Discovery of a Pulsar and Supermassive Black Hole Pairing Could Help Unlock the Enigma of Gravity


Last year, the very rare presence of a pulsar (named SGR J1745-2900) was also detected in the proximity of a supermassive black hole (Sgr A**, made up of millions of solar masses), but there is a combination that is still yet to be discovered: that of a pulsar orbiting a ‘normal’ black hole; that is, one with a similar mass to that of stars.

The intermittent light emitted by pulsars, the most precise timekeepers in the universe, allows scientists to verify Einstein’s theory of relativity, especially when these objects are paired up with another neutron star or white dwarf that interferes with their gravity. However, this theory could be analysed much more effectively if a pulsar with a black hole were found, except in two particular cases, according to researchers from Spain and India.

Pulsars are very dense neutron stars that are the size of a city (their radius approaches ten kilometres), which, like lighthouses for the universe, emit gamma radiation beams or X-rays when they rotate up to hundreds of times per second. These characteristics make them ideal for testing the validity of the theory of general relativity, published by Einstein between 1915 and 1916.

“Pulsars act as very precise timekeepers, such that any deviation in their pulses can be detected,” Diego F. Torres, ICREA researcher from the Institute of Space Sciences (IEEC-CSIC), explains to SINC. “If we compare the actual measurements with the corrections to the model that we have to use in order for the predictions to be correct, we can set limits or directly detect the deviation from the base theory.”

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These deviations can occur if there is a massive object close to the pulsar, such as another neutron star or a white dwarf. A white dwarf can be defined as the stellar remnant left when stars such as our Sun use up all of their nuclear fuel. The binary systems, comprised of a pulsar and a neutron star (including double pulsar systems) or a white dwarf, have been very successfully used to verify the theory of gravity.

Until now scientists had considered the strange pulsar/black hole pairing to be an authentic ‘holy grail’ for examining gravity, but there exist at least two cases where other pairings can be more effective. This is what is stated in the study that Torres and the physicist Manjari Bagchi, from the International Centre of Theoretical Sciences (India) and now postdoc at the IEEC-CSIC, have published in the Journal of Cosmology and Astroparticle Physics. The work also received an Honourable Mention in the 2014 Essays of Gravitation prize.

The first case occurs when the so-called principle of strong equivalence is violated. This principle of the theory of relativity indicates that the gravitational movement of a body that we test only depends on its position in space-time and not on what it is made up of, which means that the result of any experiment in a free fall laboratory is independent of the speed of the laboratory and where it is found in space and time.

The other possibility is if one considers a potential variation in the gravitational constant that determines the intensity of the gravitational pull between bodies. Its value is G = 6.67384(80) x 10-11 N m2/kg2. Despite it being a constant, it is one of those that is known with the least accuracy, with a precision of only one in 10,000.

In these two specific cases, the pulsar-black hole combination would not be the perfect ‘holy grail’, but in any case scientists are anxious to find this pair, because it could be used to analyse the majority of deviations. In fact, it is one of the desired objectives of X-ray and gamma ray space telescopes (such as Chandra, NuStar or Swift), as well as that of large radio telescopes that are currently being built, such as the enormous ‘Square Kilometre Array’ (SKA) in Australia and South Africa.

Source : Daily galaxy

What Our Milky Way Galaxy Looked Like 10 Billion Years Ago


Using two supercomputers at Oak Ridge National Laboratory and the Swiss National Supercomputing Center, a group of researchers headed by Dr Simon Portegies Zwart of Leiden Observatory has simulated the long term evolution of the Milky Way Galaxy over a period of six billion years – from 10 to 4 billion years ago.

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If you took a photo of our Milky Way Galaxy today from a distance, it would show a spiral galaxy with a bright, central bar of dense star populations.

The Sun would be located outside this bar near one of the spiral arms composed of stars and interstellar dust; beyond the visible galaxy would be a dark matter halo.

Now, if you wanted to go back in time and take a video of our Milky Way Galaxy forming, you could go back 10 billion years, but many of the galaxy’s prominent features would not be recognizable.

