In this Talking Science event, Prof Welsch took a look at a few of cinema’s most mind-boggling moments of scientific inaccuracy.
He talked about where Hollywood gets the physics wrong and how the correct science would impact on the films, as well as about how actual experiments go beyond even the most exciting movie plots.
Professor Welsch studied physics and economics at the Universities of Frankfurt (Germany) and UC Berkeley (USA) and did his PhD in accelerator physics at the University of Frankfurt. After years as Postdoc at the Max Planck Institute for Nuclear Physics in Heidelberg (Germany, 2003-2004) and as Fellow at CERN (Switzerland, 2005-2007) he founded the QUASAR Group in 2007. He has been a member academic staff at the University of Liverpool and a member of the Cockcroft Institute of Accelerator Science and Technology since 2008. In 2011 he was promoted to Full Professor of Physics and has been Head of the Physics Department since September 2016.
He is also Head of the Accelerator Physics and QUASAR Groups. His research focuses on the development of advanced sensor and beam instrumentation, as well as on beam dynamics studies for frontier accelerators and light sources, accelerator applications, as well as novel accelerating techniques.
He has initiated and coordinated the EU-funded research and training networks DITANET, LA3NET, oPAC, OMA and AVA. He is also Director of the STFC CDT on Big Data Science, LIV.DAT. These are the largest research and training initiatives ever realised in his research area. He has been put in charge of the training of more than 100 postgraduate researchers. He has organized dozens of international schools and topical workshops for students, staff and the wider scientific community. As a member of various scientific advisory committees, he has contributed to defining future research trends and the advancement of physics in general.
Answers to the many questions posed during the talk are tagged at the end of the notes/recording.
The following are notes from the on-line lecture. Even though I could stop the video and go back over things there are likely to be mistakes because I haven’t heard things correctly or not understood them. I hope the Professor Welsch and my readers will forgive any mistakes and let me know what I got wrong.
1) The Flash
The Flash is an American superhero television series developed by Greg Berlanti, Andrew Kreisberg, and Geoff Johns, airing on The CW. It is based on the Barry Allen incarnation of DC Comics character the Flash, a costumed superhero crime-fighter with the power to move at superhuman speeds. It is a spin-off from Arrow, existing in the same fictional universe known as Arrowverse. The series follows Barry Allen, portrayed by Grant Gustin, a crime scene investigator who gains super-human speed, which he uses to fight criminals, including others who have also gained superhuman abilities.
The first season follows crime-scene investigator Barry Allen who gains super-human speed after the explosion of the S.T.A.R. Labs’ particle accelerator which he uses to fight crime and hunt other metahumans in Central City as the Flash, a masked superhero.
The clip shows how the Flash got his superpowers. It shows how a particle accelerator experiment goes wrong.
Can particle accelerators create superpowers?
What are particle accelerators and what are they used for?
Answer to the second question first. (The first question is answered at the end of the talk)
The European Organization for Nuclear Research (French: Organisation européenne pour la recherche nucléaire), known as CERN (derived from the name Conseil européen pour la recherche nucléaire), is a European research organization that operates the largest particle physics laboratory in the world. Established in 1954, the organization is based in a northwest suburb of Geneva on the Franco–Swiss border and has 23 member states. Israel is the only non-European country granted full membership. CERN is an official United Nations Observer.
The acronym CERN is also used to refer to the laboratory, which in 2016 had 2,500 scientific, technical, and administrative staff members, and hosted about 12,000 users. In the same year, CERN generated 49 petabytes of data.
CERN’s main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research – as a result, numerous experiments have been constructed at CERN through international collaborations. The main site at Meyrin hosts a large computing facility, which is primarily used to store and analyse data from experiments, as well as simulate events. Researchers need remote access to these facilities, so the lab has historically been a major wide area network hub. CERN is also the birthplace of the World Wide Web.
The Large Hadron Collider (LHC) is the world’s largest and highest-energy particle collider and the largest machine in the world. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundreds of universities and laboratories, as well as more than 100 countries. It lies in a tunnel 27 kilometres in circumference and as deep as 175 metres beneath the France–Switzerland border near Geneva.
First collisions were achieved in 2010 at an energy of 3.5 teraelectronvolts (TeV) per beam, about four times the previous world record. After upgrades it reached 6.5 TeV per beam (13 TeV total collision energy, the present world record). At the end of 2018, it entered a two-year shutdown period for further upgrades.
The collider has four crossing points, around which are positioned seven detectors, each designed for certain kinds of research. The LHC primarily collides proton beams, but it can also use beams of heavy ions: lead–lead collisions and proton–lead collisions are typically done for one month per year. The aim of the LHC’s detectors is to allow physicists to test the predictions of different theories of particle physics, including measuring the properties of the Higgs boson and searching for the large family of new particles predicted by supersymmetric theories, as well as other unsolved questions of physics.
Animation of CERN’s accelerator network. Following the path of the protons from the hydrogen bottle right through to collision inside the LHC experiments.
The source of the protons is simply from a bottle of hydrogen gas.
“To make the protons”, physicists inject hydrogen gas into the metal cylinder -Duoplasmatron – then surround it with an electrical field to break down the gas into its constituent protons and electrons (ionise it). This process yields about 70 percent protons.
The process can be simplified as follows:
For the LHC beam, the number of protons needed:
A single cubic centimetre of hydrogen gas at room temperature contains
Taking into account (1) and (2), the LHC can be refilled about 100000 times with just one cubic centimetre of gas – and it only needs refilling twice a day!
The particles are accelerated by a 90 kV supply and leave the Duoplasmatron with 1.4% speed of light, i.e. ~ 4000 km/s.
The Duoplasmatron is an ion source in which a cathode filament emits electrons into a vacuum chamber. A gas such is introduced in very small quantities into the chamber, where it becomes charged or ionized through interactions with the free electrons from the cathode, forming a plasma. The plasma is then accelerated through a series of at least two highly charged grids, and becomes an ion beam, moving at fairly high speed from the aperture of the device.
Then the resultant protons are sent to a radio frequency quadrupole, QRF -an accelerating component that both speeds up and focuses the particle beam. From the quadrupole, the particles are sent to the linear accelerator (LINAC2).
A small commercial hydrogen cylinder contains about 5 kg of gas. So the amount of hydrogen molecules is:
Taking into account that the process yields about 70% protons, there are
With (1), this cylinder can be used:
Since the LHC is filled every ten hours, this cylinder could be used for:
The hydrogen will diffuse out of the bottle faster.
1.34 x 1020 protons were accelerated in the accelerator complex in 2016. This might sound like a huge number, but in reality, it corresponds to a minuscule quantity of matter, roughly equivalent to the number of protons in a grain of sand. In fact, protons are so small that this amount is enough to supply all the experiments. The LHC uses only a tiny portion of these protons, less than 0.1%.
The protons are first sent into a linear accelerator
A linear particle accelerator (often shortened to linac) is a type of particle accelerator that accelerates charged subatomic particles or ions to a high speed by subjecting them to a series of oscillating electric potentials along a linear beamline.
Animation showing how a linear accelerator works. In this example the particles accelerated (red dots) are assumed to have a positive charge. The graph V(x) shows the electrical potential along the axis of the accelerator at each point in time. The polarity of the RF voltage reverses as the particle passes through each electrode, so when the particle crosses each gap the electric field (E, arrows) has the correct direction to accelerate it. The animation shows a single particle being accelerated each cycle; in actual linacs a large number of particles are injected and accelerated each cycle. The action is shown slowed enormously.
From the linear accelerator the protons are sent to the first circular accelerator (proton synchrotron booster)
Then into a second circular accelerator (proton synchrotron)
Then into a third (super proton synchrotron)
Then finally into the LHC.
A synchrotron is a particular type of cyclic particle accelerator, descended from the cyclotron, in which the accelerating particle beam travels around a fixed closed-loop path. The magnetic field which bends the particle beam into its closed path increases with time during the accelerating process, being synchronized to the increasing kinetic energy of the particles. The synchrotron is one of the first accelerator concepts to enable the construction of large-scale facilities, since bending, beam focusing and acceleration can be separated into different components. The most powerful modern particle accelerators use versions of the synchrotron design. The largest synchrotron-type accelerator, also the largest particle accelerator in the world, is the 27-kilometre-circumference Large Hadron Collider (LHC) near Geneva, Switzerland, built in 2008 by the European Organization for Nuclear Research (CERN). It can accelerate beams of protons to an energy of 6.5 teraelectronvolts (TeV).
