Theories Of Everything

[rynner2]

Universe evolution recreated in lab
By Pallab Ghosh, Science correspondent, BBC News
[Video: Pallab Ghosh explains the significance of the visual simulation]

An international team of researchers has created the most complete visual simulation of how the Universe evolved.
The computer model shows how the first galaxies formed around clumps of a mysterious, invisible substance called dark matter.
It is the first time that the Universe has been modelled so extensively and to such great resolution.
The research has been published in the journal Nature.

The simulation will provide a test bed for emerging theories of what the Universe is made of and what makes it tick.

One of the world's leading authorities on galaxy formation, Professor Richard Ellis of the California Institute of Technology (Caltech) in Pasadena, described the simulation as "fabulous".
"Now we can get to grips with how stars and galaxies form and relate it to dark matter," he told BBC News.

The computer model draws on the theories of Professor Carlos Frenk of Durham University, UK, who said he was "pleased" that a computer model should come up with such a good result assuming that it began with dark matter.
"You can make stars and galaxies that look like the real thing. But it is the dark matter that is calling the shots".

Cosmologists have been creating computer models of how the Universe evolved for more than 20 years. It involves entering details of what the Universe was like shortly after the Big Bang, developing a computer program which encapsulates the main theories of cosmology and then letting the programme run.
The simulated Universe that comes out at the other end is usually a very rough approximation of what astronomers really see.
The latest simulation, however, comes up with the Universe that is strikingly like the real one.

Immense computing power has been used to recreate this virtual Universe. It would take a normal laptop nearly 2,000 years to run the simulation. :shock: However, using state-of-the-art supercomputers and clever software called Arepo, researchers were able to crunch the numbers in three months.

In the beginning, it shows strands of mysterious material which cosmologists call "dark matter" sprawling across the emptiness of space like branches of a cosmic tree. As millions of years pass by, the dark matter clumps and concentrates to form seeds for the first galaxies.
Then emerges the non-dark matter, the stuff that will in time go on to make stars, planets and life emerge.

But early on there are a series of cataclysmic explosions when it gets sucked into black holes and then spat out: a chaotic period which was regulating the formation of stars and galaxies. Eventually, the simulation settles into a Universe that is similar to the one we see around us.

According to Dr Mark Vogelsberger of Massachusetts Institute of Technology (MIT), who led the research, the simulations back many of the current theories of cosmology.
"Many of the simulated galaxies agree very well with the galaxies in the real Universe. It tells us that the basic understanding of how the Universe works must be correct and complete," he said.
In particular, it backs the theory that dark matter is the scaffold on which the visible Universe is hanging.
"If you don't include dark matter (in the simulation) it will not look like the real Universe," Dr Vogelsberger told BBC News.

The simulation is the first to show visible matter emerging from dark matter. It will also help cosmologists learn more about another mysterious force called dark energy that is powering the continued acceleration of the Universe.
The European Space Agency (Esa) is planning to launch a spacecraft called Euclid in 2020 to measure the acceleration of the Universe. Accurate simulations, such as the one published today, will help in that search, according to Dr Joanna Dunkley, of Oxford University.
"In order to use the data from Euclid we will need to simulate what we expect to see for dark energy and compare it with what we see," she said.

Cosmologist Dr Robin Catchpole of the Institute of Astronomy in Cambridge, added a note of caution, however.
Although he hailed the simulation as "spectacular", he added, "one must not be taken in by the sheer visual beauty of the thing. You get things that look like galaxies without them being much to do with the physics of how galaxies emerged".

http://www.bbc.co.uk/news/science-environment-27299017

(FWIW, I've actually met Dr. Joanna Dunkley! Astrophysicists and policemen all look so young to me now... )

 

[Vardoger]

What if life occured on the planets of the stars in those simulated galaxies. Would it be ethical to turn off the simulation?

:gaga:

 

[rynner2]

What if life occured on the planets of the stars in those simulated galaxies. Would it be ethical to turn off the simulation?

I doubt if the simulation went down to the scale of planets, let alone their near-surface chemical properties! Too much detail to handle - you wouldn't see the wood for the trees. I don't think we're into Matrix territory yet!

I'd guess they worked with a minimum mass limit they'd handle, perhaps that of dwarf stars or giant planets.

 

[PeteByrdie]

What if life occured on the planets of the stars in those simulated galaxies. Would it be ethical to turn off the simulation?

:gaga:

Yes! After tinkering with their worlds for our own twisted amusement. Muahahaha!

But I suspect we'll far sooner face the same question about self-conscious machines. We even debate at length the ethics of animal welfare. How long will it be before a machine can be shown to be as conscious and feeling as a crow, cat or Daily Mail reader?:shock: Surely, it's no more than a decade away.

 

[Stu73]

How long will it be before a machine can be shown to be as conscious and feeling as a crow, cat or Daily Mail reader?

Crows and Cats can be said to be intelligent creatures with the ability to learn from their experiences and environment?? Daily Mail readers on the other hand.........................

 

[rynner2]

Cosmic inflation: 'Spectacular' discovery hailed
By Jonathan Amos, Science correspondent, BBC News

Scientists say they have extraordinary new evidence to support a Big Bang Theory for the origin of the Universe.
Researchers believe they have found the signal left in the sky by the super-rapid expansion of space that must have occurred just fractions of a second after everything came into being.
It takes the form of a distinctive twist in the oldest light detectable with telescopes.
The work will be scrutinised carefully, but already there is talk of a Nobel.

http://www.bbc.co.uk/news/science-environment-26605974

That was in March. Now they're not so sure...

Cosmic inflation: Confidence lowered for Big Bang signal
By Jonathan Amos, Science correspondent, BBC News

Scientists who claimed to have found a pattern in the sky left by the super-rapid expansion of space just fractions of a second after the Big Bang say they are now less confident of their result.
The BICEP2 Collaboration used a telescope at the South Pole to detect the signal in the oldest light it is possible to observe.
At the time of the group's announcement in March, the discovery was hailed as a near-certain Nobel Prize.

But the criticism since has been sharp.
Rival groups have picked holes in the team's methods and analysis.

On Thursday, the BICEP2 collaboration formally published its research in a peer reviewed journal - Physical Research Letters (PRL).
In the paper, the US-led group stands by its work but accepts some big questions remain outstanding.

And addressing a public lecture in London, one of BICEP2's principal investigators acknowledged that circumstances had changed.
"Has my confidence gone down? Yes," Prof Clem Pryke, from the University of Minnesota, told his audience.

