Quasar 3C273

[clive milne]

A bit more on the speed of light.... (this may bend your brain a little)

From a photon's perspective, the distance it travels could be stated as the linear distance between the point of emission and absorption multiplied by 1 divided by infinity... ie) zero.
The time it takes to do this journey (at the speed of light) is again, zero.
If you wanted to describe that as a velocity, ie) distance covered per unit of time, the answer would be zero divided by zero... it is meaningless trying to describe it this way.

Another way to say it is that the Universe has no size or time dimensions for an object travelling at the speed of light.

For all intents and purposes, the photon is a waveform that exists complete in its entirety, then collapses. It is not like a bullet that flies between two points, even though we experience it like that from our distorted frame of reference.

caveat: I may have mangled the language a little, but I believe the core of the principle explained above is essentially correct.
~c

[bojan]

Originally Posted by Astrolabe

2. Gravity from the ground up, an introductory guide to gravity and special relativity, Bernard Schultz, Cambridge.
George

Now that you mentioned this reference, I've read some parts of the book, and I was puzzled by the treatment of significance of pressure, resulting from length dilation (I posted my questions on the forum earlier, can't find the thread now).
What puzzled me was that I always thought the dilation is caused by changing of the metric of space-time of the moving object from our reference.. and there could be no pressure increase as a result, but according to the above book, it isn't, and there is a pressure, energy associated with it and so on..
Some people commented that we can even have a spontaneous nuclear fusion as a result of this pressure.. which is not something I would ever think as feasible.

Or is it just an inappropriate extrapolation/speculation from basic principles by the author (Bernard Schultz)?
Could someone elaborate on this?

EDIT: I found the thread:
http://www.iceinspace.com.au/forum/s...hlight=gravity


EDIT2:
I am re-reading the thread and the links provided in the comments of others.. I forgot 98% of all that since first reading when thread was active...

[Suzy]

Originally Posted by pgc hunter

Hi Suzy, It's about mag 12.8 so will be visible in a 10". It'll look exactly like a star so you'll need detailed charts of the area to positively identify it.

Aaaah... was hoping to see the squiggle, but never mind, just seeing the Quasar in itself will be very special. Thanks Sab.
Could be challenging, but I have my new Stellarview finder now to help me, yaaaay! Oooh and the Night Sky Observers Guide. So all set.



Bojan, re-resurrecting old threads are great to do indeed as so much to learn that's just buried there hey!.