Artwork by Sandbox Studio, Chicago with Jill Preston
To accelerate particles, the accelerators are fitted with metallic chambers containing an electromagnetic field known as radiofrequency (RF) cavities. Charged particles injected into this field receive an electrical impulse that accelerates them to higher and higher energies.
In the Large Hadron Collider (LHC), 16 RF cavities are housed in four cylindrical refrigerators called cryomodules, which enable them to work in a superconducting state.
The force required to keep something moving in a circle is centripetal force and it is provided by the magnetic field from the superconducting electromagnets. You can put the two formulae together.
F = mv2/r = Bqv where B is the magnetic field strength of the system, v is the velocity (near to the speed of light eventually) of the protons, r is the bending radius produced by the magnetic field, m is the mass of the proton and q is the charge of the proton.
Simplifying the formula gives v = Bqr/m although the equations have not taken relativity into consideration.
Superconductivity is a set of physical properties observed in certain materials where electrical resistance vanishes and magnetic flux fields are expelled from the material. Any material exhibiting these properties is a superconductor. Unlike an ordinary metallic conductor, whose resistance decreases gradually as its temperature is lowered even down to near absolute zero, a superconductor has a characteristic critical temperature below which the resistance drops abruptly to zero. An electric current through a loop of superconducting wire can persist indefinitely with no power source.
At the LHC there are four main detectors
At the centre of the detectors the particles (usually protons) collide.
Particle physicists investigate the products of the collisions in order to
understand the small quantum world and also the very large Universe.
Some of the experiments replicate what was going on in the Universe 13.6 billion years ago as the particles seen were last “free” at the beginning of the Universe.
Particle physicists are investigating the origin of matter.
Particle accelerators have lots of uses in everyday life. They are found in hospitals for instance.
Proton beams can be used to treat some forms of cancer
Proton therapy is the use of beams of protons to deliver radiation to tumours. A type of particle therapy, this cancer treatment uses protons from a hydrogen atom, accelerating them to 70% of the speed of light, and targeting them at tumours. The beam is targeted by a specialised nozzle, which can be rotated into position anywhere on the patient’s body, thanks to a gantry with a 360-degree rotation. Hitachi has further improved accuracy thanks to techniques called spot scanning and image gating.
Spot-scanning proton beams have been used for over a decade.
In proton-beam therapy, the beam is controlled by a gantry that can move around the patient in all directions, helping to focus on the tumour from the best angle. The thin beam emitted was previously a generic shape, but cut-out templates, spot scanning and image gating have further improved accuracy.
Once targeted, the beam is fired for a short time at the tumour. When proton beam reaches the tumour, it releases the protons’ energy for radiation treatment, which kills the diseased cells. The more accurately the beam is targeted, the less damage there is to surrounding healthy tissue. The beam then stops, so there’s no exit dose, helping to avoid further damage to healthy tissue. That means there’s fewer side effects compared to traditional radiotherapy.
Proton therapy focuses the radiation, so less damage is done to healthy tissue than with other treatments.
The beam can be thinned (also known as pencil-beam scanning) to just a few millimetres wide and technology has allowed it to be turned on and off more quickly, delivering the dose point by point, layer by layer. Beam accuracy is controlled by computers programmed with a treatment plan. With this narrower beam, there’s less radiation spilling out on to healthy surrounding tissue, and with smaller doses, it’s easier to layer the treatment into the tumour more precisely.
Improvements also allowed for patient movement.
Ion Beam therapy
Particle therapy is a form of external beam radiotherapy using beams of energetic neutrons, protons, or other heavier positive ions for cancer treatment. The most common type of particle therapy as of 2012 is proton therapy.
In contrast to X-rays (photon beams) used in older radiotherapy, particle beams exhibit a Bragg peak in energy loss through the body, delivering their maximum radiation dose at or near the tumour and minimizing damage to surrounding normal tissues.
Particle therapy is also referred to more technically as hadron therapy, excluding photon and electron therapy. Neutron capture therapy, which depends on a secondary nuclear reaction, is also not considered here. Muon therapy, a rare type of particle therapy not within the categories above, has also been attempted.
Particle therapy works by aiming energetic ionizing particles at the target tumour. These particles damage the DNA of tissue cells, ultimately causing their death. Because of their reduced ability to repair DNA, cancerous cells are particularly vulnerable to such damage.
The figure shows how beams of electrons, X-rays or protons of different energies (expressed in MeV) penetrate human tissue (represented by the depth in water, as most of the human body is water). Electrons have a short range and are therefore only of interest close to the skin. Bremsstrahlung X-rays penetrate more deeply, but the dose absorbed by the tissue then shows the typical exponential decay with increasing thickness. For protons and heavier ions, on the other hand, the dose increases while the particle penetrates the tissue and loses energy continuously. Hence the dose increases with increasing thickness up to the Bragg peak that occurs near the end of the particle’s range. Beyond the Bragg peak, the dose drops to zero (for protons) or almost zero (for heavier ions).
The advantage of this energy deposition profile is that less energy is deposited into the healthy tissue surrounding the target tissue (unlike X-rays, which deposit energy in healthy tissues before reaching the tumour). This enables higher dose prescription to the tumour, theoretically leading to a higher local control rate, as well as achieving a low toxicity rate.
The Bragg peak is a pronounced peak on the Bragg curve which plots the energy loss of ionizing radiation during its travel through matter. For protons, α-rays, and other ion rays, the peak occurs immediately before the particles come to rest. This is called Bragg peak, after William Henry Bragg who discovered it in 1903.
When a fast charged particle moves through matter, it ionizes atoms of the material and deposits a dose along its path. A peak occurs because the interaction cross section increases as the charged particle’s energy decreases. Energy lost by charged particles is inversely proportional to the square of their velocity.
Sir William Henry Bragg OM KBE PRS (2 July 1862 – 12 March 1942) was an English physicist, chemist, mathematician, and active sportsman who uniquely shared a Nobel Prize with his son Lawrence Bragg – the 1915 Nobel Prize in Physics: “for their services in the analysis of crystal structure by means of X-rays”
An advantage of X-rays is that they can deposit energy over a greater distance if the cancer covered a large area. Unfortunately, its Bragg peak shows that most energy is deposited in the first few centimetres which is not so good if the tumour is deep inside a part of the body like the head.
Electron beams are even less favourable than X-rays. After about 13cm there is no energy left. Energy is wasted early on unless the cancer is at skin level.
The magic bullet of heavy ion beams. Most of the energy can be deposited deep within the body. This is desirable for treating tumours deep inside the body, making the dose as low as possible.
The protons/heavy ions are produced in a very similar way to the LHC, starting off in a LINAC before passing into a synchrotron and then on into the treatment rooms, via a beam transport system. Of course, the equipment is a lot smaller than the LHC.
The beam is guided to the patient and tumour.
The Christie NHS proton beam therapy centre (Manchester) opened in Autumn 2018, and the first patient was treated in December 2018.
The second NHS centre is currently being built at University College London Hospitals. UCLH will gradually ramp up PBT activity during 2021. When complete the two centres will each treat up to 750 patients every year.
Optimization of Medical Accelerators (OMA)
The Optimization of Medical Accelerators (OMA) is the aim of this European Training Network. The project joins universities, research centres and ion beam treatment facilities with industry partners to address the challenges in treatment facility design and optimization, numerical simulations for the development of advanced treatment schemes, and in beam imaging and treatment monitoring.
There are forty institutions across Europe involved with this project.
Iron Man is a fictional superhero appearing in American comic books published by Marvel Comics. The character was co-created by writer and editor Stan Lee, developed by scripter Larry Lieber, and designed by artists Don Heck and Jack Kirby. The character made his first appearance in Tales of Suspense #39 (cover dated March 1963), and received his own title in Iron Man #1 (May 1968). Also, in 1963, the character founded the Avengers alongside Thor, Ant-Man, Wasp and the Hulk.
