CERNs Large Hadron Collider

This is their web site, which should answer most of your questions:

LHC website

But from what I understand, they are firing two very high energy beams at each other and there are several detectors set around the ring that will record all the collisions.

It could find the Higgs Boson (the particle that gives all other particles their mass), why there is more matter than anti-matter in the Universe when they are produced in equal amounts, what is dark matter and dark energy, what happened at the very start of the Universe and it could also find hidden dimensions (I believe this is what string theory predicts but I'm not 100% on that).

Quote:

Original post by Calin The entry in wikipedia doesn't tell me much ). My understanding is that they're firing particles in a subway like system and use two gears to speed them up. The question is does this have anything to do with quantum physics?

Pretty much. They accelerate the particles with powerful electromagnets, and then blast them into each other and see what bits fall off. Although it's more technical that it sounds :P

I'm not sure if it's to do with quantum mechanics exactly, more subatomic particles - which the Higgs Boson is one of.

Higgs Boson is a theoretical particle that hasn't been tapped(recorded) yet? How can they research subatomic if they aren't sure how the atom works.

Quote:

Original post by Calin Higgs Boson is a theoretical particle that hasn't been tapped(recorded) yet? How can they research subatomic if they aren't sure how the atom works.

It is pretty well understood how most subatomic particles work. This is indeed described by several aspects of quantum mechanics (quantum chromodynamics, quantum field theory [although not yet complete], etc), and is condensed into what is called the standard model.

This model mathematically predicts the Higgs Boson. Yet it is the only particle of the standard model that has not yet been experimentally observed and verified (iirc). And that's what some experiments at the LHC try to achieve.

Quote:

Original post by Yann L the standard model.

That's pretty cool

Quote:

These particles make up all visible matter in the universe

Quote:

Original post by Calin That's pretty cool Quote: These particles make up all visible matter in the universe

It gets really cool when considering the non-visible matter (click and here):

Quote:

In the standard model of cosmology, dark energy currently accounts for 74% of the total mass-energy of the universe.

Quote:

Original post by Calin The entry in wikipedia doesn't tell me much ). My understanding is that they're firing particles in a subway like system and use two gears to speed them up. The question is does this have anything to do with quantum physics?

With quantum chromodynamics[smile]
In case of such high energy it will be quark-quark interaction.

Quote:

Original post by Yann LIn the standard model of cosmology...

Are those two the same? (SM of physics and SM of cosmology)

Quote:

Original post by AEdmonds what happened at the very start of the Universe and it could also find hidden dimensions.

Simple: The bootloader kicked in.

Quote:

Original post by Calin Quote: Original post by Yann LIn the standard model of cosmology... Are those two the same? (SM of physics and SM of cosmology)

Not really. They are complimentary though, of course.

The standard model of particle physics deals with the strong, electromagnetic and weak interactions. Like Yann L hints toward, the standard model of particle physics is a set of effective theories that is not quite complete -- it doesn't really cover the behaviour of extremely high energy interactions (e.g., those at the Planck scale, where gravity becomes the dominant "force").

The standard (Lambda cold dark matter) model of cosmology deals with gravitation and the existence of dark energy and dark matter at the very large scale. However it does deal a bit with particle physics, since particle physics is needed to ascertain what type(s) of particle(s) that might make up dark matter (and still produce the observed behaviour at the galactic scale).

For instance, superstring theory is a unified model of particle physics and gravitation that works all the way down to the Planck scale. It relies on an extension of the standard model called supersymmetry that predicts neutralinos as being the most appealing dark matter candidate.

Some believe that Loop Quantum Gravity is a competitor to superstring theory, but it does not include particle physics, so it's not really competing at any meaningful level. Its main focus seems to have been just a bunch of entropy/information counting exercises that demonstrate very little beyond what's already been known since Bekenstein-Hawking's hay day in the 1970s-early 1980s.

I dunno if that clears much up for you.

Quote:

Original post by Yann L Quote: Original post by Calin Higgs Boson is a theoretical particle that hasn't been tapped(recorded) yet? How can they research subatomic if they aren't sure how the atom works. It is pretty well understood how most subatomic particles work. This is indeed described by several aspects of quantum mechanics (quantum chromodynamics, quantum field theory [although not yet complete], etc), and is condensed into what is called the standard model. This model mathematically predicts the Higgs Boson. Yet it is the only particle of the standard model that has not yet been experimentally observed and verified (iirc). And that's what some experiments at the LHC try to achieve.

I would feel much safer about the scientific community if they would stop using lines like "This is very well understood" for something as abstract as subatomic theory.

"Our current model appears to fix the current tests we have been able to run, and therefore this is what we currently believe to be the most likely option to be true."

I don't know about the rest of you, but I've personally never handled an atom. All the test results that this level are based on seeing shadows basically, and while we have a high chance of being right, we could always still be completely wrong and have 80+ years of advanced science to throw out.

