Smithsonian - What Is the Universe? Real Physics Has Some Mind-Bending Answers

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What Is the Universe? Real Physics Has Some Mind-Bending Answers

Science says the universe could be a hologram, a computer program, a black hole or a bubble—and there are ways to check

By Victoria Jaggard
smithsonian.com
September 15, 2014

The questions are as big as the universe and (almost) as old as time: Where did I come from, and why am I here? That may sound like a query for a philosopher, but if you crave a more scientific response, try asking a cosmologist.

This branch of physics is hard at work trying to decode the nature of reality by matching mathematical theories with a bevy of evidence. Today most cosmologists think that the universe was created during the big bang about 13.8 billion years ago, and it is expanding at an ever-increasing rate. The cosmos is woven into a fabric we call space-time, which is embroidered with a cosmic web of brilliant galaxies and invisible dark matter.

It sounds a little strange, but piles of pictures, experimental data and models compiled over decades can back up this description. And as new information gets added to the picture, cosmologists are considering even wilder ways to describe the universe—including some outlandish proposals that are nevertheless rooted in solid science:

Will this collection of lasers and mirrors prove the universe is a 2D hologram? (Fermilab)

The universe is a hologram

Look at a standard hologram, printed on a 2D surface, and you’ll see a 3D projection of the image. Decrease the size of the individual dots that make up the image, and the hologram gets sharper. In the 1990s, physicists realized that something like this could be happening with our universe.

Classical physics describes the fabric of space-time as a four-dimensional structure, with three dimensions of space and one of time. Einstein’s theory of general relativity says that, at its most basic level, this fabric should be smooth and continuous. But that was before quantum mechanics leapt onto the scene. While relativity is great at describing the universe on visible scales, quantum physics tells us all about the way things work on the level of atoms and subatomic particles. According to quantum theories, if you examine the fabric of space-time close enough, it should be made of teeny-tiny grains of information, each a hundred billion billion times smaller than a proton.

Stanford physicist Leonard Susskind and Nobel prize winner Gerard ‘t Hooft have each presented calculations showing what happens when you try to combine quantum and relativistic descriptions of space-time. They found that, mathematically speaking, the fabric should be a 2D surface, and the grains should act like the dots in a vast cosmic image, defining the “resolution” of our 3D universe. Quantum mechanics also tells us that these grains should experience random jitters that might occasionally blur the projection and thus be detectable. Last month, physicists at the U.S. Department of Energy’s Fermi National Accelerator Laboratory started collecting data with a highly sensitive arrangement of lasers and mirrors called the Holometer. This instrument is finely tuned to pick up miniscule motion in space-time and reveal whether it is in fact grainy at the smallest scale. The experiment should gather data for at least a year, so we may know soon enough if we’re living in a hologram.

The universe is a computer simulation

Just like the plot of the Matrix, you may be living in a highly advanced computer program and not even know it. Some version of this thinking has been debated since long before Keanu uttered his first “whoa”. Plato wondered if the world as we perceive it is an illusion, and modern mathematicians grapple with the reason math is universal—why is it that no matter when or where you look, 2 + 2 must always equal 4? Maybe because that is a fundamental part of the way the universe was coded.

In 2012, physicists at the University of Washington in Seattle said that if we do live in a digital simulation, there might be a way to find out. Standard computer models are based on a 3D grid, and sometimes the grid itself generates specific anomalies in the data. If the universe is a vast grid, the motions and distributions of high-energy particles called cosmic rays may reveal similar anomalies—a glitch in the Matrix—and give us a peek at the grid’s structure. A 2013 paper by MIT engineer Seth Lloyd builds the case for an intriguing spin on the concept: If space-time is made of quantum bits, the universe must be one giant quantum computer. Of course, both notions raise a troubling quandary: If the universe is a computer program, who or what wrote the code?

An active supermassive black hole at the core of the Centaurus A galaxy blasts jets of radiation into space. (ESO/WFI (visible); MPIfR/ESO/APEX/A.Weiss et al. (microwave); NASA/CXC/CfA/R.Kraft et al. (X-ray))

The universe is a black hole

Any “Astronomy 101” book will tell you that the universe burst into being during the big bang. But what existed before that point, and what triggered the explosion? A 2010 paper by Nikodem Poplawski, then at Indiana University, made the case that our universe was forged inside a really big black hole.

While Stephen Hawking keeps changing his mind, the popular definition of a black hole is a region of space-time so dense that, past a certain point, nothing can escape its gravitational pull. Black holes are born when dense packets of matter collapse in on themselves, such as during the deaths of especially hefty stars. Some versions of the equations that describe black holes go on to say that the compressed matter does not fully collapse into a point—or singularity—but instead bounces back, spewing out hot, scrambled matter.

Poplawski crunched the numbers and found that observations of the shape and composition of the universe match the mathematical picture of a black hole being born. The initial collapse would equal the big bang, and everything in and around us would be made from the cooled, rearranged components of that scrambled matter. Even better, the theory suggests that all the black holes in our universe may themselves be the gateways to alternate realities. So how do we test it? This model is based on black holes that spin, because that rotation is part of what prevents the original matter from fully collapsing. Poplawski says we should be able to see an echo of the spin inherited from our “parent” black hole in surveys of galaxies, with vast clusters moving in a slight, but potentially detectable, preferred direction.

The universe is a bubble in an ocean of universes

Another cosmic puzzle comes up when you consider what happened in the first slivers of a second after the big bang. Maps of relic light emitted shortly after the universe was born tell us that baby space-time grew exponentially in the blink of an eye before settling into a more sedate rate of expansion. This process, called inflation, is pretty popular among cosmologists, and it got a further boost this year with the potential (but still unconfirmed) discovery of ripples in space-time called gravitational waves, which would have been products of the rapid growth spurt.

If inflation is confirmed, some theorists would argue that we must live in a frothy sea of multiple universes. Some of the earliest models of inflation say that before the big bang, space-time contained what’s known as a false vacuum, a high-energy field devoid of matter and radiation that is inherently unstable. To reach a stable state, the vacuum began to bubble like a pot of boiling water. With each bubble, a new universe was born, giving rise to an endless multiverse.

The trouble with testing this idea is that the cosmos is ridiculously huge—the observable universe stretches for about 46 billion light years in all directions—and even our best telescopes can’t hope to peer at the surface of a bubble this big. One option, then, is to look for any evidence of our bubble universe colliding with another. Today our best maps of the big bang’s relic light do show an unusual cold spot in the sky that could be a “bruise” from bumping into a cosmic neighbor. Or it could be a statistical fluke. So a team of researchers led by Carroll Wainwright at the University of California, Santa Cruz, has been running computer models to figure out what other sorts of traces a bubbly collision would leave in the big bang’s echo.

What? You mean we may not live in a multiverse?

Be that as it may, this is a brief but interesting article from Live Science.