A wealthy American business magnate, playboy, philanthropist, inventor and ingenious scientist, Anthony Edward “Tony” Stark suffers a severe chest injury during a kidnapping. When his captors attempt to force him to build a weapon of mass destruction, he instead creates a mechanized suit of armour to save his life and escape captivity. Later, Stark develops his suit, adding weapons and other technological devices he designed through his company, Stark Industries. He uses the suit and successive versions to protect the world as Iron Man. Although at first concealing his true identity, Stark eventually publicly reveals himself to be Iron Man.
Initially, Iron Man was a vehicle for Stan Lee to explore Cold War themes, particularly the role of American technology and industry in the fight against communism. Subsequent re-imaginings of Iron Man have transitioned from Cold War motifs to contemporary matters of the time.
Throughout most of the character’s publication history, Iron Man has been a founding member of the superhero team the Avengers and has been featured in several incarnations of his own various comic book series. Iron Man has been adapted for several animated TV shows and films. In the Marvel Cinematic Universe, the character was portrayed by Robert Downey Jr., appearing in the films Iron Man (2008), The Incredible Hulk (2008) in a cameo, Iron Man 2 (2010), The Avengers (2012), Iron Man 3 (2013), Avengers: Age of Ultron (2015), Captain America: Civil War (2016), Spider-Man: Homecoming (2017), Avengers: Infinity War (2018) and Avengers: Endgame (2019). The character also appeared in Spider-Man: Far From Home (2019) and in the upcoming Black Widow (2021) through archive footage.
Iron Man was ranked 12th on IGN’s “Top 100 Comic Book Heroes” in 2011 and third in their list of “The Top 50 Avengers” in 2012.
A clip from Iron-Man 2 showing Tony Stark inventing a new element
So, what was wrong with the scene:
Tony Stark built a particle accelerator in his home, although he is rich enough to have that sort of power supply at home
He is propelling particles to higher energies
He has no safety features except for wearing a pair of goggles
He is able to remove the article beam from the vacuum chamber and move it around the room, using a wrench
Manages to destroy a lot of the laboratory before guiding the beam to his experiment, a triangular shaped object where he combines the beam with it to create the new element. He places this new element into his body to protect his heart from some iron pieces, which have been in his body since the first Iron-man film.
Colliding beams in the LHC uses particle beams that have a cross-section of only 60 nanometres. This would be invisible to our eyes and you couldn’t steer them with a wrench.
If a proton beam is being delivered to a patient for cancer treatment then the operator needs carefully designed diagnostics to know that the beam is acting at the right position. He/she does not use a wrench.
Tony Stark needs to create this element that nobody has seen before to save his life.
This last bit isn’t so far fetched as scientist have been creating new elements for a number of years.
A synthetic element is one of 24 chemical elements that do not occur naturally on Earth: they have been created by human manipulation of fundamental particles in a nuclear reactor, a particle accelerator, or the explosion of an atomic bomb; thus, they are called “synthetic”, “artificial”, or “man-made”. The synthetic elements are those with atomic numbers 95–118, as shown in purple on the accompanying periodic table: these 24 elements were first created between 1944 and 2010. The mechanism for the creation of a synthetic element is to force additional protons onto the nucleus of an element with an atomic number lower than 95. All synthetic elements are unstable, but they decay at a widely varying rate: their half-lives range from 15.6 million years to a few hundred microseconds.
Five other elements that were created artificially—and thus initially considered to be synthetic—were later discovered to exist in nature in trace quantities. The first, technetium, was created in 1937. Plutonium, atomic number 94, first synthesized in 1940, is another such element. It is the element with the largest number of protons (and equivalent atomic number) to occur in nature, but it does so in such tiny quantities that it is far more practical to synthesize it. Plutonium is extremely well known due to its use in atomic bombs and nuclear reactors. No elements with an atomic number greater than 99 have any uses outside of scientific research, since they have extremely short half-lives, and thus have never been produced in large quantities.
The Facility for Antiproton and Ion Research (FAIR) is an international accelerator facility under construction which will use antiprotons and ions to perform research in the fields of: nuclear, hadron and particle physics, atomic and anti-matter physics, high density plasma physics, and applications in condensed matter physics, biology and the bio-medical sciences. It is situated in Darmstadt in Germany.
FAIR will be based upon an expansion of the GSI Helmholtz Centre for Heavy Ion Research, the details of which have been laid out in the FAIR Baseline Technical Report 2006. On October 4, 2010 the Facility for Antiproton and Ion Research in Europe limited liability company (German GmbH), abbreviated as FAIR GmbH, was founded which coordinates the construction of the new accelerators and experiments.
The construction begun at summer of 2017. Commissioning is planned for 2025.
The GSI Helmholtz Centre for Heavy Ion Research abbreviated GSI, to conduct research on and with heavy-ion accelerators. It is the only major user research centre in the State of Hesse.
The laboratory performs basic and applied research in physics and related natural science disciplines. Main fields of study include plasma physics, atomic physics, nuclear structure and reactions research, biophysics and medical research. The lab is a member of the Helmholtz Association of German Research Centres.
Elements discovered at GSI: bohrium (1981), meitnerium (1982), hassium (1984), darmstadtium (1994), roentgenium (1994), and copernicium (1996).
Elements confirmed at GSI: nihonium (2012), flerovium (2009), moscovium (2012), livermorium (2010), and tennessine (2012)
The UK is a partner in FAIR and particle acceleration is the key to the experiments, using the same technologies as CERN and hospitals.
At FAIR different particle beams will be combined to create elements that have not been seen, probably, in the Universe before.
Creating these elements is not easy and every time there is a breakthrough the information gets into newspapers (and becomes answers to questions on quiz programmes).
The names of the elements often reflect the place they were discovered, like darmstadtium (1994).
How is the detection done?
Using particle traps.
The ion trap facility SHIPTRAP at GSI has been set up to enable precision experiments on very heavy ions produced at the SHIP velocity filter well known for the search and discovery of super heavy elements. At SHIPTRAP mass measurements, laser spectroscopy, ion chemical reactions and in the future in-trap decay experiments on heavy ions will be performed. SHIPTRAP can also deliver cold and clean samples of transuranium nuclides to other experimental users. For that purpose, SHIPTRAP has the following sections: A stopping cell, a RFQ buncher and a double Penning trap system. The radioactive reactions products delivered by SHIP at a few 100keV/u are stopped and thermalized in a cell containing a highly pure helium buffer gas at a pressure of around 100 mbar. The stopped ions are extracted from the cell by the gas flow combined with electrical fields. In the next section – a RFQ structure (linear Paul trap) operated in bunched mode – they are cooled, accumulated, and bunched.
The resultant elements are carefully analysed and often there is only one particle (out of many others) produced over a large time scale, which does not last very long. However, they are very important so physicists can understand how all matter is composed and what the properties of the new exotic properties are.
So, Tony Stark’s manufacture of a new element which he can just use is very unrealistic
Questions and answers 1
1) How large a room is needed to create and house a collider in a hospital?
This is important to determine the cost of the treatment.
The size of the equipment is quite considerable, especially when you compare it to the actual treatment room.
For synchrotron-based facilities a stand-alone building is really required for the accelerator itself and this is a significant cost.
Proton therapy is only suitable for certain types of cancer so it wouldn’t be prudent to put one in every single hospital.
The facility currently being built in London is very costly due to the cost of sites.
The site up and running in Manchester wasn’t exactly the first proton therapy facility. One was set up in 1989 to treat eye cancers. But it is small and its lower energy 60 MeV proton beam has a maximum range of 31mm in water making it exceptionally suitable for treating any position within the eye (but not for cancers deeper in the body).
2) What would it look like if a particle accelerator actually failed?
Safety is incredibly important for any high energy experiment. At the LHC has many different layers which are there to prevent major damage to the machine, the detectors and staff working at CERN and related experiments.
The LHC is going through an up-grade at the moment and this means the safety procedures need to be upgraded too.
An idea of what could happen if there was a failure occurred on the 19th September 2008 when a fault occurred in one of the superconducting electromagnets.
