Slashdot Mirror
CERN Scientists Looking for the Force
An anonymous reader writes "National Geographic has a fascinating article on the God Particle, which can help explain the Standard Model and get us closer to explain the Grand Unified Theory. The obligatory Star Wars-angle summary is even better: 'CERN's scientists, the fine people who brought us the W and Z particles, anti-hydrogen atoms and hyperlinked porn web pages, are now hard at work building the Large Hadron Collider to discover something even cooler: the Force. Yes, that Force. Or like physicists call it, the Higgs boson, a particle that carries a field which interacts with every living or inert matter.'"
"Use the Large Hadron Collider, Luke."
...but shouldn't they be focusing on something much more worthwhile?
Like a working model of a lightsabre. Now that'd be really cool...
The Mothership
Basically, no.
I like to place meaningful quotes in my sig, so people will know that I know what meaningful quotes are.
I don't believe in the God Particle. ...you knew that was coming.
"...and hyperlinked porn web pages, are now hard at work building the Large Hadron Collider..."
Hadron...
Dammit, too much time on Slashdot
No. According to Newton's Law of Gravitation the force of gravitation allows two particles with mass to attract one another.
This doesn't cover all particles.
The Mothership
If there is no Higgs Boson, oh well...the collider has many other uses that can help move our scientific development along.
Christ I sounded like a politician right there...but it's true.
Living With a Nerd
From a linked article:
That's the essence of experimental particle physics: You smash stuff together and see what other stuff comes out.
and you get to do it with really expensive, shiny toys :)
The Mothership
Photons aren't supposed to have mass (otherwise they couldn't travel at light speed), so how are they affected by gravity?
These are not the particles you are looking for.
hard at work, CERN's scientists are now
the Large Hadron Collider, they are building
brought us the W and Z particles, the fine people did
anti-hydrogen atoms and hyperlinked porn web pages, they brought us as well, they did
to discover something even cooler, they are
the Force, it is
that Force, yes, it is
carries a field, it does, the particle
interacts with every living or inert matter, it does
the Higgs boson, it is
call it so, physicists do
intellectual property law is philosophically incoherent. it is your moral duty to ignore it or sabotage it
If they are to find "Grand Unified Theory" I wander if it contains not only "The Function" that explains all interactions in universe but more importantly, why is function evaluated at all and how it is evaluated. Is it possible that any mathematical function can evaluate itself, and if not, is there any other explanation? That would be perhaps more interesting answer then The Function itself.
839*929
They're affected by curved space due to gravity.
True confidence comes not from realising you are as good as your peers, but that your peers are as bad as you are.
Argh, don't these guys watch TV?, the entire planet will be reduced to the size of a pea once the mass of the Higgs boson is known ....
...)
(for the mods, its a reference to the scifi show Lexx
This signature was left intentionally blank.
Well, to people who think that a Higgs boson is gravity, I guess it is informative. For everyone else, it's sort of like saying "a watermelon is NOT a puppy dog".
I like to place meaningful quotes in my sig, so people will know that I know what meaningful quotes are.
Oh dear. This is just increasing the number of people who thing that Star Trek is real. I realise that they're merely out to sell copy, but you'd hope that National Geographic would retain some sense of integrity.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
Parent pretty much sums up particle physics, and why people don't get it.
If they don't find a Higgs boson, they're still stepping into a massive new range of collision energy. I think the LHC will produce collisions with a total energy of 14TeV (I haven't read about this for a while).
This step up allows all sorts of other interesting experiments to be run too.
Not to mention, GP smells a little under-the-bridge. But so does every post related to religion on slashdot.
That description is gravity as described by Newton's universal gravitation. Under general relativity, gravity is a warping of space-time, not a force. In the various incarnations of quantum field theory, gravity is mediated by a (hypothetical) elementary particle called the graviton. It works, put simply, much like the electromagnetic field, which is mediated by virtual photons, but in this case it would be virtual gravitons.