How Would Humans Know If They Lived in a Multiverse?

By Tanya Lewis, Staff Writer | June 02, 2014


Our universe may be one of many, physicists say.
Credit: Shutterstock/Victor Habbick
Some theories in physics give rise to the idea of multiple universes, where nearly identical versions of the known universe exist. But if such a multiverse does exist, how would people know, and what would it mean for humanity?

There may be ways to find out if the known universe is one of many, said Brian Greene, a theoretical physicist and author at Columbia University in New York.

"There are certain versions of the multiverse that, should they be correct, might be most susceptible to confirmation," Greene told Live Science. [5 Reasons We May Live in a Multiverse]

Spotting a multiverse

For example, in the multiverse suggested by string theory, a model that says the universe is composed of one-dimensional strings, the known universe might exist on a giant 3D membrane, Greene told Live Science.

In such a world, "if the universe is a loaf of bread, everything we know about takes place on one slice," he said. Conceivably, debris from collisions that migrated off our slice into the wider cosmos might leave missing energy signatures, which a particle accelerator like the Large Hadron Collider at CERN might be able to detect, Greene said.

Some theories of inflation, the notion that the universe expanded rapidly in the first fractions of a second after the Big Bang, suggest another kind of multiverse. The Big Bang could be one of many big bangs, each giving rise to its own universe — a cosmic bubble in a sea of other bubbles.

In such a scenario, the known universe might collide with another one, which might leave an imprint on the cosmic microwave background, the radiation signature left over from the Big Bang, Greene said.

Greene stressed that all of these notions are highly speculative — "There's reason to take the ideas seriously, but they are far from science fact," he said.

Is free will dead?

But if a multiverse does exist, it could have some wacky consequences. A world with an infinite number of universes would virtually ensure that conditions in one universe would repeat in another, Greene said. In other words, there would almost certainly be another version of you reading this article, written by another version of me.

In such a multiverse, you might decide to read the article in one universe and not read it in another. What would that mean for the notion of free will?

Perhaps it's a moot point. "I think free will bit the dust long before multiverse theory," Greene said.

Scientific equations describe the particles that make up all matter, including humans, Greene said. While more-complex structures arise that have no relevance to a single particle — temperature, for instance — everything still has a "fundamental microphysical underpinning," he said.

That means free will is merely a human sensation, not actual control.

"When I move my teapot, that sensation is absolutely real," Green said. "But that's all it is. It's a sensation."

Maybe in another universe, there's a Brian Greene that believes in free will.

Follow Tanya Lewis on Twitter and Google+. Follow us @livescience, Facebook & Google+. Original article on Live Science.

Scientists Detect A Particle That Could Be A New Form Of Matter (the Tetraquark)

This was posted on io9 this morning, and it comes originally from Universe Today. Researchers at the

Large Hadron Collider have discovered a new particle that may be the theoretical tetraquark, and its discovery would mean that of a new form of matter. It also the raises a lot of new possibilities, including the "quark star," for both physics and cosmology.

"Very simply, the traditional model of a neutron star is that it is made of neutrons. Neutrons consist of three quarks (two down and one up), but it is generally thought that particle interactions within a neutron star are interactions between neutrons. With the existence of tetraquarks, it is possible for neutrons within the core to interact strongly enough to create tetraquarks. This could even lead to the production of pentaquarks and hexaquarks, or even that quarks could interact individually without being bound into color neutral particles. This would produce a hypothetical object known as a quark star."

Very cool stuff.

Scientists Detect A Particle That Could Be A New Form Of Matter

Brian Koberlein — Universe Today

Physicists working at the Large Hadron Collider have spotted a long sought-after exotic particle that's the strongest evidence yet for a new form of matter called a tetraquark. Here's what the discovery could mean to astrophysics.

Above: A neutron star. Credit: Casey Reed/Penn State University.

You may have heard that CERN announced the discovery of a strange particle known as Z(4430). A paper summarizing the results has been published on the physics arxiv, which is a repository for preprint (not yet peer reviewed) physics papers.

The new particle is about four times more massive than a proton, has a negative charge, and appears to be a theoretical particle known as a tetraquark. The results are still young, but if this discovery holds up it could have implications for our understanding of neutron stars.

Image: Chandra.

A Horse Of A Different Color

The building blocks of matter are made of leptons (such as the electron and neutrinos) and quarks (which make up protons, neutrons, and other particles). Quarks are very different from other particles in that they have an electric charge that is 1/3 or 2/3 that of the electron and proton. They also possess a different kind of "charge" known as color. Just as electric charges interact through an electromagnetic force, color charges interact through the strong nuclear force. It is the color charge of quarks that works to hold the nuclei of atoms together. Color charge is much more complex than electric charge. With electric charge there is simply positive (+) and its opposite, negative (-). With color, there are three types (red, green, and blue) and their opposites (anti-red, anti-green, and anti-blue).

Because of the way the strong force works, we can never observe a free quark. The strong force requires that quarks always group together to form a particle that is color neutral. For example, a proton consists of three quarks (two up and one down), where each quark is a different color. With visible light, adding red, green and blue light gives you white light, which is colorless. In the same way, combining a red, green and blue quark gives you a particle which is color neutral. This similarity to the color properties of light is why quark charge is named after colors.
The Tetraquark

Combining a quark of each color into groups of three is one way to create a color neutral particle, and these are known as baryons. Protons and neutrons are the most common baryons. Another way to combine quarks is to pair a quark of a particular color with a quark of its anti-color. For example, a green quark and an anti-green quark could combine to form a color neutral particle. These two-quark particles are known as mesons, and were first discovered in 1947. For example, the positively charged pion consists of an up quark and an antiparticle down quark.

Under the rules of the strong force, there are other ways quarks could combine to form a neutral particle. One of these, the tetraquark, combines four quarks, where two particles have a particular color and the other two have the corresponding anti-colors. Others, such as the pentaquark (3 colors + a color anti-color pair) and the hexaquark (3 colors + 3 anti-colors) have been proposed. But so far all of these have been hypothetical. While such particles would be color neutral, it is also possible that they aren't stable and would simply decay into baryons and mesons.

The Quark Star

There has been some experimental hints of tetraquarks, but this latest result is the strongest evidence of four quarks forming a color neutral particle. This means that quarks can combine in much more complex ways than we originally expected, and this has implications for the internal structure of neutron stars.

ESO/Luís Calçada.

Very simply, the traditional model of a neutron star is that it is made of neutrons. Neutrons consist of three quarks (two down and one up), but it is generally thought that particle interactions within a neutron star are interactions between neutrons. With the existence of tetraquarks, it is possible for neutrons within the core to interact strongly enough to create tetraquarks. This could even lead to the production of pentaquarks and hexaquarks, or even that quarks could interact individually without being bound into color neutral particles. This would produce a hypothetical object known as a quark star.