Damage of the LHC magnets in sector 3-4 of the LHC, provoked by the incident which happened on 19 September 2008 (Image: CERN)
The cause of the incident was a faulty electrical connection between two of the accelerator’s magnets. This resulted in mechanical damage and release of helium from the magnet cold mass into the tunnel.
Proper safety procedures were in force, the safety systems performed as expected, and no one was put at risk. The beam was “dumped” and did no damage.
The machines are so well designed now that failure is highly unlikely.
Daresbury Laboratory is a scientific research laboratory based at Sci-Tech Daresbury campus near Daresbury in Halton, Cheshire, England. The laboratory began operations in 1962 and was officially opened on 16 June 1967 as the Daresbury Nuclear Physics Laboratory by the then Prime Minister of United Kingdom, Harold Wilson. It is operated by the Science and Technology Facilities Council, part of UK Research and Innovation. As of 2018, it employs around 300 staff, with Professor Susan Smith appointed as director in 2012.
Daresbury Laboratory carries out research in fields such as accelerator science, bio-medicine, physics, chemistry, materials, engineering and computational science. Its facilities are used by scientists and engineers, from both the university research community and industrial research base. The laboratory is based at Sci-Tech Daresbury.
Accelerator science, including the Cockcroft Institute which houses scientists from STFC, University of Manchester, University of Liverpool, University of Lancaster, and University of Strathclyde. Accelerator science facilities include: VELA, an electron compact linear accelerator, based around an RF photocathode gun. CLARA, an electron linear accelerator to be utilised for research in free-electron lasers.
Daresbury Laboratory: nuclear structure research tower Dating from the 1970s, this tower was mothballed in 1993, but is now being used for research into the “fourth generation light source”. This follows the Government’s decision to site the third generation Diamond Synchrotron facility in Oxfordshire.
The Cockcroft Institute is an international centre for Accelerator Science and Technology (AST) in the UK. It was proposed in September 2003 and officially opened in September 2006. It is a joint venture of Lancaster University, the University of Liverpool, the University of Manchester, the Science and Technology Facilities Council, and the Northwest Regional Development Agency. The Institute is located in a purpose-built building on the Sci-Tech Daresbury campus, and in centres in each of the participating universities.
The Institute’s aim is to provide the intellectual focus, educational infrastructure, and the essential scientific and technological facilities for Accelerator Science and Technology research and development, which will enable UK scientists and engineers to take a major role in accelerator design, construction, and operation for the foreseeable future.
There are plans to build new accelerators in the UK, at about 1km in size they won’t be anywhere as big as the LHC.
3) How many centres in the UK can offer the particle medical therapy?
The Christie centre began treating patients towards the end of 2018.
Another three centres are being planned.
There are a few dozen centres in Europe and the USA.
4) How does your knowledge change the way you watch Sci-fi and Marvel movies?
When I’m in the cinema I’m just enjoying the film like anybody else. I like them, no matter how crazy they are. It’s only when I go to work and we start talking about the film I realise how crazy the films are. My colleagues and I start discussing what the physics would really be like.
3) The Terminator – Rise of the Machines
The Terminator is a 1984 American science fiction film directed by James Cameron. It stars Arnold Schwarzenegger as the Terminator, a cyborg assassin sent back in time from 2029 to 1984 to kill Sarah Connor (Linda Hamilton), whose son will one day save mankind from extinction by a hostile Artificial Intelligence in a post-apocalyptic future. Michael Biehn plays Kyle Reese, a soldier sent back in time to protect Sarah. The screenplay is credited to Cameron and producer Gale Anne Hurd, while co-writer William Wisher Jr. received a credit for additional dialogue. Executive producers John Daly and Derek Gibson of Hemdale Film Corporation were instrumental in financing and production.
In 2008, The Terminator was selected by the Library of Congress for preservation in the National Film Registry as “culturally, historically, or aesthetically significant”.
Terminator 3: Rise of the Machines (also known as T3) is a 2003 science fiction action film, the third instalment in the Terminator franchise and a sequel to Terminator 2: Judgment Day, directed by Jonathan Mostow and starring Arnold Schwarzenegger, Nick Stahl, Claire Danes, and Kristanna Loken. In the film, Skynet sends a Terminator, the T-X (Loken), back in time to ensure the rise of machines by killing top members of the future human resistance, which will be led by John Connor (Stahl). Among the T-X’s targets is John’s future wife Kate Brewster (Danes), but not John himself, as his whereabouts are unknown to Skynet. John’s life is placed in danger when the T-X finds him. The Resistance has also sent their own Terminator (Schwarzenegger) back in time to protect John and Kate.
T-X is a more advanced terminator that is made from materials that allow it to change its shape.
How to catch a T-X terminator
Use powerful magnets
It gets lured in the tunnel of a particle accelerator.
Who would ever design a magnet that has the purpose of bending a particle beam inside a vacuum chamber that has an extremely strong magnetic field outside of that vacuum chamber?
What is required is for that magnetic field to be concentrated where the particle beams are, not inside the tunnel where people are walking around. So, there is a lot wrong with the scene in the above video clip.
Very high magnetic fields are used at the LHC and other particle accelerators to change the path of the beam.
ATLAS is one of the experiments at the LHC which is searching for new particles and new physics.
ATLAS (A Toroidal LHC ApparatuS) is the largest, general-purpose particle detector experiment at the Large Hadron Collider (LHC), a particle accelerator at CERN (the European Organization for Nuclear Research) in Switzerland. The experiment is designed to take advantage of the unprecedented energy available at the LHC and observe phenomena that involve highly massive particles which were not observable using earlier lower-energy accelerators. ATLAS was one of the two LHC experiments involved in the discovery of the Higgs boson in July 2012. It was also designed to search for evidence of theories of particle physics beyond the Standard Model.
The experiment is a collaboration involving roughly 3,000 physicists from 183 institutions in 38 countries.
The eight toroid magnets of the ATLAS detector.
ATLAS is 100m below ground and is large enough that Notre Dame Cathedral could fit comfortably inside,
In the above image the round object at the centre is where the particles are made to collide.
The ATLAS detector uses two large superconducting magnet systems to bend charged particles so that their momenta can be measured. This bending is due to the Lorentz force, which is proportional to velocity. Since all particles produced in the LHC’s proton collisions are traveling at very close to the speed of light, the force on particles of different momenta is equal. (In the theory of relativity, momentum is not linear proportional to velocity at such speeds.) Thus high-momentum particles curve very little, while low-momentum particles curve significantly; the amount of curvature can be quantified and the particle momentum can be determined from this value.
The inner solenoid produces a two-tesla magnetic field surrounding the Inner Detector. This high magnetic field allows even very energetic particles to curve enough for their momentum to be determined, and its nearly uniform direction and strength allow measurements to be made very precisely. Particles with momenta below roughly 400 MeV will be curved so strongly that they will loop repeatedly in the field and most likely not be measured; however, this energy is very small compared to the several TeV of energy released in each proton collision.
The outer toroidal magnetic field is produced by eight very large air-core superconducting barrel loops and two end-caps air toroidal magnets, all situated outside the calorimeters and within the muon system. This magnetic field extends in an area 26 metres long and 20 metres in diameter, and it stores 1.6 gigajoules of energy. Its magnetic field is not uniform, because a solenoid magnet of sufficient size would be prohibitively expensive to build. It varies between 2 and 8 Tesla.
Proton collision animations
Two beams collide producing lots of particles
Particle physicists analyse the trajectories to investigate what is going on in the experiment.
Event Cross Section in a computer-generated image of the ATLAS detector.
To analyse all the data produced by the detectors the world needs to work together to understand the new physics. There is far too much for one research organisation to deal with, not even CERN can analyse all the data. So, a world-wide grid of computers was set up.
This allows data analysis to occur 24 hours a day and 7 days a week, all year.
Complex algorithms and machine learning techniques are used. This allows spurious data to be filtered out so that any new events can be spotted. Things that have not been seen before, such as the Higgs particle.
