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 Be the first pioneers to continue the Astronomy Discussions at our new Astronomy meeting place...The Space and Astronomy Agora Re: Thed Per Your Statements Below Forum List | Follow Ups | Post Message | Back to Thread Topics | In Response ToPosted by Thed on December 18, 1998 04:02:21 UTC

: Thed , my friend, you are a self-important windbag,

Funny, I thought you decided to attack my statements first. Rather than using polite language and pointing out I may be in error or using bad English, you used such statements as "A brain is a terible thing to waste". Who is the self important Windbag? You my friend.

:and even after all of your excrescent verbiage I am still at a loss as to what your point is exactly.

The point was, can you convert energy into mass, that seemed obvious to me.

:Going back to what you said above, "E=pc=hf doesn't mean that photons have mass",

It does not, no. But it does mean a Mass has an energy E. Particle(s) which have rest mass can convert that mass into rest energy in the form of other particles when it decays.

:I would remind you that "the 'm' in E = mc^2 is the dreaded 'relativistic mass'. When dealing with massless particles, it's best to avoid such notions" and also "E = hf = mc^2 is essentially meaningless."

Strange that it forms the basis of all quantum mechanics though. Physics uses the above notion quite readily all the time, when approximating the behaviour of particles with mass.

When dealing with massless particles you are quite correct otherwise.

:That you fail to grasp the difference between this and the statement "The source of the gravitational field in GR is not 'E' alone but (loosely speaking) 'E^2 - p^2'" only further demonstrates your ignorance in matters of relativity.

Who said that, not me and not you either I think. You just made it up to make yourself look beter in your own eyes.

I have repeatedly said the source of the gravitational field is the "bending" of spacetime by a mass. More precisely it is the stress-energy tensor acting on a spacetime manifold. GR is too messy to begin to explain without resorting to tensor maths, which I'll admit I do not fully understand.

:You've a lot more reading to do... I suggest you get to it. Surely reading a textbook puts your time to much better use than posting uninformed blather.

No Comment. I have an post-grad diploma in Astropysics, what is your qualification in the field.

: : If we now turn to the question 'Does light have mass?' this can be taken to mean different things if the : light is moving freely or trapped in a container.

So you read John Baez's Relativity tutorials and FAQ.

: Also per your website, which is full of errors, let me point out one thing. Isotropy does not mean constant pressure for God's Sake.

There are some typos and daft mistakes on my web site. I wrote it two years ago and the arrival of two kids in that time left me with no time to correct it. I find it funny also, that most people who have read my web site have politely corrected me or complimented me, not just said "There are many errors".

I must ask, what is your problem with me. I answered a few questions or corrected a few errors in a form I thought fit that that person would understand without getting involved in the messy business of the definitions of mass and energy in a relativistic sense.

I conducted myself with decorum and good manners then you simply started attacking me. Where you have made mistakes you do not admit them, I do. You attack using the ad hominen method "your wrong! excrescent verbiage, self important windbag" first. This points to a personality that is slightly unstable and trying to proove to the world how important they are. Personally I am only trying to teach people about Physics as best I can.

As you insist in keeping up this tirade and obviously intend to keep attacking anything I say using the method of "you are a Language Removed head, I know more than you". This is the last anyone will hear of me here. You can read this and think smugly, "I won, I know more than Thed". I hope this makes you happy.