SciAm, Discover and Alan Boyle's Cosmic Log on MSNBC have all covered CERN's history and present project(s; there's two different Higgs experiments being built), and managed to do so without the silly-assed references to God particles, The Force and Star Wars. Is it too much to hope for that /. will someday stop putting out stuff written for adolescent mentalities and tastes? Probably so, since it's getting worse instead of better.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B
I could get behind that...
Understanding the scope of the problem is the first step on the path to true panic.
As the other poster mentioned, photons are affected by gravity in as much as they travel through a space-time that is curved by massive objects. So the path of a photon (e.g. light) can be deflected by a gravitational field.
To those who would then say "Aha! So clearly photons do interact with gravity!", it's important to note that photons may be affected by the curvature of spactime, but they don't have mass and thus don't interact gravitationally. For instance, photons cannot attract each other gravitationally (whereas matter does), and a photon won't attract matter gravitationally.
True confidence comes not from realising you are as good as your peers, but that your peers are as bad as you are.
The force was so much more in ep 4,5,6. Why did they have to screw it up with Midichlorians? It's more like an invisible link between all living and intert objects just like the summary says. How do you think Yoda lifted that rock?
I prefer the idea of smashing politicians into each other to see if the resultant collision creates an honest politician (the equivalent of antimatter).
Unfortunately folks are mixing Newtonian and Einsteinian explanations of gravity. In Newtonian physics, the particles exert attraction on one another, in Einsteinian physics spacial geometry is curved around gravity wells (whether that's an atom, a human or a black hole), and it is that curvature that causes bodies to attract.
Cue the bowling ball on the mattress with the marble moving towards it. That's a reasonable analogy of what goes on.
Then cue quantum mechanics, which takes such a delightful model and tosses it on its head.
The world's burning. Moped Jesus spotted on I50. Details at 11.
I think you're a little confused. The large hardon collider won't work properly if you're behind it - you want the large black hole collider, next door.
which is totally what she said
Not necessarily. Wait 'til you cut your puppy open and you'll be glad you did.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
The most incredible thing anyone could hope for is that the higgs boson isn't there.
No higgs boson would be utterly incredible.
No higgs boson would be like the sudden realization that there's no aether. When we had to swallow that one, the result was special relativity and the whole world changed.
After all, the whole concept of the higgs is a scalar field permeating the whole universe giving things inertial mass. That field quantizes into these little happy things called Higgs Bosons, which, if Higgs was right, ought to be producible like any other particle by pumping enough energy into a small enough space enough times for the odds to be in the experimenter's favor. The fact that you ought to be able to make a higgs boson (and, to be cruely explicit, watch it decay in a rather unique way that leaves little doubt that what decayed was a higgs) is a prediction that's almost something of a side-effect of the existence of the higgs.
Higgs seems a lot like the logic of aether applied to the problem of inertia, at a high level. Aether, if you recall, was some stuff permeating the universe through which light travels as waves, giving it its observed properties.
Higgs plugs a hole in the standard model, that of inertia, that happens to also come from the same fundamental something (mass) that results in gravity. Higgs lets us just sort of ignore the whole inertial mass = gravitational mass thing and therefore not worry about annoying things like relativistic quantum gravity, which is enough to give anyone enough of a headache to be unable to apply enough duct tape to make it work (renormalize the infinities away). It also doesn't hurt that the energy levels we're playing with still leave gravity a pretty meaningless force, in terms of the magnitude of its effect on the actual behavior of particles.
If higgs isn't there, there's a lot of work to do in the standard model again. There would be answers we don't have, and some of those answers could very well go to the very nature of inertia and gravity itself. That would mean physicists can stop playing with toy models of 11-dimensional energy spaghetti branes (I'm not a fan of M theory just yet) and get back to some real work that's testable in the real world with a real supercollider, which we just happen to have build, called the Large Hadron Collider.
Right now, to make physicists deal with the holes in the standard model, without going straight to energy spaghetti branes, one has to bring up something annoying like neutrino oscillation. No higgs would be a field day.
