Will civilization survive until the next century? Details of David Gross' interview.
David Gross gave interviews to journalists after receiving a special Breakthrough Prize for fundamental physics for $3 million. Formally, the reason was a new award, but the conversation quickly went beyond the biography of the laureate. Gross spoke of a theory that could unite the main forces of nature, about why fundamental physics progresses more slowly than before, and about nuclear war, which, in his opinion, can break human civilization earlier than scientists have time to finally describe the laws of the Universe.
Gross calls himself an optimist, especially when he thinks about the future of physics. He is sure that somewhere in the depths of nature there is a single theory that can connect electromagnetism, strong and weak interaction with gravity. Such a theory must close the long-standing gap between quantum physics and gravity, which does not yet fit into the same mathematical picture. But physics faces a closer assessment: humanity can destroy itself in a nuclear war sooner than it achieves this goal.
In the early 1970’s, Gross, together with colleagues, discovered asymptomatic freedom, one of the most unusual properties of strong nuclear interaction. Strong interaction keeps quarks inside protons and neutrons. Quarks can not simply be removed from the proton one: the further the particles are to be pushed, the stronger the attraction between them grows. But inside the proton itself, at very short distances, quarks behave almost freely and interact much weaker.
It is this strange behavior that is called asymptotic freedom. Physicists have repeatedly tested the idea in experiments with high energies. The discovery helped build quantum chromodynamics, the theory of strong interaction, and then fixed it as one of the pillars of the Standard Model of particle physics. For this work, Gross received the Nobel Prize in Physics in 2004.
After the success of quantum chromodynamics, Gross took up a more risky area. In the 1980's he participated in the development of heterotic string theory. This version of string theory combines different types of string models and tries to describe fundamental particles not as points, but as tiny single objects. Unlike asymptomatic freedom, string theory has not yet been experimentally confirmed. For Gross, the difference between these two parts of your career is important: one relies on data, the other remains an attempt to look beyond the available experimental area.
The new prize for him is pleasant and a little awkward for him at the same time. Gross already received the Dirac Medal in 1988, the Harvey Prize in 2000 and the Nobel Prize in 2004. He perceives the Breakthrough Prize not as a substitute for the Nobel Prize, but as a more free reward: it can go to scientists for ideas that have not yet managed to test nature. Gross has long been helping to raise funds for the Cavley Institute of Theoretical Physics at the University of California, Santa Barbara and other research centers, so the new amount gives him the opportunity to support colleagues and institutes.
In the conversation, Gross explains why the path to a unified theory is so long. When he began his career, experimental physics experienced a turbulent period. Accelerators and detectors constantly brought new particles and unexpected results, and theorists tried to collect a clear picture from this data. The situation is almost mirrored now. Physicists have a lot of strong mathematical ideas, but nature has ceased to generously throw new facts. Previously, the theorist could offer a calculation and wait for verification for a year. Now the development of the region is planned for a period of 30 to 60 years.
The slowdown Gross connects not only with money. Large experiments really require large commands, sophisticated engineering and long construction, but it’s deeper. Physicists are moving towards an increasingly smaller scale of distances, and to look there, you need ever higher energies. Over the past two centuries, science has come a long way: from molecules to atoms, from atoms to nuclei, from nuclei to the internal structure of protons and neutrons. According to Gross, progress covered from about 15 to 20 in magnitude.
The next area, which is indicated by observations and theoretical continuations of known models, lies much further. Physics may need to go through about 20 orders of magnitude. And here comes the unpleasant mathematics. Due to the asymptotic freedom and similar properties of quantum fields, physics changes at a slow distance, logarithmic. The price of access to higher energies is growing much faster, at least proportional to the square of energy. Scientific efficiency increases slowly, and the cost of experiments soars sharply. For Gross, such a gap explains why the path to new data is becoming increasingly difficult.
From here he proceeds to a nuclear threat. According to Gross logic, humanity may need centuries of new theories, accelerators and observations to test the final theory of nature. But a global nuclear war can destroy civilization in one day. Therefore, he considers reducing nuclear risk as a part of the same task as fundamental research: there is no future physics without future people, laboratories and universities.
Gross says that scientific work and public position do not contradict each other. Each scientist himself decides how to spend limited time, but a great reward gives not only recognition. She attracts attention, and with him there are requests to speak, sign letters, explain the risks and convince politicians. The scientist recognizes that publicity takes strength, but considers such work useful.
Now he, along with other scientists, is trying to revive the Mainau process - the movement of Nobel laureates against nuclear war. The new group, which is called the Assembly of Nobel laureates to prevent nuclear war, involves researchers working with the UN and European venues. In July last year, the band held a major meeting in Chicago, to which the Pope sent the cardinal as his representative. The next events are planned in the Vatican.