What the team announced at its 17 March press conference was the long sought evidence for "cosmic inflation".
Developed in the 1980s, this is the idea that the Universe experienced an exponential growth spurt in its first trillionth of a trillionth of a trillionth of a second.
It helps explain why deep space looks the same on all sides of the sky - the contention being that a very rapid expansion early on could have smoothed out any unevenness.

Inflation theory makes a very specific prediction - that it would have been accompanied by waves of gravitational energy, and that these ripples in the fabric of space-time would leave an indelible mark on the oldest light in the sky - the famous Cosmic Microwave Background.
The BICEP team claimed to have detected this signal. It is called B-mode polarisation and takes the form of a characteristic swirl in the directional properties of the CMB light.

It is, though, an extremely delicate pattern and must not be confused with the same polarisation effects that can be generated by nearby dust in our galaxy.
The critiques that have appeared since March have largely focused on this issue. And they intensified significantly when some new information describing dust polarisation in the Milky Way was released by scientists working on the European Space Agency's orbiting Planck telescope.

Planck, which everyone agrees is extremely powerful at characterising dust, will release further data before the end of the year. And, very significantly, this will include observations made in the same part of the sky as BICEP2's telescope.

Until then, or until new data emerges from other sources, the BICEP2 collaboration recognises that its inflation detection has greater uncertainty attached to it.
"[Our] models are not sufficiently constrained by external public data to exclude the possibility of dust emission bright enough to explain the entire excess signal," it writes in the PRL paper.

At his lecture at University College London, Prof Pryke explained his team's lowered confidence: "Real data from Planck are indicating that our dust models are underestimates. So the prior knowledge on the level of dust at these latitudes, in our field, has gone up; and so the confidence that there is a gravitational wave component has gone down. Quantifying that is a very hard thing to do. But data trumps models."

Prof Pryke spoke of the pressure he and his colleagues had been under since March. He said he never expected there would be such interest in their work, especially from mainstream media.
"I'm feeling like I'm at the eye of the storm," he told me.
"Look, the scientific debate has come down to this - we need more data. With the existing data that's out there, you can generate a lot of farce, a lot of blog posts, a lot of excitement and controversy, but you can't really answer the question scientifically. So, what you need is more data, and that's coming from Planck and it's coming from us."

Prof Marc Kamionkowski, from Johns Hopkins University, commented that what we were witnessing currently was "science in action".
"If it was not such an exciting result, you would not be hearing so much about it," he said in a phone conversation last week.
"We're going to need confirmation by independent groups. That's the way things work in science. We don't believe things because somebody says they're true; we believe them because different people make the measurements independently and find the same results."

http://www.bbc.co.uk/news/science-environment-27935479

 

[rynner2]

The Large Hadron Collider will soon be up and running again. This is part of an article about that which discusses an interesting aspect of the Higgs Boson:

-----------------------------------------------------------------------------------

Particle physicists have learnt more about the Higgs boson's behaviour and how well it conforms to predictions. In a paper published last week in the journal Nature Physics, researchers outlined how they have watched the Higgs decay into the particles that make up matter (known as fermions), in addition to those that convey force (bosons), which had already been observed.

This is exactly as the Standard Model predicts. Physicists know that this framework, devised in the 1970s, must be a stepping stone to a deeper understanding of the cosmos. But so far, it's standing up exceptionally well. Searches at the LHC for deviations from this elegant scheme - such as evidence for new, exotic particles - have come to nothing.

At ICHEP [International Conference on High Energy Particles], other scientists are expected to outline details of a refined mass for the fundamental particle, which has been measured at approximately 125 gigaelectronvolts (GeV). For those outside the particle physics community, this might seem like a minor detail. But the mass of the Higgs is more than a mere number.

There's something very curious about its value that could have profound implications for the Universe. Mathematical models allow for the possibility that our cosmos is long-lived yet not entirely stable, and may - at some indeterminate point - be destroyed.
"The overall stability of the Universe depends on the Higgs mass - which is a bit funny," said Prof Jordan Nash, a particle physicist from Imperial College London, who works on the CMS experiment at Cern.
"There's a long theoretical argument which I won't go into, but that value is intriguing in that it sits on the edge between what we think is the long-term stability of the Universe and a Universe that has a finite lifetime."

To use an analogy, imagine the Higgs boson is an object resting at the bottom of a curved slope. If that resting place really is the lowest point on the slope, then the vacuum of space is completely stable - in other words, the Higgs is in the lowest energy state and can go no further.
However, if at some point further along this slope, there's another dip, the potential exists for the Universe to "topple" into this lower energy state, or minimum. If that happens, the vacuum of space collapses, dooming the cosmos. :shock:

"The Higgs mass is in that place where it gets interesting, where it's no longer guaranteed that there are no other minima," Prof Nash, who works on the CMS experiment at Cern, told the BBC. But there's no need to worry, the models suggest such a rare event would not occur for a very, very long time - many times further into the future, in fact, than the current age of the Universe.

This idea of a finite lifetime for the cosmos is dependent on the Standard Model being the ultimate scheme in physics. But there is much in the Universe - gravitation and dark matter, for example - that the Standard Model can't fully explain, so there are reasons to think that's not the case.

The existence of exotic particles, such as those predicted by the theory known as supersymmetry, would shore up the stability of the Universe in those mathematical models.
But as previously mentioned, searches for these particles, called superpartners, have so far drawn a blank, as have attempts to detect dark matter, extra dimensions, and other phenomena beyond the Standard Model. Hopes that the LHC would allow scientists to lift the veil on a whole new realm of physics have proved optimistic, at least during its initial run.

Some versions of supersymmetry have already been all but ruled out by the LHC. But the theory has many forms, depending on how you tweak the mathematical parameters.
"From the theory community's point of view, this is all very interesting because it fleshes out much better what the first run of the LHC has excluded," said Prof Dave Charlton, who leads the Atlas experiment at Cern.
"Therefore, it better establishes where we should be looking for new signals next year."
Assuming the theorists are indeed correct, supersymmetry will have to wait some time longer for its big reveal.

Other hypothesised particles, such as the W prime and Z prime bosons could possibly be detected soon after the LHC returns to particle smashing.
For now, all eyes are on the engineers at Cern....

http://www.bbc.co.uk/news/science-environment-28089987

 

[PeteByrdie]

Fluid Tests Hint at Concrete Quantum Reality

For nearly a century, “reality” has been a murky concept. The laws of quantum physics seem to suggest that particles spend much of their time in a ghostly state, lacking even basic properties such as a definite location and instead existing everywhere and nowhere at once. Only when a particle is measured does it suddenly materialize, appearing to pick its position as if by a roll of the dice.