This is all hypothetical at this point, but verified evidence of tetraquarks will force astrophysicists to reexamine some the assumptions we have about the interiors of neutron stars.

This article originally appeared at Universe Today.

Have Physicists Finally Detected Gravitational Waves? (via io9)

From the io9 Space page, the has been an announcement of an impending announcement, i.e., today it was announced that there will be a press conference tomorrow by the Harvard-Smithsonian Center for Astrophysics. The speculation is that they may announce having discovered gravitational waves (the last predicted by unseen element in Einstein's General Theory of Relativity).

Have physicists finally detected gravitational waves?

Mika McKinnon

The Harvard-Smithsonian Center for Astrophysics has news so big it announced that it would announce something. The press conference will stream live tomorrow at noon, but cosmologists everywhere are gossiping about what that news could be. The leading theory: Scientists have detected gravitational waves, in what would be a landmark discovery for the field of physics.

Gravitational waves are the last chunk of Einstein's General Theory of Relativity that was predicted but not yet observed. If gravitational waves have been observed, it most likely was done by the Background Imaging of Cosmic Extragalactic Polarization (Bicep) telescope at the south pole. It stared at the cosmic microwave background radiation from 2003 to 2008, but it takes a long time to process and analyze the data when looking for a faint signal in a lot of noise.

2007 photograph of telescopes at the Dark Center at the Amundsen-Scott South Pole Station. From top to bottom, the partly-buried AST/RO, QUaD, Viper, and finally BICEP and SPT at the bottom. Image credit: Robert Schwarz

The Bicep mission page describes anticipated gravitational waves as faint, polarized, and distorted by gravitational lensing of objects between us and the cosmic microwave background radiation. They released a video of their observations in 2008. The colour scale adjusts throughout the movie to highlight temperature fluctuations of both the cosmic microwave background radiation, and the galactic plane:


Why look at the cosmic microwave background radiation for signs of gravitational waves? Because an infinitesimal moment after the universe started — 10-34 seconds after the big bang — we think it went through an inflationary period. If it did, that inflation could have amplified gravitational waves to such an extent that we can actually detect them. This would not only fill in that last missing chunk of things predicted by General Relativity that we haven't seen yet, but also offer a glimpse into the primeval universe. They won't be insta-proof that inflationary theory is correct, but they would rule out some cyclic theories for the origin of the universe.

Some pre-announcement articles are already mixing up very common gravity waves with gravitational waves. To differentiate, I'll pass things off to an exasperated Dr. Katherine Mack:

Katie Mack @AstroKatie GRAVITY WAVES are a fluid dynamics thing; we see them all the time: http://en.wikipedia.org/wiki/Gravity_wave … GRAVITATIONAL WAVES are ripples in spacetime. 

15 Mar  

Katie Mack @AstroKatie

People use "gravity waves" to mean "gravitational waves" constantly, so probably any clarification is a lost cause, but had to say it.

11:49 AM - 15 Mar 2014

Gravity waves are common phenomena in both the ocean and the sky, as seen in this MODIS image. Read more about them at the Earth Observatory.

As for the press conference, I'm already bracing for disappointment. "Breaking news! We'll have breaking news for you on Monday!" announcements produce so much hype that the actual discovery probably won't live up to expectations. I'm not the only one feeling that way — the Guardian ran an entire piece interviewing cautiously excited cosmologists warning that the observations would need to be highly robust if they're going to be momentous.

Missed the First Episode of Neil deGrasse Tyson’s Cosmos Reboot? Watch it on Hulu (US Only)

If you, like me, did not see the first episode of Neil deGrasse Tyson’s Cosmos reboot (and not having tv, there was no way for me to watch it live), Hulu has made it available for free to those in the United States (sorry to the rest of 6.7 billion people on the Earth).

Watch the First Episode of Neil deGrasse Tyson’s Cosmos Reboot on Hulu (US Viewers)

March 11th, 2014


After a long wait, Neil deGrasse Tyson’s reboot of Cosmos began airing on Fox this past Sunday night, some 34 years after Carl Sagan launched his epic series on the more heady airwaves of PBS. Fox execs predicted big numbers for the first show — 40 million viewers. But only 5.8 million showed up. But, as we know, quantity has nothing to do with quality. Critics have called Tyson’s show a “striking and worthy update” of the original. If you live in the US, you can see for yourself. Episode 1 appears above, and it looks like the remaining 12 episodes will appear on Hulu. For those outside the US, our apologies that you can’t see this one.

via Kottke

Related Content:

• Neil deGrasse Tyson Lists 8 (Free) Books Every Intelligent Person Should Read
• Neil deGrasse Tyson Delivers the Greatest Science Sermon Ever
• Stephen Colbert Talks Science with Astrophysicist Neil deGrasse Tyson
• Neil deGrasse Tyson on the Staggering Genius of Isaac Newton

Max Tegmark - How to See Yourself in a World Where Only Math Is Real

You (we) are little more than very elaborate braids in spacetime. Not sure what that means? Read this article from Nautilus and it will make a lot more sense.

Life is a Braid in Spacetime

How to see yourself in a world where only math is real,

By Max Tegmark
Illustration by Chad Hagen January 9, 2014

“Excuse me, but what’s the time?” I’m guessing that you, like me, are guilty of having asked this question, as if it were obvious that there is such a thing as the time. Yet you’ve probably never approached a stranger and asked “Excuse me, but what’s the place?”. If you were hopelessly lost, you’d probably instead have said something like “Excuse me, but where am I?” thereby acknowledging that you’re not asking about a property of space, but rather about a property of yourself. Similarly, when you ask for the time, you’re not really asking about a property of time, but rather about your location in time.

But that is not how we usually think about it. Our language reveals how differently we think of space and time: The first as a static stage, and the second as something flowing. Despite our intuition, however, the flow of time is an illusion. Einstein taught us that there are two equivalent ways of thinking about our physical reality: Either as a three-dimensional place called space, where things change over time, or as a four-dimensional place called spacetime that simply exists, unchanging, never created, and never destroyed.

I think of the two viewpoints as the different perspectives on reality that a frog and a bird might take. The bird surveys the landscape of reality from high “above,” akin to a physicist studying the mathematical structure of spacetime as described by the equations of physics. The frog, on the other hand, lives inside the landscape surveyed by the bird. Looking up at the moon over time, the frog sees something like the right panel in the figure, “The Moon’s Orbit”: Five snapshots of space with the Moon in different positions each time. But the bird sees an unchanging spiral shape in spacetime, as shown in the left panel.

  

The Moon’s Orbit: We can equivalently think of the moon as a position in space that changes over time (right), or as an unchanging spiral shape in spacetime (left), corresponding to a mathematical structure. The snapshots of space (right) are simply horizontal slices of spacetime (left). To keep things legible, I’ve drawn the orbit much smaller than to scale and made several simplifications. To get snapshots of space (right) from spacetime (left), you simply make horizontal slices through spacetime at the times you’re interested in.Max Tegmark

For the bird—and the physicist—there is no objective definition of past or future. As Einstein put it, “The distinction between past, present, and future is only a stubbornly persistent illusion.” When we think about the present, we mean the time slice through spacetime corresponding to the time when we’re having that thought. We refer to the future and past as the parts of spacetime above and below this slice.