The main task of this campaign is to remind people that nuclear annihilation has not gone along with the Cold War. Gross especially wants to reach young scientists. According to his observations, graduate students, postdocchi and professors almost always call the climate the main global fear. Then recall diversity in the academic environment, getting a constant rate, inflation or career uncertainty. Almost no one is at the top of the list of nuclear war.
Gross is astonishing that even physicists often do not pose a significant extent to the threat. He asks young colleagues how many nuclear missiles there are, how long the leaders of nuclear powers need to give the order to launch, and what makes a warhead with one megaton. According to him, the answers often show a lack of special knowledge, and a gap in the basic understanding of risk.
In the 20th century, serious experts estimated the probability of nuclear war at about 1% per year. One number seems small, and many easily dismiss him: there was no war, so you can not think. But the risk accumulates year after year. At 1% per year, according to Gross, the life expectancy of a person born today decreases to about 67 years, if we assume that the global nuclear war will lead to its death. The physicist compares this logic with radioactive decay: a single atom may not decay for a long time, but with a large number of atoms and sufficient time, a rare event becomes statistically expected.
Now the physicist considers the situation worse than in the days of old assessments. Nuclear arms control treaties have been destroyed or terminated, the number of countries with nuclear ambitions has grown, and there is a big war in Europe with the participation of Russia, which has a nuclear arsenal. Gross conservatively assesses the current risk of nuclear war at 2% per year. With this probability, the life horizon of children, according to its calculation, shrinks to about 35 years, if not reduce the threat.
At the same time, Gross does not demand to immediately destroy all nuclear weapons and does not expect that humanity will suddenly become pacifist. He talks about a more realistic goal: to reduce the likelihood of disaster. The declaration, prepared after the meeting in Chicago, lists measures that participants believe could reduce the risk. In an interview, the physicist does not disassemble these points one by one, but emphasizes the principle itself. If it is possible to omit an annual probability of at least 0.1%, humanity will benefit several centuries to solve other problems.
He cites the climate agenda as an example of how science can break through public indifference. About 40 years ago, researchers began to persistently warn of warming. The path took a long time, oil companies and related politicians resisted, but the climate has become a strong political issue. According to Gross, a similar social mechanism has previously helped in the nuclear sphere. Millions of people took to the streets against radioactive fallout from atmospheric testing, and the pressure of society helped advance the Comprehensive Nuclear-Test-Ban Treaty.
After the Cold War, attention disappeared, but the arsenals remained. Gross considers this forgetfulness dangerous. The climate is changing slowly and threatens huge damage, but in itself, in his opinion, will not destroy all of humanity. A global thermonuclear war can destroy civilization, cities, institutions and the familiar world in 24 hours. For him, inaction in the face of such a threat looks especially illogical.
Separately, Gross sharply criticizes the idea of a large-scale anti-missile defense of Golden Dome. He compares the project with the Ronald Reagan’s Star Wars program, only in a more expensive and enhanced version. According to the physicist, the defense in such a race almost always loses to the attack. The attacking side can increase the number of warheads, false targets and ways of bypass, and the defense system has to try to intercept everything.
Gross explains the problem by the example of a big city. One warhead that broke through the defense is enough for the consequences to become catastrophic. One rocket with split individual guidance warheads can direct 10 charges of half a meter oftons to the New York area. Any protection can be overloaded, deceived or bypassed. The wars of recent years, he said, are already showing asymmetry: cheap drones and missiles are forced to use expensive interception systems, where one defensive shot can cost more than a target.
The physicist sees another danger in missile defense. If the state believes that it is able to hide from a retaliatory strike, politicians are tempted to act more aggressively. According to Gross, such projects do not solve the main task, but push the world to a new arms race. He considers Golden Dome extremely expensive, technically unreliable and almost unrelated to real risk reduction.
In politics, it has become less optimistic: the United States and the world, according to him, are moving towards more and more instability. But the nuclear threat is not like an earthquake or an asteroid fall. Rockets, warheads, warning systems and command chains were built by people, people can change the rules for handling them.
Gross does not want humanity to need a small nuclear war that will kill several hundred million people and destroy a huge part of the planet to remind how close the world has come to disaster. He hopes that warnings, calculations and political pressure will be enough before.
In fundamental physics, optimism is almost a professional requirement for him. A scientist who is looking for the beginning of the universe, its future end and a single theory of all interactions, cannot wait for quick answers. Gross compares this work with climbing a mountain, the height of which no one knows. Sometimes it seems that the top is nearby. Sometimes, on the contrary, that the path goes a long way.
When a physicist doubts the pace of movement, he looks back: a year, a decade, or a whole career. According to him, such a view almost always shows how much the understanding of nature has changed. A single theory can be far away. Verification of string ideas may require a change of several generations. Accelerators and cosmic observations will become more difficult. But humanity has a more urgent task: not to destroy itself while scientists are still rising on this mountain.
