# When two particles collide



## BookStop (Mar 30, 2010)

Ahh, glee is in the air as Geneva's atom smasher set new record today 

Geneva atom smasher sets collision record - Yahoo! News

CERN - the European Organization for Nuclear Research

I am pretty certain this is a big deal, but I'm not quite sure why. Could someone please explain the point of particle collisions, and the practicle possibilites that now have everyone in an uproar.


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## j d worthington (Mar 30, 2010)

Well, part of the answer to your question is in the body of the news story itself:



> Dubbed the world's largest scientific experiment, researchers hope the machine can approach on a tiny scale what happened in the first split seconds after the Big Bang, which they theorize was the creation of the universe some 14 billion years ago.
> The extra energy in Geneva is expected to reveal even more about the unanswered questions of particle physics, such as the existence of antimatter and the search for the Higgs boson, a hypothetical particle that scientists theorize gives mass to other particles and thus to other objects and creatures in the universe.


 
In essence, this is our first chance to actually recreate, on a small scale, conditions approaching those at the beginning of our universe, and thus to confirm experimentally what the existing evidence has pointed toward, but which we have been unable to practically experience so far.

As for the fears for micro black holes... those, from my understanding, exist all the time anyway, and most likely throughout the universe (including here on Earth), but are of such brief duration and the effects of them are so weak, that any "threat" is completely negligible.


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## Karn Maeshalanadae (Mar 30, 2010)

Yeah, I just about an hour ago or so caught this on CNN. It really is big news.


Of course, also imagine the energy that must've been released when they collided. It might not seem like all that much in the broad scheme of things, but proportionately, it would be equal to that of a supernova-and we all know what sort of effect an exploding star has on any other celestial bodies close enough to it.


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## chrispenycate (Mar 30, 2010)

I suppose saying they do it to annoy me personally would be a touch egotistical? They've mucked up all the tram schedules this weekend, and I have a friend to see in St. Genis; we usually meet up in the CERN carpark, but they've chosen Easter weekend to close things down, and divert trams. And I can't even complain to my friendly local physicist; he's gone home to Scandinavia.

Supernova or not, they've got the target area at a degree and a bit absolute, to keep the magnets superconducting; that doesn't speak for many ergs of energy escaping, Very intense indeed, but terribly small to be feeding all those megawatts into.

One of the secondary holes going down through France to the tunnel is called "Alice"


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## Ursa major (Mar 30, 2010)

You know, I've only just realised that the Higgs Boson is called the God Particle because it's all to do with Mass.... 









(Yes, I can be _really_ slow picking things up sometimes. )


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## BookStop (Mar 31, 2010)

I guess I need more tutelage about the Big Bang theory and what is likely to occur(or what all occured yesterday), exactly, and what it will mean for the future peoples of the world. Where does it go from here?

Antimatter, what is it exactly?

Higgs boson?


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## Ursa major (Mar 31, 2010)

Higgs Boson

To greatly simplify things (if only so that I can understand it):
Scientists are looking for a mechanism to explain mass (which we experience as weight, because we live in Earth's gravitational field). One proposed mechanism is the Higgs Field. Finding the associated Higgs boson would go a long way to showing that this idea is valid.​From Wiki:


> The Higgs boson is a hypothetical massive scalar elementary particle predicted to exist by the Standard Model in particle physics. At present there are no known elementary scalar particles in nature. The existence of the particle is postulated as a means of resolving inconsistencies in current theoretical physics, and attempts are being made to confirm the existence of the particle by experimentation, using the Large Hadron Collider (LHC). Other theories exist that do not anticipate the Higgs boson, described elsewhere as the Higgsless model.
> 
> The Higgs boson is the only Standard Model particle that has not been observed. Experimental detection of the Higgs boson would help explain the origin of mass in the universe. The Higgs boson would explain the difference between the massless photon, which mediates electromagnetism, and the massive W and Z bosons, which mediate the weak force. If the Higgs boson exists, it is an integral and pervasive component of the material world.


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## BookStop (Mar 31, 2010)

So a photon doesn't have mass. (How do we know? Gravity?)

So the Higgs boson (a particle in thoery) would give mass to particles, such as the photon? How? And if it gives mass to photons, wouldn't the photon have mass?


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## Karn Maeshalanadae (Mar 31, 2010)

No, as far as I understand light, does NOT have mass. Therefore, light is somehow able to travel at the speeds it can and not shatter the laws of physics.


But that's another story, I suppose.