You would have to wait about 5 billion years to witness the formation of our Solar System. By this point, 4.6 billion years ago, the galaxy looks almost like it does today.

This is the timeline Dr Portegies Zwart and his colleagues are seeing emerge when they use supercomputers to simulate the Milky Way’s evolution.

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This image shows what the Milky Way Galaxy looked like ten billion years ago. Image credit: SURFsara / J. Bédorf / NVIDIA.

“We don’t really know how the structure of the galaxy came about. What we realized is we can use the positions, velocities, and masses of stars in three-dimensional space to allow the structure to emerge out of the self-gravity of the system,” Dr Portegies Zwart said.

The challenge of computing galactic structure on a star-by-star basis is, as you might imagine, the sheer number of stars in the Milky Way – at least 100 billion. Therefore, the team needed at least a 100 billion-particle simulation to connect all the dots.

Before the development of the team’s code, known as Bonsai, the largest galaxy simulation topped out around 100 million particles.

The team tested an early version of Bonsai on the Oak Ridge Leadership Computing Facility’s Titan – the second-most-powerful supercomputer in the world – to improve scalability in the code.

After scaling Bonsai, the scientists ran Bonsai on the Piz Daint supercomputer at the Swiss National Supercomputing Center and simulated galaxy formation over 6 billion years with 51 million particles representing the forces of stars and dark matter.

After a successful Piz Daint run, the team returned to Titan to maximize the code’s parallelism. Bonsai achieved nearly 25 petaflops of sustained single-precision, floating point performance on the Titan.

The team aims to compare simulation results to new observations coming from ESA’s Gaia satellite launched in 2013.

“One percent of the particles, or stars, in our simulated galaxy should match Gaia data,” Dr Portegies Zwart said.

Source : sci-news

Stephen Hawking: Artificial Intelligence could spell end of human race


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World-famous physicist Stephen Hawking told the BBC he believes future developments in artificial intelligence (AI) have the potential to eradicate mankind.

The Cambridge professor, who relies on a form of artificial intelligence to communicate, said if technology could match human capabilities “it would take off on its own, and re-design itself at an ever increasing rate.”

He also said that due to biological limitations, there would be no way humans could match the speed of development of technology.

“Humans, who are limited by slow biological evolution, couldn’t compete and would be superseded,” he said.

“The development of full artificial intelligence could spell the end of the human race.”

Hawking suffers from amyotrophic lateral sclerosis (ALS), a form of motor neuron disease, and uses AI technology as part of a system which senses how he thinks and predicts which words he will use next.

His bleak forecast came in response to questions about updates to his AI communication systems.

His latest upgrade, developed by Intel Corporation over the past three years, will allow the professor to write up to 10 times faster and communicate more effectively with friends, family and students.

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“With the improvements made, I am now able to write much faster, and it means that I can continue to give lectures, write papers and books and, of course, speak with my family and friends more easily.”

“This new system is life changing for me, and I hope it will serve me well for the next 20 years,” he said.

Other technology specialists do not share Hawking’s grim outlook. Rollo Carpenter, creator of Cleverbot, said he believes mankind will maintain control over technology.

“I believe we will remain in charge of the technology for a decently long time and the potential of it to solve many of the world problems will be realized,” he said.

Carpenter’s software responds to stimulation from conversations with actual humans, and has the capability to learn from its previous interactions.

Cleverbot has scored highly in the ‘Turing test’, which is designed to examine how closely machines can replicate human behavior.

We cannot quite know what will happen if a machine exceeds our own intelligence, so we can’t know if we’ll be infinitely helped by it, or ignored by it and sidelined, or conceivably destroyed by it,” Carpenter added.

Technology and a rise in the capabilities of AI are already affecting workplaces nationwide, as many employers opt to invest in a machine, rather than hiring people.

In November, a study from the University of Oxford suggested that a third of UK jobs could be replaced by machines over the next two decades.

Low-paid jobs featuring repetitive tasks are most likely to be superseded by technology, with clerical and support service jobs most at risk.