David Gross gave interviews to journalists after receiving a special Breakthrough Prize for fundamental physics for $3 million. Formally, the reason was a new award, but the conversation quickly went beyond the biography of the laureate. Gross spoke of a theory that could unite the main forces of nature, about why fundamental physics progresses more slowly than before, and about nuclear war, which, in his opinion, can break human civilization earlier than scientists have time to finally describe the laws of the Universe.
Gross calls himself an optimist, especially when he thinks about the future of physics. He is sure that somewhere in the depths of nature there is a single theory that can connect electromagnetism, strong and weak interaction with gravity. Such a theory must close the long-standing gap between quantum physics and gravity, which does not yet fit into the same mathematical picture. But physics faces a closer assessment: humanity can destroy itself in a nuclear war sooner than it achieves this goal.
In the early 1970’s, Gross, together with colleagues, discovered asymptomatic freedom, one of the most unusual properties of strong nuclear interaction. Strong interaction keeps quarks inside protons and neutrons. Quarks can not simply be removed from the proton one: the further the particles are to be pushed, the stronger the attraction between them grows. But inside the proton itself, at very short distances, quarks behave almost freely and interact much weaker.
It is this strange behavior that is called asymptotic freedom. Physicists have repeatedly tested the idea in experiments with high energies. The discovery helped build quantum chromodynamics, the theory of strong interaction, and then fixed it as one of the pillars of the Standard Model of particle physics. For this work, Gross received the Nobel Prize in Physics in 2004.
After the success of quantum chromodynamics, Gross took up a more risky area. In the 1980's he participated in the development of heterotic string theory. This version of string theory combines different types of string models and tries to describe fundamental particles not as points, but as tiny single objects. Unlike asymptomatic freedom, string theory has not yet been experimentally confirmed. For Gross, the difference between these two parts of your career is important: one relies on data, the other remains an attempt to look beyond the available experimental area.
The new prize for him is pleasant and a little awkward for him at the same time. Gross already received the Dirac Medal in 1988, the Harvey Prize in 2000 and the Nobel Prize in 2004. He perceives the Breakthrough Prize not as a substitute for the Nobel Prize, but as a more free reward: it can go to scientists for ideas that have not yet managed to test nature. Gross has long been helping to raise funds for the Cavley Institute of Theoretical Physics at the University of California, Santa Barbara and other research centers, so the new amount gives him the opportunity to support colleagues and institutes.
In the conversation, Gross explains why the path to a unified theory is so long. When he began his career, experimental physics experienced a turbulent period. Accelerators and detectors constantly brought new particles and unexpected results, and theorists tried to collect a clear picture from this data. The situation is almost mirrored now. Physicists have a lot of strong mathematical ideas, but nature has ceased to generously throw new facts. Previously, the theorist could offer a calculation and wait for verification for a year. Now the development of the region is planned for a period of 30 to 60 years.
The slowdown Gross connects not only with money. Large experiments really require large commands, sophisticated engineering and long construction, but it’s deeper. Physicists are moving towards an increasingly smaller scale of distances, and to look there, you need ever higher energies. Over the past two centuries, science has come a long way: from molecules to atoms, from atoms to nuclei, from nuclei to the internal structure of protons and neutrons. According to Gross, progress covered from about 15 to 20 in magnitude.
The next area, which is indicated by observations and theoretical continuations of known models, lies much further. Physics may need to go through about 20 orders of magnitude. And here comes the unpleasant mathematics. Due to the asymptotic freedom and similar properties of quantum fields, physics changes at a slow distance, logarithmic. The price of access to higher energies is growing much faster, at least proportional to the square of energy. Scientific efficiency increases slowly, and the cost of experiments soars sharply. For Gross, such a gap explains why the path to new data is becoming increasingly difficult.
From here he proceeds to a nuclear threat. According to Gross logic, humanity may need centuries of new theories, accelerators and observations to test the final theory of nature. But a global nuclear war can destroy civilization in one day. Therefore, he considers reducing nuclear risk as a part of the same task as fundamental research: there is no future physics without future people, laboratories and universities.
Gross says that scientific work and public position do not contradict each other. Each scientist himself decides how to spend limited time, but a great reward gives not only recognition. She attracts attention, and with him there are requests to speak, sign letters, explain the risks and convince politicians. The scientist recognizes that publicity takes strength, but considers such work useful.
Now he, along with other scientists, is trying to revive the Mainau process - the movement of Nobel laureates against nuclear war. The new group, which is called the Assembly of Nobel laureates to prevent nuclear war, involves researchers working with the UN and European venues. In July last year, the band held a major meeting in Chicago, to which the Pope sent the cardinal as his representative. The next events are planned in the Vatican.
