Category Archives: Quantum Physics
Clouds of supercooled atoms offer highly sensitive rotation sensors and tests of quantum mechanics.
A new device that relies on flowing clouds of ultracold atoms promises potential tests of the intersection between the weirdness of the quantum world and the familiarity of the macroscopic world we experience every day. The atomtronic Superconducting QUantum Interference Device (SQUID) is also potentially useful for ultrasensitive rotation measurements and as a component in quantum computers.
In a conventional SQUID, the quantum interference in electron currents can be used to make one of the most sensitive magnetic field detectors, said Changhyun Ryu, a physicist with the Material Physics and Applications Quantum group at Los Alamos National Laboratory. We use neutral atoms rather than charged electrons. Instead of responding to magnetic fields, the atomtronic version of a SQUID is sensitive to mechanical rotation.
A schematic of an atomtronic SQUID shows semicircular traps that separate clouds of atoms, which quantum mechanically interfere when the device is rotated. Credit: Los Alamos National Laboratory
Although small, at only about ten millionths of a meter across, the atomtronic SQUID is thousands of times larger than the molecules and atoms that are typically governed by the laws of quantum mechanics. The relatively large scale of the device lets it test theories of macroscopic realism, which could help explain how the world we are familiar with is compatible with the quantum weirdness that rules the universe on very small scales. On a more pragmatic level, atomtronic SQUIDs could offer highly sensitive rotation sensors or perform calculations as part of quantum computers.
The researchers created the device by trapping cold atoms in a sheet of laser light. A second laser intersecting the sheet painted patterns that guided the atoms into two semicircles separated by small gaps known as Josephson Junctions.
When the SQUID is rotated and the Josephson Junctions are moved toward each other, the populations of atoms in the semicircles change as a result of quantum mechanical interference of currents through Josephson Junctions. By counting the atoms in each section of the semicircle, the researchers can very precisely determine the rate the system is rotating.
As the first prototype atomtronic SQUID, the device has a long way to go before it can lead to new guidance systems or insights into the connection between the quantum and classical worlds. The researchers expect that scaling the device up to produce larger diameter atomtronic SQUIDs could open the door to practical applications and new quantum mechanical insights.
Reference: Quantum interference of currents in an atomtronic SQUID by C. Ryu, E. C. Samson and M. G. Boshier, 3 July 2020, Nature Communications.DOI: 10.1038/s41467-020-17185-6
Los Alamos National Laboratorys Laboratory Directed Research and Development program provided funding.
Originally posted here:
Written by AZoQuantumJul 17 2020
Everyone knows that the quantum world can transform communication technology. Quantum technology offers the potential of impenetrable security and unparalleled performance, and is taking its initial steps towards the decisive goal of applications such asextremely encrypted yet virtually fast-as-light financial transactions.
But the potential for quantum computers to interact with each other has been restricted by the resources needed for such kinds of exchanges. This has consequently limited the proportion of data that can be traded, and also the amount of time it can be preserved.
Now, Japan-based researchers have taken a significant step toward dealing with such limitations in resources. The team has published its findings in the Physical Review Letters journal on May 27th, 2020.
To connect remote quantum computers together, we need the capacity to perform quantum mechanical operations between them over very long distances, all while maintaining their important quantum coherence.
Kae Nemoto, Study Author, Professor and Director, Global Research Center for Quantum Information Science, National Institute of Informatics
Nemoto continued, However, interestingly, while quantum computers have emerged at the small scale, quantum communication technology is still at the device level and has not been integrated together to realize communication systems. In this work, we show a route forward.
Quantum data needs to be protected from the considerable level of noise surrounding it, and data is also likely to be lost from the preliminary message. Such a protection process is referred to as quantum error correction, which intertwines a single piece of data over several qubits. Qubits happen to be the most fundamental unit of quantum data.
Individuals can envision a letter shredded into nine pieces, with each piece placed inside an envelope and each envelope delivered to the same kind of destination to be again organized and read.
Similarly, in the quantum realm, the envelopes are sent through photons and each envelope contains a sufficient amount of data to reproduce the whole letter if any of the delivered envelopes are damaged or lost.
The overhead to protect quantum information from noise and loss will be large, and the size of the required devices to realize this will cause serious problems, as we have started to see in today's quantum computer development. As the efforts to realize the quantum internet are occurring worldwide, it is important to think of it as a system, and not simple devices.
Kae Nemoto, Study Author, Professor and Director, Global Research Center for Quantum Information Science, National Institute of Informatics
Along with her research team, Nemoto tackled this problem by employing a procedure known as quantum multiplexing, where they decreased the noise and also the number of resources required to relay the data.
In multiplexing, the data stored inside a pair of individual photons is integrated into a single photon, similar to a couple of envelopes being delivered in a portfolio, and therefore, the data is still protected individually but only a single stamp is required to transmit the information.
In this system, quantum error correction will play an essential role, not only of protecting the quantum information transmitted, but also for significantly reducing the necessary resources to achieve whatever tasks one needs. Quantum multiplexing enables significant resource reduction without requiring new technology to be developed for such quantum communication devices.
William J. Munro, Study Co-Author and Researcher, Basic Research Laboratories, NTT
At present, the scientists are extending their study to large-scale quantum complex network situations.
The quantum revolution has allowed us to design and create new technologies previously thought impossible in our classical world, added Nemoto. Small-scale quantum computers have already shown computing performance better than todays largest supercomputers.
However, many other forms of quantum technology are emerging and one of the most profound could be the quantum internet a quantum-enabled version of todays internetwhich will allow us to network devices together, including quantum computers, Nemoto further stated.
The scientists will next build on the initial steps that they have already adopted to boost the amount of data as well as the storage time.
The study was partly funded by the Japan Society for the Promotion of Science and the John Templeton Foundation.
Others who contributed to the study are Nicol Lo Piparo, Michael Hanks, Claude Gravel, and William J. Munro, all affiliated with the National Institute of Informatics. In addition, Munro is affiliated with the NTT Basic Research Laboratories as well as the NTT Research Center for Theoretical Quantum Physics.
Lo Piparo, N., et al. (2020) Resource Reduction for Distributed Quantum Information Processing Using Quantum Multiplexed Photons. Physical Review Letters. doi.org/10.1103/PhysRevLett.124.210503.
Originally posted here:
The global economic machine has taken a battering from the lockdown, and part of the recovery will involve inflation. How well placed are engineers and technologists to ride out the chaos?
