
Cosmic Gall
– John Updike
He got it absolutely
right because the neutrino is among the shyest of subatomic particles, first
predicted mathematically in 1933 by Wolfgang Pauli, and only confirmed
experimentally some two decades later. For some reason the neutrino excites a
disproportionate affection from scientists because Pauli’s learned friends
once wrote a sketch, Faust in Copenhagen, with the neutrino
starring as Gretchen, Goethe’s heroine in the original classic. It seemed to
infect this year’s Nobel laureates, too.
At a press conference called right after the Nobel Prize committee announced that he had won a share of this year’s Nobel Prize for physics, Takaaki Kajita, said, “I want to thank the neutrinos of course. And since the neutrinos are created by cosmic rays, I want to thank them too.”
Kajita’s partner was Canadian physicist Arthur McDonald for experimentally observing neutrino oscillations in independent experiments conducted at the Super-Kamiokande neutrino observatory in Japan and the Sudbury observatory in Canada.
But the neutrino’s coy charms seem to be wasted on the activists who are agitating against the India-based Neutrino Project (INO) in Tamil Nadu’s Theni district. Indeed they are positively petrified at the kind of things they believe it might do to people and things in their neighbourhood. Their suspicions span an exotic spectrum from acute radiation hazard to targeted killings to counter-nuclear weapons.
Thus, for activists opposed to the INO this scarcely detected, most elusive of elementary particles is capable of all kinds of mayhem. But they are not surprised the physics community in India is excited because they see it as part of a vast conspiracy to usher in a world government in the future. But before we examine these charges a profile of this contentious particle would be in order.
Though neutrinos flood the entire universe they are notoriously hard to catch hold of as they rarely interact with any other form of matter. Updike wrote his tongue-in-cheek lines just four years after the particle’s existence was verified by two American physicists in the Savannah River nuclear plant in Georgia. At that time they were thought to have zero mass and zero charge. They could be seen only in the laboratory, when they were emitted during nuclear reactions or by smashing sub-atomic particles in large particle accelerators.
In 1965, five years after Updike’s poetic tribute, an observatory in the Kolar Gold Fields of Karnataka, along with an observatory in South Africa, discovered the first atmospheric neutrinos in cosmic rays that reached the earth from outside the solar system.
“No one had theorised before that neutrinos could be present in cosmic rays,” says P. Indumathi, a particle physicist at the Indian Institute of Mathematical Sciences (IMSc) in Chennai and the out-reach co-ordinator of the proposed INO. “It was an exciting breakthrough, and India’s only major contribution to experimental particle physics. It led to other countries investing in major experimental projects that followed up on the discovery.”
In the following years, several countries including the US and Japan conducted experiments to detect atmospheric neutrinos. They found them everywhere, reaching earth from the sun, from stars, from active galaxies outside the Milky Way and from supernova explosions. It is estimated that 65 billion neutrinos from the sun pass through every centimetre of our skin every second. After photons, they are the most plentiful elementary particle in the universe.
Among the early experiments was one deep inside a mine in South Dakota in 1968 by Ray Davis and colleagues, with a huge tank of cleaning fluid. The other particles which are part of the cosmic radiation were absorbed by the rock. The neutrinos, which did not interact with anything, reached the tank, where they reacted with the chlorine in the cleaning fluid to produce argon.
By measuring the number of argon atoms Davis and team arrived at the number of solar neutrinos that reached the earth. But the number was only one-third of what the laws of physics predicted. This became known as the solar neutrino problem, in popular usage the case of the missing neutrinos.
Physicists came up with a brilliant theoretical solution. As neutrinos travel, they surmised, they changed type—oscillating between three different flavours called the electron neutrino, the muon neutrino, and the tau neutrino. Most experimental set-ups were sensitive only to electron neutrinos, so the other two went undetected. The problem was solved in 2001 when Kajita and McDonald discovered these oscillations.
One of the consequences of the discovery of oscillations was that neutrinos were found to have a finite mass. But the maximum mass it can have is 1/2,000th of an electron, and less than one billionth of a hydrogen atom.
When the Kolar gold mines closed in 1992, the observatory was shut down and neutrino experiments in India came to an end. But a new proposal for an underground observatory came up at a conference on high energy physics in Chennai in 2000, attended by leading particle physicists from all over the country.