This is analogous to your use of the terms here, in front of me, and behind me to refer to different parts of spacetime relative to your present position. The part that’s in front of you is clearly no less real than the part behind you—indeed, if you’re walking forward, some of what’s presently in front of you will be behind you in the future, and is presently behind various other people. Analogously, in spacetime, the future is just as real as the past—parts of spacetime that are presently in your future will, in your future, be in your past. Since spacetime is static and unchanging, no parts of it can change their reality status, and all parts must be equally real.

The idea of spacetime does more than teach us to rethink the meaning of past and future. It also introduces us to the idea of a mathematical universe. Spacetime is a purely mathematical structure in the sense that it has no properties at all except mathematical properties, for example the number four, its number of dimensions. In my book Our Mathematical Universe: My Quest for the Ultimate Nature of Reality, I argue that not only spacetime, but indeed our entire external physical reality, is a mathematical structure, which is by definition an abstract, immutable entity existing outside of space and time.

What does this actually mean? It means, for one thing, a universe that can be beautifully described by mathematics. That this is true for our universe has become increasingly clear over the centuries, with evidence piling up ever more rapidly. The latest triumph in this area is the discovery of the Higgs boson, which, just like the planet Neptune and the radio wave, was first predicted with a pencil, using mathematical equations.

That our universe is approximately described by mathematics means that some but not all of its properties are mathematical. That it is mathematical means that all of its properties are mathematical; that it has no properties at all except mathematical ones. If I’m right and this is true, then it’s good news for physics, because all properties of our universe can in principle be understood if we are intelligent and creative enough. It also implies that our reality is vastly larger than we thought, containing a diverse collection of universes obeying all mathematically possible laws of physics.

This novel way of viewing both spacetime and the stuff in it implies a novel way of viewing ourselves. Our thoughts, our emotions, our self-awareness, and that deep existential feeling “I am”—none of this feels the least bit mathematical to me. Yet we too are made of the same kinds of elementary particles that make up everything else in our physical world, which I’ve argued is purely mathematical. How can we reconcile these two perspectives?

 

Chad Hagen

The first step is to consider how we look as a spacetime structure. The cosmology pioneer George Gamow entitled his autobiography My World Line, a phrase also used by Einstein to refer to paths through spacetime. However, your own world line strictly speaking isn’t a line: It has a non-zero thickness and it’s not straight. The roughly 1029 elementary particles (quarks and electrons) that your body is made of form a tube-like shape through spacetime, analogous to the spiral shape of the Moon’s orbit (“The Moon’s Orbit”) but more complicated. If you’re swimming laps in a pool, that part of your spacetime tube has a zig-zag shape, and if you’re using a playground swing, that part of your spacetime tube has a serpentine shape.

However, the most interesting property of your spacetime tube isn’t its bulk shape, but its internal structure, which is remarkably complex. Whereas the particles that constitute the Moon are stuck together in a rather static arrangement, many of your particles are in constant motion relative to one another. Consider, for example, the particles that make up your red blood cells. As your blood circulates through your body to deliver the oxygen you need, each red blood cell traces out its own unique tube shape through spacetime, corresponding to a complex itinerary though your arteries, capillaries, and veins with regular returns to your heart and lungs. These spacetime tubes of different red blood cells are intertwined to form a braid pattern as seen in the figure “Complexity and Life” which is more elaborate than anything you’ll ever see in a hair salon: Whereas a classic braid consists of three strands with perhaps thirty thousand hairs each, intertwined in a simple repeating pattern, this spacetime braid consists of trillions of strands (one for each red blood cell), each composed of trillions of hair-like elementary-particle trajectories, intertwined in a complex pattern that never repeats. In other words, if you imagine spending a year giving a friend a truly crazy hairdo, braiding the hair by separately intertwining all their individual hairs, the pattern you’d get would still be very simple in comparison.

  

Complexity and Life: The motion of an object corresponds to a pattern in spacetime. An inanimate clump of 10 accelerating particles constitutes a simple pattern (left), while the particles that make up a living organism constitute a complex pattern (middle), corresponding to the complex motions that accomplish information processing and other vital processes. When a living organism dies, it eventually disintegrates and its particles separate from each other (right). These crude illustrations show merely 10 particles; your own spacetime pattern involves about 1029 particles and is mind-blowingly complex.Max Tegmark

Yet the complexity of all this pales in comparison to the patterns of information processing in your brain. Your roughly 100 billion neurons are constantly generating electrical signals (“firing”), which involves shuffling around billions of trillions of atoms, notably sodium, potassium, and calcium ions. The trajectories of these atoms form an extremely elaborate braid through spacetime, whose complex intertwining corresponds to storing and processing information in a way that somehow gives rise to our familiar sensation of self-awareness. There’s broad consensus in the scientific community that we still don’t understand how this works, so it’s fair to say that we humans don’t yet fully understand what we are. However, in broad brush, we might say this: You’re a pattern in spacetime. A mathematical pattern. Specifically, you’re a braid in spacetime—indeed, one of the most elaborate braids known.

Some people find it emotionally displeasing to think of themselves as a collection of particles. I got a good laugh back in my 20s when my friend Emil addressed my friend Mats as an “atomhög,” Swedish for “atom heap,” in an attempt to insult him. However, if someone says “I can’t believe I’m just a heap of atoms!’’ I object to the use of the word “just”: the elaborate spacetime braid that corresponds to their mind is hands down the most beautifully complex type of pattern we’ve ever encountered in our universe. The world’s fastest computer, the Grand Canyon or even the Sun—their spacetime patterns are all simple in comparison.

AT BOTH ENDS of your spacetime braid, corresponding to your birth and death, all the threads gradually separate, corresponding to all your particles joining, interacting and finally going their own separate ways (As seen in the right panel of “Complexity and Life”). This makes the spacetime structure of your entire life resemble a tree: At the bottom, corresponding to early times, is an elaborate system of roots corresponding to the spacetime trajectories of many particles, which gradually merge into thicker strands and culminate in a single tube-like trunk corresponding to your current body (with a remarkable braid-like pattern inside as we described above). At the top, corresponding to late times, the trunk splits into ever finer branches, corresponding to your particles going their own separate ways once your life is over. In other words, the pattern of life has only a finite extent along the time dimension, with the braid coming apart into frizz at both ends.1

This view of ourselves as mathematical braid patterns in spacetime challenges the assumption that we can never understand consciousness. It optimistically suggests that consciousness can one day be understood as a form of matter, a derivative of the most beautifully complex spacetime structure in our universe. Such understanding would enlighten our approaches to animals, unresponsive patients, and future ultra-intelligent machines, with wide-ranging ethical, legal, and technological implications.