Economists used to model their systems like engineers designed refineries, with money flowing around piping, through valves, and in and out of tanks. Its a handy metaphor, but it belongs in its time.
These days it might be better to update the model to our understanding (or lack of it) of quantum physics. Schrdingers cat makes for a good model of the global economy because right now it is both alive and dead at the same time and its going to be a while before we open the box and find the definitive answer.
However you measure the effect of the global lockdown, the economic losses of the last few weeks have been colossal. Sales tax measures suggest a near 50 per cent drop; overall taxes point to 28 per cent, while CO2 emissions show an 18 per cent drop off. So even with a stunningly strong recovery, the net loss to tax revenues in the UK will be hundreds of billions. If the budget is not slashed and the government has promised it wont be those losses will balloon into a bigger and bigger national debt.
The upshot of all this is that the UK, and for that matter pretty much every country on Earth, is going to balloon its public debt to levels that will make a mockery of previous attempts at controlling expenditure so that, for example, the UKs finances next year will look like Italys national debt of last year. All those economic benefits of those years of austerity have gone up in smoke in a few short weeks.
While the UK and Europe have been working flat out to ameliorate their economic woes by exploding their budgets into a series of bailouts, the US has gone all in on a scale only matched by World War Two budgets and it has boosted its money supply at an annualised rate of 100 per cent in the last three months, already banking in an over-30 per cent rise in M1 cash in that time.
As any of us who took GCSE or O-Level Economics will recall, a boost of money supply means a boost in inflation, unless more goods are made to quench the demand triggered by the boosted supply of buying power. Well its a certainty that fewer goods have been made during the lockdown, so a 30 per cent-plus increase in money supply in a few weeks has a South American hyperinflation ring to it. The US is also on the brink of monetising corporate debt the amount that added nine zeros to a German postage stamp in the 1920s. The Germans, if not licking their stamps, are still licking the wounds from that experience, which many blame for the rise of a certain moustachioed landscape painter to power.
Many economists disagree; they say that the money will be stashed just like the cash of the last ten years of QE. The money will be sequestered in ultra-valued bonds, stocks and houses and it wont leak into the hands of the wider population to flush into a buying frenzy that will drive a price rise spiral. That sounds good until you realise that much of the stimulus has gone into the hands of the public in the form of boosted social security payments. The US unemployment payout has been increased by $600 a week, making many people temporarily better off on their sofa watching Netflix or punting stocks on the zero-fee stock trading apps, rather than in their old jobs.
Its a mess, and to my mind it is an inflationary mess, with inflation being the only natural lubricator of the changes ahead for our societies.
Governments cant afford deflation. Recoveries dont happen quickly under deflation. The necessary redistribution of resources that has to now happen doesnt pan out smoothly under deflation. Inflation is the classic path of governance under pressure when crisis strikes, it is the get out of jail free card for rulers since antiquity. However, it is a crazy orthodoxy that inflation is ever so difficult to create, but you can discount that nonsense. If that isnt a huge lie, someone needs to tell Iran, Zimbabwe and Venezuela.
A more nuanced version of the inflation lie is that inflation is caused by the expectation of inflation, and once sparked, its a self-fulfilling loop. That sounds credible until you ask how come they always have banknotes with more zeros to hand as hyperinflation strikes. As the monetarists that killed the inflation of the 1970s tell us: Inflation is always and everywhere a monetary phenomenon.
We are certainly entering into a period of monetary phenomena.
The next few years are going to be grim, but the strategy is the same as in every crisis. Stay employed, be working in the latest thing, buy assets when you see them super cheap.
Engineers and technologists are fortunately at the tip of the value chain and will miss the worse of whats ahead, while Aesops grasshoppers are in for a pretty nasty surprise.
Sign up to the E&T News e-mail to get great stories like this delivered to your inbox every day.
Continue reading here:
Physics, the most fundamental branch of science, has two main theories quantum mechanics and general relativity. Quantum mechanics explains the very small and light; atomic and subatomic levels. General relativity explains the very large and heavy; stars, galaxies and beyond.
Our everyday world is explained by Newtonian mechanics, whose principles can be derived from general relativity. But a major problem in physics is that quantum mechanics and general relativity are mutually incompatible, although the predictions made by each are unerringly accurate.
When certain cases are considered, such as the big bang, when the world was both incredibly small and incredibly massive, both quantum mechanics and general relativity must be invoked. Applying the equations of both theories to investigate the problem produces nonsensical results.
Nevertheless, it is extremely improbable that nature needs two sets of incompatible laws, one for the very large and another for the very small. String theory is physics latest attempt to reconcile quantum mechanics and general relativity and is beautifully explained by Brian Greene in The Elegant Universe, Folio Society Edition, 2017.
Matter and force constitute the basic fabric of the physical world. The ancient Greeks guessed that matter is ultimately composed of tiny indivisible units called atoms. Science later demonstrated that atoms do exist, but they have sub-components protons, neutrons and electrons. The electron has no sub-structure but protons and neutrons are composed of particles called quarks. Quarks come in two kinds up-quarks and down-quarks. There is no evidence quarks have sub-components.
Everything we see in the universe is made of electrons, up-quarks and down-quarks. Also, a fourth fundamental particle, the neutrino, a ghostly almost mass-less entity, courses through the universe in vast numbers basically without interacting with other matter.
There are four fundamental forces in nature the strong force, the weak force, electromagnetism and gravity. The strong and weak forces operate over extremely short distances and are only important inside atoms. The strong force holds protons and neutrons within the atom, the weak force is responsible for radioactivity. The electromagnetic force holds electrons in atoms but allows them to interact with electrons in other atoms to form molecules, the building blocks of matter.
It is also responsible for most interactions we see in our environment. Gravity is a force through which all things with mass or energy are attracted towards one another. It is the weakest force but can operate over extremely long distances. Gravity keeps the planets orbiting around the sun and makes things fall to earth when we drop them.
Each force has an associated force particle that can be visualised as the smallest part of the force. The force particles of the strong force, the weak force, the electromagnetic force, and gravity are, respectively, gluons, weak gauge bosons, photons and gravitons.
If the properties of these fundamental particles and forces were only slightly different, our world could not exist. But no theory yet explains the four fundamental particles or the four forces.
There are compelling reasons to think there is a fundamental underlying reality to our world that, if understood, would explain everything. A Theory of Everything would explain the fundamental particles and forces of nature, and it would explain both the very small and the very large in one framework. Albert Einstein (1879-1955) spent the second half of his life searching for such a theory, without success.