The study further found that jobs with a salary under £30,000 are almost five times more likely to be replaced than jobs over £100,000.

Source : RT

Monster Telescope Will be World’s Largest Cosmic Eye


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An artist’s illustration depicts the European Extremely Large Telescope (E-ELT) in its enclosure. It eventually will be the world’s largest “eye on the sky.” (Click Image to Download)

The world’s largest telescope has gotten its official construction go-ahead, keeping the enormous instrument on track to start observing the heavens in 2024.

The European Extremely Large Telescope (E-ELT), which will feature a light-collecting surface 128 feet (39 meters) wide, has been greenlit for construction atop Cerro Armazones in Chile’s Atacama Desert, officials with the European Southern Observatory (ESO) announced Thursday (Dec. 4).

The current construction approval applies only to Phase 1; contracts for this work will be awarded in late 2015. The Phase 2 components will be approved as more funding becomes available, ESO officials said.

“The funds that are now committed will allow the construction of a fully working E-ELT that will be the most powerful of all the extremely large telescope projects currently planned, with superior light-collecting area and instrumentation,” de Zeeuw said. “It will allow the initial characterization of Earth-mass exoplanets, the study of the resolved stellar populations in nearby galaxies as well as ultra-sensitive observations of the deep universe.”

 the Thirty Meter Telescope (TMT) — which, not surprisingly, will boast a light-collecting surface 30 m, or 98 feet, wide — is slated to start observing from Hawaii’s Mauna Kea in 2022. Like E-ELT, TMT’s primary mirror will be composed of hundreds of relatively small segments.

All three megascopes should help researchers tackle some of the biggest questions in astronomy, including the nature of the mysterious dark matter and dark energy that make up most of the universe.

Source : Discovery.com

Cool NASA Animation Beautifully Details Every Step of Orion’s First Launch!


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Source : universetoday.com

Video Caption: Animation details NASA’s Orion Exploration Flight Test-1 (EFT-1) mission launching on Dec. 4. 2014. Credit: NASA

It’s not Science Fiction! It’s Not Star Trek!

No. It’s a really, really big NASA Mission! It’s Orion!

In fact, it’s the biggest and most important development in US Human Spaceflight since the end of the Space Shuttle Program in 2011.

Orion is launching soon on its first flight, the pathfinding Exploration Flight Test-1 (EFT-1) mission and sets NASA on the path to send humans to Mars in the 2030s.

Watch this cool NASA animation beautifully detailing every key step of Orion’s First Launch!

Orion is designed to take humans farther than they’ve ever gone before. Even farther into deep space than NASA’s Apollo moon landing which ended more than four decades ago!

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Orion atop Delta 4 Heavy Booster. Credit: NASA/Kim Shiflett (Click Image to Download)

We are T-MINUS 4 Days and Counting to the inaugural blastoff of Orion as of today, Sunday, November 30, 2014.

Every aspect of the final processing steps now in progress by engineers and technicians from NASA, rocket provider United Launch Alliance, and Orion prime contractor Lockheed Martin is proceeding smoothly and marching towards launch.

Orion will lift off on a United Launch Alliance Delta IV Heavy rocket on its inaugural test flight to space on the uncrewed Exploration Flight Test-1 (EFT-1) mission at 7:05 a.m. EST on December 4, 2014, from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.

The two-orbit, four and a half hour Orion EFT-1 flight around Earth will lift the Orion spacecraft and its attached second stage to an orbital altitude of 3,600 miles, about 15 times higher than the International Space Station (ISS) – and farther than any human spacecraft has journeyed in 40 years.

Orion is NASA’s next generation human rated vehicle that will carry America’s astronauts beyond Earth on voyages venturing farther into deep space than ever before – beyond the Moon to Asteroids, Mars, and other destinations in our Solar System.

Europe targets Ariane deal to stay in commercial space race


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  • Meeting on Tuesday expected to agree funding for new rocket
  • Franco-German compromise aims to keep Europe competitive
  • Airbus CEO urges radical shift to counter U.S. rival SpaceX

Weeks after its dramatic coup in landing a probe on a speeding comet, Europe is hoping a last-minute deal to provide funding for the workhorse Ariane rocket will prevent its space ambitions falling back to earth this week.