This idea that nature is inherently probabilistic — that particles have no hard properties, only likelihoods, until they are observed — is directly implied by the standard equations of quantum mechanics. But now a set of surprising experiments with fluids has revived old skepticism about that worldview. The bizarre results are fueling interest in an almost forgotten version of quantum mechanics, one that never gave up the idea of a single, concrete reality.

The experiments involve an oil droplet that bounces along the surface of a liquid. The droplet gently sloshes the liquid with every bounce. At the same time, ripples from past bounces affect its course. The droplet’s interaction with its own ripples, which form what’s known as a pilot wave, causes it to exhibit behaviors previously thought to be peculiar to elementary particles — including behaviors seen as evidence that these particles are spread through space like waves, without any specific location, until they are measured.

Particles at the quantum scale seem to do things that human-scale objects do not do. They can tunnel through barriers, spontaneously arise or annihilate, and occupy discrete energy levels. This new body of research reveals that oil droplets, when guided by pilot waves, also exhibit these quantum-like features.

To some researchers, the experiments suggest that quantum objects are as definite as droplets, and that they too are guided by pilot waves — in this case, fluid-like undulations in space and time. These arguments have injected new life into a deterministic (as opposed to probabilistic) theory of the microscopic world first proposed, and rejected, at the birth of quantum mechanics.

“This is a classical system that exhibits behavior that people previously thought was exclusive to the quantum realm, and we can say why,” said John Bush, a professor of applied mathematics at the Massachusetts Institute of Technology who has led several recent bouncing-droplet experiments. “The more things we understand and can provide a physical rationale for, the more difficult it will be to defend the ‘quantum mechanics is magic’ perspective.”

There's a vast amount of text on the site, far more than is worth pasting here. There are elements of science politics in there. It's hard for those of us who have got used to a quantum universe to accept all that weirdness can be somehow accounted for by fluid dynamics. Really? A century of quantum uncertainty could be obliterated by what appears to be an analogy to the classical physics? For me, exciting and unconvincing, in equal measure.

 

[kamalktk]

I'm sure they're smarter than I am and have considered it, but what about when the surface is infinite in size and the waves aren't bouncing back from the container walls?

 

[rynner2]

Fluid Tests Hint at Concrete Quantum Reality

There's a vast amount of text on the site, far more than is worth pasting here. There are elements of science politics in there. It's hard for those of us who have got used to a quantum universe to accept all that weirdness can be somehow accounted for by fluid dynamics. Really? A century of quantum uncertainty could be obliterated by what appears to be an analogy to the classical physics? For me, exciting and unconvincing, in equal measure.

Thanks for posting that. A good overview of the history of the subject, and how its problems have been dealt with (or swept under the carpet )

It was good to encounter again Einstein's dictum that God does not play dice!", and Bohr's response: "Stop telling God what to do!" 8)

Good too to hear about Bohm again, and his pilot-wave theory. He was once seen as a big name, but has since dwindled into obscurity.

And I didn't know (or had since forgotten) that "Bell supported pilot-wave theory."

There's a vast amount of text on the site, far more than is worth pasting here.

It's all worth posting, though it's length is perhaps beyond the concentration levels of many here. But those interested might like to break it into chunks, read a chunk at a time, and then think about it for a while before tackling the next chunk.

I was always interested in alternative explanations - Copenhagen's "collapse of the wave function" always seemed too undefined and irrational to be satisfactory. I'm glad to hear that people are still exploring alternative views.

 

[PeteByrdie]

I have always been extremely excited by weird quantum wave properties, and will be sad if further research dissipates some of the magic. But it would be satisfying to see quantum theory dragged into the classical physics realm. And I was also pleased to see Bohm's name attached to the pilot-wave idea, rather than it being touted as something new. And also Bohr's much more clever but less often quoted response to Einstein's comment.

As I was typing this, Sheldon Cooper on TV said something like, 'I love quantum physics. It's like looking at the Universe naked.' Just a coincidence, but a fun one.

 

[rynner2]

I was always interested in alternative explanations - Copenhagen's "collapse of the wave function" always seemed too undefined and irrational to be satisfactory. I'm glad to hear that people are still exploring alternative views.

Brian Cox: 'Multiverse' makes sense
[Video: Brian Cox explains the idea that many universes can exist at the same time]

The presenter and physicist Brian Cox says he supports the idea that many universes can exist at the same time.
The idea may sound far-fetched but the "many worlds" concept is the subject of serious debate among physicists.
It is a particular interpretation of quantum mechanics - which describes the often counter-intuitive behaviour of energy and matter at small scales.
Prof Cox made the comments during an interview with Radio 4's The Life Scientific programme.

In a famous thought experiment devised by the Austrian physicist Erwin Schrodinger, a cat sealed inside a box can be both alive and dead at the same time. Or any combination of different probabilities of being both dead and alive.
This is at odds with most common perceptions of the way the world is. And Schrodinger's experiment was designed to illustrate the problems presented by one version of quantum mechanics known as the Copenhagen interpretation.
This proposes that when we observe a system, we force it to make a choice. So, for example, when you open the box with Schrodinger's cat inside, it emerges dead or alive, not both.

But Prof Cox says the many worlds idea offers a sensible alternative.
"That there's an infinite number of universes sounds more complicated than there being one," Prof Cox told the programme.
"But actually, it's a simpler version of quantum mechanics. It's quantum mechanics without wave function collapse... the idea that by observing something you force a system to make a choice."

Accepting the many worlds interpretation of quantum mechanics means also having to accept that things can exist in several states a the same time.
But this leads to a another question: Why do we perceive only one world, not many?
A single digital photograph can be made from many different images superimposed on one another. Perhaps the single reality that we perceive is also multi-layered.

The laws of quantum mechanics describe what happens inside the nucleus of every atom, right down at the level of elementary particles such as quarks, neutrinos, gluons, muons.
The weird and wonderful world of quantum mechanics reveals that nature is at heart probabilistic. Nothing can be predicted with any certainty.

"Everybody agrees about that" says Prof Cox. But where physicists don't agree is about how these facts should be interpreted.
For decades, the Copenhagen interpretation of quantum mechanics, which allows for only one universe, dominated particle physics.

But Brian Cox supports the many worlds interpretation and, he believes, more and more physicists are now subscribing to this view.

http://www.bbc.co.uk/news/science-environment-29321771

 

[rynner2]

A long article on the nature of time, written not by some physicist but by author Will Self! At first I thought of confining this to Pseuds' Corner, but it does cover a lot of ground and thus acts as a primer for those interested in Theories of Everything.

