A vast cavern is the stage for tests to find the 'God particle'

The Times ^

[andy224]

Atlas holds key to scientists' map of Universe By Mark Henderson A vast cavern is the stage for tests to find the 'God particle'

SCIENTISTS have taken a step closer to finding the “God particle” that is thought to shape the Universe. In a concrete cavern 130ft deep and bigger than the nave of Canterbury Cathedral, they will mimic the high-energy conditions that existed fractions of a second after the Big Bang to study a beam of energy a quarter of the thickness of a human hair.

The vast Atlas cavern, which was completed last week at Cern, the European nuclear physics laboratory on the Franco-Swiss border, will house parts of a giant atom-smasher that is expected to solve the most elusive riddle in physics.

When the £1.5 billion Large Hadron Collider (LHC) is switched on in 2007, it will determine once and for all whether the Higgs boson, a mysterious fundamental particle held to give matter its mass, really exists. If the machine finds the boson, proposed by Professor Peter Higgs of Edinburgh University in 1964, it will prove that the Standard Model for the nature of the Universe is correct. If not, the maxims of modern physics will be thrown into disarray.

The boson was nicknamed the “God particle” by the Nobel laureate Leon Lederman for its centrality to the cosmos. Although it will be so small that its presence can only be calculated, not seen, the search for it requires some of the largest and most advanced scientific instruments designed.

The LHC itself is a ring 17 miles (27km) in circumference, buried up to 100m (330ft) underground, through which streams of protons will be bent by the world’s most powerful magnets and smashed into each other at close to the speed of light.

The new cavern, which will house the Atlas detector for tracking the Higgs and other particles, is 40m (130ft) deep, 55m (180ft) long and 35m (115ft) wide.

However, the proton beam that runs through both devices measures just 10 microns in diameter: less than a quarter of the thickness of the average human hair. Roger Cashmore, a British physicist and Cern’s director of research, said: “It is an astonishing feat of engineering. The consultants were on the verge of saying it was impossible to build. But the Atlas cavern is finished, the biggest of its kind in the world, and these experiments are going to tell us whether we’re right about the Universe.”

The current best guide to the nature of the Universe is the Standard Model, an elegant theory that describes how most particles and forces interact. The Higgs boson is its missing keystone: without it, there is no good explanation for why matter has mass and therefore exists.

According to the theory, the Universe is permeated by a field of Higgs bosons, which consist of mass but very little else. As particles move through the field, they interact with it like a ball dropped into a tub of treacle, getting slower, stickier and heavier. Their ultimate mass depends on the strength of the interaction.

Though mathematics predicts its existence, the Higgs boson has never been detected. It is so heavy that the biggest atom-smashers, Cern’s Large Electron-Positron collider (LEP) and the Tevatron at Fermilab in Illinois, have been unable to generate the high energy collisions needed to reveal it, although they have found hints that it is probably there. This is where the LHC comes in. It is 70 times as powerful as the LEP and seven times stronger than the Tevatron, covering all the energy values at which the Higgs might exist. If it is there, it will find it.

What is more, if the “God particle” proves to be a false deity, the LHC will unlock the secret of what is out there instead. “If it doesn’t find the Higgs, it will find what substitutes for it,” Dr Cashmore said.

Jim Virdee, Professor of Physics at Imperial College, London, and a leading Cern researcher, said: “There has to be something else, beyond what we have found already, that explains mass. We believe it’s the Higgs, but Nature may be smarter than us. Either way, the results will tell us what is the right road.”

The atom-smasher will accelerate protons so close to the speed of light that they become 7,000 times heavier than normal. The beams are bent into a circle by superconducting magnets, cooled by liquid helium at -271.4C, almost a degree colder than outer space.

When the protons collide, they are destroyed in a huge burst of energy. This energy coalesces into very heavy particles, one of which scientists hope will be the Higgs.

As the boson is unstable, it will quickly decay, scattering a characteristic signature of smaller particles and energy. These will be picked up by the LHC’s eyes — the Atlas and a sister detector — which surround the collision points.

The detectors, which stand 22m (72ft) and 15m (49ft) tall respectively, are “giant microscopes” built like onions, with several layers of instruments that track particles and measure energy.

The experiments will generate enormous quantities of data, much of it unwanted. “Colliding two protons is like colliding two oranges,” Dr Lyn Evans, director of the LHC project, said. “You’ll occasionally get a collision between two pips, the interesting bits, but you’ll get a lot of pulp. We need to reject an enormous amount of data to pick out the important bits.” Professor Virdee said that the data generated in one second was the equivalent of what all the world’s telecommunications generated in one year.

Even if this wealth of information proves the existence of the Higgs boson, the LHC will continue to serve scientific knowledge for decades.

“Let’s say we have the Higgs,” Dr Cashmore said. “I’d feel warm and content for a few microseconds, then I’d be asking new questions. Why does it affect different particles in different ways? “It would be spectacularly good to find it — I’m not trying to knock it — but it will pose a whole new set of problems. If we are an inquisitive society, these are the things we ought to be doing."