They're also trying to prove the existence of the fourth dimension in this way. The only way THAT can happen is first by measuring the amount of energy within the conductor or whatever this thing is. (Early morning for me and a little bit high on pain meds. Bear with me.)


One part of the theory of relativity is that energy can NOT be created or destroyed-only transferred. So, the way to go about proving the fourth dimension is, they get these particles to collide, like they already did, and if the energy readings drop at all, then they figure that proves the fourth dimension, since such energy would have no way of escaping on our dimension out of wherever the particles collided. Another fun bit of info there.


Now I guess we just have to sit back and wait until they crack the mysteries of time and find a way to jump into THAT stream. Michael Crighton's novel Timeline still comes to mind with that one, though.....


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## BookStop (Mar 31, 2010)

Instead of proving a forth dimension, couldn't it also prove that the thoery of relativity is worng. *gulp* Don't even want to think about htat , but now I am.


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## Karn Maeshalanadae (Mar 31, 2010)

No, actually, because I believe it would take far more to prove the theory of relativity wrong. I personally think it's wrong anyway, but I don't have a degree in quantum physics, so I really have no idea.


I think it would take something earthshattering-and I do mean that almost literally-to prove the theory of relativity wrong-such as any object with mass travelling at full warp speed, or any creature or object going through time. Of course, I don't really understand the time barrier part-except that supposedly time controls all motion-but it's said that if an object's or creature's mass gains the faster it goes, and if said object or creature were to accelerate to warp speed, then its mass would equal that of the universe.


I find that a little hard to believe but that's what the physicists are claiming, even now. Of course, they also claim that it is THEORETICALLY possible to travel lightyears upon lightyears away from any given destination instantaneously. How?

Supposedly time and space are malleable, much like a sheet of cloth or, better yet, a sheet of paper. Now imagine the universe as a sheet of basic college-ruled writing paper. There's some considerable distance proportionately from one side to the other. But, fold that paper in half, and the distance between the two sides is down to as close to zero as it can be. Like I said, though, such travel is still only theoretical at this point.....


Or am I merely making a fool of myself tonight?


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## Peter Graham (Mar 31, 2010)

> You know, I've only just realised that the Higgs Boson is called the God Particle because it's all to do with Mass....


 
Not as slow as me, me old starry plough.  Until I stumbled across this thread, I assumed that Higgs Boson was a character from _Treasure Island_.


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## PTeppic (Mar 31, 2010)

I suppose it's worth noting that this week's experiment:

a) will take days/months/years to analyse: there are literally billions of particles generated and maybe only a few will be "interesting" and they don't have any way of quickly finding the good ones amongst the ordinary ones

b) they're still only operating at relatively low power (compared to maximum available) so we're unlikely to see the really rare stuff till they've done more at this level, powered it all down, done some more maintenance and finally started firing at maximum.


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## Chinook (Apr 1, 2010)

So, folks have been throwing terms around like the Chef’s throw food at Beni-hana’s. 

  Here is a fairly accurate description of the current understanding that most physicists agree upon. Now, what is not mentioned here is the crazy half-sister of the standard model: String theory. Essentially, the notion of string theory is that all of these particles – both mass-less, and massed, are composed of tiny vibrating bits of _energy. _The issue is that the “strings” would be so un-measurably small (Planck length =  1.616252 x 10−35 meters – about 10 to the power of 20 times smaller than the size of a proton) That we have no hope of “seeing” a string anytime soon. 

CERN - The Standard Model

  What physicists have “seen” are some of the missing pieces of the “standard model”. Here is a proposed example of the standard model puzzle:

http://web.infn.it/superb/images/stories/immagini/standard_model_from_fermi_lab.jpg



  For example, with existing particle colliders, they have seen “anti-electrons" (AKA positrons), and plenty of others.


  Clues to the early Universe

  The Universe has changed a great deal in the 13.7 billion years since the Big Bang, but the basic building blocks of everything from microbes to galaxies were signed, sealed and delivered in the first few millionths of a second. This is when the fundamental quarks became locked up within the protons and neutrons that form atomic nuclei. And there they remain, stuck together by gluons, the carrier particles of the strong force. This force is so strong that experiments have not been able to prise individual quarks or gluons out of protons, neutrons or other composite particles.

  Primordial soup

  Suppose, however, that you could reverse the process. The current theory of the strong interaction predicts that at very high temperatures and very high densities, quarks and gluons should no longer be confined inside composite particles. Instead they should exist freely in a new state of matter known as ‘quark-gluon plasma’.