In 2002, the Department of Atomic Energy received an application and it allotted a site in Singara in the Nilgiris. The laboratory would be located in a two kilometre long underground tunnel housing the world’s largest magnet—a 50,000-tonne iron calorimeter, four times larger than the one in CERN. The size of the detector would allow up to three neutrino detections per day.
With a budget of Rs 1,500 crore the observatory was supposed to start collecting data in 2012. But the project ran into trouble as environmental activists objected to the construction. The site is located in a bio-sensitive zone.
In 2007, Mudumalai in the Nilgiri hills was declared a tiger sanctuary and as the site fell in the buffer zone, the Ministry of Environment and Forests refused to let INO build there. In 2009, the ministry cleared a location in Tamil Nadu’s Bodi hills in Theni. Early this year, the Union cabinet cleared the project.
But cabinet clearance just ramped up the profile of the protests from environmental groups who were joined by political parties this time. The objections are far-ranging.
Environmental activists in Tamil Nadu and Kerala allege that the project poses grave radiation risks to people living around it. They say the intention is not merely to observe atmospheric neutrinos, but to act as a detector for a neutrino beam produced from a neutrino factory in Fermilabs, the particle physics laboratory in the US. Fermilabs, situated near Chicago, is planning the Deep Underground Neutrino Experiment (DUNE).
They argue that unlike the cosmic neutrinos coming from outside our planet these high-energy neutrinos are a major radiation hazard. More seriously, the INO is supposed to be a secret military facility that will use neutrino beams sent from the US to destroy foreign military facilities. An additional objective is so-called targeted killings, à la James Bond. They do not specify who or what is going to be targeted though the net is probably cast wide.
A 2012 article that appeared on the website Countercurrents by V. T. Padmanabhan, an environmental activist based in Kerala says a “collimated high energy neutrino beam hitting an atom bomb hidden in a silo or submarine can cause its explosion. High energy neutrino beams can also be used as a tactical weapon to kill a small group of leaders/commanders with high radiation within minutes. This is useful for ‘regime changes’ or ‘war against terrorism’. Since neutrinos cannot be blocked by any material, this is a defence-less weapon. No time for early warning either.”
There are more prosaic concerns as well; that the blasting necessary for the construction of the tunnel will cause seismic disturbances that will affect the Idukki, Mullaperiyar and other dams within a 100-kilometre radius of the site. They say INO has not carried out a proper environmental impact assessment and that the blasting is also likely to affect agriculture in surrounding villages. All this seems a world away from what scientists are expecting from the neutrino observatory.
***
The August 2015 issue
of Nature has a story, “Age of the Neutrino”, on the direction
particle physics is taking because of the discovery that neutrinos have mass.
“As researchers at CERN, Europe’s particle physics laboratory in Geneva, dream
of super-high energy colliders to explore the Higgs Boson, their counterparts
in other parts of the world are pivoting towards a different subatomic entity:
the neutrino… Surprisingly little is known about the neutrino …Four
unprecedented experiments look poised to change this.
“Two—one in China and one in India—already have the go-ahead, and plans to erect detectors in Japan and the US are in the works. Buried underground to prevent interference from other particles, all four are designed to detect many more neutrinos, and to probe the switching process in more detail than any existing experiment. The results are expected to feed into some of the most fundamental questions in cosmology.”
There is no hint of weapons or military applications, simply that the experiments will feed more information to theoretical physicists to produce a better picture of the universe.
There is no hint of weapons or military applications, simply that the experiments will feed more information to theoretical physicists to produce a better picture of the universe.
It is a different story at the INO. Opposition started to gather steam once the politicians also got involved. Among them is V. S. Acchuthanandan, veteran Kerala CPI (M) leader and opposition leader who raised the issue in the state assembly in 2012. It followed allegations by some activists that part of the tunnel extends into Kerala. At press conferences, he has accused the Centre of secretly colluding with the US to send a neutrino beam from Chicago and of wanting to store hazardous waste from the Kudankulam nuclear reactor in the laboratory. Perhaps he does not know that the International Atomic Energy Agency has strict protocols to monitor the transport and storage of nuclear waste.
Another politician who got involved is MDMK leader Vaiko of Tamil Nadu. He speaks of geological damage from the drilling and says INO will forcibly acquire surrounding agricultural land. That INO has no powers to do any such thing seems quite beside the point. In any case he has succeeded in moving the Madurai bench of the Madras High Court to stay all construction till the Tamil Nadu Pollution Control Board provides a clearance.
