# Mini 'Big Bang' created



## StormFeather (Nov 8, 2010)

BBC News - Large Hadron Collider (LHC) generates a 'mini-Big Bang'



> The experiment created temperatures a million times hotter than the centre of the Sun.


 
Playing with fire perhaps?


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## mosaix (Nov 8, 2010)

Thanks for this SF. Very interesting.


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## Boneman (Nov 8, 2010)

Hmmm... sub-atomic fireballs... even so, why didn't it melt everything in sight? Probably because it wasn't in sight? Can you really measure the temperature of sub-atomic particles? Or is this a justification for the billions spent? Not that I'm cynical or anything...


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## mosaix (Nov 8, 2010)

Boneman said:


> Hmmm... sub-atomic fireballs... even so, why didn't it melt everything in sight? Probably because it wasn't in sight? Can you really measure the temperature of sub-atomic particles? Or is this a justification for the billions spent? Not that I'm cynical or anything...



I don't know the answer to your questions, Boneman but I would imagine that the particles are so small that the fireball was also very small (sub-atomic as it says) and containable.  As for measuring the temperature I would also imagine that it could be calculated from the combined speed of the particles (energy) when they collided.


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## Ursa major (Nov 8, 2010)

The use of a temperature in such a report has two purposes:

it's expressing something in a way that appears understandable** to most humans, as we feel we know about temperature in a way we don't about kinetic energy;
it gives a big number, which may not be the case if they were to use joules (and who knows what a joule is?).
 



** - Okay, all _I_ know is that a _million_ degrees is very hot, let alone a figure that's a million times that of the Sun's core (which is itself 15.7 million Kelvins), but it has so little relevance to my day-to-day experience, it's effectively meaningless. But it sounds good.


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## chrispenycate (Nov 8, 2010)

Playing with something spectacularly hotter than fire, in a space much colder than ice (the superconducting electromagnets are liquid helium cooled, only a smidgin over absolute zero and considerably cooler than the depths of space; and I was sitting at the bus stop  there yesterday evening. And do I sound worried? Naw. Not because I trust the scientists to get it right; but because the few terrawatt hours of energy they've got to play with could not spread destruction much further than Meyrin,even if they tried.


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## ScrambleEggHead (Nov 9, 2010)

Ursa major said:


> The use of a temperature in such a report has two purposes:
> 
> it's expressing something in a way that appears understandable** to most humans, as we feel we know about temperature in a way we don't about kinetic energy;
> it gives a big number, which may not be the case if they were to use joules (and who knows what a joule is?).
> ...



Well, If you must know... A "Joule", in physics, is a unit of work. eek  Same thing as a "watt-second". One Joule was originally defined as the  amount of work it took to move one Kilogram one meter. That assumed that  you had a force trying to prevent you from moving it (like gravity) so  the simplest explanation would be the work (mentioned earlier) to_ lift _one  kilogram a distance of one meter (up) on Earth. Now, that doesn't sound  like much work, and it isn't. In the other unit system, we all know  that one watt isn't very much power. The work done is one watt for one  second. That sounds smaller, but it is equivalent to the "Newton-meter".  

Now how does this relate to temperature? In Physics, the units of heat  are the same as the units of work, also known as Energy. A British  Thermal Unit (BTU) is equal to 1055 Joules.  So, when Chris says "the  few terra-watt hours", we are talking about 7,000,000,000,000 BTU's in  one hour, but I suspect Chris is referring to the total power used to  get the thing to happen (to get the nuclei of lead near the speed of  light right before they smash together.) The energy released would be  less because the equipment (the collider) would lose some of that energy  in the process. 

Probably not much less than half the energy though, and the chambers the  collisions occur in are in sizes ranging from 80 cubic meters to a chamber larger than a tennis court with a wall of detectors 3 meters thick. The collisions occur between particles about 100 times smaller than the radius of a human hair, and yet they manage to produce that much energy. What's really incredible is the computing power needed to "catch" a series of collisions for a period of only one second (For example -  the muon spectrometer has roughly one million readout channels, and  its layers of detectors have a total area of 12,000 square meters. This results in a data output of approximately 300 GigaBytes/second. Giga = 1,000,000,000 )

The energy that is used by the LHC could probably power the entire city of Geneva for several months, but that's a rough guess.

Let's put it this way: I wouldn't want to be inside one of those chambers when the particles collide.


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## Ursa major (Nov 9, 2010)

_I_ know what a joule is, otherwise I wouldn't have known to mention it.... 

As for the general public, I suspect a few hearing the word might have thought it pertained to Monsieur Verne; the heads of many of the rest might have become clogged with pictures of Holland**....






** Yes: as well as being a percussion instrument, pianos have strings, at least in theory.


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## ScrambleEggHead (Nov 9, 2010)

Ursa major said:


> _I_ know what a joule is, otherwise I wouldn't have known to mention it....
> 
> 
> ...the heads of many of the rest might have become clogged with pictures of Holland**....
> ...



Meant in a nice way: You can't blame me for not knowing what you did or didn't know, given the question you asked. 

 Regarding "...clogged with pictures of Holland", are you one of those punsters, that just can't help using one when you see the chance?  

I do love a well tuned piano, and for all we know, they may hold the_ key_ to string theory. (one bad pun deserves another).


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## Ursa major (Nov 9, 2010)

ScrambleEggHead said:


> ...are you one of those punsters, that just can't help using one when you see the chance?


 
Who, me...?


Er, not really.  


(I only use one when I can't think of more. )


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