Grid computing is the use of widely distributed computer resources to reach a common goal. A computing grid can be thought of as a distributed system with non-interactive workloads that involve many files. Grid computing is distinguished from conventional high-performance computing systems such as cluster computing in that grid computers have each node set to perform a different task/application. Grid computers also tend to be more heterogeneous and geographically dispersed (thus not physically coupled) than cluster computers. Although a single grid can be dedicated to a particular application, commonly a grid is used for a variety of purposes. Grids are often constructed with general-purpose grid middleware software libraries. Grid sizes can be quite large.
Grids are a form of distributed computing whereby a “super virtual computer” is composed of many networked loosely coupled computers acting together to perform large tasks. For certain applications, distributed or grid computing can be seen as a special type of parallel computing that relies on complete computers (with onboard CPUs, storage, power supplies, network interfaces, etc.) connected to a computer network (private or public) by a conventional network interface, such as Ethernet. This is in contrast to the traditional notion of a supercomputer, which has many processors connected by a local high-speed computer bus.
CERN, one of the largest users of grid technology, talk of The Grid: “a service for sharing computer power and data storage capacity over the Internet.”
The Worldwide LHC Computing Grid (WLCG), formerly (until 2006) the LHC Computing Grid (LCG), is an international collaborative project that consists of a grid-based computer network infrastructure incorporating over 170 computing centres in 42 countries, as of 2017. It was designed by CERN to handle the prodigious volume of data produced by Large Hadron Collider (LHC) experiments.
By 2012, data from over 300 trillion (3 x 1014) LHC proton-proton collisions had been analysed, and LHC collision data was being produced at approximately 25 petabytes per year. As of 2017 the LHC Computing Grid is the world’s largest computing grid comprising over 170 computing facilities in a worldwide network across 42 countries.
In mathematics and computer science, an algorithm is a finite sequence of well-defined, computer-implementable instructions, typically to solve a class of problems or to perform a computation. Algorithms are always unambiguous and are used as specifications for performing calculations, data processing, automated reasoning, and other tasks.
Machine learning (ML) is the study of computer algorithms that improve automatically through experience. It is seen as a part of artificial intelligence. Machine learning algorithms build a model based on sample data, known as “training data”, in order to make predictions or decisions without being explicitly programmed to do so. Machine learning algorithms are used in a wide variety of applications, such as email filtering and computer vision, where it is difficult or unfeasible to develop conventional algorithms to perform the needed tasks.
The Higgs boson is an elementary particle in the Standard Model of particle physics produced by the quantum excitation of the Higgs field, one of the fields in particle physics theory. The Higgs mechanism was proposed to explain why some particles have mass. This mechanism required that a spinless particle known as a boson should exist with properties as described by the Higgs Mechanism theory. This particle was called the Higgs boson.
A subatomic particle with the expected properties was discovered in 2012 by the ATLAS and CMS experiments at the Large Hadron Collider (LHC) at CERN near Geneva, Switzerland. The new particle was subsequently confirmed to match the expected properties of a Higgs boson.
The Liverpool Big Data Science (LIV.DAT) Centre for Doctoral Training (CDT) is a hub for training students in managing, analysing and interpreting large, complex datasets and high rates of data flow.
Big data refers to data that is so large that it cannot be processed by using traditional applications. Although significant computer technology exists, new skills are needed to fully understand the power of Big Data.
Cutting edge data science applications including accelerator research as well as astrophysics, particle physics, nuclear physics and condensed matter physics.
The Liverpool Big Data Network (LBDN) brings together experts with an interest in Big Data from right across the University of Liverpool. LBDN is also a cornerstone for the University’s strategic partnership with STFC Hartree, a nearby facility that enables LBDN to access state-of-the-art computing facilities and the people that enable such computers to be used to solve tough problems.
Questions and answers 2
1) What is the heaviest element that can be created?
Fundamentally we are always trying to push the boundaries. There is no theoretical limit to what we can combine.
At the time of writing the heaviest element is Oganesson.
Oganesson is a synthetic chemical element with the symbol Og and atomic number 118. It was first synthesized in 2002 at the Joint Institute for Nuclear Research (JINR) in Dubna, near Moscow, Russia, by a joint team of Russian and American scientists. In December 2015, it was recognized as one of four new elements by the Joint Working Party of the international scientific bodies IUPAC and IUPAP. It was formally named on 28 November 2016
It has the highest atomic number and highest atomic mass of all known elements. The radioactive oganesson atom is very unstable, and since 2005, only five (possibly six) atoms of the isotope oganesson-294 have been detected. Although this allowed very little experimental characterisation of its properties and possible compounds, theoretical calculations have resulted in many predictions, including some surprising ones. For example, although oganesson is a member of group 18 (the noble gases) – the first synthetic element to be so – it may be significantly reactive, unlike all the other elements of that group. It was formerly thought to be a gas under normal conditions but is now predicted to be a solid due to relativistic effects. On the periodic table of the elements, it is a p-block element and the last one of period 7.
2) What are the lifespans of the new heavy particles when they are created? Do they rapidly deteriorate?
Most of them are extremely short lived which is why we need sophisticated detectors that capture them as soon as they are created. The properties need to be discovered very quickly. Very few atoms are produced so they need to be filtered out from other events and their properties discovered very quickly.
3) How often are new elements made?
Some elements have taken 5 to 10 years to be created.
There is a collaboration between theorists who work out what elements might exist and experimentalists who set out to see if they actually do exist.
So, when an element is predicted experimentalist accept the challenge and go looking for it. If it can’t be found the experimentalists can tell the theorists they were wrong.
Some of the experiments have to be done over very long time scales (too long for a PhD, which typically lasts four years including writing up time and viva),
4) How does CERN compensate for small movements underground?
Some of the movements are not that small. The ATLAS cavern is 100m underground. If you are basically inserting a bubble of air into a solid the bubble will tend to rise upwards. The ATLAS cavern rises about 1mm a year. If you compare that the proton beam cross section of 60nm you can see that there could be a problem. The beams need to be steered.
High speed trains move in and out of Geneva and the detectors can actually pick up when the trains are arriving and departing. Initially nobody knew what the data was but there are now specific elements in the machinery to compensate for these movements. Small magnets are used to keep the proton beam in place. Up-down or left-right or any other direction in between these.
5) My father has just bought a classic car, a DeLorean, which he is keeping to modify. Do you know where he could get hold of a flux capacitor?
Back to the Future is a 1985 American science fiction film directed by Robert Zemeckis. Written by Zemeckis and Bob Gale, it stars Michael J. Fox, Christopher Lloyd, Lea Thompson, Crispin Glover, and Thomas F. Wilson. Set in 1985, the story follows Marty McFly (Fox), a teenager accidentally sent back to 1955 in a time-traveling DeLorean automobile built by his eccentric scientist friend Doctor Emmett “Doc” Brown (Lloyd).
In the Back to the Future franchise, the DeLorean time machine is a time travel device made by retrofitting a DMC DeLorean vehicle with a flux capacitor.
We’re working on it
I have done a talk about the science of back to the future in the past.
4) Angels and Demons
Building an antimatter bomb
The film is based on a best-selling book by Dan Brown
Angels & Demons is a 2000 bestselling mystery-thriller novel written by American author Dan Brown. The novel introduces the character Robert Langdon, who recurs as the protagonist of Brown’s subsequent novels. Angels & Demons shares many stylistic literary elements with its sequels, such as conspiracies of secret societies, a single-day time frame, and the Catholic Church. Ancient history, architecture, and symbology are also heavily referenced throughout the book. A film adaptation was released on May 15, 2009.
Daniel Gerhard Brown (born June 22, 1964) is an American author best known for his thriller novels, including the Robert Langdon novels Angels & Demons (2000), The Da Vinci Code (2003), The Lost Symbol (2009), Inferno (2013) and Origin (2017).
The book says there is a group of crazy scientists and they are working at a big international laboratory called CERN, At CERN they are using the LHC to create anti-matter.
The bad guys want to steal the anti-matter because if it comes into contact with ordinary matter, they both get annihilated and a great deal of energy is released,
The mass of the matter and the mass of the antimatter with 100% efficiency is turned into energy. E = mc2. The energy released is equal to the total mass x (the speed of light in a vacuum)2
The plan is to put the antimatter in a particle trap and take it to the Vatican. Let the antimatter come into contact with matter and blow up the Vatican and kill the Pope.