Anxious to preserve its own access to space, the 20-nation European Space Agency will seek to put aside differences over how to respond to U.S. low-cost rival SpaceX and safeguard thousands of high-tech jobs at ministerial talks on Tuesday.

After two years of wrangling, the outlines of an accord to fund development of a new Ariane 6 satellite launch vehicle appeared to be in place after Germany dropped its insistence on a prior upgrade to the current Ariane 5, officials said.

France is likely in return to back continued European funding for the International Space Station.

“It would be very serious if there is no decision on Dec 2 because Europe would have a competitive delay that it would never manage to reverse,” said Karim Michel Sabbagh, chief executive of Luxembourg-based satellite operator SES.

With the arrival in 2013 of SpaceX, founded by electric car entrepreneur Elon Musk and offering cut-price satellite launches, Ariane needs to lower costs dramatically.

The chief executive of Europe’s largest space contractor Airbus Group, Tom Enders, told Reuters a deal would mark a “new chapter” in the way Europe approaches space.

But he called for a clean break with bureaucratic public-private space industry structures to avoid Europe being “marginalized” by international competition.

“A departure from current ways of working is a precondition for future competitiveness of the European space business”.

Airbus Group, which builds the Ariane 5 launch vehicle, is expected to inaugurate a previously announced joint venture with engine maker Safran on the eve of the talks to help secure Ariane’s future. It will incorporate Arianespace, the launch services firm which operates Europe’s satellite launcher.

CALL FOR REFORM

The new venture is the most serious effort to reorganise Europe’s space industry and is being set up in the hope the one-day ministerial meeting in Luxembourg will back Ariane 6 – ending a compromise two years ago which split potential funding between the upgrade known as Ariane 5ME and an eventual new Ariane 6.

But Europe’s space industry remains heavily influenced by state agencies and industry sources say removing multiple layers of management is key to keeping Europe’s commercial activities competitive.

SpaceX offers launches for around $60 million (50 million euros) compared to 70-90 million euros a shot expected for the Ariane 6 and an average Ariane 5 launch price of 130 million euros ($160 million).

Efficiency comes into play in a cut-throat global commercial market where most companies can only rely on national links when it comes to sensitive defence satellites.

RUSSIA’S ROLE

The European Space Agency, an intergovernmental organisation with 20 member states from across Europe, was founded in 1975 to pool the continent’s finances and brains at a time when the United States and Russia had virtually monopolised space.

But despite Europe’s Ariane capturing 50 percent of the market, a costly system of job distribution and rival design offices has cast a shadow over Europe’s commercial activity even as it basks in scientific success like the Philae comet lander.

Science ministers will also decide on whether the ESA’s participation in the International Space Station will continue beyond 2020, its original shutdown date, and in what way.

The United States earlier this year said it would keep the ISS running until at least 2024, but Russia is looking at going alone and creating its own orbital station. Europe and Russia are also working on a two-mission ExoMars probe shot to Mars.

“(The ISS) shows we can achieve a lot if we all work together and it’s important to highlight that given the tensions building up between Russia and the West,” Daniel Brown, an astronomy expert at Nottingham Trent University, said.

ESA’s budget for 2014 was about 4.1 billion euros ($5.12 billion), and roughly equates to the price of one cinema ticket each year per each European tax payer.

NASA’s budget is $17.6 billion in 2014. The budget gap has made the achievements of Rosetta appear all the more impressive to many observers, but Europe’s space industry is lobbying for a healthy commercial launch activity to support such projects.

ESA plans also include a mission to orbit one of the icy moons of Jupiter and one going to Mercury.

The Horizon 2000 programme, developed in 1984, transformed Europe into a world leader in many areas, including solar physics, cosmology and X-ray Astronomy, said Ken Pounds, former CEO of the Particle Physics and Astronomy Research Council.

Pounds said he hoped the success of Philae would lead to a virtuous circle “where Europe is proving it can do world-class things, people feel warm about it, and the political class respond to that.”