***
The low-lying Bodi
hills are crowned by a blanket of white clouds as we approach from Pottipuram
village. Behind the first line of peaks, misty clouds half-shield the range
behind from view. The 26-hectare site sits at the foot of the hills. It is
cordoned off by a white fence. The area is dry scrub, located on porambokku revenue
land. We are led to the site by Maran, who lives in a nearby village and is a
prominent opponent of the neutrino project. The wind gets up as you draw
closer, and if you lean backward you run the risk of being knocked off your
feet.
“The INO says this is porambokku land and not forest, but this scrub is important in conserving the water table. And when it rains heavily and rushes down the hill, the water lodges here,” he says as he leads the way down the slope to the gate. Pottipuram has no regular water supply or toilets. Maran complains that the government intends to lay a pipeline to get lakhs of litres of water for the INO project, while there’s no tap water in any of the five panchayats in the area. Before the court order stayed construction, the path to the hill was closed by forest officials for more than a year, he says.
Villagers whom we meet complain that they are not allowed into the grazing land in the hills, forcing them to graze on dryer land. As we walk across the site, empty except for a huge water tank with India-based Neutrino Observatory in Tamil, Maran points to the rock face where the tunnel will be dug.
“The wind is so strong it will blow the debris towards the fields. It used to blow stones as far as 12 kilometres away. It will damage the fields,” he says. A wooded area nearby that the villagers planted over the years protects fields from the dust the wind carries. Maran says the trees will have to be felled to enable the half-constructed access road to reach the observatory site.
Jawahar, president of the nearby Thamminayakapatti panchayat tells me that two of the five panchayats have passed resolutions demanding that the state government stop the INO project. “We saw Fukushima happen on TV. All the Tamil news channels showed it for days. And we know what happened in the Second World War in Hiroshima and Nagasaki. I have seen it on Discovery channel and National Geographic. We do not want to face that. During the protests over the Kudankulam nuclear plant too, the government and scientists did not tell the public the truth. [Former president] Abdul Kalam came and declared that the plant was safe, but he was not even a nuclear scientist,” he says.
Jawahar also believes the project will threaten agriculture in the area, another reason why his panchayat opposed it in a resolution. He says panchayat members faced pressure from the collector’s office and the police not to pass the resolution. Vaiko visited Theni recently and spoke about the risks of radioactivity and the threat to farmlands in the villages.
Radioactivity is on everyone’s mind. It’s Maran’s big worry too. Back in the small two-room house in which he lives with his family, the farmer sits down in front of a desktop computer and opens a list of folders. My eyes scroll down the list: “How particle physics can save your life”, “International Design for Neutrino Factory”, “Benefits of Neutrinos”, “CERN LAB”, “FERMI LAB”, “Ten things about anti-matter”.
When he bought the PC in 2010, Maran did not expect that it would change his world. Though Maran can read English, he cannot speak the language. But the proliferation of websites and social media that use Tamil script has opened up the web to him. Maran left his studies after Class 12 but retained what he calls a thirst for “deep knowledge”.
A member of the Peasant’s Liberation Organisation, he was active in protests against globalisation in the mid-Nineties and later against Bt cotton. Soon, he started using an Internet café to research the GM crops debate.
When he first heard about the neutrino project, he was not perturbed. He read arguments by both scientists and activists in the Tamil press, without being convinced by either. That changed in February 2015, when he read an article by a researcher in nanotechnology called Vijay Asokan, at that time doing his Phd in a Norwegian university. Asokan criticised the argument of Indian scientists that neutrino experiments were safe and accused them of not being transparent. “He was a scientist too. And hailed from Tamil Nadu. So I decided I needed to understand the issue for myself,” Maran says.
He immersed himself online for the next three months, reading up on neutrino physics, on the documents available on the INO project and scouring scientific papers on neutrino experiments online. He subscribed to Symmetry, the particle physics magazine published jointly by Fermilabs and the SLAC National Accelerator observatory operated by Fermilabs. It was a painstakingly slow process.
“You are educated. What you can read and understand in an hour it would take me three days to do,” he tells me. For words and terms that he did not understand, he would use a Tamil translator. Serendipity played its part. When Maran was having a heated discussion on Facebook about INO with a member of the Tamil Nadu Scientific Forum on Facebook, the author of the magazine article joined in on Maran’s side. From then on, when he came across literature on neutrinos he did not understand, Maran would get Asokan to explain. By the end of May, he was convinced INO was a threat to the community’s safety.