6 March 2015 Last updated at 16:39
A Point of View: To the end of time

Is a point being reached where time is revealed as an illusion, asks Will Self.
"Time present and time past/ Are both perhaps present in time future/ And time future contained in time past./ If all time is eternally present/ All time is unredeemable." The opening lines of TS Eliot's Burnt Norton, the first of his Four Quartets, were written in the 1930s, but while they may be familiar to many of you, I wonder if any of us have really stopped to consider their full import. True, Eliot sounds a speculative note with that "perhaps" in the second line, yet his meaning still seems clear enough - if our perception of time as moving ever forward like a river is purely subjective, and the whole span of time - together with all actual events - has already transpired, then nothing we will ever do or say can alter the future, let alone the past.

The inclination is, I think, to relate Eliot's insight directly to notions of free will, and hence to moral responsibility - the attribution of which is the thing that most preoccupies us in our social existence. However, I don't really want to discuss that but instead focus on time itself, and our conception of it.
The fourth dimension appears so much slipperier to us than the first three - so slippery, indeed, that when we attempt to fix it in our minds it slithers away from our grasp in a faintly nauseating way.

etc, etc...

http://www.bbc.co.uk/news/magazine-31762129

His qualifications for writing this?

"Self was a voracious reader from a young age. At ten he developed an interest in works of science fiction such as Frank Herbert's Dune, J. G. Ballard and Philip K. Dick. Into his teenage years, Self claimed to have been "overawed by the canon", stifling his ability to express himself."

http://en.wikipedia.org/wiki/Will_Self

That's good enough for me!

 

[rynner2]

Horizon: Aftershock - The Hunt for Gravitational Waves

2014-2015, Episode 9
Today on BBC2 from 9:00pm to 10:00pm

Series exploring topical scientific issues. Horizon travels to the South Pole to tell the inside story of one of the greatest scientific quests of our time. In March 2014, a discovery there made headlines around the world, with evidence from the Big Bang itself - ripples in space and time called gravitational waves. In the world of theoretical physics, this was a bombshell. For some it meant Nobel Prizes, while for others, their ideas were in shreds. This is the story of this extraordinary discovery, and what happened when it all began to unravel.

 

[rynner2]

16 March 2015 Last updated at 21:16
Dancing in the dark: The search for the 'missing Universe'
By Peter Leonard BBC Horizon

They say the hardest pieces of music to perform are often the simplest ones. And so it is with science - straightforward questions like "what is the Universe made from?" have so far defeated the brightest minds in physics.
Until - perhaps - now. Next week, the Large Hadron Collider at Cern will be fired up again after a two-year programme of maintenance and upgrading.
When it is, the energy with which it smashes particles will be twice what it was during the LHC's Higgs boson-discovering glory days.

It is anticipated - hoped, even - that this increased capability might finally reveal the identity of "dark matter" - an invisible but critical entity that makes up about a quarter of the Universe.
This is the topic of this week's Horizon programme on BBC Two. [Today, Tuesday, 2100]
Dark matter arrived on most scientists' radar in 1974 thanks to the observations of American astronomer Vera Rubin, who noticed that stars orbiting the gravity-providing black holes at the centre of spiral galaxies like ours did so at the same speed regardless of their distance from the centre.

etc...

http://www.bbc.co.uk/news/science-environment-31912381

 

[rynner2]

Big Bang theory could be debunked by Large Hadron Collider
Scientists at Cern could prove the controversial theory of ‘rainbow gravity’ which suggests that the universe stretches back into time infinitely, with no Big Bang
By Sarah Knapton, Science Editor
10:33AM GMT 23 Mar 2015

The detection of miniature black holes by the Large Hadron Collider could prove the existence of parallel universes and show that the Big Bang did not happen, scientists believe.

The particle accelerator, which will be restarted this week, has already found the Higgs boson – the God Particle – which is thought to give mass to other particles.
Now scientists at Cern in Switzerland believe they might find miniature black holes which would reveal the existence of a parallel universe.

And if the holes are found at a certain energy, it could prove the controversial theory of ‘rainbow gravity’ which suggests that the universe stretches back into time infinitely with no singular point where it started, and no Big Bang.
The theory was postulated to reconcile Einstein’s theory of general relativity – which deals with very large objects, and quantum mechanics – which looks at the tiniest building blocks of the universe. It takes its name from a suggestion that gravity's effect on the cosmos is felt differently by varying wavelengths of light.

The huge amounts of energy needed to make ‘rainbow gravity’ would mean that the early universe was very different. One result would be that if you retrace time backward, the universe gets denser, approaching an infinite density but never quite reaching it.
The effect of rainbow gravity is small for objects like the Earth but it is significant and measurable for black holes. It could be detected by the Large Hadron Collider if it picks up or creates black holes within the accelerator.

etc...

http://www.telegraph.co.uk/news/sci...uld-be-debunked-by-Large-Hadron-Collider.html

My brain hurts...

 

[rynner2]

TV Tonight:

Horizon: Which Universe are We In?
2014-2015, Episode 17
Today on BBC2 HD from 8:00pm to 9:00pm

Imagine a world where dinosaurs still walk the earth. A world where the Germans won World War II and you are President of the United States. Imagine a world where the laws of physics no longer apply and where infinite copies of you are playing out every storyline of your life.

It sounds like a plot stolen straight from Hollywood, but far from it. This is the multiverse. Until very recently the whole idea of the multiverse was dismissed as a fantasy, but now this strangest of ideas is at the cutting edge of science. And for a growing number of scientists, the multiverse is the only way we will ever truly make sense of the world we are in. Horizon asks the question: Do multiple universes exist? And if so, which one are we actually in?

 

[rynner2]

Relativity versus quantum mechanics: the battle for the universe
Physicists have spent decades trying to reconcile two very different theories. But is a winner about to emerge – and transform our understanding of everything from time to gravity?
Corey S Powell
Wednesday 4 November 2015 06.00 GMT

t is the biggest of problems, it is the smallest of problems. At present physicists have two separate rulebooks explaining how nature works. There is general relativity, which beautifully accounts for gravity and all of the things it dominates: orbiting planets, colliding galaxies, the dynamics of the expanding universe as a whole. That’s big. Then there is quantum mechanics, which handles the other three forces – electromagnetism and the two nuclear forces. Quantum theory is extremely adept at describing what happens when a uranium atom decays, or when individual particles of light hit a solar cell. That’s small.

Now for the problem: relativity and quantum mechanics are fundamentally different theories that have different formulations. It is not just a matter of scientific terminology; it is a clash of genuinely incompatible descriptions of reality.

The conflict between the two halves of physics has been brewing for more than a century – sparked by a pair of 1905 papers by Einstein, one outlining relativity and the other introducing the quantum – but recently it has entered an intriguing, unpredictable new phase. Two notable physicists have staked out extreme positions in their camps, conducting experiments that could finally settle which approach is paramount.

