Comments on: Panels, panels, panels…

By: LuboÂš Motl's reference frame

LuboÂš Motl's reference frame — Sat, 27 Aug 2005 21:14:00 +0000

Let us build the ILC

JoAnne Hewett has encouraged everyone to promote the ILC, the “Imaginary Linear Collider”, as our phenomenological friends call it. It is a pleasure to follow her instructions. My comments are primarily addressed to the true American patriots who, I …

By: JoAnne

JoAnne — Sat, 27 Aug 2005 04:28:25 +0000

TM, Both Matthew and Sean gave you very good answers (while I was eating dinner..) regarding the differences between the ILC and LHC. I will be writing many longish posts in the future, further demonstrating the physics capabilities and complementarity of the 2 machines. It is like having two different sets of tools in your toolbox – some tools are good at one job and the other are needed for other jobs. To paint a very broad picture, the LHC is good at discovering particles, while the ILC is good for discovering just what the particles are and what theory they originate from.

By: Sean

Sean — Sat, 27 Aug 2005 02:59:28 +0000

For an idea of just how messy the LHC will be, see my old post about CERN. Smashing protons together allows you to reach very high energies, but not to do delicate fine-scale investigations of what you find. For example, if the dark matter is the lightest supersymmetric particle, to calculate its abundance you need to know the masses and couplings of a whole set of supersymmetric particles to high precision. This is exactly the kind of thing a large linear collider will do for you (after you've, hopefully, used the LHC to actually discover supersymmetry).

By: Matthew

Matthew — Sat, 27 Aug 2005 02:32:59 +0000

What is the difference between the ILC and LHC? What
is the former to contribute that the latter won’t.

The LHC is going to smash protons together, the ILC will smash electrons. The protons have the advantage that they can be accelerated to much higher energies. However, they are “messy”, you’ve got 6 quarks, all strongly interacting. This seriously complicates things. Whereas the electrons are “clean”. All you have is the electron and the positron, and you know exactly what they do (anihilate to a virtual photon or Z0).

By: Adam

Adam — Fri, 26 Aug 2005 23:54:17 +0000

I’m not feeling the love here, Quantoken.

By: Quantoken

Quantoken — Fri, 26 Aug 2005 23:49:22 +0000

How shallow minded are that this bunch of super string theoretists, who have no business in experiments, are discussing how to beat their peers in science research and extract more taxpayer dollars to build the next generation super size particle colliders, at the time when the world has something much more urgent to worry about. As I discussed our current model of civilization is simply not sustainable. Is it totally by chance, or by market manipulation, that we see oil price reaching $68 a barrel and shotting up fast? NO! The world's oil has PEAKED And there is no viable replacement in sight. The civilization is facing an unprecedented crisis. We are going to see oil price to continue spiral up and it could only get worse. And in a few decades it will be all gone. Isn't it time that we start to concentrate a considerable amount of resource on researches how we are going to deal with this very real and imminent crisis? Quantoken

By: tm

tm — Fri, 26 Aug 2005 23:00:13 +0000

What is the difference between the ILC and LHC? What
is the former to contribute that the latter won’t.

By: JoAnne

JoAnne — Fri, 26 Aug 2005 22:13:15 +0000

Yes, we have learned many lessons from the SSC, and we are just starting to present the ILC physics case to the broader scientific community. For their part, I hope that the broader scientific community noticed that their budgets also decreased when the SSC was cancelled and learned that it is not a zero-sum game.

Turns out the ILC is damned good at measuring the properties of WIMPS. Stayed tuned….

By: Risa

Risa — Fri, 26 Aug 2005 21:53:28 +0000

Oh, I completely agree with this, Sean. I think how likely astronomers in particular are to support the ILC depends strongly on how well the case is made by those who care about it.