He believes INO scientists are lying about the true purpose of the laboratory and that he has evidence. “The scientists have been lying from day one. All the proof, all the documents are there on the Fermilab website. Unlike scientists here, they publish everything. The far detector of Fermilab will be located in India and Indian scientists are constructing it.”
As he shows me his trove of downloaded documents, I realise he is talking of a completely different kind of collaboration. The Long Base Line Neutrino Facility (LBNF) which manages the DUNE project at Fermilab is an international collaboration involving 148 research institutes, including several from India.
The documents detail a proposal for Indian scientists to fabricate one of the detectors DUNE will use, and then install it in Fermilabs. The documents refer to the INO project only in terms of how the LBNF collaboration can help in interpreting the data INO gathers.
Tim Burners-Lee once said, “There was a time when people felt the Internet was another world, but now people realise that it is a tool that we use in the world.” Maran could not have agreed more. For him, the Internet is not only a tool to gather information, but a resource of political empowerment as well.
Burners-Lee developed the World Wide Web in 1989 as a computer engineer in CERN. Named ENQUIRE, the project was intended to allow information sharing between physicists working at CERN. Over the decades the information-sharing physicists exceeded the technology available, with the need to share large data from immensely complex experiments in real time among various universities and research facilities across the world.
The early adapters of the World Wide Web were mainly scientific departments in universities and experimental physics labs such as Fermilab and SLAC. In 1993, CERN released the World Wide Web for free as open software, thus beginning the Internet revolution.
While Berners-Lee was working on the web in 1989, scientists at CERN’s most advanced accelerator, the LHP, made an important discovery. They confirmed that there were only three generations of fundamental particles. This completed the picture of the Standard Model of Physics, the theory that explains interactions between all fundamental particles.
According to the standard model, there are two types of fundamental particles, quarks and leptons. And the types are exhausted in three generations. The larger subatomic particles like neutrons and protons are made up of quarks. The small electron, however, is a lepton, a fundamental particle.
After the electron, physicists discovered two more negatively charged leptons—the muon and the tao—both heavier than the electron but unstable. The neutrino is also a lepton, but without any charge. Every time an electron is produced in a chemical reaction, it is accompanied by an electron anti-neutrino. In the same way, muons and taos are always accompanied by anti-muon and anti-tao neutrinos respectively.
During the Nineties, experimental evidence mounted that the Standard Model was correct, with more of its predictions being confirmed by experiment. The last remaining fundamental particle the Standard Model predicted, the top quark, was discovered in 1995. The mysterious Higgs Boson, the particle that the theory said gives mass to fundamental particles, was discovered by CERN’s Large Hadron Collider in 2012. However, the model predicted that neutrinos were massless particles. With Kajita’s and McDonald’s discovery of neutrino oscillations by 2001 it was clear that this was wrong. The question of how the neutrino gets its mass is something that the Standard model cannot explain. Physicists needed to go beyond the Standard Model. Suddenly, neutrino research became fundamental in answering some of the deepest questions about reality.
***
I meet Vijay
Asokan at the office of Sundar Rajan, of Poovulagin Nanbargal (Friends of the
Earth), an environmental NGO based in Chennai. Back in India after his PhD in
nanophysics from Bergen University, he’s bound for China for post-doctorate
studies. Asokan has written several articles in the Tamil and English press
against the neutrino project since the beginning of 2015.
“I became suspicious of the project as soon as I heard about it because of fraudulent statements from the INO team. They say they only plan to measure atmospheric neutrinos. But INO scientists are part of the International Design Study for Neutrino Factory group, which is planning to build a neutrino factory from where they will send a neutrino beam to India.
“India is located at the ideal distance from Fermilabs and the term they use for it is ‘magic baseline’. INO scientists have made presentations. The detailed project report that INO submitted to the government says clearly that the second stage would be for the observatory to act as a detector for a neutrino beam send from a neutrino factory located abroad. Why are they now denying it?”
Asokan adds: “The magnetised iron calorimeter INO plans to build is 50 kilotons. You can detect atmospheric neutrinos with seven kilotons. Why are they building such a large magnet? The published papers of International Design Study for Neutrino show that they want a 50 kiloton magnet to act as the detector for the beam.”
Given that neutrinos are almost massless and do not interact with anything, would it really matter if a neutrino beam is received at the Theni observatory? After all, trillions of neutrinos pass through our body every second. What harm can it do?