This is where string theory comes on stage. It was postulated in the 1980s that the fundamental particles each consists of a tiny one-dimensional vibrating loop called a string. Replacing point-particle material constituents (electrons and quarks) with strings mathematically resolves the incompatibility between quantum mechanics and general relativity. Strings are the common basis for everything.
Just as violin strings produce different notes when they vibrate at different frequencies, string theory says that vibrations of these tiny loops produce the different realities that make up the entire natural world the electron is a string vibrating one way, quarks are strings vibrating another way.
The mathematics underlying string theory are horrendously difficult and progress in developing string theory has been slow. But achievements have been realised, such as understanding some puzzling behaviour of black holes. It is to be hoped that the eventual complete elucidation of string theory will prove to be our Theory of Everything.
William Reville is an emeritus professor of biochemistry at UCC
Go here to read the rest:
The smallest conceivable length of time might be no larger than a millionth of a billionth of a billionth of a billionth of a second. That's according to a new theory describing the implications of the universe having a fundamental clock-like property whose ticks would interact with our best atomic timepieces.
Such an idea could help scientists get closer to doing experiments that would illuminate a theory of everything, an overarching framework that would reconcile the two pillars of 20th-century physics quantum mechanics, which looks at the smallest objects in existence, and Albert Einstein's relativity, which describes the most massive ones.
Related: The 18 biggest unsolved mysteries in physics
Most of us have some sense of time's passage. But what exactly is time?
"We don't know," Martin Bojowald, a physicist at Pennsylvania State University in University Park, told Live Science. "We know that things change, and we describe that change in terms of time."
Physics presents two conflicting views of time, he added. One, which stems from quantum mechanics, speaks of time as a parameter that never stops flowing at a steady pace. The other, derived from relativity, tells scientists that time can contract and expand for two observers moving at different speeds, who will disagree about the span between events.
In most cases, this discrepancy isn't terribly important. The separate realms described by quantum mechanics and relativity hardly overlap. But certain objects like black holes, which condense enormous mass into an inconceivably tiny space can't be fully described without a theory of everything known as quantum gravity.
In some versions of quantum gravity, time itself would be quantized, meaning it would be made from discrete units, which would be the fundamental period of time. It would be as if the universe contained an underlying field that sets the minimum tick rate for everything inside of it, sort of like the famous Higgs field that gives rise to the Higgs boson particle which lends other particles mass. But for this universal clock, "instead of providing mass, it provides time," said Bojowald.
By modeling such a universal clock, he and his colleagues were able to show that it would have implications for human-built atomic clocks, which use the pendulum-like oscillation of certain atoms to provide our best measurements of time. According to this model, atomic clocks' ticks would sometimes be out of sync with the universal clock's ticks.
This would limit the precision of an individual atomic clock's time measurements, meaning two different atomic clocks might eventually disagree about how long a span of time has passed. Given that our best atomic clocks agree with one another and can measure ticks as small as 10^(minus19) seconds, or a tenth of a billionth of a billionth of a second, the fundamental unit of time can be no larger than 10^(minus 33)seconds, according to the team's paper, which appeared June 19 in the journal Physical Review Letters.
"What I like the most about the paper is the neatness of the model," Esteban Castro-Ruiz, a quantum physicist at the Universit Libre de Bruxelles in Belgium who was not involved in the work, told Live Science. "They get an actual bound that you can in principle measure, and I find this amazing."
Research of this type tends to be extremely abstract, he added, so it was nice to see a concrete result with observational consequences for quantum gravity, meaning the theory could one day be tested.
While verifying that such a fundamental unit of time exists is beyond our current technological capabilities, it is more accessible than previous proposals, such as the Planck time, the researchers said in their paper. Derived from fundamental constants, the Planck time would set the tiniest measureable ticks at 10^(minus 44) seconds, or a ten-thousandth of a billionth of a billionth of a billionth of a billionth of a billionth of a second, according to Universe Today.
Whether or not there is some length of time smaller than the Planck time is up for debate, since neither quantum mechanics nor relativity can explain what happens below that scale. "It makes no sense to talk about time beyond these units, at least in our current theories," said Castro-Ruiz.
Because the universe itself began as a massive object in a tiny space that then rapidly expanded, Bojowald said that cosmological observations, such as careful measurements of the cosmic microwave background, a relic from the Big Bang, might help constrain the fundamental period of time to an even smaller level.
Originally published on Live Science.
See the rest here:
Richard Feynman once said, If you think you understand quantum mechanics, then you dont understand quantum mechanics. While that may be true, it certainly doesnt mean we cant try. After all, where would we be without our innate curiosity?
To understand the power of the unknown, were going to untangle the key concepts behind quantum physics two of them, to be exact (phew!). Its all rather abstract, really, but thats good news for us, because you dont need to be a Nobel-winning theoretical physicist to understand whats going on. And whats going on? Well, lets find out.
Well start with a brief thought experiment. Austrian physicist Erwin Schrdinger wants you to imagine a cat in a sealed box. So far, so good. Now imagine a vial containing a deadly substance is placed inside the box. What happened to the cat? We cannot know to a certainty. Thus, until the situation is observed, i.e. we open the box, the cat is both dead and alive, or in more scientific terms, it is in a superposition of states. This famous thought experiment is known as the Schrdingers cat paradox, and it perfectly explains one of the two main phenomena of quantum mechanics.
Superposition dictates that, much like our beloved cat, a particle exists in all possible states up until the moment it is measured. Observing the particle immediately destroys its quantum properties, and voil, it is once again governed by the rules of classical mechanics.
Now, things are about to get more tricky, but dont be deterred even Einstein was thrown-back by the idea. Described by the man himself as spooky action at a distance, entanglement is a connection between a pair of particles a physical interaction that results in their shared state (or lack thereof, if we go by superposition).
Entanglement dictates that a change in the state of one entangled particle triggers an immediate, predictable response from the remaining particle. To put things into perspective, lets throw two entangled coins into the air. Subsequently, lets observe the result. Did the first coin land on heads? Then the measurement of the remaining coin must be tales. In other words, when observed, entangled particles counter each others measurements. No need to be afraid, though entanglement is not that common. Not yet, that is.
Whats the point of all this knowledge if I cant use it?, you may be asking. Whatever your question, chances are a quantum computer has the answer. In a digital computer, the system requires bits to increase its processing power. Thus, in order to double the processing power, you would simply double the amount of bits this is not at all similar in quantum computers.