Source : Reuters

NASA contracts two firms to work on asteroid mining


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NASA has contracted with two private space firms to prepare for and ultimately execute missions to land on and mine asteroids for valuable resources. The contracts, forged between NASA and both Deep Space Industries and Planetary Resources, are further evidence of a the kinds of new and interesting partnerships as space exploration increasingly becomes the domain of private industry.
Both companies have been forging plans to launch asteroid-landing probes for months-long stints on near Earth objects — with the aim of extracting valuable resources. Although such expeditions could theoretically return to Earth with valuable minerals, the financial viability of the concept relies on the prospects of supplying other space missions with an extracted assets. That’s where NASA comes in.

With a spate of deep space missions planned in the coming century, NASA would be able to save time and money by supplying some of those missions (including International Space Station expeditions) with vital resources mined from asteroids — water, silicate, carbonaceous minerals and more.

“Deep Space brings commercial insight to NASA’s asteroid planning, because our business is based on supplying what commercial customers in Earth orbit need to operate, as well as serving NASA’s needs for its moon and Mars exploration,” Deep Space CEO Daniel Faber said in a press release earlier this year. “The fuel, water, and metals that we will harvest and process will be sold into both markets, making available industrial quantities of material for expanding space applications and services.”

The fuel it takes to rocket out of the grasp of Earth’s gravity makes launching anything — much less a massive cargo ship — exceptionally expensive. By contrast, asteroids have minuscule centers of gravity, making coming and going from them much less fuel (and cost) intensive.

“Right now it costs $17 million per ton to get anything up to geosynchronous orbit,” David Gump, vice chairman of Deep Space, told The Boston Globe. “If we can beat whatever that price is in 2022, we’ll have a big market.”

“Asteroids hold the resources necessary to enable a sustainable, even indefinite presence in space — for science, commerce and continued prosperity here on Earth,” Chris Lewicki, president and chief engineer of Planetary Resources, echoed in a statement released by NASA last week.

As part of Planetary Resources’ ongoing cooperation with NASA’s asteroid exploration efforts, the company will help sort through the near Earth object-finding algorithms being submitted by citizen scientists as part of the agency’s Asteroid Data Hunter challenge.

“By harnessing the public’s interest in space and asteroid detection, we can more quickly identify the potential threats, as well as the opportunities,” Lewicki added.

Following in the wake of European Space Agency’s history-making comet landing, NASA will attempt to land its own spacecraft, the OSIRIS-Rex, on an asteroid named Bennu in September 2016.

Source : upi.com

Is Dark Energy Evaporating Dark Matter?


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cientists at the University of Rome and Portsmouth recently published a paper which describes dark matter slowly being engulfed by dark energy.

Dark matter is almost completely undetectable matter that astronomers and cosmologists have calculated to exist within our universe, hence the name “dark”. Whereas dark energy is an accepted model of energy that permeates all matter and space, and is responsible for the acceleration of the expansion of the universe (to find out more about the two, click on the links above)

Why are they of interest now?

In the paper, the cosmologists discuss how recent astronomical data favours the idea that dark energy grows as it interacts with dark matter, which can help explain the mechanics of the expansion of the universe.

“If the dark energy is growing and dark matter is evaporating we will end up with a big, empty, boring universe with almost nothing in it,” said the Director of Portsmouth’s Institute of Cosmology and Gravitation, Professor David Wands.

Professor Wands continues by stating that “Dark matter provides a framework for structures to grow in the Universe. The galaxies we see are built on that scaffolding and what we are seeing here, in these findings, suggests that dark matter is evaporating, slowing that growth of structure,”.

How does this play a role in the understanding of our universe?

As our understanding of the universe changes, so does our approach in pursuing more knowledge about its every aspect. In 1998, researchers observing distant supernovae found that they were fainter than expected. The most accepted explanation for the variance is that the light emitted from the supernovae traveled a greater distance than theorists had predicted. This observation lead to the conclusion that space must have expanded at an accelerating rate as it traveled. The phenomenon was later attributed to the existence of dark energy, which completely revolutionized the scientific community’s way of looking at the structure of the universe, and in essence, the very foundation of our existence.