Sundar Rajan and Asokan both claim that the situation is entirely different with artificially produced neutrino beams. And INO scientists are concealing this fact from the public.
“These are neutrinos of very high energy and are highly collimated. They have radiation hazards. Lots of physicists have studied this.” As proof of their assertion they refer me to a set of scientific papers by particle and nuclear physicists.
Two of them are internal reports by CERN (1998 and 2002) analysing the radiation hazards due to neutrinos from a muon collider to be built at CERN in the future. Muons are fundamental elementary particles that decay to produce neutrinos. The other two are similar papers published by physicists Bruce King and by John Bevelacqua. Sundar Rajan argues that even atmospheric neutrinos pose radiation hazards.
“Eighty per cent of atmospheric neutrinos are low energy. Twenty per cent are high energy and can cause damage to humans. People used to develop cancer even before the industrial revolution and pollution came.”
If all this information is freely available online including on the INO website, why would the scientists try to conceal it? Because something much more is going on, deduces Asokan. They are afraid that the trail may lead to the true purpose of the neutrino laboratory, which is that it is a weapons programme instituted by western powers.
“In 10 to 15 years, the world will have neutrino weapons. Neutrinos can penetrate anything so they can’t be stopped.”
Can neutrino beams be used as weapons? Even if it is conceivable that they pose radiation health risks in high energies, can they be used as weapons to blow up things?
Asokan’s theory that neutrino beams can be used as weapons comes from a paper called “Neutrino anti-neutrino counter nuclear weapon” by particle physicist Alfred Tang. He theorised about a neutrino and anti-neutrino beam which could simultaneously target nuclear missile installations and cause the bombs to blow up. He also refers to an earlier paper published by Japanese physicists where only a neutrino beam would be used to achieve the same effect.
Sundar Rajan quotes Tang: “The idea of using neutrinos to detonate or melt a nuclear weapon was first proposed by H. Sugawara, H. Hagura and T. Sanami. Their futuristic design is based on a 1 PeV neutrino beam operating at 50GW. It is unlikely that such an intense ultra-high energy neutrino beam will be made available in the near future. Even if such a beam is made available, its radiation hazard will render it politically unviable.”
Sundar Rajan picks out the comments about radioactivity as proof that Indian INO scientists are lying. Asokan says: “The Sugawara paper says that the condition for this neutrino weapon being used is that there should be a world government. That is what these universities collaborating in this weapons project are trying to do. Developing neutrino factories and detectors in several countries for neutrino weapons are the first steps towards the eventual goal of creating a world government.”
Fountain Ink consulted several leading authorities in theoretical and experimental particle physics in the US, UK and Germany to check these claims. Five physicists, Professor Giorgio Gratta of Stanford University, Professor Peter Meyers of Princeton University, Professor Georg Raffelt and Professor Alan Caldwell of the Max Planck Institute, Germany, and Dr Alfons Weber, Rokos-Clarendon Professor at Oxford University, independently confirmed that neutrinos do not pose any kind of radiation risks. All of them dismissed Sundar Rajan’s claim that highly energetic atmospheric neutrinos can cause radiation diseases in humans.
“Neutrinos are extremely weakly interacting particles, so to measure any of them requires huge detectors such as INO. Their rate of interaction is so extremely small that it is very difficult to see any consequence of their existence in the first place. They have no impact whatsoever on humans,” says Dr Raffelt.
Dr Gratta explains that the neutrinos are a very small part of the natural radiation spectrum. The cosmic rays that bombard us are far more intense. “This is the reason why one has to go underground to shield the rest of the cosmic rays. We live on the surface of the earth and are bombarded by cosmic rays that have a much higher intensity than atmospheric neutrinos.”
All the physicists said that while scientists have conceptualised neutrino factories and have done preliminary studies to build them, the technology to construct such facilities is still a long way off in the future. They are categorical that even if such factories were built the neutrino beams they produced would be no riskier than the trillions of neutrinos streaming through us every second. The papers on neutrino radiation that Asokan and Sundar Rajan cites are talking about something completely different.
Neutrino laboratories produce neutrino beams using intense high energy proton beams. Futuristic neutrino factories would smash together beams of muons to generate neutrinos. All the studies the activists referred to are studies of radiation doses in and around the facility that produces neutrinos, not of the neutrino beams that would propagate hundreds or thousands of kilometres. The upper energy limit for neutrino beams in futuristic neutrino factories is around 50 GeV.