Basically you can think of the division between the relativity and quantum systems as “smooth” versus “chunky”. In general relativity, events are continuous and deterministic, meaning that every cause matches up to a specific, local effect. In quantum mechanics, events produced by the interaction of subatomic particles happen in jumps (yes, quantum leaps), with probabilistic rather than definite outcomes. Quantum rules allow connections forbidden by classical physics. This was demonstrated in a much-discussed recent experiment in which Dutch researchers defied the local effect. They showed that two particles – in this case, electrons – could influence each other instantly, even though they were a mile apart. When you try to interpret smooth relativistic laws in a chunky quantum style, or vice versa, things go dreadfully wrong.

Relativity gives nonsensical answers when you try to scale it down to quantum size, eventually descending to infinite values in its description of gravity. Likewise, quantum mechanics runs into serious trouble when you blow it up to cosmic dimensions. Quantum fields carry a certain amount of energy, even in seemingly empty space, and the amount of energy gets bigger as the fields get bigger. According to Einstein, energy and mass are equivalent (that’s the message of E=mc2), so piling up energy is exactly like piling up mass. Go big enough, and the amount of energy in the quantum fields becomes so great that it creates a black hole that causes the universe to fold in on itself. Oops.

Craig Hogan, a theoretical astrophysicist at the University of Chicago and the director of the Center for Particle Astrophysics at Fermilab, is reinterpreting the quantum side with a novel theory in which the quantum units of space itself might be large enough to be studied directly. Meanwhile, Lee Smolin, a founding member of the Perimeter Institute for Theoretical Physics in Waterloo, Canada, is seeking to push physics forward by returning to Einstein’s philosophical roots and extending them in an exciting direction.

To understand what is at stake, look back at the precedents. When Einstein unveiled general relativity, he not only superseded Isaac Newton’s theory of gravity; he also unleashed a new way of looking at physics that led to the modern conception of the Big Bang and black holes, not to mention atomic bombs and the time adjustments essential to your phone’s GPS. Likewise, quantum mechanics did much more than reformulate James Clerk Maxwell’s textbook equations of electricity, magnetism and light. It provided the conceptual tools for the Large Hadron Collider, solar cells, all of modern microelectronics.

What emerges from the dust-up could be nothing less than a third revolution in modern physics, with staggering implications. It could tell us where the laws of nature came from, and whether the cosmos is built on uncertainty or whether it is fundamentally deterministic, with every event linked definitively to a cause.

etc... (very long article)

http://www.theguardian.com/news/2015/nov/04/relativity-quantum-mechanics-universe-physicists

I could go through the rest of this and cherry-pick a few quotes, but it's probably best if you set aside the time to read it all for yourself. It's clearly written, and involves no maths, so it's not hard work, and it'll surely reinforce the view that we live in an amazing universe! Enjoy!

 

[Mystereaux1]

I've no idea where this belongs, but there may well be a place somewhere. Mods will help, I expect.

"An astrophysicist says he may have found evidence of alternate or parallel universes by looking back in time to just after the Big Bang more than 13 billion years ago.

While mapping the so-called "cosmic microwave background," which is the light left over from the early universe, scientist Ranga-Ram Chary found what he called a mysterious glow, the International Business Times reported.

Chary, a researcher at the European Space Agency's Planck Space Telescope data center at CalTech, said the glow could be due to matter from a neighboring universe "leaking" into ours, according to New Scientist magazine.

"Our universe may simply be a region within an eternally inflating super-region," scientist Chary wrote in a recent study in the Astrophysical Journal.

"Many other regions beyond our observable universe would exist with each such region governed by a different set of physical parameters than the ones we have measured for our universe," Chary wrote in the study."

http://www.usatoday.com/story/tech/sciencefair/2015/11/03/alternate-universes-discovered/75102502/

 

[rynner2]

Will this European satellite confirm Einstein’s last unproven idea?
The Lisa Pathfinder will test equipment for an orbiting observatory that will peer into the universe’s darkest corners
Robin McKie
Last modified on Sunday 22 November 2015 00.26 GMT

It was perhaps the greatest scientific achievement of the 20th century. And next week space scientists will celebrate the 100th anniversary of the publication of Albert Einstein’s theory of general relativity in fitting style – by launching a probe to help demonstrate the accuracy of the theory’s last unproven prediction: the existence of gravitational waves.

At 4.15am on 2 December, the satellite, known as Lisa Pathfinder, is scheduled to be blasted into orbit from the European Space Agency’s centre in Kourou, French Guiana. It will carry equipment that will be tested as components for a future orbiting gravitational wave observatory.

“The theory of general relativity is the scientific equivalent of Michelangelo’s Sistine Chapel,” said Pedro Ferreira, professor of astrophysics at Oxford University. “Both are unique works of genius and each could only have been done by one individual. And it is quite stunning that the Lisa Pathfinder satellite – which is designed to help find gravitational waves whose existence is predicted by the theory – is going to be launched on the exact anniversary of the publication of Einstein’s work.”

Gravitational waves are thought to be hurled across space when stars start throwing their weight around, for example, when they collapse into black holes or when pairs of super-dense neutron stars start to spin closer and closer to each other. These processes put massive strains on the fabric of space-time, pushing and stretching it so that ripples of gravitational energy radiate across the universe. These are gravitational waves.
Observations by US astronomers Joseph Taylor and Russell Hulse in the 1980s provided key supporting evidence of their existence. The pair showed that a neutron star, now known as the Hulse-Taylor pulsar, was part of a binary system whose orbit was decaying at a rate consistent with it pumping out gravitational waves. This work won Hulse and Taylor the 1993 Nobel prize in physics.

Since then, physicists have tried to spot gravitational waves directly, using ground-based devices with a common design: two long arms, set at right angles to each other, extending from a central point.
When a gravitational wave strikes, it should temporarily shrink one arm and slightly extend the other. That change can then be measured – albeit with considerable difficulty, because any change induced in an arm’s length by a gravitational wave will only be a few hundred billion-billionths of a metre.