  Such a transition should occur when the temperature goes above a value around 2000 billion degrees - about 100 000 times hotter than the core of the Sun! For a few millionths of a second after the Big Bang the temperature of the Universe was indeed above this value, so the entire Universe would have been in a state of quark-gluon plasma – a hot, dense ‘soup’ of quarks and gluons. Then as the Universe cooled below the critical value, the soup condensed into composite particles, including the building blocks of atomic nuclei.

  The thing to realize here is that a particle accelerator such as the LHC only smashes tiny beams of particles together, like the nuclei of atoms. For the size of particles we are talking about, yes it is an immense amount of energy, but in terms of the size of everyday things, it’s easy to contain. From a published paper on the LHC: “The total energy stored in each beam is about 360 MJ.” The MJ stands for “Mega-Joules” in layman’s terms we can first see the relationship to something we are familiar with: the watt. 
  A Watt is power. A Joule is Energy. A Joule is 1 Watt X 1 Second. Watts are units of Power, whereas Joules are units of Energy. Power is Energy in accordance to time: P = E/t. So One Watt of Power is equal to one Joule per second. P=E/t

  1 Watt = 1 Joule/ 1 second

  The whole colliding process is over in about 85 micro-seconds. (85 millionths of a second). So the power released is roughly 360,000,000 J / .000085 s = 4 trillion watts. 

  But, the beam is deflected by magnets within 89 micro-seconds of the initial collision, and travels through a 700 m long transfer line towards the graphite block located about 940 m downstream from the deflection magnets. Each beam hits a separate location on the graphite block, limiting the maximum temperature inside the graphite to about 
  700 0C.


  Each fundamental force has its own corresponding boson particle – the strong force is carried by the ‘gluon’, the electromagnetic force is carried by the ‘photon’, and the ‘W and Z bosons’ are responsible for the weak force. Although not yet found, the ‘graviton’ should be the corresponding force-carrying particle of gravity. When it comes to the minuscule scale of particles, the effect of gravity is so weak as to be negligible. Only when we have matter in bulk, such as in ourselves or in planets, does the effect of gravity dominate. So the Standard Model still works well despite its reluctant exclusion of one of the fundamental forces.

  Now, all of this crazy-making that has physicists in such a frenzy is to combine all four of the known forces The strong nuclear force (holds nuclei together) the weak nuclear force (holds atoms together), the electromagnetic force (carries all of the energy from place to place) and gravity (holds the universe together – sort of). There is a theory that combines the first three forces. The Standard Model includes the electromagnetic, strong and weak forces and all their carrier particles, and explains extremely well how these forces act on all the matter particles. However, the most familiar force in our everyday lives, gravity, is not part of the Standard Model. The following is one attempt at a “Unification theory” (AKA - Theory of Everything AKA - TOE):

Loop quantum gravity - Wikipedia, the free encyclopedia

Each fundamental force has its own corresponding boson particle – the strong force is carried by the ‘gluon’, the electromagnetic force is carried by the ‘photon’, and the ‘W and Z bosons’ are responsible for the weak force. Although not yet found, the ‘graviton’ should be the corresponding force-carrying particle of gravity. When it comes to the minuscule scale of particles, the effect of gravity is so weak as to be negligible. Only when we have matter in bulk, such as in ourselves or in planets, does the effect of gravity dominate. So the Standard Model still works well despite its reluctant exclusion of one of the fundamental forces.


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## Dave (Apr 1, 2010)

Ursa major said:


> Scientists are looking for a mechanism to explain mass (which we experience as weight, because we live in Earth's gravitational field).


I think the Bear has hit upon the reason why we all (me included) find this all so difficult to understand. Living on the surface of the Earth, we always think of Mass as weight. We find it hard to think of it in any other way, but Relativity tells us that really it is a curvature of space-time. You must have seen those pictures of ball-bearings in a funnel simulating planets orbiting a star - only those are 3 dimensional and in reality Gravity works in 4 dimensions - or is it 9 dimensions? Or, is it the 21 dimensions that these super-strings inhabit? My brain just finds it difficult if not impossible to comprehend that many dimensions, but I can see that the Universe would look very, very different in so many more dimensions to what it does in 4 dimensions.


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## chrispenycate (Apr 1, 2010)

A photon has mass; what it doesn't have is any rest mass, but since they never stop moving, this is no handicap. Since energy =k X mass,(where, as every schoolboy knows, k is cee squared) to have any energy it's forced to create a small quantity of gravity, and de diverted by large quantities of it. 