This a high energy level for a subatomic particle, but not very large compared to the world of large objects. A calorie, for instance, is 190 cores higher than 50 GeV. Weber says “Neutrinos with energies as high as 50 GeV are totally harmless, most would just pass through the environment or humans and never interact or cause any damage. This is even true when standing 50m from a neutrino factory. INO would potentially be 5,000 km away from any neutrino factory and because of the distance the radiation would be at least (50m/5000km)^2 = 1/10,000,000,000 (10 billion) times smaller.”
Weber’s calculation uses the fact that radiation is inversely proportional to the distance from the source. Professor Indumathi used the same formula to calculate that someone standing in front of a 50 GeV beam that reaches INO from 5,000 kilometres away would be exposed to radiation equivalent to one part in ten cores millisieverts in a year. In other words, the person would have to stand there for a hundred core years to receive the radiation dose equivalent to a single CT scan.
The physicists Fountain Ink consulted said that though they have not made exact calculations, the radiation dose given by Indumathi fell within the reasonable range for a GeV range neutrino beam from such a distance.
Fountain Ink also wrote to Dr John Bevelacqua, the nuclear health physicist whose published work was one of the sources for Sundar Rajan and Asokan’s claim that neutrino beams carry radiation risks.
When told that various physicists have said that radiation would be confined to the site of a neutrino factory, he responded: “The physicists are right. My papers deal with TeV scale muon colliders which are vastly different than an observatory. In addition, the energy scales used in my papers are about 1,000 times larger than will be encountered in the observatory based on 50 GeV. In short, my papers are not applicable for an assessment of an observatory operating in the GeV region.” A TeV is equivalent to 1,000 GeV.
Dr Marco Silari, co-author of the two CERN papers Asokan cites, says: “The study I have done almost 20 years ago was for a future muon-muon collider (an accelerator never built so far). Our study at that time was limited to a distance of up to 80 kilometres from a potential, future CERN muon collider. It showed that at such distances the radiological hazard produced by the high neutrino flux would become a problem only if the accelerator energy exceeds 2 TeV.”
If there are no radiation risks even in higher energy ranges, what is the explanation for Alfred Tang’s work on neutrino beams capable of tremendous destructive power and of blowing up nuclear weapons? The answer is to be found in two things: why Tang wrote his paper and how nuclear bombs work.
Tang’s purpose in developing the theoretical concept of a “Counter-nuclear weapon”, as stated in the introduction of his paper, is worry over the proliferation of nuclear weapons. Developing a more powerful weapon does not get rid of that problem. What Tang wants to do instead is use neutrinos to make nuclear weapons self-destruct.
In a fission bomb, the radioactive nuclear material, usually uranium 235 or plutonium 295, is bombarded with neutrons (not to be confused with the elusive neutrino). If it is uranium, the uranium atom decays, releasing energy and three neutrons. If even one of these neutrons hits another atom, the same process will happen.
This leads to a chain reaction and finally a nuclear explosion. But for this to happen, there has to be a minimum mass of the nuclear material, which is called the critical mass. In the simplest kind of fission bomb, like the Little Boy bomb used on Hiroshima, two sub-critical masses of uranium 235 are kept apart. The bomb is set off with an explosive device that smashes the two masses into each other, so that the total mass is above the critical mass. This sets off the chain reaction.
One of the most exciting discoveries of early particle physics was what is called anti-matter. All particles have an associated anti-particle. Thus positrons are particles identical to electrons, except that they carry positive electric charge. In the same way, anti-protons are exactly like protons except that they carry negative charge. If a particle and its anti-particle collide they annihilate themselves, producing energy.
Tang proposes directing a beam of neutrinos and anti-neutrinos at a nuclear weapon. The annihilation process will produce a shower of particles, including neutrons. The extra neutrons released act as a catalyst increasing the number of decay reactions. As more and more energy is released, the heat will ignite the explosive material around the nuclear material, blowing it up. But since it never reaches critical mass, the explosion is much less powerful than a nuclear explosion.
In e-mail correspondence with Fountain Ink, Tang dismissed the idea that the LBNF accelerator at Fermilabs was capable of producing the kind of weapon he theorised. He also said it was doubtful whether even a neutrino beam for scientific study could be sent to India from the US.