So far, researchers have yet to detect such changes. Once they do, one of the final hurdles to a complete understanding of the makeup of our universe will have been achieved. However, they are now extending their efforts to space because, in orbit, it should be possible to fly detectors that are 5 million kilometres apart and which will be better able to spot the compressing and stretching of space-time.

etc...

http://www.theguardian.com/science/2015/nov/21/satellite-to-solve-einstein-last-theory

 

[rynner2]

A huge leap towards a theory of everything took place in the 19th century, with Maxwell's Equations of the electromagnetic field:
What are Maxwell's Equations?
How a Scottish physicist formulated the equations that showed us how to electrify the world
Alok Jha
Sunday 15 September 2013 09.01 BST

Maxwell's Equations first appeared in "A dynamical theory of the electromagnetic field", Philosophical Transactions of the Royal Society of London, in 1865. These are the equations of light, the mathematical relationships that showed us how to electrify our world and transmit energy and information through the air.
At the start of the 19th century, we lit our homes and offices with candles and oil lamps. Communications took the form of handwritten letters that took days to travel across the country, and several weeks across oceans. Today we use electricity to power everything and radio waves to talk to each other, anywhere around the world, instantaneously.

The seeds of that enormous change were planted in the 1830s, when the British physicist Michael Faraday built electric motors and showed that two natural forces, electricity and magnetism, were related. He proposed that these forces existed as "fields" that permeated space. In the latter half of the 19th century, the Scottish physicist James Clerk Maxwell formulated the equations that described these fields.

Maxwell modelled the fields as if they were invisible fluids that filled space. At each point in space, the electric field has a direction and a strength that can be measured if you put something there that can feel the effects of the field – an electron, say. If you could somehow measure the field at every point in space, you would know how it flowed and changed.

The two equations on the left in the picture show that the net flow of electric (E) and magnetic (H) field out of a closed volume of space, away from any electrical charges or magnetic materials, is zero. The triangle and dot symbol in front of the field symbols (called the "divergence" operator) is a mathematical way to measure if a field behaves as a source or a sink at a specific point in space.

The equation for the magnetic field (H) stays the same even when there's a magnet around – think of a bar magnet, the magnetic field lines around it start at the north pole and circle their way around to the south pole. And these field lines will always stop and start at a magnetic object, they do not appear or disappear in empty space.

The equation for the electrical field (E) is slightly different, though, when there are electrical charges around. A positive charge is a net source of electric fields and a negative charge is a sink. In that case, the net amount of field coming out of or into a volume is proportional to the charge contained within it.

The two equations on the right explain what happens when you move an electrical or magnetic field. The "curl" operator (the triangle and x symbol in combination) on the left of each equation is a way to measure a field moving in a tiny circle. A changing electric field (E) produces a changing magnetic field (H). And vice versa. The curly d/dts on the right measure a rate of change, a tiny change in a field (E or H) divided by a tiny change in time (t).

These equations are the basis of electromagnetic induction, the idea that if you move a magnet near an electrical conductor (or vice versa), you generate electricity. The electricity you use every day is made like this, using generators that work according to these equations.

Which leaves us with the letter "c" on the right side of the second two equations. This is a constant with a value of about 300,000 kilometres per second, which just happens to be the speed of light.
Bear in mind Maxwell did not put this in there because he was studying light; the number just popped out, unexpectedly, from the mathematics of the materials he was studying.

Maxwell had started by examining the properties of electricity and magnetism and stumbled upon a much deeper truth about them: the electromagnetic field was a medium for waves that, like ripples across the surface of a pond, travelled at a speed "c". And the light we see is one of those electromagnetic waves.

That meant there should be other electromagnetic waves. The wavelengths we can detect with our eyes appear to us as colours. Shorter wavelengths of light include UV and gamma rays.
Longer wavelengths include heat (infra-red waves), microwaves and radio waves. The latter, of course, are the communications method of the 20th century – everything from radios to televisions to radar to mobile phones are based on our manipulation of the electromagnetic field, as described by Maxwell's equations.

http://www.theguardian.com/science/2013/sep/15/maxwells-equations-electrify-world

More on Maxwell's life and work is here:
James Clerk Maxwell: Scotland’s forgotten Einstein

"I never try to dissuade a man from trying an experiment. If he does not find what he wants, he may find out something else."
James Clerk Maxwell

Maxwell's legacy
Alan Wilson

In 1905 Albert Einstein said his theory of relativity owed its origins to Maxwell’s equations. So why aren’t we more aware of James Clark Maxwell?

His ideas were complicated and ahead of the time, often unappreciated until many years after they were introduced. His short life was packed with incredible achievements in a variety of scientific areas, but he was a humble man not prone to self-promotion. All these factors have clouded his fame but there is a growing movement to give greater acclaim to this modest yet hugely influential Scotsman.

http://www.bbc.co.uk/timelines/zyp34j6

 

[rynner2]

One of the earliest attempts at a theory of everything was the science of Thermodynamics. It was a fusion of physics and engineering - but the introduction of the concept of Entropy took it far beyond designing better steam engines and out into the depths of Space and Time.

All this is covered in another of the BBC's excellent illustrated Guides:

How will the Universe end?
http://www.bbc.co.uk/guides/zwtj2hv#zc79d2p

(But there are some nice steam train pictures before we reach the end of the universe. )

 

[rynner2]

The ultra-violent origins of gold
It seems supernova aren’t enough. Nature has an even more extreme way of making heavy elements. And we may be on the point of observing the distortions of space-time caused in the process
Jon Butterworth
Saturday 16 January 2016 15.27 GMT

As far as we can tell, the age of the Universe is about 13.82 billion years, and that of the Solar system is about 4.6 billion. The Sun is not one of the first generation of stars born in the universe.

The hot, dense moments after the Big Bang produced protons, and a few small clumps of at most seven protons and neutrons bound together - that is, the elements hydrogen, helium and a tiny bit of lithium. These elements came together under gravity, ignited under their own pressure as fusion reactors – the first generation of stars – and produced the heavier elements. The heaviest elements were produced in the final stages of the stars’ life, as they ran short of helium and hydrogen and eventually exploded, distributing oxygen, carbon, silicon and the rest into space. Eventually some of that condensed again, with more hydrogen and helium, forming not just the next generation of stars, but also planets and, on at least one of them, life.

All the above is ‘common knowledge’, albeit of the somewhat jaw-dropping variety. But there is more, it turns out.
In December I was at a meeting organised by Durham University at the Royal Society, celebrating the 50th anniversary of the discovery¹ of atmospheric neutrinos. Talking with two Durham colleagues over drinks afterwards about a new ‘Saturday Morning Physics’ programme they are running, Prof Paula Chadwick described how, in preparing for her talk to school children, she had learned something astonishing.

Paula is a world expert in astronomy using gamma-rays – very high-energy packets of light. But when giving a public talk, you don’t usually just talk about your speciality, you broaden out a bit. In this case she was going to talk about how stars are born and how they die, how we know about that, and what the consequences are. She’d talked about this before, including the story in my first two paragraphs of how the heavier elements are made. But she thought she would just do some reading to make sure she had the details right. She discovered that things had moved on.