By: Sean

Sean — Fri, 26 Aug 2005 21:51:02 +0000

Well, as the explained in the Augustine article that Steinn mentioned in comments to another post, it's often scientists of one specialty that undermine the funding requests for scientists of another specialty. And astronomers and particle physicists have not always treated each other nicely in this respect. The SSC was hopefully a good lesson to the particle-physics community on the need to explain themselves; "Well, it's higher energy, so of course we need it" will just not cut it. I remember giving talks to astronomers and mentioning that the SSC might help us understand baryogenesis (by exploring electroweak symmetry breaking), and hearing "Wow, nobody ever told me that." So, yeah, we should do our part to explain the ILC and its motivation as clearly as possible.

By: Risa

Risa — Fri, 26 Aug 2005 21:42:13 +0000

JoAnne, I certainly encourage more such posts, as I would guess that the detailed case for a new linear collider is not probably appreciated by most physicists who aren’t working directly in the field. Start with us friendly astronomers, since we’ll likely be easier to convince than the rest of the world =)

By: Clifford

Clifford — Fri, 26 Aug 2005 21:33:42 +0000

JoAnne, I was certainly not completely joking. That battle will be for real.

-cvj

By: JoAnne

JoAnne — Fri, 26 Aug 2005 21:19:26 +0000

Wolfgang, we tried that comparison with the SSC, with obviously little success. My view is that comparisons are rarely effective in funding discussions; it’s always better to just be positive about the science you want to do and to not put down anybody else.

By: JoAnne

JoAnne — Fri, 26 Aug 2005 21:15:44 +0000

Clifford, don’t laugh – we were concerned about the press taking hold on this issue and reporting the wrong impression. I decided to post anyway, because I think the message of the outcome is important and is what everyone needs to stayed focused on.

Peter, CLIC was not specifically discussed yesterday, but it is certainly part of the mix. However, there is much, probably decades worth, of technology R&D that needs to be done for CLIC. These things take alot of time. (Keep in mind that we are 3-4 years away from a design for the ILC and its technology is proven!) The CLIC machine people themselves have recently said that the knowledge gained from the operation of a TeV-scale Linear Collider (i.e., the ILC) is a necessary step in developing a CLIC design. I do hope that we will have a multi-TeV electron-positron collider someday, and I hope that I am not pushing up daisies when it is built!

By: tmccort

tmccort — Fri, 26 Aug 2005 21:11:33 +0000

Wolfgang, I wasn’t aware the ISS had any scientific value.

By: Peter Woit

Peter Woit — Fri, 26 Aug 2005 20:59:38 +0000

Clifford, I know you were teasing. Me too, it’s not like I’m serious about putting off the book. Must figure out how to insert those little smiley things….

By: Wolfgang

Wolfgang — Fri, 26 Aug 2005 19:47:52 +0000

Maybe it would help in public discussions to compare the cost of the ILC with the ISS (the international space station) and also compare the scientific value.

By: Clifford

Clifford — Fri, 26 Aug 2005 19:31:31 +0000

Peter…. I was teasing a little. Not really aimed specifically at you or anyone in particular, ok?

Just a little humour.

-cvj

By: Peter Woit

Peter Woit — Fri, 26 Aug 2005 19:25:22 +0000

Last comment cut off due to use of less than sign. The cut off part was just “less than 20 years)?”

By: Peter Woit

Peter Woit — Fri, 26 Aug 2005 19:23:39 +0000

Clifford,
Just wondering what blogs you have in mind that question whether high-energy physics colliders are doing science or not, I don’t know any…. And if the string theory community is willing to agree that roughly four years is the time frame for giving up on string theory if it hasn’t had any experimental success, let me know and I’ll hold off on publication of my book until then.

Joanne,

Was there any discussion of CLIC at the panel discussion? My impression was that one reason CERN was encouraging the idea of waiting for LHC results was that they hoped that CLIC might be far enough along by then to make it an attractive alternative to the ILC. Does any one believe that CLIC is something feasible within a reasonable time-frame (e.g