The main task of this campaign is to remind people that nuclear annihilation has not gone along with the Cold War. Gross especially wants to reach young scientists. According to his observations, graduate students, postdocchi and professors almost always call the climate the main global fear. Then recall diversity in the academic environment, getting a constant rate, inflation or career uncertainty. Almost no one is at the top of the list of nuclear war.
Gross is astonishing that even physicists often do not pose a significant extent to the threat. He asks young colleagues how many nuclear missiles there are, how long the leaders of nuclear powers need to give the order to launch, and what makes a warhead with one megaton. According to him, the answers often show a lack of special knowledge, and a gap in the basic understanding of risk.
In the 20th century, serious experts estimated the probability of nuclear war at about 1% per year. One number seems small, and many easily dismiss him: there was no war, so you can not think. But the risk accumulates year after year. At 1% per year, according to Gross, the life expectancy of a person born today decreases to about 67 years, if we assume that the global nuclear war will lead to its death. The physicist compares this logic with radioactive decay: a single atom may not decay for a long time, but with a large number of atoms and sufficient time, a rare event becomes statistically expected.
Now the physicist considers the situation worse than in the days of old assessments. Nuclear arms control treaties have been destroyed or terminated, the number of countries with nuclear ambitions has grown, and there is a big war in Europe with the participation of Russia, which has a nuclear arsenal. Gross conservatively assesses the current risk of nuclear war at 2% per year. With this probability, the life horizon of children, according to its calculation, shrinks to about 35 years, if not reduce the threat.
At the same time, Gross does not demand to immediately destroy all nuclear weapons and does not expect that humanity will suddenly become pacifist. He talks about a more realistic goal: to reduce the likelihood of disaster. The declaration, prepared after the meeting in Chicago, lists measures that participants believe could reduce the risk. In an interview, the physicist does not disassemble these points one by one, but emphasizes the principle itself. If it is possible to omit an annual probability of at least 0.1%, humanity will benefit several centuries to solve other problems.
He cites the climate agenda as an example of how science can break through public indifference. About 40 years ago, researchers began to persistently warn of warming. The path took a long time, oil companies and related politicians resisted, but the climate has become a strong political issue. According to Gross, a similar social mechanism has previously helped in the nuclear sphere. Millions of people took to the streets against radioactive fallout from atmospheric testing, and the pressure of society helped advance the Comprehensive Nuclear-Test-Ban Treaty.
After the Cold War, attention disappeared, but the arsenals remained. Gross considers this forgetfulness dangerous. The climate is changing slowly and threatens huge damage, but in itself, in his opinion, will not destroy all of humanity. A global thermonuclear war can destroy civilization, cities, institutions and the familiar world in 24 hours. For him, inaction in the face of such a threat looks especially illogical.
Separately, Gross sharply criticizes the idea of a large-scale anti-missile defense of Golden Dome. He compares the project with the Ronald Reagan’s Star Wars program, only in a more expensive and enhanced version. According to the physicist, the defense in such a race almost always loses to the attack. The attacking side can increase the number of warheads, false targets and ways of bypass, and the defense system has to try to intercept everything.
Gross explains the problem by the example of a big city. One warhead that broke through the defense is enough for the consequences to become catastrophic. One rocket with split individual guidance warheads can direct 10 charges of half a meter oftons to the New York area. Any protection can be overloaded, deceived or bypassed. The wars of recent years, he said, are already showing asymmetry: cheap drones and missiles are forced to use expensive interception systems, where one defensive shot can cost more than a target.
The physicist sees another danger in missile defense. If the state believes that it is able to hide from a retaliatory strike, politicians are tempted to act more aggressively. According to Gross, such projects do not solve the main task, but push the world to a new arms race. He considers Golden Dome extremely expensive, technically unreliable and almost unrelated to real risk reduction.
In politics, it has become less optimistic: the United States and the world, according to him, are moving towards more and more instability. But the nuclear threat is not like an earthquake or an asteroid fall. Rockets, warheads, warning systems and command chains were built by people, people can change the rules for handling them.
Gross does not want humanity to need a small nuclear war that will kill several hundred million people and destroy a huge part of the planet to remind how close the world has come to disaster. He hopes that warnings, calculations and political pressure will be enough before.
In fundamental physics, optimism is almost a professional requirement for him. A scientist who is looking for the beginning of the universe, its future end and a single theory of all interactions, cannot wait for quick answers. Gross compares this work with climbing a mountain, the height of which no one knows. Sometimes it seems that the top is nearby. Sometimes, on the contrary, that the path goes a long way.
When a physicist doubts the pace of movement, he looks back: a year, a decade, or a whole career. According to him, such a view almost always shows how much the understanding of nature has changed. A single theory can be far away. Verification of string ideas may require a change of several generations. Accelerators and cosmic observations will become more difficult. But humanity has a more urgent task: not to destroy itself while scientists are still rising on this mountain.
