
The Circular Electron Positron Collider - mathgenius
https://johncarlosbaez.wordpress.com/2016/09/16/the-circular-electron-positron-collider/
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Jizzle
I'm under the impression that the reason we couldn't confirm the Higgs boson
before the LHC was that electron-positron colliders could not easily produce
the massive particles needed. Proton-proton or Proton-antiproton collisions
seem to be much more useful for Higgs production. The Large Electron–Positron
Collider _almost_ got us there and it exceeded 200 GeV. What then would a 250
GeV machine do for us?

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mattheww
The argument in favor of an electron-positron collider is that there is much
less "junk" in the detector from the hadron collision. So the trade-off is
that you produce a lot fewer Higgs bosons, but, in principle, you are able to
measure each Higgs much more precisely. Having a machine at 250 GeV puts us at
the sweet spot for producing the Higgs with mass 125 GeV.

There is some discussion in the community about whether it truly is going to
advance the field to build such a machine. It's not super clear whether the
various proposed 250 GeV machines will improve on what will be done by HL-LHC.
From the Chinese point of view, though, it absolutely is the right decision to
build this machine on the way to a 100 TeV hadron collider, since they
desperately need to build up some local expertise in constructing/operating a
large collider.

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Jizzle
Ah, thanks. This gives me better perspective.

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jfoutz
I don't know if it matters that much, if there are direct results from the
research itself. I mean, the World Wide Web worked out pretty well. I don't
know if that would be a thing without CERN. There's lots of cool engineering
that has to happen to build stuff at that scale. Maybe the age of cool side
effects is over, but it seems like time and time again, we get great stuff.

NASA with smoke detectors and aluminum cnc machining. Cracking the enigma gave
general purpose computers. Just trying to do something no one has done before
forces discovery of other cool stuff, independent of the actual research goal.

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stephengillie
What new technologies have been developed at CERN, for the LHC?

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captainmuon
I'm more involved in the analysis / software side of research, and somebody
who is working on hardware can probably tell you more about technology spin-
offs. In fact, I'd like to hear about them, too.

One thing that has been pioneered at the LHC is grid computing. Basically we
were doing cloud computing before it was cool. Of course, the requirements of
science and industry are different, and we were quickly overtaken in scale by
Amazon, Google, etc.. But still, particle physicists were among the first to
connect different data centers across the world to a unified resource. You
just say "do this computation on this dataset" and the system finds the
optimal place to perform the calculation without copying too much data around,
and delivers the packaged up datasets back when it's done.

Many spin-offs are small improvements of existing technology, giant leaps are
rare. An example of an incremental step are improved solar panels [1] using
LHC vacuum technology. There is also a lot of work done on superconductors and
magnets that is cutting-edge, but I don't know if it has found application
yet.

We have a lot of hardware development that is really interesting, but too far
away from consumer electronics to be used as a spin-off, like radiation hard
electronics, or high precision particle detectors. Maybe some of this will go
into medical devices.

We used to be early adopters of machine learning (e.g. neural networks) and
pattern recognition techniques, but have been utterly surpassed in these
fields by industry recently, and are only starting to import modern
techniques, like deep neural networks.

[1]: [http://www.symmetrymagazine.org/breaking/2012/03/16/cern-
spi...](http://www.symmetrymagazine.org/breaking/2012/03/16/cern-spin-off-
more-efficient-solar-panels)

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dnautics
The superconductor stuff is persistent physics myth; commercial
superconductors were largely developed for NMR spectrometers used by the
petrochemical industry about a decade before superconducting supercolliders.

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jakub_h
Interesting, any references?

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dnautics
[http://www.nmr2.buffalo.edu/resources/edu/matr/40yearsofPNMR...](http://www.nmr2.buffalo.edu/resources/edu/matr/40yearsofPNMRS.pdf)

first superconducting NMR magnet was built in 1962, by a commercial NMR
company (bruker). 1970 was the first commercial superconducting FT-NMR.

The first superconducting synchrotron was planned around 1974 (ESCAR) and
wasn't completed. the SSC was first discussed in 1976. CEBAF is the first
accelerator to actually deploy superconducting technology in any form... But
its use is in the RF chambers (the walls of the rf chambers are
superconducting which allows them to transfer energy by charge oscillation
more efficiently to the electron beam), not in the bend magnets.

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hossbeast
If you build it, they will come

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CamperBob2
_The Chinese political landscape is entirely different from that of the US. In
particular, for large scale constructions, the political system is superior.
China has already accomplished to date many tasks which the Americans would
not, or could not do; many more will happen in the future._

Eh? Speak up, it's hard to hear anything up here on the Moon.

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vilhelm_s
List of countries who have landed on the moon in the last 40 years: China.

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Maken
In the last 40 years?: China, USSR.

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vilhelm_s
I was working off
[https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon](https://en.wikipedia.org/wiki/List_of_missions_to_the_Moon)
, which says the last Soviet moon landing was 40 years and a month ago.

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sperglord
I don't understand. There are plenty of probes from other countries listed in
that article.

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antientropic
Those were all orbiters (plus two impactors).