A quantum computer uses qubits, the basic unit of quantum information, to provide processing capabilities unmatched even by the worlds most powerful supercomputers. How? Superposed qubits can simultaneously tackle a number of potential outcomes (or states, to be more consistent with our previous segments). In comparison, a digital computer can only crunch through one calculation at a time. Furthermore, through entanglement, we are able to exponentially amplify the power of a quantum computer, particularly when comparing this to the efficiency of traditional bits in a digital machine. To visualise the scale, consider the sheer amount of processing power each qubit provides, and now double it.
But theres a catch even the slightest vibrations and temperature changes, referred to by scientists as noise, can cause quantum properties to decay and eventually, disappear altogether. While you cant observe this in real time, what you will experience is a computational error. The decay of quantum properties is known as decoherence, and it is one of the biggest setbacks when it comes to technology relying on quantum mechanics.
In an ideal scenario, a quantum processor is completely isolated from its surroundings. To do so, scientists use specialised fridges, known as cryogenic refrigerators. These cryogenic refrigerators are colder than interstellar space, and they enable our quantum processor to conduct electricity with virtually no resistance. This is known as a superconducting state, and it makes quantum computers extremely efficient. As a result, our quantum processor requires a fraction of the energy a digital processor would use, generating exponentially more power and substantially less heat in the process. In an ideal scenario, that is.
Weather forecasting, financial and molecular modelling, particle physics the application possibilities for quantum computation are both enormous and prosperous.
Still, one of the most tantalising prospects is perhaps that of quantum artificial intelligence. This is because quantum systems excel at calculating probabilities for many possible choices their ability to provide continuous feedback to intelligent software is unparalleled in todays market. The estimated impact is immeasurable, spanning across fields and industries from AI in the automotive all the way to medical research. Lockheed Martin, American aerospace giant, was quick to realise the benefits, and is already leading by example with its quantum computer, using it for autopilot software testing. Take notes.
The principles of quantum mechanics are also used to address issues in cybersecurity. RSA (Rivest-Shamir-Adleman) cryptography, one of the worlds go-to methods of data encryption, relies on the difficulty of factoring (very) large prime numbers. While this may work with traditional computers, which arent particularly effective at solving multi-factor problems, quantum computers will easily crack these encryptions thanks to their unique ability to calculate numerous outcomes simultaneously.
Theoretically, Quantum key distribution takes care of this with a superposition-based encryption system. Imagine youre trying to relay sensitive information to a friend. To do so, you create an encryption key using qubits, which are then sent to the recipient over an optical cable. Had the encoded qubits been observed by a third party, both you and your friend will have been notified by an unexpected error in the operation. However, to maximise the benefits of QKD, the encryption keys would have to maintain their quantum properties at all times. Easier said than done.
It doesnt stop there. The brightest minds around the globe are constantly trying to utilise entanglement as a mode of quantum communication. So far, Chinese researchers were able to successfully beam entangled pairs of photons through their Micius satellite over a record-holding 745 miles. Thats the good news. The bad news is that, out of the 6 million entangled photons beamed each second, only one pair survived the journey (thanks, decoherence). An incredible feat nonetheless, this experiment outlines the kind of infrastructure we may use in the future to secure quantum networks.
The quantum race also saw a recent breakthrough advancement from QuTech, a research centre at TU Delft in the Netherlands their quantum system operates at a temperature over one degree warmer than absolute zero (-273 degrees Celsius).
While these achievements may seem insignificant to you and I, the truth is that, try after try, such groundbreaking research is bringing us a step closer to the tech of tomorrow. One thing remains unchanged, however, and that is the glaring reality that those who manage to successfully harness the power of quantum mechanics will have supremacy over the rest of the world. How do you think they will use it?
Read more here:
Quantum technology and quantum computing more specifically has become quite the popular topic in national security circles. The extraordinary level of interest emerges from the potential impacts of quantum computers on information security and general issues of international strategic technological advantage. While academic strength in quantum computing research is globally distributed, U.S. industry maintains substantive international leadership. The most significant technical demonstration of state-of-the-art quantum computing was reported by Google this year, and the first cloud-based quantum-as-a-service offerings are available from IBM and Rigetti, with forthcoming services announced by Amazon Web Services and Microsoft.
With these developments, quantum computing has been identified as a possible target technology for export controls as well as foreign-investment review in emerging tech companies. And the new U.S. National Quantum Initiative is framed around strategic competition and even directly addresses the notion of a technological race with China.
And so now, you Madam, Mister, or Doctor National Security Professional need to understand and speak intelligently about how this technology impacts your portfolio. Where should you begin and how? What are the important lessons to embrace and pitfalls to avoid as you begin your educational journey?
It is easy to find yourself going down the wrong path; there are many new analysts offering expert advice on the technology underlying quantum computing. Many of them merit your skepticism. A combination of technical complexity and competitive media positioning has led to a wide variety of pervasive misconceptions in the field. Watching these flawed and false narratives take off in the national security world that I have worked in for years at DARPA, working with the intelligence community, and now at my own company has been frustrating. And so, as someone with 20 years of experience designing, building, and optimizing quantum computing hardware, I aim to offer friendly advice and insights that arent readily available otherwise.
Learn the Basics
Following many years in which information was found only in specialist technical journals, high-quality educational resources supporting new entrants to the field are finally emerging. I offer some of the better ones below. Turn to them in order to gain proficiency in the underlying technology at either a contextual or technical level, no matter what level of technical expertise you have (or lack).
Q-CTRL the organization I founded and lead has produced an introductory video series for those who have limited background knowledge and are seeking to orient themselves in the field. This is a great place to start if youve encountered various keywords in quantum computing such as qubit, NISQ, or quantum advantage and now want to understand their meaning and context at a high level.
Quantum Computing for the Very Curious is an excellent online e-book introducing quantum computing in an accessible but technical fashion. Its prepared by Michael Nielsen, one of the most recognized textbook authors in the field, and covers material from qubits to universal quantum computing.
The online Qiskit textbook from IBM provides a detailed technical overview of this material, with a focus on programming quantum computers for future quantum developers.
Various supporting tools exist to help build intuition for quantum computing, including BLACK OPAL from my organization, the IBM Quantum Experience, and the Quantum User Interface from the University of Melbourne.
The Massachusetts Institute of Technologys xPRO offers an online course in quantum computing built and taught by actual leading practitioners, such as Peter Shor, Will Oliver, and Isaac Chuang (not consultants, dabblers, or marketers).