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If dark energy continues its dominance in the Universe, every galaxy beyond our neighborhood will one day no longer be visible

Now, researchers believe that it is the evaporation of dark matter that can explain why the growth of cosmic structures, such as galaxies and clusters of galaxies, seems to be slower than expected.

The availability of more data allows researchers such as Professor Wands, to examine the mechanics and interactions of various cosmic phenomena more precisely.

“Much more data is available now than was available in 1998 and it appears that the standard model is no longer sufficient to describe all of the data. We think we’ve found a better model of dark energy,” Wands continues, “However there is growing evidence that this simple model cannot explain the full range of astronomical data researchers now have access to; in particular the growth of cosmic structure, galaxies and clusters of galaxies, seems to be slower than expected”.

The paper itself was published by the American Physical Society, and although it looks very interesting, one must keep in mind that dark energy and dark matter is a subject in which very little is understood. As more data becomes available, a finer structure of our universe can be developed, which cannot be possible without the researchers such as Prof. Wands, Dr. Marco Bruni and their research students.

Source : from quarks to quasars

Mystery of the ‘spooky’ pattern in the universe: Scientists find that supermassive black holes are ALIGNED


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A European research team has found that the rotation axes of the central supermassive black holes in a sample of quasars are parallel to each other over distances of billions of light-years. An artist’s impression of the alignment is pictured

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Black holes are one of the strangest objects in the universe, preventing anything from escaping their grip – even light.

Now astronomers have discovered something even more peculiar about these enigmatic objects; they are aligned with each other over distances stretching billions of light-years

The remarkable observations were made by the Very Large Telescope (VLT) in Chile, which found an eerie alignment between enormous interstellar objects called quasars.

Quasars are galaxies with very active supermassive black holes at their centres. They shine more brightly than all the stars in the rest of their host galaxies put together.

A European research team has found that the rotation axes of the central supermassive black holes in a sample of quasars are parallel to each other over vast distances.

Source : Dailymail

Gravity May Have Saved Very Early Universe – Study


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A team of physicists from Denmark, Finland and the United Kingdom, led by Dr Matti Herranen University of Copenhagen, says that the spacetime curvature – in effect, gravity – is what may have saved the Universe from collapse immediately after the Big Bang.

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Some previous studies have suggested that the production of Higgs particles during the accelerating expansion of the very early Universe (inflation period) should have led to instability and collapse. Physicists have been trying to find out why this didn’t happen, leading to hypotheses that there must be some new physics that will help explain the origins of the Universe that has not yet been discovered.

Dr Herranen and his colleagues, however, believe there is a simpler explanation.

In a new study, published in the journal Physical Review Letters, they describe how the spacetime curvature provided the stability needed for the Universe to survive expansion in that early period.

They investigated the interaction between the Higgs bosons and gravity, taking into account how it would vary with energy.

The results show that even a small interaction would have been enough to stabilize the Universe against decay.

“The Standard Model of particle physics, which scientists use to explain elementary particles and their interactions, has so far not provided an answer to why the Universe did not collapse following the Big Bang,” said co-author Prof Arttu Rajantie of Imperial College London.

“Our research investigates the last unknown parameter in the Standard Model – the interaction between the Higgs particle and gravity.”

This parameter cannot be measured in particle accelerator experiments, but it has a big effect on the Higgs instability during inflation. Even a relatively small value is enough to explain the survival of the Universe without any new physics!”

The physicists plan to continue their research using cosmological observations to look at this interaction in more detail and explain what effect it would have had on the development of the early Universe.

In particular, they will use data from current and future ESA’s missions measuring cosmic microwave background radiation and gravitational waves.

“Our aim is to measure the interaction between gravity and the Higgs field using cosmological data,” Prof Rajantie said.

“If we are able to do that, we will have supplied the last unknown number in the Standard Model of particle physics and be closer to answering fundamental questions about how we are all here.”

Source : Sci-news