[Ichneumon]

Nowadays we don't worry about that problem, because the theory of Inflationary Cosmology accounts for that exquisite balance.

I guess I'm behind on my cosmology. Could you quickly expand on the above statement? Thanks.

[TomB]

Thanks for the support.

The book is very intricately constructed, and at times I felt that if any paragraph had been lost, the whole thing would unravel like a tapestry with a broken thread.

That is EXACTLY the way I'm reading it. Each statement seems to build on the last, so I spend a lot of time working my way through it.

But I'll take your advice and try to enjoy the reading more.

Thanks again.

[Reelect President Dubya]

Maybe because mathematics was invented by humans to be a notational representation of agreed-on human logic, and human logic is far from perfect.

That's pretty much what it says, just that the agreed-upon human logic is mathematics.

[RightWhale]

mathematics was invented by humans

Math is something men have, it defines man. It is the ability to learn. It was required of those wishing to enter Plato's Academy.

[tictoc]

The Coming of the Storm.

This is what happened. On the night that the worst heat wave in northern New England history finally broke-the night of July 19-the entire western Maine region was lashed with the most vicious thunderstorms I have ever seen.

We lived on Long Lake, and we saw the first of the storms beating its way across the water toward us just before dark. For an hour before, the air had been utterly still. The American flag that my father put up on our boathouse in 1936 lay limp against its pole. Not even its hem fluttered. The heat was like a solid thing, and it seemed as deep as sullen quarry-water.

...

The air began to move, jerkily at first, lifting the flag and then dropping it again. it began to freshen and grew steady, first cooling the perspiration on our bodies and then seeming to freeze it.

That was when I saw the silver veil rolling across the lake. It blotted out Harrison in seconds and then came straight at us. The powerboats had vacated the scene.

...

I went downstairs again. All three of us slept together in the guest bed, Billy between Steff and me. I had a dream that I saw God walking across Harrison on the far side of the lake, a God so gigantic that above his waist He was lost in a clear blue sky. In the dream I could hear the rending crack and splinter of breaking trees as God stamped the woods into the shape of His footsteps. He was circling the lake, coming toward the Bridgton side, toward us, and all the houses and cottages and summer places were bursting into purple-white flame like lightning, and soon the smoke covered everything. The smoke covered everything like a Mist.

...

That was the direction that funny fogbank had come from. And it was the direction Shaymore (pronounced Shammore by the locals) lay in. Shaymore was where the Arrowhead Project was.

That was old Bill Giosti's theory about the so-called Black Spring: the Arrowhead Project. In the western part of Shaymore, not far from where the town borders on Stoneham, there was a small government preserve surrounded with wire. There were sentries and closed circuit television cameras and God knew what else. Or so I had heard; I'd never actually seen it, although the Old Shaymore Road runs along the eastern side of the government land for a mile or so.

No one knew for sure where the name Arrowhead Project came from and no one could tell you for one hundred percent sure that that really was the name of the project-if there was a project. Bill Giosti said there was, but when you asked him how and where he came by his information, he got vague. His niece, he said, worked for the Continental Phone Company, and she had heard things. It got like that. "Atomic things," Bill said that day, leaning in the Scout's window and blowing a healthy draught of Pabst into my face. "That's what they're fooling around with up there. Shooting atoms into the air and all that."

...

A tentacle came over the far lip of the concrete loading platform and grabbed Norm around the calf. My mouth dropped wide open. Ollie made a very short glottal sound of surprise - uk! The tentacle tapered from a thickness of a foot-the size of a grass snake-at the point where it had wrapped itself around Norm's lower leg to a thickness of maybe four or five feet where it disappeared into the mist. It was slate gray on top, shading to a fleshy pink underneath. And there were rows of suckers on the underside. They were moving and writhing like hundreds of small, puckering mouths.

Excerpts from The Mist, a Stephen King story.

[longshadow]

It is an experimental fact that the "empty" vacuum can be polarized in this fashion.

But can an Electrolux be modified to work in the Arctic? ("polarized vacuum" - nyuk-nyuk!)

[longshadow]

I guess I'm behind on my cosmology. Could you quickly expand on the above statement?

I'll try to give the "Cliff-notes" version:

First, gravitational fields have a negative energy associated with them; the stronger the field, the greater the negative energy ("Physicist" can give you an example which illustrates that gravitational fields have negative energy.)

Whatever matter/energy existed immediately after the BB took place has some gravitational field(s) associated with it. The Inflation phase creates new space that wasn't there before (again, see "Physicist" for an explanation of the mechanism by which the rapid expansion of space occurs).