Finally, if youd like a broader overview of the intersection between quantum technology and national security, I wrote a primer on quantum technology for national security professionals with Richard Fontaine in these virtual pages.
Start with the History
Many in national security circles became familiar with quantum information and quantum technologies only in the last few years. Understanding the origins of U.S. government activity in the field is essential to evaluating the national security landscape around quantum computing today.
The history of the field is traced back to early intelligence community investments in open university research, following public announcements surrounding the development of Shors algorithm (an algorithm potentially enabling quantum computers to attack public key cryptosystems, named after Peter Shor). Since the late 1990s, the vast majority of participants in the international research field has been supported by competitive programs sponsored by the U.S. Army Research Office and the Intelligence Advanced Research Projects Activity (and its predecessor organizations, the Advanced Research and Development Activity and the Disruptive Technology Office). Ultimately, this targeted, highly competitive funding has been foundational to the development of the international quantum computing research community.. Very broadly, this technical leadership (as measured by recognizable research programs and/or publicly acknowledged funding) has come from the United States, United Kingdom, Germany, Austria, Switzerland, Australia, the Netherlands, and Canada. Much more recently, China has risen independently as it has made quantum information matter of national priority. Singapore and Russia have also made strategic investments in quantum technology.
What should we take from this history? First, openness, collaboration, and international engagement with allied nations have been central to the success we have seen in building this technological discipline. This success, a global public good, is the result of American international leadership. And it therefore risks being undermined by aggressive actions to curtail international collaboration, especially as so much exploratory science remains to be undertaken. Emerging nationalist sentiment seeking to limit international support for research among allies or to add new export control regimes on immature technologies are regressive. Second, the U.S. defense and intelligence communities have played a critical and irreplaceable role in the field. Todays U.S. National Quantum Initiative is seeking to establish expanded research activity through programs administered by new organizations, including the National Science Foundation and Department of Energy through the national labs. The foundational leadership from within the Department of Defense and the intelligence community places the United States at a strategic advantage in knowledge and internal capability within government. Finally, aside from long-term research and development efforts at industrial organizations such as IBM, large-scale industry-led programs have only emerged since about 2013 at Microsoft, Google, and other tech giants, often grown by acquiring academic research teams. Similarly, the boom in quantum technology startups largely derived from academic programs has been growing for about five years. Notably, all of the relevant industrial research leaders and efforts have had substantial overlap with Army Research Office and IARPA programs. This makes clear both the connectivity of personnel running these programs with research leaders, and demonstrates how these government funding initiatives have been instrumental in seeding todays quantum industry.
True Technical Expertise Is Out There, So Reach Out
Maybe youve been asked to write a memo on something at the intersection of national security and quantum technology. Or maybe youre an international security scholar looking to research and write about the implications of the second quantum revolution. Why not collaborate with, or at least reach out to, someone with technical expertise? Quantum computing is not an easy field to understand, even for sharp minds with a deep understanding of other technical topics. So, look (and ask) before you leap.
Most contemporary leaders in the field have built their entire careers in quantum computing and have come up through advanced Ph.D.-level training programs at major universities around the world. Looking across the growing quantum computing startup ecosystem, almost every chief executive officer, chief technology officer, or other sort of senior executive has come from a senior academic appointment. Similarly, the broad U.S. industrial sector in quantum computing is heavily populated with seasoned experts in the field. Many of us have worked with the U.S. defense and the intelligence communities for years. And this cross-sector collaboration means there are a number of practitioner-experts working in government. Substantive expertise exists within various organizations, including the National Security Agencys Laboratory for Physical Sciences, the Sandia National Laboratories, the Lawrence Berkeley National Laboratory, the National Institute of Standards and Technology (having generated multiple Nobel laureates in quantum physics), the U.S. Army Research Laboratory, and the Army Research Office.
Unfortunately, growth in the field has led to a commensurate growth in the number of consultants and analysts claiming to be experts in quantum computing. Most of these voices are amateur observers, although there are a small number of formally trained experts who have crossed into analytical positions in defense contracting, management consulting, or the like. Third-party business analysts can bring valuable insights into the shape of emerging commercial markets or opportunities for quantum computing to contribute in novel sectors. Use caution when looking to such consultants for expert technical advice on the utility or functionality of quantum computers. As a general matter, beware the LinkedIn profile claiming expertise in quantum computing without evidence!
How to See Through the Hype
The level of true potential for quantum technology in national security and more broadly is profound and fully justifies major investments such as the U.S. National Quantum Initiative. However, this level of promise has inevitably led to hype in the popular media, company press releases, venture-capital newsletters, and (international) government program announcements. It is essential that in making an informed assessment you seek the truth beyond the hype.
The most important leading message is that quantum technology is a deep-tech field and represents a long-term strategic play; the benefits may be enormous in the national security space, but timescales to delivery remain measured in years and decade. We have recently seen an acceleration of commercial and public-sector interest and activity and there is no doubt that this is furthering progress but there has not been an obvious fundamental change in the pace of technological development. Quantum computing has been described erroneously as just engineering at this stage, where all we need to do to realize quantum advantage for useful problems is execute. While there is much room to incorporate lessons from the engineering community, creativity and serendipity remain essential.
Expert leaders in our community feel confident that within five to 10 years we may realize quantum advantage for a problem of general commercial interest. This would certainly be a profound demonstration, but it is supported by the (consistent) rate of progress since the early 2000s and the relatively small scale of machine we believe is needed to achieve this goal. By contrast, codebreaking using Shors algorithm remains a multi-decadal play because the scale of the system required is likely to be gigantic (thousands of high-performing logical qubits, each capable of performing billions of operations).
This highlights another essential piece of advice for quantum novices: caveat emptor. Question the messenger when reading media reports about technological breakthroughs. In many cases commercial and nationalist motives have clouded the landscape of media reporting on the true state of progress in the field. This is especially true at the intersection of quantum computing and national security for obvious reasons. For instance, in their excellent report, Elsa B. Kania and John Costello explain that quantum technology has clearly become a matter of national priority in China, but that it has become difficult to discern real progress from strategic hyperbole in state media. Unfortunately, the same can be true for corporate media releases closer to home. Many journalists have repeated press-release pronouncements without applying the skepticism the topic demands. National security professionals might then use such articles as a source, leaving an important debate ill-served. It is therefore important that such professionals seek validation of claims via primary-source information. This is of utmost importance in understanding the intersection between national security and quantum technology, as misunderstandings of the capabilities of the underlying technology can completely change the associated security implications.