No higgs would make the LHC immediately worth every cent, and woth every politician some physicist had to give head to to make it a funded reality.
I hope the Higgs boson isn't real.
Even if it doesn't, I'd consider the experiment a success.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
But this all has nothing to do with Gravity in the sense of "things attracting each other due to their mass", or rather "mass curving space-time". The Standard Model does not incorporate Gravity in the picture (that's why it's called the Standard Model of Particle Physics, not Physics as a whole). The theory for this force is (still!) called "General Relativity". Despite a lot of really intelligent people (no self-compliments here, I have stopped working in the field as I felt way too stupid for it) trying really hard, we still don't have a generally accepted theory for how Gravity and the other, (quantum) theories can be combined in a principled manner. CERN might help a lot with this but, ultimately, we might have to wait till the big crunch, if it ever comes, to see how all those fields really unite.
But really people, why do we need Star Wars to make this sound cool? This is an amazing universe of ours. It doesn't need George Lucas to make Light and Magic.
I know we shouldn't rely on /. for physics advice, but last weekend, on the advice of a misguided commenter, I kicked a deuterium atom down the linear accelerator in my backyard the wrong way, and hoo boy! I won't be hearing the last of that one for awhile.
Your mind is clear / The things that you fear / Will fade with how much you / Believe what you hear
Curved spacetime is a mathematical model we use to describe the motion of matter in a gravitational field, it doesn't mean space is physically curved. "Spacetime" doesn't really exist, it's an abstract mathematical concept that combines physical space with the fourth time dimension and that is what physicists use to model gravitational effects.
That's why physicists are so keen on finding a so called "God Particle", because gravity still can't be explained. We can model its effects, but since space doesn't curve some other mechanism must be at work to transfer gravitational force between objects.
IANAP, so if there are any real physicists out there correct me if I'm wrong.
Murphey's fighting Occam, and we're in the stands.
Not on a Tempurpedic matress. Maybe that's why NASA uses it, it defies the laws of gravity!
As our way of thanking you for your positive contributions to Slashdot, you are eligible to disable Slashdot 2.0.
All matter is made from the same fundamental particles whether it's "living" or "inert". That is until we discover the lifeform field they use on Star Trek.
Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
Er, photon has sufficient momentum to kick other things around. Normally, momentum is given by p = gamma * m * v (gamma = 1 for v much less than c), but for particles with m = 0, this is wrong and momentum is now given by p = E / c (where E, for photons, is given by h*f).
Unless you are going to invoke "relativistic mass" (fewer and fewer physicists use this term—mainly because a relativistic mass is the same damned thing as relativistic energy, given the correspondence between mass and energy), photon has no mass.
Nevertheless, my sibling posters are right, and the source of gravity (the source term in the Einstein equations, analogous to the electric charges in Maxwell's equations) is the stress-energy tensor (not simply rest mass of particles) and photons do contribute to that.
Not quite, he does raise the valid question of why spacetime curves, something which I've never seen answered anywhere. It can't be gravity causing the curve, as gravity is the curve, so what causes it is a good question. Obviously the answer is mass, but why and how that mass curves spacetime is still a good question...
There are two kinds of fool One says 'This is old therefore good' Another says 'This is new therefore better'- Dean Ing
When I was in high school I read the book "The God Particle" by Leon Letterman (This is a really good book). I was wondering if the he was the first person to call the higgs boson the "god particle".
Written nicely in an entertaining way for the layman such as myself.
I couldn't help noticing this statement though :
"He has long, gray hair and a long, white beard and, with all due respect, looks as if he belongs on a mountaintop in Tibet."
Those physical features are notably absent from the stereotypical mountain top Tibetan dweller - ie the Tibetan monk. Ah, using Google images shows a couple of people with long beards, but not typical, judging from the results.
My guess is that he's talking about the Unix lab named "Tibet" at Berkeley University where you'll undoubtedly find many such specimens.
