Quantum Physics

this is far bigger than the detection of gravity waves.  

http://blogs.scientificamerican.com/guest-blog/is-particle-physics-about-to-crack-wide-open/

Is Particle Physics About to Crack Wide Open?
Hints of an unexpected new particle could be confirmed within days—and if it is, the Standard Model could be going down
By Michele Redi on June 13, 2016


It’s December 15, 2015, and an auditorium in Geneva is packed with physicists. The air is filled with tension and excitement because everybody knows that something important is about to be announced. The CERN Large Hadron Collider (LHC) has recently restarted operations at the highest energies ever achieved in a laboratory experiment, and the first new results from two enormous, complex detectors known as ATLAS and CMS are being presented. This announcement has been organized hastily because both detectors have picked up something completely unexpected. Rumors have been circulating for days about what it might be, but nobody knows for sure what is really going on, and the speculations are wild.  

The CMS spokesperson takes the stage first, giving a presentation with no surprises until the very end, when two plots appear showing the energies—theoretical and actual—carried by a flood of particles emerging from head-on collisions between protons traveling at nearly the speed of light. If you squint, there appears to be bump in the experimental curve, suggesting too many events at one point than theory would predict. It could be evidence for a new, unexpected particle—but at a level that’s merely interesting, not definitive. We’ve seen things like this before, and they almost always go away when you look more closely.

Then Marumi Kado from ATLAS steps up, with a strangely confident look in his eye—and when the results finally flash on the screen, the audience understands why. ATLAS has seen the bump too, at the same point as CMS did, but now it’s so prominent that you can’t miss it. This really does look like a new particle, and if it is, there is suddenly an enormous crack at the very heart of high-energy physics.

The signal is one of the simplest you can imagine: it represents two high energy photons emerging from the decay of a subatomic particle created in a proton-proton collision. It’s very similar to the signal that led to the discovery of the Higgs boson in 2012. But this particle is not the Higgs boson: it is six times more massive. Nobody had predicted anything like this. It is shocking to the physicists in the auditorium. People look around, astonished, trying to confirm that their own reactions are reflected in what they see in their colleagues’ faces. If the observations are confirmed, it will be revolutionary. This could mean nothing less than the fall of the Standard Model of particle physics (SM), which has passed every experimental test thrown at it since it was first put together over four decades ago.

The SM describes what the building blocks of the universe are and how they work, and from there, at least in principle, explains every other phenomenon in nature. Originally theorists thought that the SM would be an approximation of a more fundamental theory that would be quickly discovered. This is what has always happened in the past. Newton’s theory of gravity, for example, doesn’t apply to bodies that are extremely massive, or which are moving close to the speed of light. It is accurate enough that engineers could use it to send the New Horizons space probe toward Pluto and have it arrive in just the right place nine years later. Einstein’s theory of General Relativity, however, is more fundamental, and applies in those extreme where Newton’s theory breaks down.

Moreover, there are many reasons to believe that the SM is incomplete. In particular, the mechanism that generates the mass of the elementary particles suggests that the theory must be modified at higher energies. To discover this new physics was the number one motivation for the construction of the LHC and several other experiments before that.

To theorists’ surprise, however, the SM has performed much better than originally expected. This has been both a blessing and a curse for particle physics for many years. On one hand, the discovery of the Higgs boson was an enormous success, identifying the SM’s last, and arguably most important, building block. On the other, the fact that the Higgs has just the mass and all the properties everyone expected generated a widespread pessimism about new discoveries. The search for a more fundamental theory might drag on indefinitely.

But the bumps in the ATLAS and CMS data, which showed up at an energy of 750 billion electron-volts (GeV), would completely change this situation overnight, making it virtually certain that more discoveries will be coming during coming years. If the hint of a new particle is real, the successes of the SM suddenly will have come to an end.

The importance of this result is clear to everybody working in the field and it has immediately triggered a huge amount of work on the possible implications. None of the more fundamental models that currently exist as possible replacements for the SM can explain the bump. If the SM has fallen it is likely not for any reason we expected. If the new particle is real, it is absolutely unclear what might be its role in the greater scheme of things. Maybe it is related indirectly to the Higgs boson somehow, or maybe it is connected with the puzzle of dark matter in the universe. Or maybe it is just there by chance. Certainly these are questions that scientist will have to answer in the future and more data will help to understand what lies ahead.