As an example of such a negative impact on national security assessments, the combination of a rise in corporate and nationalist marketing and credulous media reporting has led to many misleading lay descriptions of how quantum technology operates in the security space. The research area perhaps most subject to misrepresentation is quantum communications, which has become an area of major Chinese investment and clear technical leadership. Quantum communications uses concepts of quantum physics (such as the destructive nature of measurement) in order to offer information security. In particular, these systems are theoretically provably secure a term that has a specific quantitative technical definition relating to the probability of eavesdropping in a nominally successful round of communication. This suggestive nomenclature has led to the broad use of popular terms such as unhackable communications or unbreakable quantum security. But these claims are specious. People have translated a technical definition (provably secure) into an accessible but incorrect lay term (unhackable or unbreakable) when, in fact, there is an entire subfield dedicated to cryptographic attacks on quantum communications systems. None of this means that advances in quantum communications wouldnt be enormously valuable, but it does reveal the shallow nature of some aspects of the popular narrative.
On a final and lighter note, its my pleasure to inform you that quantum radar is not likely to be an imminent threat to stealth technology as is sometimes claimed by Chinese media. There is global research interest in the application of quantum illumination to suppress certain kinds of technical noise in radar systems. It is possible that China has built functional prototypes and could in principle be far ahead of the United States and its allies, but there is no evidence that this has made Chinas radars able to detect stealthy or low-observable aircraft in ways they could not before. Public-domain, state-of-the art research from a Canadian team also publicly claiming they hope to defeat stealth technology does not support such claims. Demonstrated benefits show approximately two times improvement in imaging quality using quantum illumination at one-meter imaging distance in a laboratory. This is far from field-deployable, and a factor of two times improvement in imaging even if it did carry over to realistic distances and conditions does not necessarily render low-observable aircraft vulnerable. Nonetheless, media reporting on this topic has been breathless, even within national security publications. Unfortunately, the primary source material which could be used to raise doubts about claims surrounding quantum radar is highly technical and inaccessible to most analysts. While highly specific, this example illustrates how a lack of understanding of the technical material coupled with nationalistic media releases and credulous journalists can produce deleterious strategic assessments.
The advice I offer here is broad and aims to help national security professionals seeking to build a knowledge base in quantum technology. This is an essential undertaking for anyone seeking to engage meaningfully with this emerging and high-impact field.
Michael J. Biercuk is a professor of quantum physics and quantum technology at the University of Sydney and a chief investigator in the ARC Centre of Excellence for Engineered Quantum Systems. In 2017, he founded Q-CTRL, a quantum technology company for which he serves as CEO.
Image: National Institute of Standards and Technology (Photo by Y. Colombe)
Like a metronome that sets the tempo for a musician, a fundamental cosmic clock may be keeping time throughout the universe. But if such a clock exists, it ticks extremely fast.
In physics, time is typically thought of as a fourth dimension. But some physicists have speculated that time may be the result of a physical process, like the ticking of a built-in clock.
If the universe does have a fundamental clock, it must tick faster than a billion trillion trillion times per second, according to a theoretical study published June 19 in Physical Review Letters.
In particle physics, tiny fundamental particles can attain properties by interactions with other particles or fields. Particles acquire mass, for example, by interacting with the Higgs field, a sort of molasses that pervades all of space (SN: 7/4/12). Perhaps particles could experience time by interacting with a similar type of field, says physicist Martin Bojowald of Penn State. That field could oscillate, with each cycle serving as a regular tick. Its really just like what we do with our clocks, says Bojowald, a coauthor of the study.
Headlines and summaries of the latest Science News articles, delivered to your inbox
Time is a puzzling concept in physics: Two key physics theories clash on how they define it. In quantum mechanics, which describes tiny atoms and particles, time is just there. Its fixed. Its a background, says physicist Flaminia Giacomini of the Perimeter Institute in Waterloo, Canada. But in the general theory of relativity, which describes gravity, time shifts in bizarre ways. A clock near a massive object ticks slower than one farther away, so a clock on the surface of the Earth lags behind one aboard an orbiting satellite, for example (SN: 12/10/18).
In attempts to combine these two theories into one theory of quantum gravity, the problem of time is actually quite important, says Giacomini, who was not involved with the research. Studying different mechanisms for time, including fundamental clocks, could help physicists formulate that new theory.
The researchers considered the effect that a fundamental clock would have on the behavior of atomic clocks, the most precise clocks ever made (SN: 10/5/17). If the fundamental clock ticked too slowly, these atomic clocks would be unreliable because they would get out of sync with the fundamental clock. As a result, the atomic clocks would tick at irregular intervals, like a metronome that cant keep a steady beat. But so far, atomic clocks have been highly reliable, allowing Bojowald and colleagues to constrain how fast that fundamental clock must tick, if it exists.
Physicists suspect that theres an ultimate limit to how finely seconds can be divided. Quantum physics prohibits any slice of time smaller than about 10-43 seconds, a period known as the Planck time. If a fundamental clock exists, the Planck time might be a reasonable pace for it to tick.
To test that idea, scientists would need to increase their current limit on the clocks ticking rate that billion trillion trillion times per second number by a factor of about 20 billion. That seems like a huge gap, but to some physicists, its unexpectedly close. This is already surprisingly near to the Planck regime, says Perimeter physicist Bianca Dittrich, who was not involved with the research. Usually the Planck regime is really far away from what we do.
However, Dittrich thinks that theres probably not one fundamental clock in the universe, but rather there are likely a variety of processes that could be used to measure time.
Still, the new result edges closer to the Planck regime than experiments at the worlds largest particle accelerator, the Large Hadron Collider, Bojowald says. In the future, even more precise atomic clocks could provide further information about what makes the universe tick.
See the original post here:
Epigenetics and pandemics: How allopathy can turn into a curse from a cure – The Times of India Blog
As a Gen-X child, I am lucky to have watched the birth of genetics and also its golden period when there was a phase (similar to that experienced by classic physics during Newtonian era) that we had a feeling that we were on the verge of unveiling the ultimate secret of life.
When Watson and Crick discovered DNA, the code of life, it was a serendipitous shock as scientists felt that they now have a key to understand everything about life.
As genetics moved forward, it appeared as if each life-form was constructed using a set of instructions and nothing more, and the quest was all about reading that code.