This is how I see it. However, although this idea of an unchanging reality is venerable and dates back to Einstein, it remains controversial and subject to vibrant scientific debate, with scientists I greatly respect expressing a spectrum of views. For example, in his book The Hidden Reality, Brian Greene expresses unease toward letting go of the notions change and creation as fundamental, writing “I’m partial to there being a process, however tentative [...] that we can imagine generating the multiverse.” Lee Smolin goes further in his book Time Reborn, arguing that not only is change real, but that time may be the only thing that’s real. At the other end of the spectrum, Julian Barbour argues in his book The End of Time not only that change is illusory, but that one can even describe physical reality without introducing the concept of time at all.

If we discover the ultimate nature of time, this will answer many of the most exciting open questions facing physics today. Did time have some sort of beginning before our Big Bang? Will it ultimately end? Did it emerge out of some sort of timeless quantum fuzz into which it will eventually dissolve? We physicists haven’t found the mathematical theory of quantum gravity required to convincingly answer these questions, but whatever this “theory of everything” turns out to be, time will be the key to unlocking its mysteries.


~ Max Tegmark is an MIT physics professor who has authored more than 200 technical papers. Known as “Mad Max” for his unorthodox ideas and passion for adventure, his scientific interests range from precision cosmology to the ultimate nature of reality, all explored in his new popular science book Our Mathematical Universe.

Lee Billings is the author of Five Billion Years of Solitude: The Search for Life Among the Stars (2013), "an intimate history of Earth and the quest for life beyond the solar system.

For 4.6 billion years our living planet has been alone in a vast and silent universe. But soon, Earth’s isolation could come to an end. Over the past two decades, astronomers have discovered thousands of planets orbiting other stars. Some of these exoplanets may be mirror images of our own world. And more are being found all the time.

Yet as the pace of discovery quickens, an answer to the universe’s greatest riddle still remains just out of reach: Is the great silence and emptiness of the cosmos a sign that we and our world are somehow singular, special, and profoundly alone, or does it just mean that we’re looking for life in all the wrong places? As star-gazing scientists come closer to learning the truth, their insights are proving ever more crucial to understanding life’s intricate mysteries and possibilities right here on Earth.

Science journalist Lee Billings explores the past and future of the “exoplanet boom” through in-depth reporting and interviews with the astronomers and planetary scientists at its forefront. He recounts the stories behind their world-changing discoveries and captures the pivotal moments that drove them forward in their historic search for the fi rst habitable planets beyond our solar system. Billings brings readers close to a wide range of fascinating characters, such as:

FRANK DRAKE, a pioneer who has used the world’s greatest radio telescopes to conduct the first searches for extraterrestrial intelligence and to transmit a message to the stars so powerful that it briefly outshone our Sun.

JIM KASTING, a mild-mannered former NASA scientist whose research into the Earth’s atmosphere and climate reveals the deepest foundations of life on our planet, foretells the end of life on Earth in the distant future, and guides the planet hunters in their search for alien life.

SARA SEAGER, a visionary and iron-willed MIT professor who dreams of escaping the solar system and building the giant space telescopes required to discover and study life-bearing planets around hundreds of the Sun’s neighboring stars.
Through these and other captivating tales, Billings traces the triumphs, tragedies, and betrayals of the extraordinary men and women seeking life among the stars. In spite of insu cient funding, clashing opinions, and the failings of some of our world’s most prominent and powerful scientifi c organizations, these planet hunters will not rest until they fi nd the meaning of life in the infi nite depths of space. Billings emphasizes that the heroic quest for other Earth-like planets is not only a scientifi c pursuit, but also a refl ection of our own culture’s timeless hopes and fears.

Billings discussed his new book a few days ago at Google.

Lee Billings, "Five Billion Years of Solitude" | Talks at Google

Published on Dec 3, 2013


Since its formation nearly five billion years ago, our planet has been the sole living world in a vast and silent universe. Now, Earth's isolation is coming to an end. Over the past two decades, astronomers have discovered thousands of "exoplanets" orbiting other stars, including some that could be similar to our own world. Studying those distant planets for signs of life will be crucial to understanding life's intricate mysteries right here on Earth.

In a firsthand account of this unfolding revolution, Lee Billings draws on interviews with top researchers. He reveals how the search for other Earth-like planets is not only a scientific pursuit, but also a reflection of our culture's timeless hopes, dreams, and fears.

Matthew Francis - Where Nature Hides the Darkest Mystery of All

From Nautilus Magazine, Facts So Romantic: on Matter, Matthew Francis offers up a brief tour of what we know about those mysteries of space, the back hole.

Where Nature Hides the Darkest Mystery of All

Posted By Matthew Francis on Oct 14, 2013

  

A computer simulation of a gas cloud passing near the supermassive black hole at the center of the Milky Way, and the gravitational effects on the cloud. ESO/MPE/Marc Schartmann

No known object in existence has as clear a division between “inside” and “outside” as a black hole. We live and see the outside, and no probe will bring us information about the inside. We can send radio messages or robotic spacecraft, but once they cross over into a black hole’s interior, we’ll never get back those emissaries…or any information about what happened to them.

The boundary of a black hole is its event horizon. It’s not a surface in the usual sense—there’s no physical barrier—but it’s very much a real thing. Outside the horizon, an object can escape the black hole’s gravitational pull if it’s moving sufficiently fast; inside, it would need to move faster than light-speed, something forbidden by the laws of nature.

In a meaningful sense, a black hole is its event horizon, since we can’t observe anything inside it by any method. The interior is nature’s biggest secret, enshrouded by a barrier that lets everything in but nothing out.

To make black holes even more enigmatic, they are also perfectly featureless, according to general relativity, our best explanation of how gravity works. They may be born from situations as different as the deaths of stars and the gravitational collapse of huge amounts of gas in the early Universe, but the result is the same. Even the chemical composition of what gets sucked into and forms it is irrelevant. The only properties a black hole exhibits to the wider cosmos are its mass and how fast it’s rotating.

This result is puckishly known as the “no-hair theorem”: Whatever is going on in the interior, no “hair” sticks out of the event horizon. (The name was coined by prominent physicist John Archibald Wheeler, obviously not a man sensitive about a receding hairline.) That theorem presents a challenging conundrum: We don’t know whether a black hole actually deletes its autobiography, “forgetting” its past and its progenitor’s composition, or preserves it somehow in a way we don’t know yet. If that information is destroyed, it’s a violation of one of the principles of quantum mechanics; if it’s preserved, it requires a theory beyond general relativity.

The interior of a black hole isn’t merely a an inaccessible region of the cosmos. It’s a laboratory for the most extreme physics: the strongest gravity and the most intense of quantum processes. For that reason, physicists are interested in understanding what goes on inside, even while they are frustrated by the lack of direct experiments or observations that could test their ideas.

