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Where did you publish it?

I wanted to know if any of you are members of an astronomical society? Joining a society is a great way to learn new skills and to spread ones interest in astronomy. Maybe members would like to post links to their society? I am going to join the Manchester Astronomical society, which is one of the oldest societies in the UK. http://www.mikeoates.org/mas/

Unfortunately it is not in my library. When it is I may be interested in joining the book club.

For exact solutions you must consult Stephani, H.; Kramer, D.; MacCallum, M.; Hoenselaers, C.; & Herlt, E. (2003). Exact Solutions of Einstein's Field Equations (2nd edn.). Cambridge: Cambridge University Press. ISBN 0-52-146136-7. Bonnor, W. B.; Griffiths, J. B.; & MacCallum, M. A. H. (1994). "Physical interpretation of vacuum solutions of Einstein's equations. Part II. Time-dependent solutions". Gen. Rel. Grav. 26: 637-729. Bonnor, W. B. (1992). "Physical interpretation of vacuum solutions of Einstein's equations. Part I. Time-independent solutions". Gen. Rel. Grav. 24: 551-573. A wise review, first of two parts. I have used all three references in the past. (I did have paper copies of the last two, I will see if I can find them). The papers by Felber can be found here http://www-spires.dur.ac.uk/cgi-bin/spiface/hep/www?rawcmd=a+Felber,+F+S

Can you give more detailed references for Cahill? It will depend exactly what you mean by "Einstein was wrong". For example, his equations of general relativity may not hold at all scales. It is possible that at small scales that general relativity needs modifying to include quantum mechanics. In this sence Einstein was not wrong, just not included the full picture. So tell us exactly what you are talking about and we can take it from there.

They indicate that you have done your pertubation expansion around an unstable vacuum. This false vacuum will decay to a stable true vacuum. In doing so we get particles that now have positive mass squared. It is not really the boundary conditions on the fields that are the problem, but our poor choice in selecting a vacuum to expand about. In string theory it is hoped that a similar thing may happen to remove tachyons. This is under the name "tachyon condensation".

Nottingham has a relatively new particle theory group within the department of physics. It is headed by Ed Copeland (formally of Sussex). The group has an interest in string cosmology. So indeed Nottingham would be an interesting place to be as you have both string theorists and loop gravity people. Barrett is with the quantum gravity group which is based in the mathematics department. I have several friends at Nottingham in the particle group , both students and members of staff. I plan to visit at some point soon. More a social visit I think! Here is a link http://www.nottingham.ac.uk/physics/research/particles/index.html

Since all the matereials we use to construct buldings, cars etc comes from the earth then they will not effect the mass after their production (up to [math]E = m c^{2}[/math]) I don't think we gain or lose much mass to the cosmos. I was thinking about astoroids, comets etc...

For a good review of tachyons in string theory see http://arxiv.org/abs/hep-th/0410103 For a field theory view see http://arxiv.org/abs/hep-th/0204143 I worn you both are advanced and not for beginers. Severian is right, in quantum field theory tachyons are due to our poor choice of vacuum when doing pertubation theory. However, in string theory which is usually formulated via first quantisation things are not so clear. The first review paper I suggested deals with this.

I was out camping in the woods. Only when I phoned my Mum the day after did I know about the twin towers.

I think you will be fine. However, if you are in any doubt go see your doctor.

I don't think they are very good, but the whole idea is funny.

This may help http://mathworld.wolfram.com/Line-LineIntersection.html http://mathworld.wolfram.com/Line-PlaneIntersection.html

"Les Horribles Cernettes are the one and only High Energy Rock Band. They sing about colliders, quarks, microwaves, antiprotons and Internet. They are known and loved by some 20000 High Energy Physicists worldwide. Check these few songs to have an idea, and if you are music producer, you have found your gold mine!" http://musiclub.web.cern.ch/MusiClub/bands/cernettes/

sorry pressed "post" when I wanted to press "preview"

We know that the set of all Killing vectors on a Riemannian manifold [math] (M,g)[/math] form a lie subalgebra of the Lie algebra of vector fields on [math] (M,g)[/math]. This is the Lie algebra of isometries of [math](M,g)[/math]. For example, the Killing fields on [math]S^{2}[/math] with the standard metric [math]g = d\theta \otimes d\theta + \sin \theta ^{2} d \phi \otimes d \phi[/math] form the Lie algebra [math]\mathfrak{so}(3)[/math]. My question is, does anyone know what the conformal Killing vector fields on [math] S^{2}[/math] (again with the standard metric) are? What is the Lie algebra of conformal isometries of [math](S^{2}, g)[/math]? I ask because I have been "playing" with the conformal Killing equation on [math]S^{2}[/math] and have got no where. I am positive that someone has calculated these things. Do you know the references I should be reading? Cheers

So how does it work?

It looks like I am indeed qualified to be an "expert". Does such a position come with some kind of reponsability or extra duties? If so, I am quite happy being a "non-expert".

I too with to express my regret at his death. However, I cannot say I am suprised. The only shocking thing is that he was not eaten by a croc!

What area are you an "expert" in Transdecimal? Expert is a bit of a relative term I think.

LateX once you learn how to use it is much easier than Word. It is simply better than using Word for mathematics. There are loads of packages that give you more symbols, diagrams etc... Word has a habit of changing the format and moving things about. LaTex will do exactly what you tell it. Also, it is free. LateX and Adobe Reader are free. You don't have to sign up to the Microsoft monopoly and you don't force others to do so. (You could of course use Open Office!)

Not everyone uses Microsoft Word. You are always better off writting things in formats that everyone can read. I would suggest PDF or PS.

If they have made A-level easier, that would explain why first year students are weak in mathematical knowledge.

My own experiences are the same as Drug addict, the jump to A-level from GCSE is huge. Mathematics is not easy, but don't use that as a reason not to study it. A-level mathematics will help you get onto any degree sceme at university.