As genetic expression was presumed to be based only on the code available in the DNA, it was felt that body construction and pathology it will lead to was completely and totally governed by the code with no real way of altering it. For example, if you have a gene with a specific error, say one more (third) copy of chromosome 21, you have no escape from developing Downs syndrome.
As genetics offered a very clear cause-and-effect relationship model, it made allopathy feel very happy with itself, because it strengthened the belief that doctors already had thanks to discovery of pathogens that cause diseases.
So, the early days of genetics was also the golden age of allopathy that was already empowered by antibiotics that killed pathogens and cured diseases and now knew that finding a way to correct genetic errors would cover the rest of the systemic malaises.
Unfortunately for us today, both these optimistic beliefs of allopathy have taken a severe beating, and allopathy is now on the verge of breakdown.
As evolution has started blunting the edge of antibiotics, allopathy is now desperately trying to find newer toxins to be a step ahead of the pathogens that are fast developing resistance, but it looks like a hopeless quest now.
While evolution is beating allopathy (on a front it had arguably won some great battles), on the genetic front, the situation is not looking too good thanks to a newly discovered concept called epigenetics.
In the early years of genetics, DNA looked like an instruction manual written in a linear way to build a life-form. Each protein had its code and each process had a fixed assembly line, so there was a clear one-to-one relationship and hence the comfort of predictable cause-and-effect logic that science thrives on was available.
Unfortunately, scientists soon realised that the book of life was not as simple or linear. It was actually a book that you have to keep flipping through because it had multiple options for a given decoding.
The science of epigenetics is based in this new understanding that DNA code is read by life depending on the given situation.
In simple terms, it is like a book where you read the instructions of what to do on the page 32 if a man coming at you is wearing a white shirt; but, if he is wearing a blue short, you need to read the instructions on page 245.
Similarly, the book of genes gets read depending on external circumstances, and hence genetics is now added with an epi, i.e. outside of to describe it more correctly.
So, epigenetics did what quantum physics did to classical physics. It destroyed the hope of having a deterministic view of a life-form, and what nCovid19 has done today is to tell that secret to the whole world.
While biology or genetics is not mainstream information that the masses are aware of, thanks to the coronavirus pandemic, the whole world saw how the great allopathy that claimed having the best cause-and-effect understanding of human body and its diseases actually failed completely in answering even the most simple questions.
It is about time allopathy recognises that the local cause-and-effect model it is pursing is not the only way to look at health and healthcare.
There are deeper and bigger systems at play in each illness and hence the brute-force cure of antibiotics or same-treatment-for-everyone cant be looked at as a future of healthcare.
We need a new allopathy that is ready to grow beyond the current idea of local cause-and-effect and widen its scope to understand the larger global systems that impact behaviour of the micro-systems it is focusing on.
If allopathy is not re-invented soon, it will cause far too many disruptions in larger systems (like what antibiotics have done to the web of life) and if they are agitated to cascade (as we can see with the HIV or coronavirus pandemics) into a problem, they have the power to send our species down the path of existence in a jiffy.
Allopathy may have cured a billion individuals in its golden age, but it is about to turn into a curse from a cure for human species at large. It needs to grow into becoming a holistic system that recognises the idea of optimisation in this chaotic interwoven universe instead of struggling to find cause-and-effect relationships in local systems.
DISCLAIMER : Views expressed above are the author's own.
Continue reading here:
What is the most important phrase in all science according to the Nobel Prize for Physics Richard Feynman and why – Explica
.What would be your message?
If, in some cataclysm, all scientific knowledge were destroyed but we had the opportunity to pass on a single sentence to the next generations of creatures, what should that sentence be?
That is the question that physicist Richard Feynman posed on the shoulders of some undergraduate students one day in 1961, in one of his legendary lectures given at the California Institute of Technology or Caltech.
If you are taking pity on the poor students, put aside the pity.
Not only did Feynman himself answer the question immediately, but they were fortunate enough to stand before who is widely regarded as the most influential physicist since Albert Einstein.
On top of that, he was the most charismatic, fun and irreverent teacher they could have had.
In short, one of the most extraordinary scientists of the 20th century and someone to whom it hurts to compare.
He was born in 1918, during the Depression, into a working class family outside of New York, USA and, at age 17, he won a math contest in which his talent in that subject was clear .
That same year, he went to study at the Massachusetts Institute of Technology, MIT, and then moved to Princeton, achieving a top score on the mathematics and physics entrance exam, an unprecedented feat.
But soon after, he received sad news: Arline Greenbaum, his girlfriend, had tuberculosis, a disease for which there was no cure at the time. Feynman decided to marry her so that he could take care of her.
Science Photo LibraryRichard and Arline married in 1942, when he was 24 years old and she, 22, under the shadow of a disease that was incurable at the time.
Soon, another threat loomed over the couple: A few months before Richard and Arline were married, the United States was embroiled in World War II, after the Pearl Harbor bombing.
Feynman was asked to join a top-secret project based at a government laboratory in Los Alamos, New Mexico. Code-named Manhattan, their goal was to build an atomic bomb.
Germany was the intellectual center of theoretical physics and we had to make sure that they did not rule the world. I felt like I should do it to protect civilizationFeynman said.
Extraordinary physicists of the stature of Julius Robert Oppenheimer, Niels Bohr, and Enrico Fermi combined their intellectual abilities, but the challenge of developing an atomic bomb so quickly was a titanic task.
A fundamental problem was the large volume of calculations required. Without computers, everything had to be done manually, greatly hampering progress.
Science Photo LibraryAs part of the Manhattan Project, Feynman made human computer equipment work at an inhuman pace.
Feynman devised a way to do calculations in parallel, reducing problem solving time exponentially.
He became a key member of the team, but he also made a name for himself by playing tricks like opening locks behind which top-secret documents were kept just to show that he could.
When he was in Los lamos, he received the sad news that his wife, who was confined to a nearby sanitarium, died.
She was 25 years old. He, 27 and a broken heart.
Shortly after, he was forced to face the reality of what he had helped create.
.The devastation left behind by the bomb he had helped create.
The bomb exploded over the Japanese city of Hiroshima on August 6, 1945. It killed more than 80,000 people. Three days later, a second bomb was detonated, in Nagasaki.
Feynman was deeply disturbed to have contributed to the deaths of so many.
In the months after the double trauma, was plunged into a dark depression.
In the fall of 1945, Feynman was invited to become a professor in the Physics Department at Cornell University.
He was still shocked by the events of that summer, but reflected and remembered that I used to enjoy physics and mathematics because I played with them, so I decided that I was going to do things just for fun.