He says: “The energy profile of neutrinos generated by LBNF typically peaks at 2-3 GeV. My paper suggests that the minimum neutrino energy required for a neutrino counter-nuclear weapon is about 91 GeV. LBNF is not tuned for a neutrino counter nuclear weapon, to say the least. Besides, the beam is aiming at Stanford—not India.
“It is not easy to build a conventional accelerator aiming at India from the US because the beam has to traverse the earth so that the accelerator has to aim downward toward the centre of the earth and the tunnel has to go vertically down. No one will invest that much money and effort into something that is not yet proven to work.” He also said that it is very doubtful that any current accelerator was capable of producing neutrinos that caused any serious health risk.
DMDK’s Vaiko did not respond to requests to talk on the INO issue despite several attempts to contact him over a week. The Fermilabs press office told Fountain Ink in an email that the DUNE project has no direct collaboration with INO. The project’s far detector would be in Dakota not India.
***
At her office in IMSc
in Chennai Indumathi clarifies some of the points raised by villagers. As I
walk in, she is sitting with her swivel chair turned towards the computer next
to her desk, working on a simulation. There is a large blackboard covered with
equations. Indumathi says the villagers’ worries about the debris are
unwarranted. She claims it would be wetted and covered, preventing the winds
from creating dust contamination.
She says INO has nothing to do with blocking access to the grazing lands. “The reserve forests in the Bodi hills are managed by the Forest Department. We have not visited the site in six months. The situation is too volatile for us to go there, though we want to talk to the villagers.
“The INO is an observatory that plans to measure only atmospheric neutrinos. There were plans when the project was conceived to collaborate in a future neutrino factory. It was discussed in several conferences and a study group formed. But the parameters it wanted to measure were discovered by other experiments. At the current state of neutrino research, there is no point in trying to build such a facility.”
Indumathi has been part of the project since the early days. Now she wonders whether she will be in active research by the time the observatory comes up, or whether it will come up at all.
“The delays have cost us badly. The observatory should have started giving data by now. China has started JUNO, an observatory to do exactly what we plan to do, measure the mass hierarchy of the neutrinos.”
One of the bizarre effects of quantum mechanics is that while there are three mass values associated with the three flavours of neutrinos, the flavours keep changing their mass. Instead of measuring the mass directly, the magnetised calorimeter will measure the hierarchy—which mass is the largest and which the smallest. “Neutrinos interact with matter extremely rarely. The idea of having a massive detector is that there are more iron atoms for neutrinos to interact with. Even then, we expect only three interactions a day. But this is a very high number because of how weakly neutrinos interact.”
Indumathi explains why a lot of physicists in India and elsewhere in the world are excited about the neutrino more than any other particle. Research might open the doors to answering three of the most fundamental questions about the universe.
The greatest mystery that troubles scientists is that most of the mass of the universe seems, well, missing. The matter we know of accounts for slightly more than one-sixth of the mass.
The rest is made up of so called dark matter. As the name implies, dark matter is total, hidden from any instrument of observation. It does not seem to interact with anything, but we know it is there through its gravitational effect.
Since we know now that neutrinos have mass, they are the only candidate we know to fill the dark matter hole. The weakness of neutrino interaction can possibly explain why dark matter goes undetected.
The second mystery also has to do with mass. In the Standard Model, all particles get their mass by interacting with a mysterious field called the Higgs field, which is present everywhere. The Higgs mechanism is the bedrock of the model. Neutrinos becoming massive should not have been a problem for the Higgs mechanism, except for an odd property called chirality that neutrinos have. All particles have a quantum spin. If the direction in which the particle travels is the opposite of its spin, the particle is called left-handed. Right handed particles travel in the same direction as spin. All elementary particles have two forms: left-handed and right-handed. This is because all particles that get their mass by interacting with the Higgs field need to have left-handed as well as right-handed types.
Only left-handed neutrinos have been detected, so physicists assumed they must be massless. But now that neutrino oscillations have been discovered and neutrinos have mass—right-handed neutrinos are needed. But if they are there, why can’t they be found? One answer is to tweak the Standard model so that right-handed neutrinos exist, but interact with the Higgs field very, very weakly. The more exciting possibility is to go beyond the Standard Model and find another mechanism for generating mass. One theory is that neutrinos are majorana particles.
Majorana particles, fermions that are their own anti-particles, were first theorised by Ettore Majorana in 1937 but none have been detected so far.