This is by far the most exciting thing that has happened in particle physics over the last three decades. If this hint of new physics is confirmed—something that could happen within just a few weeks, or possibly even within days—it is difficult to state the importance of such a discovery. It would be bigger than the detection of the Higgs boson, which was just confirmation of what was already known.
If the bump is real, we are about to start writing a whole new chapter in the history of fundamental physics. It is impossible to imagine where this could lead.
We could know the answer very, very soon.


ABOUT THE AUTHOR(S)
Michele Redi
Michele Redi is a research scientist at INFN Florence, Italy. He received his Ph.D. from Johns Hopkins University in 2004 before holding positions at New York University, EPFL and CERN. His research focuses on physics beyond the Standard Model of elementary particles

None of the more fundamental models that currently exist as possible replacements for the SM can explain the bump. If the SM has fallen it is likely not for any reason we expected.

He's talking about supersymmetry, possibly string theory. But neither of these explains dark matter either. I hope the bump is confirmed, and leads to something that gets us out of the current cosmological logjam.

A more measured article in the Guardian, published in March. The Scientific American article was a retrospective of past events, and I'm rather surprised I hadn't heard about it before.

https://www.theguardian.com/science/2016/mar/18/excitement-grows-over-large-hadron-colliders-possible-new-particle-lhc

OOOooooOO!!! This is exciting!

He writes well, too!

To discover this new physics was the number one motivation for the construction of the LHC and several other experiments before that.
To theorists’ surprise, however, the SM has performed much better than originally expected. This has been both a blessing and a curse for particle physics for many years.

I think that says it nicely. Researchers want to be correct, but not too correct 'cause that would spoil the game!

The Standard Model always felt like duct tape and baling wire to me. I never learned the mathematics because it felt totally ad hoc, which is not the way math should feel. If this pans out I hope something that feels as inevitable as General Relativity pops out, but I really doubt it. Feynman's QED feels inevitable, but the particles it pastes together do not.

Nothing wrong with baling wire and duct tape. It gets the job done. Our farm wouldn't run without it. Still, there are days when I dream of shiny new vehicles where all the doors open and all the lights and switches work. Not gonna happen, but I can dream. I guess it's the same for particle physicists...

does this new particle come in pink?

The catalogue is not in production yet. But we don't even know if it will have quarks. If it does, it will obey quantum chromodynamics and hence will have color.

If you mix a red gluon with a red, blue and green gluon, you'd get pink. But that ain't supposed to happen....

it would be ironic if Dark matter turned out to be pink.

Ah, the headlines: "Dark Matter a Pinko Plot"

{{{Just another spurious drunken rambling thought for the brain boxes to tell me why Im wrong about it!

I was thinking about time and space. Now as I understand they are the same thing, time is just space looked at a different way, space is just time looked at a certain way. Cant have space with no time to happen in, and cant have time with no space for it to happen it. They are one and the same- spocaeace/time continuum ect.

Now shamanistically it could be said that ever person exists in their own universe, not in the same one. But scientifically I have never heard the phrase space relativity.

Einstein showed that time was relative to the person experiencing it, its individual- my time is not your time, if I get abducted by aliens, and I always have my towel on standby, and head off for a few months into space at the speed of light and come back, you lot will have grown old and died in the same amount of time. Time is relative to the perceiver, and affected by your movement in space, what them being the same thing.

So surely it follows the shaman view is correct too? If time is relative, and time and space are the same, then space must also be relative? No? }}}}

No, time and space are not treated as the same thing. They go together into a sort of pythagorean addition with 4 instead of 3 dimensions, but whereas you square each space dimension and add it in, you square the time dimension and then subtract it!

If you have a stick of a given length, and look at each component in x,y, and z, then if you look at it from different directions, x,y,z will all change, but the total length represented by x^2 + y^2 + z^2 will remain the same.

Turns out you can change your time by speeding up or slowing down, and then x^2 + y^2 + z^2 - t^2 will remain the same. Note the minus sign.

{{{The problem of course with asking people smarter than yourself a question is figuring out the answer! So if length doesn't change what happens if you accelerate a thing to near the speed of light? Doesnt its mass increase exponentially as time dilates? Isnt that changing its dimensions? }}}

I have to remember the general public doesn't recognize when a classical example is put forth before diving into relativity.

If a stick is sitting still relative to you so that if it originally lined up with the x coordinate, so that x^2 = Length^2 (with the y and z components being zero), then if it (or you) rotates around so that for example it's halfway between the x and y axes, the x component will become shorter as the y component becomes longer, so that x^2 + y^2 = L^2.

