forum which is of course way way down at the bottom of the main page, where (currently) 30 people have viewed it and no one has commented...

I read the field theory paper in your second reference, and it soon became clear it was actually written in some form of english - way beyond my background, I'm afraid, but thanks anyway... It did prompt me to tour wikipedia pages on false vacuum and related issues... Also, I just published that speculation - it's called 'Superluminal Inertial Frames in Special Relativity?'. Have fun.

A short while ago, in responding to another thread, I constructed a spacetime diagram and formula for the radial Doppler shift of a superluminal object. This v > c diagram mirrors two similar but entirely conventional v < c diagrams found in the text ‘Introducing Einstein’s Relativity’ by Ray D’Inverno. This diagram differs from that required for v < c in that here the photon reflected at event P crosses the t axis a period T before the path of the second inertial frame, rather than after it. The result is the inverse of the usual term for v in terms of k, and the value for k will be real only if |v| > 1, as required. How does this relate to the Lorentz Transform (LT)? Firstly, let’s try to design an experiment to formally derive the LT for v > c. The Lorentz Transform is most often derived via a thought experiment in which the (proper) time of flight of a light signal travelling to and reflected from a specific event is measured using (initially synchronised) clocks in two inertial frames that are in motion relative to each other. The experiment requires that, in each inertial frame, a light signal passes through a detector in twice for time of flight to be measured, allowing the co-ordinates of the event to be found and in principle compared between frames. It should be obvious that this experiment cannot be performed if the relative speed of the two frames is greater than that of light. It seems reasonable therefore that a thought experiment deriving the LT for v > c must use two related signals that allow the position of an event to be determined by both frames. In this example, the relevant event sits in the future of the superluminal frame S’ (it could equally well have sat in the past). In the S frame, it is at the convergence of two light signals originally emitted simultaneously at Q. Comparing the co-ordinates of the reflection points along the line of simultaneity in S with the points of arrival in S’, and using the k term once again we have: x’ – c.t’ = k(x – ct) x + c.t = k(x’ + c.t’) After some re-arrangement this gives: This is just the standard LT written in terms of the radial Doppler shift. But substituting k for v > c rather than k for v < c produces Notes 1. The k term can be used to derive the SR composition law for velocities: kac = kab.kbc where a, b, and c are inertial frames Using k v < c this normally gives: vac = (vab + vbc) / (1 + vab.vbc) Given two values for k, there are now 8 possible routes to vac As k v > c = - k v < c these outcomes can be divided into two sets which produce either the conventional value for vac given above or its inverse. This supports two views of the three frames, depending on whether the observer of these three frames is moving with v < c or v > c relative to ‘a’. 2. If you use the LT for v > c to derive the SR composition law, it gives the inverse of the normal result. This appears consistent with the note 1 above… Any comments?

there are people out there! Many thanks to both for the feedback and references (169 pages?). I'm really only familiar with undergraduate physics (what little I remember) and have been playing around with SR and the 'classical' tachyon hypothesis, so you're right in guessing any string theory papers will blow me away... I assume from your comments tachyons are considered a pathology in a theory or indicative of unrealistic boundry conditions... I think I'll still post what I have as a 'speculation' as the feedback may be helpful. Also, I've almost finished writing a first draft - even if its rubbish at least the effort is keeping my brain alive.