We can’t penetrate the bald event horizon, but that doesn’t mean we know nothing about a black hole’s interior. We’re pretty sure black holes don’t contain a portal to another region of space (a wormhole) or another reality, whatever sci-fi may have told us. Most physicists are also reasonably certain that a full description of the interior of black holes will require quantum gravity, a theory unifying quantum physics and general relativity—or possibly a modified version of our current model of gravity. The full structure of such a theory is unknown, but researchers have some thumbnail sketches about what it might look like.

One hybrid approach was put together by Yakov Borisovich Zel’dovich, Jacob Bekenstein, and especially Stephen Hawking. Without a quantum theory of gravity, they used particle physics in combination with general relativity to show that the event horizon has a non-zero temperature and therefore glows, albeit very faintly. This glow is known as Hawking radiation; it arises when partnered particles—one electron and one positron, pairs of photons, etc.—are created in the intense gravitational field. One particle falls into the black hole, while the other escapes.

Since the energy from the black hole was the source of the newly created particles’ mass (via E = mc²), the black hole’s mass shrinks slightly with every escaped particle. Unfortunately, the event horizon temperature is low for black holes like the ones we see, so Hawking radiation is correspondingly much fainter than other sources of light. However, if very low-mass black holes exist, they would shine brightly by Hawking radiation, and decay relatively quickly, evaporating away to nothing. Watching such a black hole vanish might help answer the question of whether information is truly lost or just hidden from us by the event horizon.

Interestingly, Hawking himself thinks the problem has been solved, at least in principle: Black holes preserve the information they swallow, much as a hologram preserves information about three dimensions even though they are two-dimensional pictures. His hypothesis, based on an idea in string theory, doesn’t yet work in our four-dimensional cosmos (three spatial dimensions plus time), but rather for an abstract, higher-dimensional universe. As a result, not everyone is convinced by Hawking’s demonstration, even if they agree that black holes don’t forget their origins.

Hawking radiation presumably consists of all sorts of things, including exotic particles like dark matter and gravitons, which we’ve never seen in the lab. That’s an intriguing notion, though again nature cruelly interferes with our best efforts to study it, by making tiny black holes rare or perhaps nonexistent. We might be able to see Hawking radiation from a larger black hole, but only if it’s not actively feeding on matter and if the hole is very close by. (Another option would be to create a tiny black hole in the lab, but without some new, exotic kind of physics, the necessary energy is beyond our reach.)

The nearest known black hole to Earth, which carries the highly memorable name V404 Cygni, is about 8,000 light-years away. While that’s a mere hair’s breadth in cosmic terms, it’s far enough that we can’t study it up close. (For comparison, Voyager 1—the farthest human-built probe—is a little over 17 light-hours away at the time of writing.) The closest supermassive black hole (one that exceeds a 100,000 times the mass of the Sun) is even farther away: 26,000 light-years. That’s the monster at the center of the Milky Way, known as Sagittarius A* (pronounced “A star”).

We see black holes like V404 Cygni by the matter surrounding them: Material stripped off companion stars, for example, heats up as it orbits the black hole, emitting strong X-ray and radio radiation. Thanks to high-resolution observations made last year, astronomers have measured swirling gas at very close orbits to the giant black hole in the galaxy M87. And the dance of stars and plasma near Sagittarius A* reveals the presence of the black hole that helps keep our galaxy together.

With continued improvements, we’ll be able to get an even better view of black holes, drawing ever closer to the event horizon. Yet nature still hides the mystery of what lies inside a black hole, perhaps forever.


~ Matthew Francis is a physicist, science writer, public speaker, educator, and frequent wearer of jaunty hats. He’s currently writing a book on cosmology with the working title Back Roads, Dark Skies: A Cosmological Journey.

Alva Noë - There's Nothing To Do Here, And It's Perfect

Over at NPR's 13.7 Cosmos and Culture blog, philosopher Alva Noë riffs on the experience of an art exhibit (Robert Irwin's Scrim Veil—Black Rectangle—Natural Light at the Whitney Museum of American Art) that just recently closed. 

Make me wish I lived in  New York City (or close enough to drive there).

There's Nothing To Do Here, And It's Perfect

by Alva Noë
August 31, 2013

Visitors explore Robert Irwin's Scrim Veil—Black Rectangle—Natural Light during its 2013 reprise at the Whitney Museum of American Art.©Robert Irwin/Photography ©2013 Philipp Scholz Rittermann/Courtesy of the Whitney Museum

The elements of Robert Irwin's installation at the Whitney Museum of American Art — the show ends today — are named in the work's title: Scrim Veil—Black rectangle—Natural Light. There's no mystery. No magical ingredient.

It's a large rectangular room with a black floor divided lengthwise by a taut curtain of thin fabric hanging down to about head height; the fabric is translucent, from some angles invisibly transparent, from others impossible to see through; the fabric has a thick black border (another rectangle); there is a thick black line (rectangle) painted on the walls, bisecting them horizontally; light coming through a single large window at the end of the room.

A photo from the 1977 debut of Robert Irwin's Scrim Veil—Black Rectangle—Natural Light at the Whitney Museum of American Art.©Robert Irwin/Photograph ©1977 Warren Silverman/Courtesy of the Whitney Museum

And yet you could practically hear people gasp as they entered the room on the Whitney's fourth floor. Somehow the combined effect of the elements was not only gorgeous, but astonishing.

Yes, there was an optical trick. You could not always quite see the scrim. And because of the black bar of its border, and the similar bar on the wall behind, you had a sense that the two bars were one. You lost a sense of their location in space.

But the fascination of the piece doesn't come down to mere optical play.

I wish I understood what it does come down to.

One remarkable feature of the installation is that it has no focus. You're in it, for one thing, so you can't look at it. There isn't any one thing for you to contemplate. Or rather, everything — the window, the scrim, its border, the floor, the wall, the other people in the gallery — command attention equally.

Compare this with James Turrell's thematically kindred exhibition now at the Guggenheim just uptown. With Turrell you know just what to look at; there is something to inspect.


Or compare it with the installations of Richard Serra, which I've discussed here in the past. Serra's work disorients you and compels exploration. You can't just stand there. You need to do something.

But not so with Irwin. There is nothing to do here. Or, I suppose, there is everything to do. The installation is just a place. A place to be. It is a pure place. Space. And light. Could this be why it feels so good to be there?

Bookforum Omnivore - The Vast Majority of the Universe

From Bookforum's Omnivore blog, this is a coo collection of links on cosmology, including a couple of articles on the ever-mysterious "dark matter," and an article on the largest "object" ever discovered in the universe, which is composed of 73 quasars.