Yes, I made that up - I've no idea if there's a Unix lab named "Tibet" at Berkeley.
Max.
I've never understood something about the Higgs boson. It is supposed to give the massive bosons their mass, right? And yet, at the same time, it is itself supposed to be a massive boson, right?
Yes that is correct, the Higgs boson gives itself mass. If you use John Ellis' example of the Higgs field being like mud and the more the mud sticks to an object the heavier, and harder, to move it becomes. Well imagine you try to move a lump of mud. Mud sticks to mud so even just moving a lump of mud will be hard. This is what the Higgs boson is, metaphorically speaking.
Ok. Considering a curvature in spacetime is just a convienience. It is useful to construct field theories because you don't have to worry about the time it takes energy to propagate. You just calculate the field at every point and at any point in time. Then you can ignore the particles that created the field and just consider what happens locally to determine the motion of your particle. In other words, the field is just a construction of a differential (as opposed to integral) form of the force equation.
That being said, photons are most definitely affected by gravity. Gravitational fields are created and interact with energy. Thus photons have a gravitational field and attract each other gravitationally (at least theorically, because the induced gravitional field is both incredibly small and utterly dwarfed by the electromagnetic interation of the photon so we haven't been able to measure it yet). Energy is equivalent to mass (think E=mc^2). It is true that photons have no rest mass, but they do have an effective mass, seeing how they are energy carriers. Electrons have a gravitational field. Electric fields have a gravitational field. Even gravity induces a gravitational field (the self-interaction effect, AKA inertia).
ANYTHING that is deflected by a gravitational field's curved spacetime is by definition interacting with gravity. Curved spacetime IS gravity, not just an effect of it. If two objects don't attract each other gravitationally, then they wouldn't be deflected by a gravitational field. Think neutrons in an electromagnetic field. They have no electric attraction (to first order anyway) and they are, for exactly the same reason, unaffected by a magnetic or electric field (again to first order).
I browse with a +6 bias on troll (for the comedy), so your comment was near the top :)
About a year ago I was lucky enough to attend an informal talk given by Dr Helen Heath of Bristol University, who is involved in the LHC project. At the talk, somebody asked pretty much the same question; what if it finds nothing? Isn't it an awful waste of money that could be spent on $GOOD_CAUSE?
The answer was this: While it certainly is an expensive great big hole in the ground, the project has been funded by taxes on European citizens, and there's quite a lot of them. The grand total came out at something like 2 pounds sterling (~$4) per taxpayer. It has already advanced our technology to the point where pretty much anybody would be happy with the cost.
First IAAP (just not a PhD Physicist, so if that is your definition of a real Physicist, well then I guess I don't qualify).
Secondly, it is not necessarily true to say Space doesn't curve. We are three-dimensional beings and thus cannot perceive anything in the fourth dimension. That is not to say that space-time is a physical dimension. It is a handy mathematical model which may or may not have an actual physical representation. The simple fact is, that if there is a fourth physical dimension to space, and there are many who believe there may be, and it doesn't violate any laws, so it is possible. Thus it is possible that Space is truly curved and we in like manner to Flatlanders cannot directly perceive higher dimensions. So the answer, as in many advanced Physics problems is that we really just don't know whether Space is curved or not, although you'll get all kinds of science speak that makes you think we do know.
Lastly, it is common to refer to space as curved when dealing with many problems, and there are real reasons to consider the possiblility that space is truly curved, due to the properties of space around massively heavy objects, such as blackholes and our own Sun, which is massive enough to "bend" light. Or perhaps space-time is curved by the mass of the Sun.
Your pencil doesn't move, everything else does. /itsallrelative
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Let's start with your followup question: the curvature of space is no more a "mental model" than other objects more modern science, such as photons, DNA, or other galaxies. It is a fact in the following sense: the world around us behaves (to a great accuracy) as if it is "really" curved, there "really are" electrons and photons, "there is" a big molecule called DNA with a double-helix structure etc. If you want, a pattern of dots on a photographic plate is a "fact". The double helix is a mental model that explains this fact. But the distinction is not useful when you're doing physics. If you accept that the goal of physics is to predict the behaviour of the world to a given accuracy, you should also accept that it is not useful to make the distinction between what the world "really is" and what it "appears to be" (for our purposes here -- not as a metaphysical question).
