They are doing that, are are doing upgrades to get more use of out of the LHC. The new planned collider is for about a generation from now.
If this goes ahead, it will be starting construction in nearly 20 years from now.
> If there is no new physics from the last experiment, why do we think that building a bigger microscope will be any different?
CERN has a specific remit. They're planning for that remit. If their funding sources do not think the odds justifies the expense, they'll cut funding, but it's not CERNs job to sit back and not come up with plans for what to do next. It's CERNs job to look at what they can do to enable further science within their remit.
They've come up with this as one option and decided to move forward with planning. That does not mean it will happen - if they don't get funding in place it won't, or will be delayed.
In the meantime the shorter term upgrades to the LHC may or may not end up supporting their case for the new collider depending on the results they get.
The LHC was built between 1998 and 2008, but its design started in the 1980's. Many of the people who worked on the LHC at its early stages have either already retired, or will be expected to retire relatively soon. The FCC is still in its very early stages and similarly long timescales are predicted for its completion. Building and operating a huge, complex machine like this isn't something we can just stop for a generation or two and pick up where we left off. In my view, if we want to maintain the skills required to build these facilities we need to invest in new, large projects now.
However, honesty about the situation should be rewarded; not punished.
2. Even successful research leads to papers with impenetrable names like “An MgB-Superconducting Shield Prototype for the Future Circular Collider Septum Magnet”, whose value I am not even qualified to comprehend unless someone explained it to me with a YouTube video
3. Because I don’t understand it and I can observe the value of it without understanding it, I’ll trust the physicists doing the experiments when they tell me they want a bigger and more expensive tool for their future experiments
Is it too difficult to estimate the EVSI ?
If you fail once, fail again but bigger... who cares it’s not our money and the bigger our project the more we pay ourselves...
The LHC likely would keep running for a generation, even if this new collider is constructed. The article notes that construction wouldn't begin until 2038. It doesn't say how long construction would take, but my guess is at least a decade (the LHC took a decade to build). So that's 30 years between now and the likely earliest time a new collider would be constructed, or 40 years since the LHC first went operational. Since the new collider would require construction of a new ring, it's possible the LHC would continue to operate while the new one is under construction, collecting more data.
The reason one needs a "bigger microscope" is due how signal to noise typically increases. In a simplified scenario, you're talking about poisson noise (shot noise, counting noise) dominating the error budget. The Signal-to-noise goes as the square root of the number of counts. So in order to double the S/N, you need to quadruple the number of events. In the case of a particle accelerator, that means doubling the amount of time.
The proposed collider would be 100 TeV, so ~6x more powerful than the LHC. All else being equal, the LHC could do some of the same experiments, but it would take it 36x longer to do them to the same statistical significance. Put another way, 1 year of operation of this proposed collider could achieve results it would take 36 years of the LHC to build up. 4 years of the new collider (doubling the signal to noise over the 1 year) would require 144 years (4 * 36) of the LHC.
But particle physics isn't a slow ramp-up in energy. There are collisions that can only be accessed once you reach particular energy thresholds. Unfortunately my understanding is that there aren't predicted "interesting" features above the LHC's energy range which are even remotely accessible in the distant future. So if you want to build a facility solely to find things that theories predict, this new collider may not get you much. But science is often advanced by experiments which find unexpected things, and you don't find those unless you look.
Overall I think the argument "let the LHC run for 40 years instead" is not a compelling one because of how shot noise works. The "maybe we'll find something new!" argument for a new collider is high-risk / high-reward, so I'm not sure how compelling I personally find it.
> In the case of a particle accelerator, that means doubling the amount of time.
This should say: "means quadrupling the amount of time" [to double the S/N].
https://en.wikipedia.org/wiki/Higgs_boson
>why do we think that building a bigger microscope will be any different?
Why do we think building a bigger telescope then Hubble will be any different:
The JWST is also hugely behind schedule, to the point that XKCD mocks it [2]. Originally scheduled for 2007, the launch date repeatedly slipped. The latest date, 2021, is now in doubt.
I think there's a big risk that this CERN supercollider would have the same cost and schedule risks.
[1] https://www.nature.com/news/2010/101027/full/4671028a.html [2] https://xkcd.com/2014/
The Large Hadron Collider went over budget by about double, which is bad but frankly for these sorts of cutting edge systems hardly unprecedented. Some of that was ironically due to budget cuts causing delays which in the long term increased costs.
If you want a prime reason things go over budget this is the prime one, not fully funding a project in order to save money. If you look at well executed projects they spend years setting up and then execute as fast as possible.
(2) Hubble is dieing. It will not last forever but still makes new discoveries, new science, regularly. A replacement is needed. And the JWST is a totally different device, not just bigger. We probably need both the JWST and a new Hubble.
The problem with colliders is that the next energy thresholds where we expect to observe unexplained phenomena are a couple orders of magnitude greater than the proposed collider. So we could really only confirm existing theories unless something major is hiding in the energy gap. This seems unlikely.
Critics want to put the money towards avenues where we're likely to observe new things instead of confirming validated theories.
And no, the higgs was a theory, now proven right (maybe you mean that by 'new physics'?)
Sorry but your view on the world is just depressing, its like we need 'new science' 'new physics' whatever that means, but building the experiment to proof a theory is right, is too expensive?
And no the JWST is a space telescope NOT something completely different from hubble, it's a telescope.
I would argue that the goal of a top-tier collider is to go to new energy ranges, plain and simple. Absence of new phenomena is gained knowledge, albeit a bit boring, but still.