Search found 76 matches

by photino
Sun Jun 27, 2010 11:32 pm
Forum: The Accelerator
Topic: Current Events Discussion
Replies: 512
Views: 73442

Re: Current Events Discussion

Back to physics - in style! :)

Thanks for that helpful blog post Philg!
by photino
Wed Jun 23, 2010 4:32 pm
Forum: Off topic
Topic: Can any of you give me some idea's on books?
Replies: 13
Views: 10933

Re: Can any of you give me some idea's on books?

Field medalist Tim Gowers' "Very Short Introduction to Mathematics" is good (if very short ;-) ). Actually, some of the other books in the "Very Short Introduction" series might be worth a look as well. http://www.amazon.co.uk/Mathematics-Very-Short-Introduction-Introductions/dp/0192853619 Not a tex...
by photino
Wed Jun 09, 2010 3:17 pm
Forum: The Accelerator
Topic: Physics At LHC 2010 - conference
Replies: 4
Views: 1697

Re: Physics At LHC 2010 - conference

Thanks for posting this!
by photino
Sat May 22, 2010 1:02 am
Forum: The Accelerator
Topic: Current Events Discussion
Replies: 512
Views: 73442

Re: Current Events Discussion

LHC Operations Status Report - a nice summary of the state of play
http://indico.cern.ch/conferenceDisplay.py?confId=95508

(Apologies if this has been posted already)
by photino
Tue May 18, 2010 3:13 pm
Forum: Science
Topic: Where does the energy go?
Replies: 13
Views: 5675

Re: Where does the energy go?

PhilG, thanks for your long reply! Really sorry I have not responded yet - I hope to have the time to do so properly soon.
by photino
Tue May 18, 2010 3:10 pm
Forum: Science
Topic: Luminance, luminosity, squeezing explained in English
Replies: 14
Views: 9487

Re: Luminance, luminosity, squeezing explained in English

I am not sure why you included the length of the tunnel and the length of a bunch in your calculation? Also, the number of protons enters the luminosity quadratically (they must hit each other, not a brick wall!). There is also a geometric factor due to the beams crossing at an angle, rather than he...
by photino
Wed May 05, 2010 9:35 am
Forum: Science
Topic: Where does the energy go?
Replies: 13
Views: 5675

Re: Where does the energy go?

@PhilG: I hesitate to say this because you are not quoting anyone or anything specific - but I think you are rather quick to call "nonsense" when referring to statements taken completely out of context. Quite often what happens is that a particular mathematical fact is expressed in words, and that c...
by photino
Tue May 04, 2010 9:20 pm
Forum: Science
Topic: Where does the energy go?
Replies: 13
Views: 5675

Re: Where does the energy go?

Photons have an energy proportional to their frequency. By E=mc^2, this means they have a mass (though no rest mass - so they cannot be at rest). Therefore, they source a gravitational field and bend spacetime, just like any other mass. However, this does not explain the apparent violation of energy...
by photino
Mon Apr 26, 2010 6:19 pm
Forum: Science
Topic: Luminance, luminosity, squeezing explained in English
Replies: 14
Views: 9487

Re: Luminance, luminosity, squeezing explained in English

why they don't collect a given number of events... Ultimately this is of course just a convention, but I think it is because one is usually interested in the number of collision events *of a particular type* (e.g., Beauty production). A calculation on the theory side will traditionally produce the ...
by photino
Sat Apr 17, 2010 1:21 pm
Forum: The Accelerator
Topic: Conference
Replies: 5
Views: 1504

Re: Conference

:happy-sunny: That's great news - Congratulations! :happy-sunny:
by photino
Tue Mar 23, 2010 7:39 pm
Forum: The Accelerator
Topic: Proton vs Graphite
Replies: 44
Views: 5246

Re: Proton vs Graphite

Excellent :)
So, what energy is released into the block in total ? the 3.5TeV?
Yes! No energy is ever lost... it all has to go somewhere...
by photino
Tue Mar 23, 2010 9:47 am
Forum: The Accelerator
Topic: Proton vs Graphite
Replies: 44
Views: 5246

Re: Proton vs Graphite

I think I see your misunderstanding. Of course if you send a 3.5 TeV proton into a beam dump, that energy will not disappear - it will end up in the beam dump, making the beam dump hotter. It will end up there like the previous 2 posts describe - a cascade of collisions and scatterings, a bit like a...
by photino
Mon Mar 22, 2010 8:18 pm
Forum: The Accelerator
Topic: Proton vs Graphite
Replies: 44
Views: 5246

Re: Proton vs Graphite

The details of the beam dump are not really important for Xymox' question, because for the comparison with head-on collisions only the first collision of each proton matters. The reason his intuition is failing him is because the beam is moving so close to the speed of light, so relativistic effects...
by photino
Tue Feb 23, 2010 1:20 pm
Forum: Science
Topic: Infinite series in quantum phyics
Replies: 29
Views: 6041

Re: Infinite series in quantum phyics

@chriwi While it's fun to speculate, and I'm not sure I understand your idea, ultimately we'll find out when some quantum gravity theory is experimentally proven... BUT Lorentz invariance (which is experimentally very well established) does rule out a lot of things. @ansgar: I see what you're gettin...