There’s a problem with making heavy elements in stars. Stars burn because fusing light elements together releases energy. But this only works as far as nickel and iron, with 56 or so protons and neutrons. To get heavier elements than those – such as gold, for example, with nearly 200 protons and neutrons – energy has to be put in. This is understood in terms of the balance of the forces which hold nuclei together, and it is the reason that nuclear power stations can release energy by breaking up heavy elements – fission – while stars (and terrestrial fusion reactors, if we ever work out how to build them) release energy by fusing them together. Both are moving along the energy curve toward iron and nickel. If you want to do anything to change iron or nickel – fission or fusion – you have to put energy in.

This all means that in ‘normal operation’, stars won’t make anything heavier than iron. Heavy elements can, however, be made in the maelstrom of a supernova, when a star finally explodes and there is so much energy around that zooming up the nuclear energy curve is no problem. But it turns out there’s another way, which is probably more important. That’s what Paula read about during her preparation.

Of the many weird things going on in space, gamma ray bursts are one of the weirder. These are short bursts of high-energy photons² which are detected fairly frequently and come from beyond our galaxy. The best guess as to their cause is the merging (that is, catastrophic ultra-violent collision) of two neutron stars.

Neutron stars are the superdense leftovers of supernovae. Quite recently, astronomers working with the Hubble Space Telescope zoomed in on a gamma ray burst detected by the Swift satellite, and spotted an infrared afterglow – essentially a hot dot, in the place where the burst had occurred.

Studying the pattern of this radiation – the wavelength and brightness, and how they changed over time – fitted the “neutron star” hypothesis very well. It also implied that in the process of these collisions, heavy elements were being made. In fact, if the estimates of the masses involved and the rate of these events are right, they are the main source of heavy elements. Including gold, platinum and uranium.

This means that by breaking up uranium, nuclear power stations are releasing energy that was stored in neutron star collisions billions of years ago. It also makes me look at my wedding ring with a new sense of wonder. It was probably made in a neutron star collision. Hmm.


The study of those observations by Swift and Hubble was released in 2013, and there is a good article with some more detail here. But there is more recent news too, or at least rumour.

In order to actually collide and fuse together, a pair of orbiting neutron stars has to get rid of the energy and momentum of the rotation. They do this, according to general relativity, by radiating gravitational waves. These waves, distortions in space-time, have never been directly observed, but they are the same gravitational waves about which rumours are currently flying. Whether or not these particular rumours stand up, we may soon see the emissions from nature’s ultra-violent gold factories.

http://www.theguardian.com/science/life-and-physics/2016/jan/16/the-ultra-violent-origins-of-gold

 

[rynner2]

A huge leap towards a theory of everything took place in the 19th century, with Maxwell's Equations of the electromagnetic field:
What are Maxwell's Equations?
How a Scottish physicist formulated the equations that showed us how to electrify the world
etc...

http://www.theguardian.com/science/2013/sep/15/maxwells-equations-electrify-world

Tonight on TV: 9pm - 10pm BBC Four

James Clerk Maxwell: The Man Who Changed the World

Professor Iain Stewart reveals the story behind James Clerk Maxwell, the Scottish physicist who has been dubbed as `Scotland's Einstein'. Despite his discoveries causing a revolution in physics and shaping the modern world, Maxwell is largely unknown outside his native land. Iain sets out to change that by celebrating his life, work and legacy, 150 years after his greatest work was published.

http://www.radiotimes.com/episode/dvyx58/james-clerk-maxwell-the-man-who-changed-the-world

 

[rynner2]

Watch this spacetime: gravitational wave discovery expected
For decades signs of gravitational waves have been sought without success. On Thursday, scientists believe the first clear evidence will be revealed
Ian Sample Science editor
Tuesday 9 February 2016 15.59 GMT

A decades-long search for gravitational waves is expected to end in triumph this week when scientists declare they have discovered ripples in the fabric of spacetime, possibly created by the collision of two massive black holes travelling at close to the speed of light.

First predicted by Einstein, and generated by the most cataclysmic events in the cosmos, gravitational waves stretch and squeeze space and all within it as they spread out across the universe. Their discovery, if confirmed, is certain to earn a Nobel prize. Scientists have hunted for signs of the waves for decades, but until now, their attempts have been frustrated by false signals and instruments that were not sensitive enough to detect the waves by the time they reached Earth.

A decades-long search for gravitational waves is expected to end in triumph this week when scientists declare they have discovered ripples in the fabric of spacetime, possibly created by the collision of two massive black holes travelling at close to the speed of light.

That is expected to change on Thursday, when physicists in the US reveal their latest data from an experiment known as LIGO, or the Advanced Laser Interferometer Gravitational-Wave Observatory. The team have detectors in Washington and Louisiana that can spot passing gravitational waves via the minuscule changes in length they produce in two 4km-long pipes.

At a press conference in Washington, LIGO scientists are anticipated to reveal a clear, unambiguous gravitational wave signal. It may have come from two vast black holes, one 29 times more massive than the sun, the other 36 times more massive, spiralling around each other and finally crashing together to form a new black hole 62 times the mass of the sun. For all its heft, the new body may be no more than 200 miles wide.
The missing mass - equivalent to that of three suns, or six trillion trillion kilotonnes - was converted into energy and released as the gravitational waves LIGO is believed to have detected.

“People are hugely excited. The rumour is that it’s a whopping big signal, in other words, it’s unambiguous, and that is fantastic,” said Pedro Ferreira, professor of astrophysics at Oxford University, and author of the 2014 book, The Perfect Theory: a century of geniuses and the battle over general relativity.

When Einstein published his theory of general relativity in 1915, he changed forever how scientists view the universe. The theory showed that mass makes spacetime curve, an effect that has a multitude of implications. One, that light from distant stars will bend around the sun, was confirmed by Arthur Eddington during the solar eclipse of 1919.

The detection of gravitational waves would tick off the last major prediction of general relativity. It would demonstrate that the equations drawn up by Einstein, who refused to believe in black holes himself, hold true in what ranks as the most extreme realm of physics.

But there is more to the discovery of gravitational waves than simply proving they exist. If the LIGO signal is as strong as rumours suggest, new instruments could be built to detect gravity waves from colliding black holes and other hugely energetic events all over the universe.

“It would be like having a telescope that, instead of looking at objects in the electromagnetic spectrum, is looking at them with gravitational waves,” said Ferreira. “We could see things in a completely different way. It would be very blurred vision - gravitational waves are not good at pinpointing objects - but they would help us understand what happens when black holes fall into one another.”
“The fact is whenever we’ve looked at the universe in new ways, with x-rays, with radio waves, we’ve discovered incredible stuff, exotica. So this is going to open up a new window, and for sure we’ll discover bizarre stuff,” he added.