We know CERN exists.
Now in the book and film the CERN scientists need to go to conferences. They are too busy to hang around for domestic flights. Does CERN have an X-33 airplane? This plane is supposed to take the scientists anywhere in about two hours.
Unfortunately for the scientists there is no such plane. They have to fly economy.
Does CERN have a wind tunnel to help the scientists relax?
Unfortunately, no, but there is excellent skiing.
Are there secret laboratories where the antimatter is created? Do the scientists have to have their iris scanned to get into them?
When the book was first written this was complete nonsense. At that time all the labs were freely accessible. If there were radiation issues you were given a CERN access card.
Today some of the labs to require an iris scan to gain admittance, but they are not secret.
Iris recognition is an automated method of biometric identification that uses mathematical pattern-recognition techniques on video images of one or both of the irises of an individual’s eyes, whose complex patterns are unique, stable, and can be seen from some distance.
Are there crazy scientists at CERN?
Does the LHC exist at CERN?
Yes. It is the most powerful accelerator ever built and has been in operation since 2009.
Is the LHC used for the production of antimatter?
No. The LHC does produce all sorts of particles including very small amounts of antimatter but it isn’t an antimatter factory and it does not produce enough to make a bomb.
There is a facility at CERN that does make antimatter and that is the antiproton decelerator.
The Antiproton Decelerator (AD) is a storage ring at the CERN laboratory near Geneva. It was built from the Antiproton Collector (AC) machine to be a successor to the Low Energy Antiproton Ring (LEAR) and started operation in the year 2000. Antiprotons are created by impinging a proton beam from the Proton Synchrotron on a metal target. The AD decelerates the resultant antiprotons to an energy of 5.3 MeV, which are then ejected to one of several connected experiments.
ELENA (Extra Low ENergy Antiproton) is a 30 m hexagonal storage ring situated inside the AD complex. It is designed to further decelerate the antiproton beam to an energy of 0.1 MeV for more precise measurements. The first beam circulated ELENA on 18 November 2016. The ring is expected to be fully operational by the end of the LS2 period. GBAR was the first experiment to use a beam from ELENA, with the rest of the AD experiments following suit following the end of the shutdown period. (shown above right)
How is antimatter produce in the laboratory?
A high energy beam of protons is fired onto a target (a block of metal with good heat conductivity)
When you fire enough energy into a small region of space the E = mc2 equation tells you that you can produce mass. The equation doesn’t tell you what mass you are creating but there is a small probability that you will create antimatter.
For every one million protons that are being fired onto that metal block just one anti-proton will be created. These particles are captured and used for precision experiments.
At the Cockcroft institute in Liverpool and Manchester there is a large-scale project called AVA
The project will enable an interdisciplinary and cross-sector program on antimatter research. It will investigate the properties of antimatter. It will also look at the accelerators, detectors and the instrumentation required to understand antimatter that is created in the laboratories, better. It will also try to understand where all the antimatter has gone as it would have been expected that at the beginning of the Universe there should have been equal amounts of matter and antimatter.
Can antimatter be transported to the Vatican?
The above is an image found by Professor Welsch in the Guardian newspaper. Taken from the Angels and Demons film.
Until very recently the answer to the question was, no.
The only place where antimatter experiments are being carried out is at CERN and there is a new scientific project which has just been approved by the European Research Council. It is called BASE-STEP.
A transportable antiproton trap to unlock the secrets of antimatter.
The BASE collaboration is developing a transportable antiproton trap to make higher-precision measurements of the properties of antimatter.
The layout of the transportable antiproton trap that BASE is developing. The device features a first trap for injection and ejection of the antiprotons produced at CERN’s Antiproton Decelerator, and a second trap for storing the antiprotons. (Image: Christian Smorra)
The idea is to produce a trap that will capture antimatter and take it to a laboratory in Germany where they will study the properties of these particles in more detail.
The reason is that CERN experiences a lot of noise and there are other laboratories that are much quieter and more stable so experiments can be carried out with a much higher precision.
The aim of the experiments is to find out more about antimatter.
What is needed to make an antimatter bomb?
Professor Welsch carried out a thought experiment.
There is matter Anakin and antimatter Darth Vader. Each has a mass of 100kg
E = mc2 would give 18 x 1018J (5 x 1012 kWh). That is the yearly output of 500 nuclear power stations. A lot of energy. It is also equivalent to the energy from a 4200 Megaton TNT explosion
Is it actually a threat?
Efficiency = Energy released/mass of fuel used.
It would seem that for annihilation the efficiency would be 100%
For nuclear fission the efficiency is only 0.1%, for nuclear fusion it would only be about 0.1% and for a chemical fuel such as petrol it would only be 0.0000003%
So, could antimatter be used to blow up the Vatican?
There is a missing detail in the calculations and that is if all the antiprotons made in history were annihilated at the same time there wouldn’t be enough energy to boil a kettle to make a pot of tea
The problem lies in the efficiency and cost of antimatter production and storage. Making 1 gram of antimatter would require approximately 25 million billion kilowatt-hours of energy and cost over a million billion dollars.
It would produce annihilation but there are just too few particles and it would be the most expensive method of blowing something up in the world.
The next step in accelerator research is to shrink things. At the Cockcroft Institute they are pioneering new technologies including micro-accelerators.
They are hoping to make these accelerators a thousand or more times more compact that a conventional accelerator.
This will make particle accelerators more accessible and creating accelerators that can fit in the palm of a hand.
The Cockcroft Institute is a centre of excellence for accelerator research.
So, can a particle accelerator produce superheroes?
All scientists have some form of superpower (Professor Welsch pretended his was disappearing in a flash of lightning)
Questions and answers 3
1) If a student wanted to work on proton therapy which A levels would you encourage them to study?
Physics and maths, Chemistry and biology would be a good base too.
Daresbury has internships for students of all age groups. They can take part in the work going on there. Because of Covid-19 virtual internships have been offered.
2) How in the proton treatment is the beam adapted for different depths within a body?
This is done by tuning the energy of the particle beam. The penetration depth is a direct function of the energy of the beam. Setting the energy of the beam causes it to be directed to just the right spot.
3) Because the energy is deposited at a specific depth do you also have to calculate and adjust the angle of the beam to a patient’s anatomy and the size and position of the tumour?
Yes. The gantry and beam delivery system rotates around the patient.
Once the tumour has been located in the body, medical experts will produce a treatment plan which tells the machine operators the energy level and angle required.
At the moment one patient is treated at a time, but the treatment is not very long so one patient can be prepared whilst another one is being treated. So, one particle accelerator can serve several treatment rooms at the same time.
4) Will this new cancer treatment need specialised doctors and nurses to use them or would normal staff be suitably qualified.
It really depends on the type of treatment. A synchrotron proton beam facility is a complex machine and requires a team of experts to run it. It would be expected that an oncologist would have had training to produce a treatment plan with radiation therapists (medical physics is a branch of physics). It is an advanced treatment which requires advance infrastructure and suitably trained experts.
5) Why are proton beams only suitable in some cases?
There are many different types of cancer. Proton beams have a distinct advantage in that they can deliver a well-defined dose to a very specific region of the body. But there are cancers that spread all over the body, e.g., skin cancer, so it wouldn’t be sensible to use a narrow proton beam.
Oncologists and radiation therapists decide which of the cancer therapies should be used.
6) How often are new elements created or discovered?
It can take years to discover and verify new elements.
7) Who gets to name the new elements?
It’s typically down to the place the scientists were when the element was discovered. In the past elements were named after places and people (some of whom made the discovery. Marie Curie named polonium after her home country, Poland).
8) What is the purpose of creating new elements and can their properties be designed?
The main purpose is to understand if their fundamental nature is correct. There are some predictions when it comes to certain heavy elements. For example, there is a long-standing prediction that at some point there will be an island of stability. So, for very heavy nuclei, that normally decay very, very, quickly and are not found in nature easily or at all, there is a theoretical prediction that a point will be reached where there will be a combination of neutrons and protons in the core of a nucleus that will produce stable nuclei, that may exist in nature, somewhere. We may not know they are there because they exist in such small quantities.
Scientists are after fundamental knowledge which helps us to understand all aspects of nature.
