The Large Hadron Collider is Powering Back Up, What Next?

A segment of the Large Hadron Collider's super-cooled electromagnets. Credit: CERN/LHC

A segment of the Large Hadron Collider’s super-cooled electromagnets. Credit: CERN/LHC

After a 2 year hiatus for a significant upgrade, the Large Hadron Collider is being switched back on and, early on Sunday, the world’s most powerful particle accelerator saw the first circulation of protons around its 27 kilometer ring of superconducting electromagnets.

This is awesome news, especially as there was a minor electrical short last week that could have derailed this momentous occasion for weeks, or maybe months. In one of magnet segments, a metallic piece of debris from the upgrade work had become jammed in a diode box, triggering the short. Manual removal of the debris would have forced a lengthy warm up and then cool down back to cryogenic temperatures, but CERN engineers were able to find a quick fix — by passing an electrical current through the problem circuit the tiny piece of debris was burnt away, no warm-up required.

With this small hiccup out of the way, the complex task of circulating protons around the LHC began this weekend, resulting in two sparsely populated beams of protons speeding around the LHC in opposite directions. So far, so good, but the particle accelerator is far from being ready to recommence particle collisions.

“Bringing the LHC back on, from a complete shutdown to doing physics, is not a question of pushing a button and away you go,” Paul Collier, head of beams at CERN, told Nature News.

Sure, the LHC is circulating protons, but it is far from restarting high-energy collisions. In fact, over the coming weeks and months, engineers will be tuning the machine to finely collimate the counter-rotating beams of protons and gradually ramping-up their speed. The first collisions aren’t expected to begin until June at the earliest.

But seeing protons pump around the LHC for the first time since 2013 is an awesome sign that all the high-energy plumbing is in place and the electrical backbone of the accelerator appears to be working in synergy with the massive magnetic hardware.

Over the next 8 weeks, engineers will turn on the LHC’s acceleration systems, boosting the beam energy from 450 GeV to 6.5 TeV, gradually focusing the beams in preparation for the first collisions.

According to Nature, the re-started LHC will slam 1 billion pairs of protons together every second inside the various detectors dotted around the accelerator ring with a collision energy of 13 TeV, boosting the LHC’s energy into a whole new regime. During the LHC’s first run, the maximum energy recorded was 8 TeV.

This makes for a curious time in cutting-edge particle physics.

Before the LHC was fully commissioned in 2008, its clear task was to track down, discover and characterize the Higgs boson, the last remaining piece of the Standard Model. Having achieved the Higgs discovery in 2012 — resulting in the 2013 Nobel Prize being awarded to Peter Higgs and François Englert — physicists have been combing through the reams of data to understand the new particle’s characteristics. Although a lot still needs to be learnt about the famous boson that endows all matter with mass, Run 2 of the LHC has a rather vague mission. But “vague” certainly doesn’t mean dull, we could be entering into a new era of physics discovery.

I always imagine that powering up the LHC is like this... completely inaccurate, mind you.

I always imagine that powering up the LHC is like this… completely inaccurate, mind you.

We’ve never seen collision energies this high before, and with the Standard Model all but tied up, physicists are on the lookout for phenomena with an “exotic” flavor. Exotic, in this case, means the production of quantum effects that cannot be easily explained or may be driven by mechanics that have, until now, been considered pure speculation.

Personally, I’m excited that the LHC may generate a signature that we cannot explain. I’m also trilled by the possibility of micro-black holes, the discovery of dark matter particles, potential hints of supersymmetry and quantum gravity. But I’m doubly-thrilled by the prospect of something popping out of the collision debris that doesn’t make any sense.

As the LHC will now slam protons (and, later, ions) at energies nearly double of what it was previously capable of, we are in uncharted territory. Physicists are recreating the conditions of the Big Bang, condensing primordial particles and forces from the concentrated energy of colliding beams of charged particles. So far, after only 7 years since the LHC was first powered up, it has already confirmed the existence of a Standard Model Higgs boson. So now, without a single ultimate goal, the LHC will do what physics does best, discovery-driven science that could answer many quantum mysteries and, hopefully, create many more.

Advertisements

Forget Black Holes, Let’s Look For Black Rings

A bubble ring. Could a black hole take on this shape at higher dimensions? (©letsdiveguam.com)

Black holes are as extreme as anything can get. When a massive structure can no longer sustain its own gravity, it will collapse to a point known as a singularity. For example, a massive star after it has gone supernova may leave one of these singularities behind, a remnant of massive star death, sucking any local matter into a one-way trip to the guts of space-time.

At a certain point, when light itself succumbs to the black hole’s gravity, an event horizon forms, beyond which universal physics breaks down; we have very little idea about what lies inside the event horizon. All we do know is that you don’t want to fall into one, you’d be stretched and spaghettified. Spaghettification is due to extreme (and when I say extreme, I mean as-extreme-as-it-can-get) tidal forces between your head to your toes.

So, the message is: Don’t play with black holes, it can only end in tears.

Now the Black Hole Health & Safety lecture is over, it’s time to talk about “black rings”. Under certain conditions, black holes may not be the mathematical singularities we once knew and (thought we) understood.

In a recent publication by Masashi Kimura at Osaka City University in Japan, the black ring idea is explored in 5-dimensional space. In the space-time we know and love, there are three spatial dimensions and one temporal dimension. We are four-dimensional creatures. When string theory came along in the 1980’s we really began to appreciate that there could be more than the four dimensions we live in.