Gravity operates in three dimensions. We know this because it drops off as the square of the distance from the centre of gravity of the generating mass ( unless you are inside a hollow body in which case– oh, never mind) Which demonstrates that a constant quantity is spreading out over an ever larger area, not volume.

Einstein's theory of special relativity is just that; a theory. It is not Revealed Truth, and is almost certainly wrong. In fact, if quantum entanglement can be proved it kicks out one of the basic premises; that simultaneity has no meaning, and any frame of reference is as valid as any other. What it is is better than any competing model at describing the universe as we see it, and whatever theory supersedes it will definitely contain elements of it, or even be a mildly corrected version of the original.


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## Ursa major (Apr 1, 2010)

I understand that for all practical purposes, *c* is the maximum possible velocity observed in our universe (putting entanglement to one side, for a moment).

However, doesn't the current theory include events which are not bound by this limit. Inflation, for one. Isn't one of the desired effects of Inflation that it explains the rather uniform universe we see (with respect to background radiation), even though the passage of photons _through_ that universe is limited to *c*?


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## GrownUp (Apr 2, 2010)

Ursa major said:


> I understand that for all practical purposes, *c* is the maximum possible velocity observed in our universe (putting entanglement to one side, for a moment).
> 
> However, doesn't the current theory include events which are not bound by this limit. Inflation, for one. Isn't one of the desired effects of Inflation that it explains the rather uniform universe we see (with respect to background radiation), even though the passage of photons _through_ that universe is limited to *c*?



Yep. Inflation = superluminal expansion.

(I was going to just say yep, but the forum wouldn't let me post a reply of less than 7 characters. Wonder why? 
I mean, sometimes yep is all you need...)


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## Ursa major (Apr 2, 2010)

Yep....


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## GrownUp (Apr 2, 2010)

Ursa major said:


> Yep....



How did you do that?


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## Boneman (Apr 2, 2010)

Highlight his speech as if you were going to copy it, keep going - all will be revealed!


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## GrownUp (Apr 2, 2010)

Ah! Yer a divil.


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## Chinook (Apr 3, 2010)

chrispenycate said:


> A photon has mass; what it doesn't have is any rest mass, but since they never stop moving, this is no handicap. Since energy =k X mass,(where, as every schoolboy knows, k is cee squared) to have any energy it's forced to create a small quantity of gravity, and de diverted by large quantities of it.



No wonder schoolboys have so much energy.  (When I was a schoolboy I always wanted a 'k' for X mass.) *groan*



chrispenycate said:


> Gravity operates in three dimensions. We know this because it drops off as the square of the distance from the centre of gravity of the generating mass ( unless you are inside a hollow body in which case– oh, never mind) Which demonstrates that a constant quantity is spreading out over an ever larger area, not volume.



Didn't you mean an ever larger volume, not area?



chrispenycate said:


> Einstein's theory of special relativity is just that; a theory. It is not Revealed Truth, and is almost certainly wrong. In fact, if quantum entanglement can be proved it kicks out one of the basic premises; that simultaneity has no meaning, and any frame of reference is as valid as any other. What it is is better than any competing model at describing the universe as we see it, and whatever theory supersedes it will definitely contain elements of it, or even be a mildly corrected version of the original.



Yep. And gravity can be shown to travel much faster than light. If folks care to see the pure mathematics, and science, they are here:
The Speed of Gravity - What the Experiments Say

Essentially, if it took gravity the same amount of to reach Earth as does light (8.3 minutes) the effects would be largely noticeable in measurements taken to determine the mass, and angular velocity of the planets. The delay involved would accumulate to the extent that the planets would no longer stay in a near perfect orbit around the sun, and would in fact slowly spiral out further and further. From the abstract: 





> If gravity from the Sun propagated outward at the speed of light, the transmission delay would progressively increase the angular momentum of bodies orbiting the Sun at so great a rate that orbital radii would double in about 1000 revolutions.


  I read somewhere (now I can't find it! ), that experiments were done showing that lights' trajectory upon hitting a flat surface on the moving Earth could be shown to take on the slightest trace of momentum (like throwing a ball at a moving train - only the speeds involved would be much greater). The light is "shifted" ever so slightly when it "bounces" back. I guess this has more to do with proving Chris's first statement (photons have mass). Anyway, the paper comes to this conclusion:

*The Speed of Gravity is ( 2x10 to the power of 10) times (C)  (at least)
*


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## BookStop (Apr 3, 2010)

What's the difference between mass and rest mass? The Higgs boson is supposed to give mass to objects with no rest mass? How does it supposedly do this?