Next, you are confused because you are trying to use two different mental pictures of gravity at the same time, and probably don't have a good mental picture of photons. So I will analyze the situation from the points of view of both Newtonian mechanics+Special relativity and General Relativity. In Newtonian gravity, particles are affected by gravity which is an interaction between all pairs of particles. If A attracts B then B attracts A, in fact with the same magnitude of force. The interaction is proportional to the mass, so an object of "zero mass" won't interact with anything, but such an object doesn't make sense anyway (what happens to F=ma in this case?).
Now what about electromagnetic radiation? You can treat it either as a electric and magnetic fields filling space, or as composed of photons. In either case, it has momentum (do you know about light sails?) and also energy (you can be heated by sunlight!). Special relativity says (E=mc^2) that if you have energy you also have mass. You can now make a naive model in which the elecromagnetic field generates gravity according to its energy density (every small piece of space contains some elecromagentic field, this has energy and hence mass; it is a source of gravity), or you can make a model in which each photon generates gravity according to its mass. In the second case you can even calculate the effect of other masses on the photon -- the deflection you will see for a photon passing near the sum is about half what is observed in practice.
The picture above is not self-consistent. The reason is that Newtonian mechanics allows for action-at-a-distance (gravitational fields propagate at infinite speeds) which cotnradicts relativity. A better picture is that of General Relativity: the space itself is now allowed to change with time. Now there are two separate effects: first, bodies moves along the analogue of "straight lines" in a curved space; second, the curvature of space changes with time -- both under its own effect (gravitational radiation, if you want) and under the effect of the "contents" of space. The "contents" including everything in space. That includes elecromagnetic radiation -- it has mass, momentum, and can act as a source for gravity, by changing the curvature of spacetime.
Part o
The large hardon is looking for Higg's bosoms? I can relate to that.
~ I am logged on, therefore I am.
I never liked the bowling ball on the mattress analogy because actual gravity is needed to make the bowling ball move, so the analogy is muddled. Is there another analogy that would work without the use of actual gravity?
LS
There is a fine line between being a cultivated citizen and being someone else's crop. - A. J. Patrick Liszkie
You wanna knock off the fat jokes!
My other car is a 1984 Nark Avenger.
It doesn't. Curved space is a perfect explanation for why things moving in a straight line curve through space, aka planets, stars, light, etc. But nobody is sure why the gravity attracts to objects together in the first place. The theoretical graviton is supposed to transfer force in the same way that the other forces are transmitted but none has been seen because the energies required are phenomenal. Phenomenal as in about a billion times what the LHC can produce. Gravitons - in theory again - act at Plank lengths (10-33 cm) which is why its hard to test.
Nobody was sure why electromagnetism produced electricity for a while either even though Faraday had proven the relationship through observation. This had to wait for relativity and the concept of electrons to explain. Magnetism is caused by the time dilation of electrons as they travel down the wire - yes its a relevalistic effect of the transmission of electricity.
Gravity is not cracked yet.
We do not inherit the Earth from our parents. We borrow it from our children.
I've been wondering about the same thing, particularly when it comes to the marbles-on-a-rubber-sheet analogy. The sheet is obviously curved because our familiar Newtonian gravity pulls the ball/marble downwards. But that curvature then becomes Einsteinian gravity. So the analogy is a prime example of circular reasoning.
A somewhat related issue is, why is the speed of light constant? Special relativity seems merely an observation of how the universe works, not a particular insight as it doesn't explain the basic premise.
Escher was the first MC and Giger invented the HR department.
In his book Lederman estimates that a third of the world's GNP is somehow related to quantum mechanics. Seems a pretty good return on investment so far.