The vast majority of the universe

JAN 18 2013 

9:00AM

• From Cosmos, the vast majority of the universe is something we can't see, can't touch and is expanding the universe at ever-increasing speeds; Tamara Davis explains why dark energy poses more questions than answers. 
• Can time just stop? Michael Byrne wonders. 
• The God Particle: What explains the current wave of popular physics? 
• Virginia Trimble reviews Gravity's Engines: The Other Side of Black Holes by Caleb Scharf. 
• Dark matter mystery may soon be solved: Experiments to detect dark matter, which scientists believe makes up about a quarter of the universe, are underway and may yield direct evidence within a decade. 
• What is string theory, and why should we bother finding out? Steven Gubser explains. 
• Most fundamental clock ever could redefine kilogram: Physicists have created the first clock with a tick that depends on the hyper-regular frequency of matter itself. 
• Rebecca J. Rosen on the largest structure ever observed in the universe: At 4 billion light years across, this quote-unquote "object" throws astronomical assumptions that go back to Einstein into doubt.

Whatever Reality Is . . . Bookforum Omnivore

Another interesting collection of links form the god folks at Bookforum's Omnivore blog - on space, quantum physics, cosmology, the universe, and everything.

Whatever Reality Is

Nov 21 2012  

1:00PM

• From New Scientist, a tour of our fundamental understanding of the world around us, starting with an attempt to define reality and ending with the idea that whatever reality is, it isn’t what it seems. 
• David Berman on the ten dimensions of string theory (and part 2). 
• The measurement that would reveal the universe as a computer simulation: If the cosmos is a numerical simulation, there ought to be clues in the spectrum of high energy cosmic rays, say theorists. 
• Digging up the early universe: Cosmologists are uncovering relics from the dawn of time, letting them look back almost all the way to the Big Bang. 
• The universe is almost done making stars: Star formation is now 30 times lower than at its peak 11 billion years ago. 
• Constructor theory: David Deutsch on how many mathematicians to this day don't realize that information is physical and that there is no such thing as an abstract computer — only a physical object can compute things. 
• Clay Dillow goes inside the largest simulation of the universe ever created: A giant supercomputer is making massively detailed models of the cosmos. 
• Should 16–18 year olds be taught modern physics such as quantum mechanics?

Raymond Tallis - Did Time Begin With A Bang?

Raymond Tallis is writing a new book to "rescue our thinking about time (and a good deal of metaphysics) from the domination of physics." In this column from Philosophy Now, he explains a little bit of where he is heading in the new book.

Did Time Begin With A Bang?

Raymond Tallis doesn’t know, at present.

I am half way through writing Of Time and Lamentation, an attempt to rescue our thinking about time (and a good deal of metaphysics) from the domination of physics. I justify this shameless self-promotion by presenting it as a warning: you must expect your columnist, over the next year or so, occasionally to share with you some of his puzzles about the nature of time. The one that is preoccupying me at present is the question of whether time does or does not have a beginning. It’s an issue that has wandered through Western thought on the border between philosophy and theology for millennia, and no end seems to be in sight.

Some of you will be familiar with Kant’s cunning argument in The Critique of Pure Reason (1781), in which he demonstrates to his own satisfaction that time cannot be something in the world out there, a property of things in themselves: on the contrary, he says, time belongs to the perceiving subject. (For those who don’t feel up to reading the original, Robin Le Poidevin’s discussion in his brilliant Travels in Four Dimensions: The Enigmas of Space and Time is an ideal starting point.) Kant’s argument revolves around the question of whether or not the world has a beginning in time. He shows that we can prove both that the world must have and that it can’t have a beginning in time, so there must be something wrong with the idea. This is the first of his famous four ‘antinomies’ – philosophical problems with contradictory but apparently necessary solutions – the others relating to atoms, freedom, and God.

The world, Kant says, must have a beginning in time, otherwise an infinite amount of time – an ‘eternity’, as Kant called it – would have already passed in this world – but no infinite series can be completed. On the other hand, the world can’t have had a beginning in time, because this would imply a period of empty time before the world came into being, and nothing (least of all a whole world) can come into being in empty time, as there isn’t anything to distinguish one moment in empty time from another. To put this another way: since successive moments of empty time are identical, there would not be a sufficient reason for one moment to give birth to the world while its predecessors were sterile.

One current standard response to Kant’s Antinomy of Time is to say that the world did have a beginning – at the Big Bang, 13.75 billion years ago – but that it was not a beginning in already-existing empty time, since the beginning of the world also started time itself. This solution echoes St Augustine’s assertion that “the world was made, not in time, but simultaneously with time”: God brought the world and time into being together, so that the question of (say) what God was doing before the Creation does not arise. Kant’s First Antinomy is therefore based on a false premise. Job done. Tick in box. Next question please.

Not so fast. Let us look at the claim that time and the world began with the Big Bang 13.75 billion years ago. This is claiming two rather remarkable things: that time began at a particular time; and that time and the world began at the same time. Let us look at these assumptions, starting with the assertion that time began at a particular time.

Time Zero

Since the Big Bang can be assigned a date, Something must have come out of Nothing at a particular moment. What was special about a specific moment 13.75 billion years ago? The cosmologists say that there was nothing special about it: the universe is a random event that happened for no particular reason. It grew out of a quantum field – the ‘inflaton’ – which found itself in a false vacuum – temporarily stable, but not in the lowest energy state. Random fluctuation (uncaused, as things are in the quantum world) sent the inflaton tumbling into a true vacuum, which generated an equal amount of positive energy (matter) and negative energy (gravity). Thus the Big Bang didn’t need causes to bring it about because no net stuff is created. Far from solving the problem of creation, this has multiplied the problems beyond those the physicists were struggling with: an energetic quantum vacuum – a fidgety Nothing – looks a little dodgy, for a start.

Never mind, that’s quantum physics for you. What seems more vulnerable is the idea that we can finesse Something out of Nothing by the generation of equal amounts of positive and negative energy, so that the universe has zero total energy. This seems to be somewhat literal-minded, taking the pluses and minuses in an equation for reality. Worse, it looks as if in pursuit of an explanation we have doubled the number of unexplainables: we have to explain two lots of energy. In short, Kant’s problem of explaining why one moment of empty time should be privileged to deliver a universe is not solved by appealing to random fluctuations, because fluctuations in Nothing – even if they generate pairs of virtual particles (virtual particle plus virtual antiparticle) – don’t seem likely to help us to explain Something.

Some scientists have given up on the idea that the Big Bang is at the beginning of time (and space); rather, it is but a recent event in a much longer history. (See for example, ‘Bang Goes The Theory’, New Scientist, 30th June 2012.) Instead of one Big Bang, there is a series of big bangs livening up a cosmos that has been around forever. This, of course, only displaces the problem of the emergence of Something out of Nothing, and Kant’s problem of an infinite time having already passed is back.