This is far away from designing elements as understanding the nature of those created is more important.
9) Do these synthetic elements not exist in nature because the energy needed to create them isn’t available in the first place or because their lifespans are so short?
The energy to create them is very large
If we go back to the time of the Big Bang or very violent cosmic events there was the energy available to create elements much, much, heavier than iron. This energy is much higher than could be produced in any current particle accelerator. If these elements can be produced in a particle accelerator then it stands to reason that they must have been created at some point in the Universe.
Most of the synthetic elements have incredibly short lifetimes which is another reason why they don’t seem to exist in nature.
10) Which artificial element has the longest lifespan?
These studies are still ongoing and it is hoped that elements will be found in this predicted island of stability.
Tennessine is a synthetic chemical element with the symbol Ts and atomic number 117. It is the second-heaviest known element and the penultimate element of the 7th period of the periodic table.
The discovery of tennessine was officially announced in Dubna, Russia, by a Russian–American collaboration in April 2010, which makes it the most recently discovered element as of 2021. The experiment itself was repeated successfully by the same collaboration in 2012 and by a joint German–American team in May 2014. In December 2015, the Joint Working Party of the International Union of Pure and Applied Chemistry (IUPAC) and the International Union of Pure and Applied Physics, which evaluates claims of discovery of new elements, recognized the element and assigned the priority to the Russian–American team. In June 2016, the IUPAC published a declaration stating that the discoverers had suggested the name tennessine after Tennessee, United States, a name which was officially adopted in November 2016.
Tennessine may be located in the “island of stability”, a concept that explains why some superheavy elements are more stable compared to an overall trend of decreasing stability for elements beyond bismuth on the periodic table. The synthesized tennessine atoms have lasted tens and hundreds of milliseconds. In the periodic table, tennessine is expected to be a member of group 17, all other members of which are halogens. Some of its properties may differ significantly from those of the halogens due to relativistic effects. As a result, tennessine is expected to be a volatile metal that neither forms anions nor achieves high oxidation states. A few key properties, such as its melting and boiling points and its first ionization energy, are nevertheless expected to follow the periodic trends of the halogens.
It took a while to identify this element (from 2010 to 2016) at different laboratories.
117 Tennessine 2009 Y. Oganessian et al. (JINR in Dubna) Prepared by bombardment of berkelium with calcium
On average experts only manage to create one atom of this new element per week. The production rate is incredibly small. This makes it incredibly difficult to identify them/
11) Who has access to all the data generated by a computing grid and particle detector?
A lot of science these days is open access and there are a number of data bases that provide free access to the data generated in detectors, or in other ways through experiments.
If you are interested you can reach out to certain collaborations and in principle you could get access to the data. There are citizen science projects
Citizen science (CS; also known as community science, crowd science, crowd-sourced science, civic science, or volunteer monitoring) is scientific research conducted, in whole or in part, by amateur (or nonprofessional) scientists. Citizen science is sometimes described as “public participation in scientific research,” participatory monitoring, and participatory action research whose outcomes are often advancements in scientific research by improving the scientific communities’ capacity, as well as increasing the public’s understanding of science.
SETI is a famous example, you can donate some of you computing power to search for extra-terrestrial life.
12) Is the X-32 plane in the Angels and Demons film based on Concorde?
Yes, I think so. The book doesn’t describe the plane in detail. It only says that the plane enables the scientists to reach any destination withing a couple of hours.
13) Do anti-particles travel back in time?
That is an interesting question as scientists are still looking at the properties of antimatter. Our understanding is that antimatter is the mirror particle of a matter particle (positron is the antiparticle of the electron) and fundamentally the way that they interact causes them to annihilate each other when they meet. There is a 100% conversion of their mass into energy and it is not seriously considered that the antimatter particle is travelling back in time.
14) If matter and antimatter destroy each other when they meet why doesn’t antimatter get destroyed immediately after it is made?
In modern physics, antimatter is defined as matter that is composed of the antiparticles (or “partners”) of the corresponding particles of “ordinary” matter.
The only way to prevent it annihilating is by placing it in a very good vacuum. A good vacuum means there is nothing for the antimatter to interact with.
Antimatter cannot be stored in a container made of ordinary matter because antimatter reacts with any matter it touches, annihilating itself and an equal amount of the container. Antimatter in the form of charged particles can be contained by a combination of electric and magnetic fields, in a device called a Penning trap. This device cannot, however, contain antimatter that consists of uncharged particles, for which atomic traps are used. In particular, such a trap may use the dipole moment (electric or magnetic) of the trapped particles. At high vacuum, the matter or antimatter particles can be trapped and cooled with slightly off-resonant laser radiation using a magneto-optical trap or magnetic trap. Small particles can also be suspended with optical tweezers, using a highly focused laser beam.
In 2011, CERN scientists were able to preserve antihydrogen for approximately 17 minutes. The record for storing antiparticles is currently held by the TRAP experiment at CERN: antiprotons were kept in a Penning trap for 405 days. A proposal was made in 2018, to develop containment technology advanced enough to contain a billion anti-protons in a portable device to be driven to another lab for further experimentation.
Electric and magnetic fields hold the antiprotons separate from positrons in a near-perfect vacuum that keeps them away from regular matter.
The antiprotons pass through a dense electron gas, which slows them down further.
When the energy is low enough, ALPHA physicists use the electric potential to nudge the antiprotons into a cloud of positrons suspended within the vacuum. The two types of charged antiparticles combine into low-energy antihydrogen atoms. Since antihydrogen atoms don’t have an electric charge, the electric field can no longer hold them in place. So instead, two superconducting magnets generate a strong magnetic field that takes advantage of the antihydrogen’s magnetic properties. If the antihydrogen atoms have a low enough energy, they can stay in this magnetic “bottle” for a long time.
A Penning trap is a device for the storage of charged particles using a homogeneous axial magnetic field and an inhomogeneous quadrupole electric field. This kind of trap is particularly well suited to precision measurements of properties of ions and stable subatomic particles. Geonium atoms have been created and studied this way, to measure the electron magnetic moment. Recently these traps have been used in the physical realization of quantum computation and quantum information processing by trapping qubits. Penning traps are used in many laboratories worldwide, including CERN, to store antimatter such as antiprotons.
15) What does antimatter look like?
That is exactly what scientists are trying to find out. What are the properties of something like anti-hydrogen? What are their energy levels? How does it behave in a gravitational field of the Earth? How does it interact with other particles?
16) Can the work at CERN tell us anything about dark matter?
Yes, it can. It can also give us information about dark energy.
It is a very hot topic in modern physics and some accelerator experiments are actually designed to possibly detect dark matter particles. So far they haven’t been successful.
Dark matter is a form of matter thought to account for approximately 85% of the matter in the universe and about a quarter of its total mass–energy density or about 2.241 x 10−27 kg/m3. Its presence is implied in a variety of astrophysical observations, including gravitational effects that cannot be explained by accepted theories of gravity unless more matter is present than can be seen. For this reason, most experts think that dark matter is abundant in the universe and that it has had a strong influence on its structure and evolution. Dark matter is called dark because it does not appear to interact with the electromagnetic field, which means it does not absorb, reflect or emit electromagnetic radiation, and is therefore difficult to detect.
In physical cosmology and astronomy, dark energy is an unknown form of energy that affects the universe on the largest scales. The first observational evidence for its existence came from supernovae measurements, which showed that the universe does not expand at a constant rate; rather, the expansion of the universe is accelerating.
17) Is it possible to create a black hole in an accelerator?
We know there are black holes in the Universe. They have been observed directly.
Creating a Black Hole in an accelerator is very, very, unlikely. If you were to investigate the energies needed for such an experiment you would find they would be huge.
There are some theories that talk about the creation of tiny Black Holes but they are nothing like galactic star-eaters that you read about in science fiction.
These Black Holes would be microscopic or sub-microscopic. Some theories use them to explain certain things but there is no need to worry about anything bad being generated by a particle accelerator.
In familiar three-dimensional gravity, the minimum energy of a microscopic black hole is 1019 GeV (equivalent to 1.6 GJ or 444 kWh), which would have to be condensed into a region on the order of the Planck length. This is far beyond the limits of any current technology. It is suggested that to collide two particles to within a distance of a Planck length with currently achievable magnetic field strengths would require a ring accelerator about 1,000 light years in diameter to keep the particles on track.