(byt he way, when I picture particles in my head, I picture solid chunks of ...I was going to say mass, but maybe stuff is better here...stuff, like grains of sand or balls. However, seeing as particles can be be enegry an not solid stuff, I'm not sure how to picture the photon or the corresponding quarks, glouns, and definitely the boson that the science geeks* are trying to find)

*when I say science geeks, I mean the brilliant minds that think these things up and whose intellect is far superior to mine (likely) and it is a term of respect in my household. I have a science geek kid, but she's not so educated yet as to be able to explain these concepts in simple terms to her mother


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## Chinook (Apr 3, 2010)

BookStop said:


> What's the difference between mass and rest mass? The Higgs boson is supposed to give mass to objects with no rest mass? How does it supposedly do this?


 
  Particles simplified:

  An atom was once thought to be the smallest part of individual matter that we could find. As technology marches on, we find new ways of "measuring" smaller and smaller parts of things and it seems the deeper we go, the more mystery we keep finding. We now know that an atom is made up of a nucleus with paired up neutrons and protons circled by spinning electrons (I'm sure you've heard this). What is not stressed as often is the relative size of these things, or the difficulty involved in actually observing them. The distance in relative terms between the nucleus and the electron (even in the simplest atom - Hydrogen) can be compared to the distance (if a nucleus were as big as the sun) between the sun and Jupiter. What's interesting to me about that is that the whole of our existence is mostly empty space. (as far as we can tell) It is the speed (of light) at which the electron whirls around the nucleus that makes it seem solid. A photon seems to exist only in it's "moving" form. Even if we try to freeze it (literally) we cannot get it below a certain level of energy. This is why it is said that a photon has no "rest mass". It's totally restless.  When we try to "look" at atoms, if we bombard them with light (bunches of photons) the photons impart their energy to the atoms, nuclei, etc., and knock the particles around like balls on a pool table. That's why they have to "smash" them together and surround them with detectors to see what's inside. Each basic particle has a force that acts upon it. Boson is another word for the force acting upon the photon. The standard model I have referred to has been developed by physicists over the last century, partly because they can also use mathematics to "predict" the existence of various particles, and much of what has been predicted has been found in the labratory or in particle accelerator experiments. Some of these particles only exist for millionths of a second before they get absorbed back into whatever is around. The accelerator has a very fast shutter so it can "catch" a picture of the particles before they dissipate, disappear, etc. The Higgs boson is a theoretical particle (also described as a "field") that is predicted by the mathematics of particle physics. If we could reproduce it, even for the tiniest flash of a second, we could watch how it gives mass to the other so called "mass-less" things, basically converting them into neutrons, protons, electrons, and such. I hope that clarifies it a bit and didn't confuse things even more.


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## BookStop (Apr 4, 2010)

Chinook said:


> Particles simplified:
> 
> *A photon seems to exist only in it's "moving" form. Even if we try to freeze it (literally) we cannot get it below a certain level of energy. This is why it is said that a photon has no "rest mass". It's totally restless*.  When we try to "look" at atoms, if we bombard them with light (bunches of photons) the photons impart their energy to the atoms, nuclei, etc., and knock the particles around like balls on a pool table. That's why they have to "smash" them together and surround them with detectors to see what's inside. Each basic particle has a force that acts upon it. *Boson is another word for the force acting upon the photon.* The standard model I have referred to has been developed by physicists over the last century, partly because they can also use mathematics to "predict" the existence of various particles, and much of what has been predicted has been found in the labratory or in particle accelerator experiments. Some of these particles only exist for millionths of a second before they get absorbed back into whatever is around. The accelerator has a very fast shutter so it can "catch" a picture of the particles before they dissipate, disappear, etc. *The Higgs boson is a theoretical particle (also described as a "field") that is predicted by the mathematics of particle physics.* If we could reproduce it, even for the tiniest flash of a second, we could watch how it gives mass to the other so called "mass-less" things, basically converting them into neutrons, protons, electrons, and such. I hope that clarifies it a bit and didn't confuse things even more.


 
Thank you, Chinook, I think I am starting to have a glimmer of understanding. The bold text was exactly what I was having trouble getting my head around. Turns out it is because I was thinking things that were not correct, not correct at all. This seems simple now


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