Previously, cosmologists have entertained the thought that black rings may exist in our 4D space-time. However, the big problem comes when trying to understand how these structures maintain their shapes; surely they should simply collapse and form your regular black holes? Actually, it depends on how big they are and how the competing forces balance out.

As the Universe is expanding, it is thought black rings could exist if they are of scales similar to the cosmological constant (this constant was derived by Einstein to explain a “flat” Universe, but later it was found the constant was required to characterize the universal expansion as observed by Edwin Hubble in 1929). If a black ring exists in 4D space-time, its gravitational collapse would be countered by the expansion of space-time (as characterized by the cosmological constant).

A bubble ring, as made by a dolphin, for fun (©deepocean.net)

A bubble ring, as made by a dolphin, for fun (©deepocean.net)

The only analogy I can relate this to in the terrestrial world is bubble rings (or, indeed, smoke rings). When under water, a bubble will rise to the surface. However, under the constriction of surface tension, the bubble will form the smallest possible shape. When a bubble ring is produced, there needs to be a balance between surface tension and a vortex. The surface tension pulls in, while the vortex maintains the bubble ring shape, pushing out.

In the case of the black ring, gravity is pulling inward, while the expansion of space-time is countering it, pushing out. In this situation, in an expanding Universe, there could be enduring examples of black rings out there.

In Kimura’s research, not only are black rings a possibility, there could be a number of different complex shapes that could form when considering these extra dimensions. When the Universe was young, multiple interacting black rings may have been possible, eventually coalescing to form black holes.

Although this research is very interesting, it is hard to imagine how we could observe these higher-dimensional black rings. Would we see them as a singularity (i.e. a black hole) in our 4D space-time? Or would they even be unobservable for lower-dimensional beings such as ourselves?

Publication: Dynamical Black Rings with a Positive Cosmological Constant, Masashi Kimura, 2009. arXiv:0904.4311v2 [gr-qc]

Via: arXiv blog

Will the LHC Peel Open Some New Dimensions?

A possible visualization of microscopic extra dimensions. Source: http://www.physto.se/~troms/

A possible visualization of microscopic extra dimensions. Source: http://www.physto.se/~troms/

As we near the Large Hadron Collider’s (LHC) maiden relativistic collision later this year, speculation and excitement continues to mount. There are a host of possibilities as to what we may observe from the most powerful, focused collisions ever carried out in a laboratory environment. Fundamentally, the search for the Higgs boson will be taken to a new level, but there may be a few surprises for the particle physicists analysing the detector data. What if the LHC uncovers an alternative to the Higgs boson? What if the “standard model” of quantum theory isn’t to a universal standard? Putting the Higgs boson to one side, forgetting the exciting possibility of a micro-black hole (and confirmation of Hawking Radiation) and leaving the production of wormholes and stranglets in the “unlikely” drawer, what possibility intrigues me the most? The discovery of microscopic, curled-up dimensions the LHC may unravel as it focuses its energy on scales previously unthinkable…
Continue reading

Could Warp Drive Become a Reality?

The physics behind the warp drive (Richard Obousy and Gerald Cleaver)

The physics behind the warp drive (Richard Obousy and Gerald Cleaver)

In science fiction, the “warp drive” helps Captain Kirk, Jean-Luc Picard, Commander Janeway and Benjamin Sisko potter around space with ease. Without warp speed, TV episodes of Star Trek would stretch into months and seasons would last decades. Alas, even science fiction succumbs to the laws of relativity: Nothing, not even light (or a Klingon) can travel faster than the speed of light. As I researched for a recent Universe Today article, the space between the stars is prohibitively large, even the nearest star is over 4 light years away (Proxima Centauri), so how could it be possible for USS Enterprise to flit from one star system to the next without putting a dent in Einstein’s theory of relativity? The answer comes if we realise that although light speed is a physical limit on how fast things can travel through space-time, there is no limit on how fast space-time can travel if it is warped. Suddenly we have a theoretically possible means of travelling between the stars by altering the fabric of the Universe in a warp “bubble”…
Continue reading

Large Hadron Collider May Help Us Glimpse Into another Dimension

Superstring theory could have some observational basis with the LHC. Image credit: New Scientist

High energy collisions by the nearly-completed Large Hadron Collider (LHC) may be able to generate particles that are sensitive to dimensions beyond our four dimensional space-time. These exotic particles, called Kaluza-Klein gravitons, would be highly sensitive to the geometry of extra-dimensions, giving scientists an idea about what lies beyond our universe. If these particles are detected, and if their characteristics can be measured, then perhaps the extra dimensions predicted by string theory may be proven to exist… [more]

Will Time be Replaced by Another Space Dimension?

Space-time cones - what if time were to disappear?

What if time disappeared? Yes, it sounds like a silly question – and if the cosmos sticks to the current laws of physics – it’s a question we need never ask beyond this article. Writing this article would in itself be a waste of my time if the cosmos was that simple. But I’m hedging my bets and continuing to type, as I believe we have only just scratched the surface of the universal laws of physics; the universe is anything but simple. There may in fact be something to this crazy notion that the nature of the universe could be turned on its head should the fundamental quantity of time be transformed into another dimension of space. An idea like this falls out of the domain of classical thought, and into the realms of “braneworlds”, a view that encapsulates the 4-dimensional universe we know and love with superstrings threaded straight through… [more]