Meanwhile, there are variants of the Big Bang theory in which it is suggested that time doesn’t arrive on the scene at once; or rather, it behaves at first like another dimension of space – in the earliest universe there is a period in which it is too early for time. If so, we have to ask what ‘too early’ could possibly mean in this context. Are we referring to a time before time exists – before it makes sense to speak of ‘before’?

There is something dubious about dating the beginning of time in any case. Allocating a time to the beginning of time is like allocating a time to any moment in time. Saying that a time t₁ took place at a particular time t₁ seems like a harmless tautology, but it is actively misleading, because it treats a moment in time as if it were itself a kind of occurrence in time, as opposed to part of the framework within which things can occur. To say that time began at t_beginning is thus to treat the beginning of time more like a kind of occurrence. This impression is confirmed when it is asserted that t_beginning occurred 13.75 billion years ago.

Those who want to defend the notion of a moment in time as being like an occurrence, might be tempted to say we often think this way when we talk about stretches of time. For example, there is nothing wrong with saying that Wednesday – not in itself an event, but simply a holder for events – began, came into being, at twelve midnight on Tuesday. The analogy is not sound, however. Tuesday or Wednesday are not time in itself, but divisions placed upon time. However, the Big Bang is supposed to be both timeless and at a particular time: at the beginning of, and yet not part of, the series that it begins.

The problem with saying that time began at a particular time is highlighted by this obvious question: If it is perfectly valid to speak of 13.2, 13.3 and 13.75 billion years ago, why is it not valid to talk about 13.8, 13.76 or even 13.755 billion years ago? Steven Hawking addresses this question by arguing that to talk of time before the Big Bang is like talking about points north of the North Pole. Once you have got to the North Pole, it makes no sense to imagine you can go any further north.

This analogy does not work. As mathematical philosopher J.R. Lucas has pointed out, there is a deeper, astronomical sense of north which allows a line pointing in that direction to be extended indefinitely. North is a direction that has no terminus: you can be north of the North Pole. So the question still stands.

What about the second assumption: the supposed simultaneity of the beginning of the universe and the origin of time? How can we think of the start of time itself (as opposed to the time of something) being at the same time as an event (the creation of the universe)? There is no ‘at the same time as’ until the universe has differentiated to the point where one event can be temporally related to other events via an observer. What’s more, once the universe has come into being, and more than one event has occurred, the notion of simultaneity as absolute and observer-independent is invalidated by the Special Theory of Relativity. Finally, there is a mismatch between a universe, whose coming-into-being is extended over time, and time itself, whose coming into being is presumably instantaneous, or at least not extended through time.

Haunted By Kant

So Kant’s First Antinomy still haunts us. But we have good reason not to jump from its problems to Kant’s conclusion that time is somehow internal to the human mind. If time were only a property of human minds, we would not be able to make sense of what in After Finitude (2008) the French philosopher Quentin Meillassoux called ‘ancestrals’. Ancestrals are those realities that pre-date human consciousness and yet have a clear temporal order. For example, the Earth came into being 4.56 billion years ago, before life on Earth originated (3.5 billion years ago) and before conscious humans began emerging (several million years ago). So if we believe what evolutionary science tells us, we cannot reduce time to one of Kant’s two ‘forms of sensible intuition’ (roughly, modes of human perception, the other form being space).

However, this conclusion, too, can be challenged, by arguing that the allocation of events to past dates is itself internal to the calendar time that humans have invented – that we project the framework we have established to structure our time beyond the situation within which it arose: that the very idea of ‘ago’ is established with respect to a system that has been built up by humans and extrapolated from ways of seeing that serve us well but do not necessarily reveal truths about how the universe is in itself, beyond our manner of perceiving it. On this matter, the jury remains out.

Many physicists despise the kinds of arguments I have presented. Their feeling about philosophers (or even physicists) who want to make other than mathematical sense of what physics tells us about the fundamental nature of things could be summarised in David Mirmin’s “Shut up and calculate!” And Steven Hawking has dismissed philosophers as poor sods who haven’t kept up with physics. It is important not to lose one’s nerve and to note that physicists who dismiss philosophy are often doing philosophy themselves, but very badly.

The question of whether time has a beginning is far from resolution. Equally vexing is the opposite question, as to whether it has an end. Another time, perhaps.

© Prof. Raymond Tallis 2012

Raymond Tallis is a physician, philosopher, poet, broadcaster and novelist. His latest book, In Defence of Wonder, is out now from Acumen.

The Wright Show - Robert Speaks w/ Lawrence Krauss on "A Universe from Nothing"

On this week's episode of The Wright Show, Robert Wright speaks with physicist Lawrence Krauss about his most recent book, A Universe from Nothing: Why There Is Something Rather than Nothing.

Here is the publisher's description of the book:

“WHERE DID THE UNIVERSE COME FROM? WHAT WAS THERE BEFORE IT? WHAT WILL THE FUTURE BRING? AND FINALLY, WHY IS THERE SOMETHING RATHER THAN NOTHING?”
 
Lawrence Krauss’s provocative answers to these and other timeless questions in a wildly popular lecture now on YouTube have attracted almost a million viewers. The last of these questions in particular has been at the center of religious and philosophical debates about the existence of God, and it’s the supposed counterargument to anyone who questions the need for God. As Krauss argues, scientists have, however, historically focused on other, more pressing issues—such as figuring out how the universe actually functions, which can ultimately help us to improve the quality of our lives.

Now, in a cosmological story that rivets as it enlightens, pioneering theoretical physicist Lawrence Krauss explains the groundbreaking new scientific advances that turn the most basic philosophical questions on their heads. One of the few prominent scientists today to have actively crossed the chasm between science and popular culture, Krauss reveals that modern science is addressing the question of why there is something rather than nothing, with surprising and fascinating results. The staggeringly beautiful experimental observations and mind-bending new theories are all described accessibly in A Universe from Nothing, and they suggest that not only can something arise from nothing, something will always arise from nothing.

It's an interesting dialogue - and of course, the Higgs Boson is part of the discussion.

The Wright Show

 

Robert Wright (Bloggingheads.tv, The Evolution of God, Nonzero) and Lawrence Krauss (A Universe from Nothing, The Physics of Star Trek)

• Lawrence tries to get Bob to understand the Higgs boson   7:19
• Is the universe an accident?   4:08
• Why Lawrence was betting on the Higgs not existing   7:51
• Is the Higgs a particle or a field (or both)?   11:08
• How mass gets its mass   5:44
• Can the human mind truly comprehend reality?   3:23

Play entire video

Links Mentioned

• Lawrence's book, A Universe from Nothing: Why There Is Something Rather than Nothing
• Bob on the Higgs Boson, part 1
• Bob on the Higgs Boson, part 2
• Bob on the Higgs Boson, part 3
• Lawrence in the NYT on the Higgs Boson
• Lawrence's book, "Quantum Man: Richard Feynman's Life in Science"
• Bob on Feynman on quantum mechanics