Science Photo LibraryHaving fun was a priority.
While Feynman was rediscovering the fun in physics, science was in crisis.
New discoveries about atoms had caused confusion in physics.
The old assumptions about the world were wrong and there was a new problem area called Quantum Mechanics.
Quantum mechanics, in many ways, was the most profound psychological shock that physicists have had in all of history.
Isaac Newton was not right: you can know everything there is to know about the world, and yet you cannot predict with perfect precision what will happen next.
Quantum mechanics had revealed the problems of anticipating the behavior of atoms and their electromagnetic forces.
And since they are the fundamental building blocks of nature, everything else was also in doubt.
.Electromagnetism is one of the four fundamental forces of the known universe and it is everywhere.
Think about it: everything that happens around you, apart from gravity, is due to electromagnetism.
When two atoms come together to form a molecule, that is electromagnetism, so all chemistry is electromagnetism. And if all chemistry is electromagnetism, then all biology is electromagnetism.
Literally everything around us is a manifestation of electromagnetism in one way or another.
To greatiwe show features
To try to make sense of electromagnetism and subatomic matter, a new field called quantum electrodynamics or QED, for its acronym in English.
The problem was that while sometimes it seemed to work, other times it didnt make any sense. He was confusing the smartest physicists on the planet, even QEDs father Paul Dirac.
Science Photo LibraryEnglish theoretical physicist Paul Dirac (left) conversing with Feynman in 1962 at the International Conference on Relativistic Theories of Gravitation in Warsaw, Poland. Dirac and Feynman won the Nobel Prize in Physics in 1933 and 1965, respectively.
Feynman had read a book by Dirac, describing problems that no one knew how to solve.
I didnt understand the book very well. But there, in the last paragraph of the book, it said: Some new ideas are needed hereso I started thinking of new ideas, Feynman recalled in an interview.
Typically, Feynman approached the matter in an unconventional way: with drawings.
He found a pictorial way of thinking, inventing a brilliant way to bypass the complicated calculations necessary for QED.
The result were Feynman diagrams, which put the finishing touches on QED, the most numerically accurate physical theory ever invented.
The diagrams turned out to be so useful that today they are applied in completely different fields to particle physics, such as calculating the evolution of galaxies and large-scale structure in the Universe.
Drawing, in fact, would later become another of his hobbies, in addition to playing bongos, which for him were what the violin for Einstein and the piano for Werner Heisenberg.
He decided to learn to draw in his fourth decade of life, helped by an artist friend, and was so enthusiastic that he adopted a topless bar as his secondary office, where he sketched the girls and physics equations.
But it was the QED related drawings that made him deserving of the Nobel Prize in Physics, which he shared with Julian Schwinger and Shinichiro Tomonaga, in 1965.
.Although he accepted the Nobel Prize and had fun at the gala dancing with Gweneth Howarth, his third wife and mother of their two children, Feynman always said that the true award was the pleasure of discovery and seeing that it is useful to other people.
Among those who live in the quantum world, Feynman is also known for works that amaze us, such as the theory of quantum electrodynamics and the physics of superfluidity of subcooled liquid helium.
Let us stay with knowing that he was one of the pioneers in the field of quantum computing and that introduced the concept of nanotechnology.
And his involvement in 1986, when he was already fatally ill, in the Space Shuttle Challenger disaster investigation, when he revealed what NASA was reluctant to accept: the cause of the ships disintegration 73 seconds after its launch put him in the center of public attention.
The phrase with which he summarized his conclusions became famous: For a successful technology, reality must prevail over public relations, since you cant fool nature
But it was his solution to another problem related to physics, this time in university classrooms, that would reveal his gift for spreading the science that would make him famous in the outside world.
In the early 1960s, Caltech was struggling as it failed to attract students to physics classes. Looking for ways to get them excited about the subject, they asked Feynman to redo the curriculum.
His work was a series of lectures that were so engaging that they were edited and published under the title The Feynman Lectures of Physics, one of the most popular physics books in history.
It was in the first of those classes that, after confirming that if they wanted to be physicists, they would have a lot to study (200 years on the fastest developing field of knowledge that exists) and warn them that it would take many more years to learn it (Theyll have to go to graduate school!), He wondered where to start and asked them that question.
But, What was for Feynman the statement that would contain the most information in the fewest words?
BBCCaltech made all of Feynmans legendary lectures available to the public on the website The Feynman Lectures on Physics http://www.feynmanlectures.caltech.edu/.
I think it is the atomic hypothesis (or the atomic fact, or whatever you want to call it) that all things are made of atoms: small particles that move in perpetual motion, attracting each other when they are within walking distance, but repelling when trying to press them against each other
In that single sentence there is an enormous amount of information about the world, if only a little imagination and thought is applied
If you know that all matter is made of atoms that are constantly moving, you can start to understand phenomena like temperature, pressure and electricity.
They all have to do with the speed at which the atoms are moving and how many and / or what parts of them are doing it.
ANDit can only lead you to discover, for example, the power of steam, the pressure of gases, weather patterns and inventing things like motors, telephones and electric light.
Science Photo LibraryWith his lively and lucid explanations, Feynman made abstract concepts tangible, and his warm presence inspired (and continues to inspire thanks to books and films) the interest and wonder of even the most science-averse.
The final part of his sentence, which refers to the way atoms interact with each other (attracting and repelling each other) reveals the chemistry to you.
Once you understand how Atoms come together to form molecules, you can do it to create antibiotics, vaccines, gasoline and air mixed together form an explosive mixture (combustion engines), batteries, asphalt, steel and even the essence of life: amino acids, carbohydrates, DNA.
For all that Feynman chose that phrase as a legacy for creatures to start again, after everything was lost (and to spark his students interest in physics).
Of course, that is not the only answer.
In fact, there are those who criticize it, such as neuroscientist Daniel Toker who pointed out in an article that strictly speaking, the atomic hypothesis turns out to be false, because according to the theory of the quantum field, a discipline in which Feynman played a key role in development, () subatomic particles are not actually particles, but simply local excitations of quantum fields.
Fortunately, science is not a dogma and as it develops it constantly throws up new possibilities.
Six decades later, the question remains intriguing. And the spirit of the second part of Feynmans answer, eternal.
It will always be urgent to bequeath to the new generations clues so that, with a little imagination and thought, they can discover the world.
Remember that you can receive notifications from BBC Mundo. Download the new version of our app and activate them to not miss our best content.
Continue reading here: