# Tag Info

1

Nuclear-fusion experiments have been extensively performed with accelerators in the last decades of the 20th century reaching the proton drip-line. Today they are still object of interest allowing the study of superheavy elements. However the energy of the LHC is way too high. At that energy scale you go in the regime of quark-gluon plasmas and the nuclear ...

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No, because the LHC puts too much energy into its particles for them to fuse. While we need enough energy to fuse particles, too much will stop it from happening.

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The simple answer is No. Fusion happens at nuclear energies between particles to be fused, i.e. MeVs, because it is at the framework of nuclear bound states. LHC particles start with energies of TeV, so particle particle interactions are way over any nuclear bound state levels. Even if one accelerates deuterium nuclei the phase space is way over the ...

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Since all that 360MJ is concentrated in a beam of 2800 segments each about 30cm in length and 1mm diameter and it's total equivalent energy is about that of 77kg of TNT, if you got hit with it there would not be much left. The beam would dump its energy in about 100uS, resulting in a power of about 3.6 petaWatts

3

The current collision energy of the restarted, upgraded LHC is 13 TeV. This is about $2 \times 10^{-6}$ Joules. Water has a specific heat capacity of about 4.2 Joules per gram per degree Kelvin. So this tiny amount of energy would heat up a gram of water (i.e. a large drop) by about $5 \times 10^{-7}$ degrees. That's for a single collision between two ...

2

On average the density of dark matter in the universe is about the same as two hydrogen atoms per cubic metre. That's about 0.00000000000000000000001% of the density of air (a factor of $10^{-25}$). So even if it did interact with light, the effect of the relative permittivity and permeability would be negligable. But dark matter doesn't interact strongly ...

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Concerning EM force: According to modern understanding, even if all matter could be removed from a volume, it would still not be "empty" due to vacuum fluctuations, dark energy, transiting gamma- and cosmic rays, neutrinos, along with other phenomena in quantum physics. Is the “quantum vacuum” contaminated given there is nothing that can block a magnetic ...

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The permittivity and permeability of free space are non-zero in 'absolute vacuum' and they will be unaffected by dark matter which interacts extremely weakly (if at all) with the EM force. We might need to modify gravity to account for dark matter (hopefully not) but that's all.

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As irish guessed in the comment, this is about beam alignment and tuning. A high intensity beam can damage the beam pipe (as in cut right through to the helium jacket) or cause a unusually hard superconducting magnet quench. The former is disastrous and the latter has some potential outrun the quench protection with similarly unhappy consequences. Having a ...

1

I've found this computer generated picture of the engravings in an article in the CERN document server about the sculpture. You can't see everything, but it's quite high resolution and you can make out a lot of the writing if you zoom. I'm not convinced that that computer generated image, however, matches the sculpture that was built in these photos in the ...

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One has to be aware that the data from the LHC experiments are studied by about 3000 physicists in each collaboration, which include students for a PhD. Thus, even though many people study the same favorite theory, all the possible predictions from theoretical models are evaluated at some study group and a publication will come out giving either direct ...

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Let me begin with your naive estimation of the significance. Sixteen ($o=16$) events are observed over an expected background of $b=4.2\pm1.6$. I presume that you have calculated that $$\frac{o - b}{\delta b} \simeq 7.4,$$ concluding that the excess has a significance of $7.4\sigma$. There are a two main mistakes in this interpretation of the data and ...

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The first difficulty in making a measurement of this kind is, of course, to build the facility. However once you solve all the engineering issues and put your machines in place, the experiment flow is pretty straightforward: you run and you get the data, in principle without any human intervention. Up to here you just let Nature do its work in a pretty ...

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Most of the reproduction of results in particle physics comes from two sources: Competing experiments running nearly simultaneously. In this case both ATLAS and CMS got comparable results. Now, they are both using the beam from the LHC, so how do we know the beam is properly understood? Because while they were commissioning those machines they reproduced ...

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Do we have any similar experiments where we confirm a theory without being able to reproduce those results? Not today, but once we know how it works we can repeat it on a smaller and cheaper scale. The first electronic calculators required an entire floor, consumed staggering amounts of power and cost a budget-busting amount of money. Today, my phone ...

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The question is "how much scientific confidence can we put into things like the mass of the Higgs". Well, what is the level of certainty? According to CERN it is around 7 sigma. In simple terms at 7 sigma, both the CMS and ATLAS teams are reporting that there’s only a 0.0000000001% chance that they haven’t found a Higgs-like particle.

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