Rumours that the LIGO team had detected gravitational waves have been circulating in the astrophysics community for months. But many researchers were sceptical and feared the rumours might have been sparked by synthetic signals which are added to the data to test the team’s analytical procedures.

“After all the rumours over the past few months I certainly expect them to announce a detection at this point,” said Alberto Sesana, a researcher at the University of Birmingham’s Gravitational Wave Group. “We have to bear in mind that LIGO is one experiment and the only one that can detect such sources. If they claim to have detected gravitational waves, it cannot be confirmed by another instrument, and that is always an issue. But they have been very cautious in doing this properly. I’m confident they have clear and strong evidence for it.”

There is a chance a signal will be announced from another source, such as a pair of neutron stars spinning around one another, or a neutron star falling into a black hole. But such cosmic events would be expected to produce weaker signals than the large spike scientists anticipate the LIGO team to reveal.

Scientists have declared the discovery of gravitational waves before only to have their hopes dashed. In 2014, researchers on an experiment called Bicep2 claimed to have found evidence for gravitational waves from the big bang, but further analysis by other groups showed that the signals they picked up could be entirely explained by space dust interfering with their measurements.

Ulrich Sperhake, a theorist at Cambridge University who studies how gravitational waves are generated by black holes, said the community was very excited and expectant. “ I don’t know anyone in the field who expects anything other than a detection to be announced,” he said. “Anything but the onset of a new era in observational gravitational astronomy would come as a major surprise on Thursday, but there remains a tiny speculative element to it until we’ll have the official LIGO announcement.”

Martin Hendry, a member of the LIGO team at Glasgow University, would not be drawn on the details of Thursday’s announcement. “I can’t say anything more at this stage than wait and see. Or should that be “watch this spacetime?” he said.

https://www.theguardian.com/science...acetime-gravitational-wave-discovery-expected

 

[rynner2]

Live online:
Anticipation mounts ahead of gravitational wave announcement - live
Is physics about to change forever? All the latest news and reaction on today’s anticipated announcement from the Ligo observatories

https://www.theguardian.com/science...latest-physics-einstein-ligo-black-holes-live

Starts 1530 GMT


EDIT 1730: Well, not much that hadn't already been telegraphed in the media, but this may prove more interesting:

The Perimeter Institute for Theoretical Physics, Ontario, Canada, will be hosting a live panel at 18:00 GMT to discuss the implications of today’s discovery. We’ll be webcasting that too so stay tuned!

 

[Mythopoeika]

Whoa.
Amazing discovery!

 

[kamalktk]

Kip Thorne looks like he is practically crying in joy.

 

[rynner2]

Beeb report (highlights)
Einstein's gravitational waves 'seen' from black holes
By Pallab Ghosh Science correspondent, BBC News

Scientists are claiming a stunning discovery in their quest to fully understand gravity.
They have observed the warping of space-time generated by the collision of two black holes more than a billion light-years from Earth.
The international team says the first detection of these gravitational waves will usher in a new era for astronomy.
It is the culmination of decades of searching and could ultimately offer a window on the Big Bang.

The research, by the Ligo Collaboration, has been published today in the journal Physical Review Letters.
...

"We have detected gravitational waves," David Reitze, executive director of the Ligo project, told journalists at a news conference in Washington DC.
"It's the first time the Universe has spoken to us through gravitational waves. Up until now, we've been deaf."

Prof Karsten Danzmann, from the Max Planck Institute for Gravitational Physics and Leibniz University in Hannover, Germany, is a European leader on the collaboration.
He said the detection was one of the most important developments in science since the discovery of the Higgs particle, and on a par with the determination of the structure of DNA.
"There is a Nobel Prize in it - there is no doubt," he told the BBC.
"It is the first ever direct detection of gravitational waves; it's the first ever direct detection of black holes and it is a confirmation of General Relativity because the property of these black holes agrees exactly with what Einstein predicted almost exactly 100 years ago."
...
That view was reinforced by Professor Stephen Hawking, who is an expert on black holes. Speaking exclusively to BBC News he said he believed that the detection marked a moment in scientific history.
"Gravitational waves provide a completely new way at looking at the Universe. The ability to detect them has the potential to revolutionise astronomy. This discovery is the first detection of a black hole binary system and the first observation of black holes merging," he said.

"Apart from testing (Albert Einstein's theory of) General Relativity, we could hope to see black holes through the history of the Universe. We may even see relics of the very early Universe during the Big Bang at some of the most extreme energies possible."
...
Prof Sheila Rowan, who is one of the lead UK researchers involved in the project, said that the first detection of gravitational waves was just the start of a "terrifically exciting" journey.

"The fact that we are sitting here on Earth feeling the actual fabric of the Universe stretch and compress slightly due to the merger of black holes that occurred just over a billion years ago - I think that's phenomenal. It's amazing that when we first turned on our detectors, the Universe was ready and waiting to say 'hello'," the Glasgow University scientist told the BBC.
...
"Gravitational waves go through everything. They are hardly affected by what they pass through, and that means that they are perfect messengers," said Prof Bernard Schutz, from Cardiff University, UK.
"The information carried on the gravitational wave is exactly the same as when the system sent it out; and that is unusual in astronomy. We can't see light from whole regions of our own galaxy because of the dust that is in the way, and we can't see the early part of the Big Bang because the Universe was opaque to light earlier than a certain time.
"With gravitational waves, we do expect eventually to see the Big Bang itself," he told the BBC.

etc...

http://www.bbc.co.uk/news/science-environment-35524440

More, plus diags and videos, on page.

 

[rynner2]

This is possibly the greatest scientific advance I will witness in my lifetime. I arrived too late to follow the work in quantum physics that led to nuclear theory and atomic power. (Even the A-bombs on Japan were just before my time).

Einstein's theory of General Relativity (which ultimately led to the ideas of Black Holes and Gravity Waves) came thirty years before my birth!

I did follow the early years of radio astronomy that rapidly developed after WWII. Pulsars and quasars were discovered, and the Big Bang theory displaced the continuous creation theory.

Perhaps one other big scientific discovery that did happen in my lifetime was the structure of DNA
( https://en.wikipedia.org/wiki/Molec...ids:_A_Structure_for_Deoxyribose_Nucleic_Acid ).
This simplified many problems in biology, and also gave a solid scientific basis for Darwin's theory of evolution.

There have of course been many other scientific and technological discoveries in my lifetime, but I can't at the moment think of any others that are so wide-ranging and powerful in their impact as to qualify as Theories of Everything.