Quote:

Original post by Talroth Quote: Original post by Yann L Quote: Original post by Calin Higgs Boson is a theoretical particle that hasn't been tapped(recorded) yet? How can they research subatomic if they aren't sure how the atom works. It is pretty well understood how most subatomic particles work. This is indeed described by several aspects of quantum mechanics (quantum chromodynamics, quantum field theory [although not yet complete], etc), and is condensed into what is called the standard model. This model mathematically predicts the Higgs Boson. Yet it is the only particle of the standard model that has not yet been experimentally observed and verified (iirc). And that's what some experiments at the LHC try to achieve. I would feel much safer about the scientific community if they would stop using lines like "This is very well understood" for something as abstract as subatomic theory. "Our current model appears to fix the current tests we have been able to run, and therefore this is what we currently believe to be the most likely option to be true." I don't know about the rest of you, but I've personally never handled an atom. All the test results that this level are based on seeing shadows basically, and while we have a high chance of being right, we could always still be completely wrong and have 80+ years of advanced science to throw out.

That's a perfectly respectable approach to take. However, when I read Einstein's paper on Brownian motion, I have no choice but to believe in an atomistic universe.

e.g., http://www.aip.org/history/einstein/essay-brownian.htm ... "This connection, he declared in obvious understatement, 'ought not to be ascribed to chance.'"

Quite literally, a continuous universe just doesn't make any sense at all.

Quote:

Original post by Talroth I would feel much safer about the scientific community if they would stop using lines like "This is very well understood" for something as abstract as subatomic theory. "Our current model appears to fix the current tests we have been able to run, and therefore this is what we currently believe to be the most likely option to be true." I don't know about the rest of you, but I've personally never handled an atom. All the test results that this level are based on seeing shadows basically, and while we have a high chance of being right, we could always still be completely wrong and have 80+ years of advanced science to throw out.

Yes but even if it is 'completely wrong' it would not mean we would have to throw everything out. It still works as far as we've tested it so it's still very valuable knowledge.

As an example, Newtonian mechanics (i.e the equations of everyday sized objects) could be seen as 'completely wrong' as they don't work at very large or very small masses/velocities etc. Yet it still got us to the Moon and back (I remember hearing somewhere that they didn't use General Relativity to get to the Moon but I may be wrong).

Quote:

Original post by AEdmonds Quote: Original post by Talroth I would feel much safer about the scientific community if they would stop using lines like "This is very well understood" for something as abstract as subatomic theory. "Our current model appears to fix the current tests we have been able to run, and therefore this is what we currently believe to be the most likely option to be true." I don't know about the rest of you, but I've personally never handled an atom. All the test results that this level are based on seeing shadows basically, and while we have a high chance of being right, we could always still be completely wrong and have 80+ years of advanced science to throw out. Yes but even if it is 'completely wrong' it would not mean we would have to throw everything out. It still works as far as we've tested it so it's still very valuable knowledge. As an example, Newtonian mechanics (i.e the equations of everyday sized objects) could be seen as 'completely wrong' as they don't work at very large or very small masses/velocities etc. Yet it still got us to the Moon and back (I remember hearing somewhere that they didn't use General Relativity to get to the Moon but I may be wrong).

Well, that all depends on what could be found to prove the current theories wrong. Newtonian physics is still used because it is still useful and 'close enough' for many things. I don't know what we could find, but it could be enough to completely change science's views on the subject, and show that we are currently off my a major margin.

Quote:

Original post by Talroth I don't know what we could find, but it could be enough to completely change science's views on the subject, and show that we are currently off my a major margin.

It won't be by a major margin, at least not within the currently tested energetic domains. If the current theories are proven wrong (which is a very real possibility), then it will be within an energy domain beyond of what we're currently experimenting in. Anything else, we would have noticed by now. Simply through experimental evidence.

Newtonian physics are a good approximation within certain bounds. Relativity takes over where Newtonian physics break down. However, General Relativity again is just an approximation, valid within a certain domain. Quantum Mechanics currently seem to be a good candidate to take on where General Relativity becomes shaky, although QM are still very incomplete. It is quite possible that QM end up being just an approximation of something else entirely in the end.

But it doesn't really matter. That's how science works. Eventhough being approximations, and arguably 'wrong', these theories have lead to tons of new technological developments. Ironically, these theories allow us to build machines that are used to disprove said theories :)

Quote:

Original post by Yann L Newtonian physics are a good approximation within certain bounds. Relativity takes over where Newtonian physics break down. However, General Relativity again is just an approximation, valid within a certain domain. Quantum Mechanics currently seem to be a good candidate to take on where General Relativity becomes shaky, although QM are still very incomplete. It is quite possible that QM end up being just an approximation of something else entirely in the end.

From what I've heard, the story is slightly different: General Relativity works well for large distances, high speeds, and so on. Quantum Mechanics works well at very small distances. Perhaps the biggest open mystery of physics is finding a theory that can combine these two.

AFAIK quantum theory consist from two divisions (actualy appoximations): relative and non-relative(at least I remember that in Landaw phisics course there are two corresponding books for it).Thus, I don't understand what you are talking about at all.

I think relativistic (special relativity iirc) quantum mechanics is needed to explain the existance of antiparticles and spin, whereas non-relativistic quantum mechanics is just an approximation of this.

Special relativity concerns things moving at very high constant velocities (I'm pretty sure on this) and general realtivity is to do with large masses and acceleration (not so sure on this).

Although maybe someone more in the know could clarify?

Quote:

Original post by AEdmonds I think relativistic (special relativity iirc) quantum mechanics is needed to explain the existance of antiparticles and spin, whereas non-relativistic quantum mechanics is just an approximation of this.

Firstly,relativity quantum mechanics describe photon field (quantum electrodynamic etc)