Alaa Abdelhaq Blog
The Large Hadron Collider (LHC) is a gigantic scientific instrument near Geneva, where it spans the border between Switzerland and France about 100 m underground. It is a particle accelerator used by physicists to study the smallest known particles – the fundamental building blocks of all things. It will revolutionise our understanding, from the minuscule world deep within atoms to the vastness of the Universe.
Two beams of subatomic particles called ‘hadrons’ – either protons or lead ions – will travel in opposite directions inside the circular accelerator, gaining energy with every lap. Physicists will use the LHC to recreate the conditions just after the Big Bang, by colliding the two beams head-on at very high energy. Teams of physicists from around the world will analyse the particles created in the collisions using special detectors in a number of experiments dedicated to the LHC.
The LHC, the world’s largest and most powerful particle accelerator, is the latest addition to CERN’s accelerator complex. It mainly consists of a 27 km ring of superconducting magnets with a number of accelerating structures to boost the energy of the particles along the way.
Inside the accelerator, two beams of particles travel at close to the speed of light with very high energies before colliding with one another. The beams travel in opposite directions in separate beam pipes – two tubes kept at ultrahigh vacuum. They are guided around the accelerator ring by a strong magnetic field, achieved using superconducting electromagnets. These are built from coils of special electric cable that operates in a superconducting state, efficiently conducting electricity without resistance or loss of energy. This requires chilling the magnets to about ‑271°C – a temperature colder than outer space! For this reason, much of the accelerator is connected to a distribution system of liquid helium, which cools the magnets, as well as to other supply services.them collide is akin to firing needles from two positions 10 km apart with such precision that they meet halfway!
Thousands of magnets of different varieties and sizes are used to direct the beams around the accelerator. These include 1232 dipole magnets of 15 m length which are used to bend the beams, and 392 quadrupole magnets, each 5–7 m long, to focus the beams. Just prior to collision, another type of magnet is used to ‘squeeze’ the particles closer together to increase the chances of collisions. The particles are so tiny that the task of making
The LHC was built to help scientists to answer key unresolved questions in particle physics. The unprecedented energy it achieves may even reveal some unexpected results that no one has ever thought of!
For the past few decades, physicists have been able to describe with increasing detail the fundamental particles that make up the Universe and the interactions between them. This understanding is encapsulated in the Standard Model of particle physics, but it contains gaps and cannot tell us the whole story. To fill in the missing knowledge requires experimental data, and the next big step to achieving this is with LHC.
The precise circumference of the LHC accelerator is 26 659 m, with a total of 9300 magnets inside. Not only is the LHC the world’s largest particle accelerator, just one-eighth of its cryogenic distribution system would qualify as the world’s largest fridge. All the magnets will be pre‑cooled to -193.2°C (80 K) using 10 080 tonnes of liquid nitrogen, before they are filled with nearly 60 tonnes of liquid helium to bring them down to -271.3°C (1.9 K).
At full power, trillions of protons will race around the LHC accelerator ring 11 245 times a second, travelling at 99.99% the speed of light. Two beams of protons will each travel at a maximum energy of 7 TeV (tera-electronvolt), corresponding to head-to-head collisions of 14 TeV. Altogether some 600 million collisions will take place every second.
To avoid colliding with gas molecules inside the accelerator, the beams of particles travel in an ultra-high vacuum – a cavity as empty as interplanetary space. The internal pressure of the LHC is 10-13 atm, ten times less than the pressure on the Moon!
The LHC is a machine of extreme hot and cold. When two beams of protons collide, they will generate temperatures more than 100 000 times hotter than the heart of the Sun, concentrated within a minuscule space. By contrast, the ‘cryogenic distribution system’, which circulates superfluid helium around the accelerator ring, keeps the LHC at a super cool temperature of -271.3°C (1.9 K) – even colder than outer space!
To sample and record the results of up to 600 million proton collisions per second, physicists and engineers have built gargantuan devices that measure particles with micron precision. The LHC’s detectors have sophisticated electronic trigger systems that precisely measure the passage time of a particle to accuracies in the region of a few billionths of a second. The trigger system also registers the location of the particles to millionths of a metre. This incredibly quick and precise response is essential for ensuring that the particle recorded in successive layers of a detector is one and the same.
The data recorded by each of the big experiments at the LHC will fill around 100 000 dual layer DVDs every year. To allow the thousands of scientists scattered around the globe to collaborate on the analysis over the next 15 years (the estimated lifetime of the LHC), tens of thousands of computers located around the world are being harnessed in a distributed computing network called the Grid.
If a black hole formed, we actually know a fair bit about what it would behave like. The first thing is, if you stuck a black hole in the middle of the Earth, the layperson’s point of view is that it would be like a vacuum cleaner that sucks the Earth in. But that’s not the right picture. If you took the sun and you replaced it with a black hole the same mass as the sun, the orbit of the Earth wouldn’t change at all. We’d still orbit it — the force of gravity doesn’t care whether it’s a black hole or the sun, all it cares about is the mass. The big problem for us is it would be dark, but the gravity wouldn’t change.
It’s not so unlikely that the LHC could produce black holes, but it’s almost certainly true that if it produces those black holes, they are going to evaporate very quickly.
Any black hole that you know about in astrophysics is much, much heavier than the ones being produced in the LHC. If the LHC produced black holes which is uncertain they might be a couple hundred times more heavy than a proton, but way less than fractions of a gram. And at that size limit, we expect them to evaporate extremely quickly through a process called Hawking radiation [which takes its name from physicist Stephen Hawking, who first proposed the theory in 1974]. It would almost certainly radiate into particles we know about like photons, and so it would look like a regular collision. The hard thing would be to actually know you had a black hole in there.
The Large Hadron Collider (LHC) can achieve an energy that no other particle accelerators have reached before, but Nature routinely produces higher energies in cosmic-ray collisions. Concerns about the safety of whatever may be created in such high-energy particle collisions have been addressed for many years. In the light of new experimental data and theoretical understanding, the LHC Safety Assessment Group (LSAG) has updated a review of the analysis made in 2003 by the LHC Safety Study Group, a group of independent scientists.
LSAG reaffirms and extends the conclusions of the 2003 report that LHC collisions present no danger and that there are no reasons for concern. Whatever the LHC will do, Nature has already done many times over during the lifetime of the Earth and other astronomical bodies. The LSAG report has been reviewed and endorsed by CERN’s Scientific Policy Committee, a group of external scientists that advises CERN’s governing body, its Council.
Lately I was reading deeply about LHC (Large Hadron Collider).
and to be honest I was impressed of what these folks have done so far.
frankly I envy them! for the level they reach in their life, a level where they want to discover new thing and prove the big bang theory!!
in a 27 km tunnel, 100m underground they want to accelerate 2 protons to the nearest level of “light speed” and then bnag bang!!!
huge computers will be monitoring the collision results and hopefully they will get what they want!
hopefully no black holes
on the other hand my colleges at work were talking about (Bab 2l7ara) and (Nour and Muhanad)
when i toled them about LHC they didn’t believe it and start laughing about it!
I really feel sorry for them for our Arabic and Islamic Nation for the emptiness our youth suffering from!
I feel sorry for the old fashioned educational systems we have in our schools and universities!
I feel sorry for each smart person who got lost and confused cause of no jobs no money cause of old stupid people who don’t know how to use a computer WHO for sorrow leads us!!
and i feel sorry for myself!!