If the stick is not moving relative to you, then if an ant crawls along the stick, it will measure the same length you do in the same amount of time you measure it crawling along. But if the stick does move relative to you, you will see the length of the stick shorten as the time it takes the ant to move from one end to the other gets longer (yeah, it's weird). Meanwhile the ant doesn't see any change in time or length.

hmm...I seem to have gotten things confused so that time is acting like the space dimension, going up as length goes down. I'll have to come back to this. But there is a definite twist in the way time works compared to space. I just have to get that minus sign to show itself.

Okay, I was so focussed on the length of my stick that I failed to realize the stick was itself travelling through space, so I do get the time and space relations I expected. But here's a video which explains things somewhat briefly but with diagrams.

http://www.popularmechanics.com/science/a22449/time-dilation-confusing/

halfwise wrote: I was so focussed on the length of my stick ...

{{{{Of course another problem with asking folk cleverer than yourself a question, is not just understanding the answer, but understanding the clarification of the answer }}}}

Okay, the twin paradox is the best way to do this.  But let me set the stage again.  when you rotate a stick around, as the x component gets shorter the y component gets longer, satisfying the pythagorean equation so that the length stays the same.

If I sent my twin off galivanting off around space, by the time he got back I'd say that he had travelled a long distance in a long amount of time.  He'd say (since I'd locked him inside a space ship with no windows) that he'd travelled nowhere, but not as much time had passed (he'd be younger than me).

With the stick example as one spacial dimension got shorter, another spatial dimension got longer to compensate, so that they would all ADD to the same thing.  But with time, as the spatial distance he thought he travelled got shorter, his time also got shorter, so that if you SUBTRACT space and time you get the same thing.  That's how time is different from space.

halfwise wrote:Okay, the twin paradox is the best way to do this.

I think that's right, and I'd suggest people stop and think about the meaning of "paradox" before going any deeper.  Relativity theory is basically a clever solution to a paradox, and paradoxes by their very nature require you to let go of something you took for truth before they let you solve them. Tricksy things, paradoxes!

{{{Ok- lets start with a new assumption- I am much stupidier and drunker than you already believe me to be, that might be hard to believe but go with it.

So lets break down what you said Halfy-

'when you rotate a stick around, as the x component gets shorter the y component gets longer, satisfying the pythagorean equation so that the length stays the same.'

Ok all I get from this is that it makes Pythagoras happy

So I have a pencil in my hand right now, the wonders of one handed typing!

If I am holding it upright, are you saying the y axis would be large and the x small, but if I hold the pencil horizontally the x axis is now long, but the y axis is now small?
Thus, to borrow a technical term from Doctor Who, it prevents the object in space going all wibbly?

Is that the sort of thing you are getting at? And where has z gone in all this if we are talking about a 3-dimensional object in space?

Anyhow, so next you say-

'With the stick example as one spacial dimension got shorter, another spatial dimension got longer to compensate, so that they would all ADD to the same thing.  But with time, as the spatial distance he thought he travelled got shorter, his time also got shorter, so that if you SUBTRACT space and time you get the same thing.'

Um.....ok......so why does that show they are not the same thing? I mean, sorry, I realise I am missing the whole point contained, mysteriously, somewhere in this paragraph, but um, yeah.....  }}}}

Let me see if I can translate.

Suppose you're a young hobbit of a certain age(t), height(x), breadth(y) and thickness(z). As you travel through time you'll continue to perceive yourself as the same height, breadth and thickness as you've always been. Observers in another frame of reference however may perceive you to become older and shorter, and also broader and thicker (which will keep Pythagoras happy )

I hope that helps!

Petty - the example of the pencil is to remind you how everyday reality works - you have to sum up lengths in different directions (actually their squares) to preserve the reality of a pencil in space not changing length when you rotate it. It's so simple and commonplace we don't give the idea the credit it deserves.

But in space-time, the time part subtracts instead of adds. If that doesn't show that time is different from space, I don't know what does.

Relativity is fiendishly difficult, even when mathematically simple, because it takes the non-intuitive assumption that the speed of light is constant even if you are moving towards or away from the source, and applies ruthless logic to it. It's hard to keep your mind from rebelling against even the simplest arguments, and losing track of the logic. Quantum mechanics is actually much easier.

{{{Um I still dont see why that has to mean they cant be just two apsects of one thing- a coin has a head on one side and a tail (actually usually a crest or design of some sort) on the other, and if your flipping one on something that matters then its quit an importance difference- but they are still the same coin.}}}


{{{From the first two short clips here- trailer and a clip from the program, you might think this belongs on the Who thread- but Who is just the draw for the audience, the main meal is science served up by the ever likeable Professor Cox}}

{{{Jupiter- from above}}