Neutrinos may also potentially solve the problem of why there is more matter than anti-matter in the Universe. At the time of the Big Bang, matter and anti-matter were created in equal quantities and started annihilating each other, releasing energy. But, somehow, more matter than anti-matter has been left over. If physicists can detect enough reactions that violate a law called charge-parity conservation, the Standard Model could explain the matter anti-matter asymmetry.
But so far the required numbers of CP violations have not been spotted in most hadrons and leptons. If enough CP violations are detected in neutrino interactions, the question of why the universe has more matter can be solved.
Sundar Rajan as well as activists from Kerala have claimed for years that INO would result in large-scale environmental, ecological and geological damage. Apart from allegations of radiological contamination and targeted killings using neutrino beams, V. T. Padmanabhan’s article alleged that blasting to dig the tunnel would endanger the Idukki dam.
Sundar Rajan says: “The area where the INO site is located is an ecologically and seismically sensitive zone. The INO will be using five lakh kilograms of explosives. They cannot control or predict how far the shockwaves will travel. In February, there was a massive earthquake near Japan that registered 6.9 on the Richter scale. Scientists discovered that it was the aftermath of the 2001 earthquake. There can be such delayed effects of shock waves.”
Fountain Ink asked Professor Boominathan of IIT Madras, an expert in the area of vibrations and earthquake geotectonics to evaluate the effect of blasting and tunnel drilling in the INO site India. Along with his colleague Dr V. B. Maji, who works in the area of rock tunnelling and drilling, he prepared a technical evaluation based on a report prepared by the Geological Survey of India.
“The frequency content of ground vibration due to blasting is different from earthquakes. Temblors produce relatively low frequency content excitation whereas rock blasting produces high frequency content excitation and hence it will not cause any problems to dams, particularly those which are located far from the site,” they say.
Boominathan categorically refutes the activists’ claim that the site lies in a seismically sensitive zone. “No. The site lies in the Zone II as per Indian Standard which indicates the site lies in the very low seismicity areas. Based on the type of rock and stress conditions reported I am of the strong opinion that the site will not be in any way affected by any seismic activity in the region including reservoir induced earthquakes.”
According to him, the vibrations typically fall to 0.1 mm per second for blasting used in tunnelling. These are barely perceptible vibrations and are thirty times lower than that allowed near protected historical monuments in countries like Germany and Switzerland.
According to the scientists, it’s a mare’s nest and they should know because it’s their province. Neither Boominathan nor Maji have any connection with INO apart from the fact that they are scientists. So unless, as the activists allege, there really is a vast conspiracy involving scientists and governments from all over the world INO is a long-overdue project that should be implemented now to better understand how the cosmos works.
Unfortunately, the fact-free hyper ventilations of a disparate group of activists and politicians have created an atmosphere of fear that no one in power apparently wishes to dispel.
Unfortunately, the fact-free hyper ventilations of a disparate group of activists and politicians have created an atmosphere of fear that no one in power apparently wishes to dispel.
Maran accompanied us to the bus stand from where we would take a bus to Theni town. On our way, he talks about the overconfidence of Indian scientists and how it was putting people’s lives at risk. “They keep claiming that neutrinos are not harmful to humans. But how can they know that unless they shoot a neutrino beam at someone and see what happens,” he says. I thought of telling him that this was not quite how scientific predictions work. But I doubted that he would believe me.
A week later, I came across an article on the technology website ars technica. John Trimmer, ars technica’s science editor wrote in 2011 about how on a visit to Fermilabs he had the unusual experience of standing in front of a particle accelerator without any protective gear. This was a neutrino beam.
I dropped Trimmer a line, and he wrote back saying: “Yes, I’d be happy to confirm that I stood in the middle of a neutrino beam while it was active. It poses no risk.”
This was followed by an extract from Symmetry, the magazine that Maran had signed up for, on the number of neutrinos that stream through our body as we carry on with our daily lives, eating sleeping, drinking, fighting, making love and reading articles online.
John Updike said it best. And Dr Raffelt, of the Max Planck Institute, who told me that to ask if neutrinos can harm humans or the environment, was “like asking if we can drown in a droplet of water”.
Correction, Nov 19
2015: An earlier version of this story referred to electron anti-neutrinos as
electron neutrinos, and to anti-muon and anti-tao neutrinos as muon and tao
neutrinos. This has been corrected. The errors are regretted.
(Published in the November 2015 edition of Fountain Ink)