Now, for the really cool part: whenever new space is created, it gets permeated by the existing gravitational fields, which means the negative energy associated with those fields is decreasing (meaning increasing negatively). But the Law of Conservation of Energy says you can't create (or destroy) energy like that, so something has to happen to balance the energy equation so that the net result is zero energy change. That mechanism is the creation of new matter/energy in the newly created space! And the really cool thing is that the Conservation of Energy requirement means that the quantity of new matter/energy being created is EXACTLY equal to the negative energy of the gravitational fields! This means that as the Universe Inflated, the end result HAS TO BE a Universe in which the matter density is equal to the "critical" value at which the energy of the gravitation fields is counterbalanced by the positive matter/energy in the Universe.

IOW, the "perfect balance" isn't a case of extraordinary "fine tuning" or dumb luck, but rather is a consequence of one of the most basic Laws of Physics, the Conservation of Energy. The Universe had no choice but to turn out this way.

[Another geek alert]: Conservation of Energy is intimately connected with a fundamental feature of the Universe, by way of Noether's Theorem. Energy is conserved iff the rules of physics are invariant under continuous temporal transformation, which is true iff the Universe is temporally homogeneous. Similar relations exist for Conservation of momentum, and angular momentum, which relate respectively to the spatial homogeneity and isotropy of the Universe.

Or so I understand....

[Moonman62]

So we're confident that Inflation is reasonably close to the truth. From there, inferring the conditions close to the Big Bang is a matter of straightforward calculation. If those conditions had been ever so slightly different, the universe would look very different from the way it does now.

You said as an example that 50th decimal place values could be significant without Inflation. Above you seem to be saying that there is still some sensitivity to initial values even with inflation. Is that correct?

BTW, I really enjoy your Geek Alerts!

[Aric2000]

Eyes boggling, brain exploding placemarker.

[PoorMuttly]

I just threw away one of those particle thingies last week.

Didn't know it was worth anything.

I'll ask Shaggy if he has any left from his last party.

[PatrickHenry]

OK, now you try composing a sentence with "stuff stuff is is."

What I say is stuff your "stuff stuff is is" stuff, is that clear?

[tortoise]

Anybody read it?

Of course. It is a classic, and for good reason. It isn't really written for Joe Layman, unlike many of the pop-sci books. GEB is more like a clever and lucid introduction to computational theory for people who are at least somewhat mathematically inclined but not requiring a rigorous mathematical education to understand. When it was written, a few of the ideas in the book were pretty cutting edge, but that is less true now. Nonetheless, it is a worthwhile read if one is inclined.

[shaggy eel]

,,, an emerging market in particles? Whoa! Got one in your size.

[Consort]

I was referring to your homo apologist posts of the past.

---

I don't apologize for anybody and don't ever make that sick accusation again.

Were you not suggesting that there is some "Greater" logic outside what science knows through measurable natural law.

---

My statement dealt strictly with logic and stands on its own merit. It says nothing about "Greater" logic or about natural law, so stop jumping to idiotic conclusions.

We don't live in the 5th dimension...we live in this one.

---

You didn't get that 5th diminsion crap from my post.

So what ever discoveries we have must be explained by the mathematics or science of where we are now.

---

You finally got something almost right. But science and mathematics are not always correct and is often wrong. Keep that in mind. And get a life.

[Physicist]

Then we must limit what is produced in the vacuum to the electron-positron pairs?

No, but because there is only one kind of electrical charge, any other charged particles can simply be treated as a heavy kind of electron. The calculation is otherwise the same.

Or has a similar calculation been done for all virtual particles?

For the strong, weak and electromagnetic forces, yes. That, for example, is what makes the muon g-2 experiment so sensitive a test of new physics: any new particle that hasn't been accounted for will change the experimental value at some level of sensitivity. As that sensitivity gets pushed to finer and finer levels, new physics gets discovered (or excluded, as the case may be).

[Outer Limits]

Cheap at any price, even £1.5 billion, to get us a little closer to understanding the universe.

2 Timothy 3:7

Ever learning, and never able to come to the knowledge of the truth.

[Consort]

Math is something men have, it defines man. It is the ability to learn. It was required of those wishing to enter Plato's Academy.

No, it's not. Most people don't know any math above arithmetic. And Plato is dead. Math has evolved over the ages.

[jwalsh07]

IOW, the "perfect balance" isn't a case of extraordinary "fine tuning" or dumb luck, but rather is a consequence of one of the most basic Laws of Physics, the Conservation of Energy. The Universe had no choice but to turn out this way.

Prior to t=0 the Laws of Physics were already firmly in place?

[Aric2000]

LOL, no they appeared as we made them up...

Sorry, solipsism is a sickness, and boy am I diseased!! LOL

[VadeRetro]

What I say is stuff your "stuff stuff is is" stuff, is that clear?

Quite clear, but ... really! Just stick the whole string in a quote!?? Talk about your cheap gimmicks!

Of course, my original example is worse. I was simply writing a sentence, noted that it contained a couple of awkward repeats, and was getting ready to recast the whole thing to get rid of them ...