However, in some scenarios involving extra dimensions of space, the Planck mass can be as low as the TeV range. The Large Hadron Collider (LHC) has a design energy of 14 TeV for proton–proton collisions and 1,150 TeV for Pb–Pb collisions. It was argued in 2001 that, in these circumstances, black hole production could be an important and observable effect at the LHC or future higher-energy colliders. Such quantum black holes should decay emitting sprays of particles that could be seen by detectors at these facilities. A paper by Choptuik and Pretorius, published in 2010 in Physical Review Letters, presented a computer-generated proof that micro black holes must form from two colliding particles with sufficient energy, which might be allowable at the energies of the LHC if additional dimensions are present other than the customary four (three spatial, one temporal).
In physics, the Planck length is a unit of length. It is equal to 1.616255 x 10−35 m.
18) There was some excitement a number of years ago when some researchers at CERN thought they had detected a particle that travelled faster than the speed of light. What happened? Did they really detect tachyons or did someone just make a mistake?
There were a number of mistakes. There was a broken connector. There was a problem with the error analysis.
At the time the scientists did detailed analysis and couldn’t find any mistakes. They thought they had discovered particles that travelled faster than the speed of light. This wasn’t allowed with the laws of physics so they reached out to physicists around the world and asked them to look at the experiment and see if they could find any mistakes. Could they repeat the experiment and get the same results?
The latter approach is just good science. A theory is only as good as the moment it is proved, or something better comes along.
A tachyon or tachyonic particle is a hypothetical particle that always travels faster than light. Most physicists believe that faster-than-light particles cannot exist because they are not consistent with the known laws of physics.
Repeating the experiment showed that there were no particles travelling faster than the speed of light. It was a measurement mistake.
19) What difference would it make to build an accelerator on Earth compared to building it on the International Space Station?
It was noted in the talk how a particle beam can be influenced by things going on around it like the movement of trains. On the ISS gravity would play a different role compared to Earth and the gravitational field is taken into account in beam control so the control system on the ISS would have to take this into account.
It would be easier in space to create a vacuum although the vacuum in the LHC is better than the vacuum found in outer space. So even in space a vacuum chamber would be needed to reproduce LHC conditions.
20) Nuclear reactions release energy that can be used to generate electricity. Are there some systems that could potentially release energy more efficiently?
Accelerators could potentially be used to produce energy. There are schemes like accelerator driven subcritical reactors
An accelerator-driven subcritical reactor is a nuclear reactor design formed by coupling a substantially subcritical nuclear reactor core with a high-energy proton or electron accelerator. It could use thorium as a fuel, which is more abundant than uranium.
The neutrons needed for sustaining the fission process would be provided by a particle accelerator producing neutrons by spallation or photo-neutron production. These neutrons activate the thorium, enabling fission without needing to make the reactor critical. One benefit of such reactors is the relatively short half-lives of their waste products. For proton accelerators, the high-energy proton beam impacts a molten lead target inside the core, chipping or “spalling” neutrons from the lead nuclei. These spallation neutrons convert fertile thorium to protactinium-233 and after 27 days into fissile uranium-233 and drive the fission reaction in the uranium.
Thorium reactors can generate power from the plutonium residue left by uranium reactors. Thorium does not require significant refining, unlike uranium, and has a higher neutron yield per neutron absorbed.
21) Has being a physicist changed your view of the world and your approach to problem solving?
One of the strengths of physicists is we have a problem-solving ability no matter what area we work in.
Quantum mechanics can certainly have an affect on ones view of the world. It often goes against what is considered “normal”.
But any changes to this world view are positive.
22) What would your dream scientific discovery or breakthrough?
We need to find more efficient ways of living together, caring about the environment, finding solutions to global warming.
We need to find out more about the fundamental forces. Were there other forces at the beginning of the Universe.
In physics, the fundamental interactions, also known as fundamental forces, are the interactions that do not appear to be reducible to more basic interactions. There are four fundamental interactions known to exist: the gravitational and electromagnetic interactions, which produce significant long-range forces whose effects can be seen directly in everyday life, and the strong and weak interactions, which produce forces at minuscule, subatomic distances and govern nuclear interactions. Some scientists hypothesize that a fifth force might exist, but these hypotheses remain speculative.
Each of the known fundamental interactions can be described mathematically as a field. The gravitational force is attributed to the curvature of spacetime, described by Einstein’s general theory of relativity. The other three are discrete quantum fields, and their interactions are mediated by elementary particles described by the Standard Model of particle physics.
One major breakthrough would be able to include gravity in the standard model.
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (the electromagnetic, weak, and strong interactions, and not including the gravitational force) in the universe, as well as classifying all known elementary particles.
23) What are your favourite books?
I do like the books of Dan Brown. He has a great attention to detail and the science he writes about is actually quite close to what is being done. He does put an effort into finding things out.
24) In the Marvel movies some of the superheroes travel by entering the quantum realm. Is this just fiction or is there a possibility that this could happen in real life?
Hollywood has a lot of interesting concepts including time travel and teleportation. They are the kind of dreams that humans are after and science would quite like to know if they are possible.
For time travel one of the interesting experiments at the moment is looking at corelation, of how particles that are related to each other, but spatially separated, can communicate with each other.
There are experiments at microscopic scales that have shown that information might be transmitted at velocities faster than the speed of light, which ultimately means time travel. But if you go to macroscopic scales this is a very long way off from what Hollywood suggests. However, it is a very interesting area of science.
25) Is it possible to create a terminator with resources that we have now.
Not as they are shown in the terminator movies but there are robots that have amazing capabilities and they are used in every aspect of life. The advent of artificial intelligence is expected to have the most dramatic influence on humankind in our history over the next five to ten years.
If you want to see how far we have come then a good company to look at is Boston dynamics.
Boston Dynamics is an American engineering and robotics design company founded in 1992 as a spin-off from the Massachusetts Institute of Technology. Headquartered in Waltham, Massachusetts, Boston Dynamics is owned by the Hyundai Motor Group since December 2020.
Boston Dynamics is best known for the development of a series of dynamic highly-mobile robots, including BigDog, Spot, Atlas, and Handle. Since 2019, Spot has been made commercially available, making it the first commercially available robot from Boston Dynamics, with the company stating its intent to commercialize other robots as well, including Handle.
26) Has an Ironman suit that runs on jet fuel been created?
There are jet-based suits at the moment. The inventor is having talks with the military and film producers.
Of course, Ironman can go into space in his suit and has an unlimited source of power.
27) Will your research be impacted by Brexit as you had a number of European Union grants.
One of the positive outcomes of the negotiations is that the UK will remain an associate partner in the European Union framework programmes. That is a very large research framework and Liverpool has received a lot of funding over the years.
Now fundamentally I would say is that science is all about international collaboration and the more this is made easier the better it is for science.
It is clear that Brexit won’t do anything to simplify international collaboration and we are already seeing an impact on recruitment, research projects etc. None of this is positive.
I am optimistic that science will find a way to mitigate these changes and ultimately that is a political process. There is nothing positive in the development of Brexit from my view (or mine).
28) How much does it cost to build a particle accelerator?
This is really to do with what energies you wish to use and what type of particles that you want to make. It can start with relatively modest amounts of money.
If you are looking at an electron accelerator for material treatment for example you won’t need to pay out as much money as building the next generation particle accelerator which will cost enormous amounts of money. Multi-billion-pound project.
29) Is an accelerator environmentally friendly?
I don’t think that would be a badge that you could stick on an accelerator at the moment, however, there are definitely research projects happening that are looking into making them much more environmentally friendly. From “green” magnets that consume a lot less energy to finding alternative ways to producing the energy for use in the accelerators in the first place
30) Visits to the facilities like Daresbury and CERN.
That is possible. Every now-and-then there are open days when the general public are welcomed into the labs. To get an insight into what is going on. At the moment this can’t happen because of the pandemic
Note: Professor Welsch said he would be more than happy to answer further questions if you contact him (don’t contact me, I know very little).