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A couple of days after seeing Christopher Nolan’s Interstellar, I bumped into Sir Roger Penrose. If you haven’t seen the movie and don’t want spoilers, I’m sorry but you’d better stop reading now.

Still with me? Excellent.

Some of you may know that Sir Roger developed much of modern black hole theory with his collaborator, Stephen Hawking, and at the heart of Interstellar lies a very unusual black hole. Straightaway, I asked Sir Roger if he’d seen the film. What’s unusual about Gargantua, the black hole in Interstellar, is that it’s scientifically accurate, computer-modeled using Einstein’s field equations from General Relativity.

Scientists reckon they spend far too much time applying for funding and far too little thinking about their research as a consequence. And, generally, scientific budgets are dwarfed by those of Hollywood movies. To give you an idea, Alfonso Cuarón actually told me he briefly considered filming Gravity in space, and that was what’s officially classed as an “independent” movie. For big-budget studio blockbuster Interstellar, Kip Thorne, scientific advisor to Nolan and Caltech’s “Feynman Professor of Theoretical Physics”, seized his opportunity, making use of Nolan’s millions to see what a real black hole actually looks like. He wasn’t disappointed and neither was the director who decided to use the real thing in his movie without tweaks.

Black holes are so called because their gravitational fields are so strong that not even light can escape them. Originally, we thought these would be dark areas of the sky, blacker than space itself, meaning future starship captains might fall into them unawares. Nowadays we know the opposite is true – gravitational forces acting on the material spiralling into the black hole heat it to such high temperatures that it shines super-bright, forming a glowing “accretion disk”.

The computer program the visual effects team created revealed a curious rainbowed halo surrounding Gargantua’s accretion disk. At first they and Thorne presumed it was a glitch, but careful analysis revealed it was behavior buried in Einstein’s equations all along – the result of gravitational lensing. The movie had discovered a new scientific phenomenon and at least two academic papers will result: one aimed at the computer graphics community and the other for astrophysicists.

I knew Sir Roger would want to see the movie because there’s a long scene where you, the viewer, fly over the accretion disk–not something made up to look good for the IMAX audience (you have to see this in full IMAX) but our very best prediction of what a real black hole should look like. I was blown away.

Some parts of the movie are a little cringeworthy, not least the oft-repeated line, “that’s relativity”. But there’s a reason for the characters spelling this out. As well as accurately modeling the black hole, the plot requires relativistic “time dilation”. Even though every physicist has known how to travel in time for over a century (go very fast or enter a very strong gravitational field) the general public don’t seem to have cottoned on.

Most people don’t understand relativity, but they’re not alone. As a science editor, I’m privileged to meet many of the world’s most brilliant people. Early in my publishing career I was befriended by Subramanian Chandrasekhar, after whom the Chandra space telescope is now named. Penrose and Hawking built on Chandra’s groundbreaking work for which he received the Nobel Prize; his The Mathematical Theory of Black Holes (1954) is still in print and going strong.

When visiting Oxford from Chicago in the 1990s, Chandra and his wife Lalitha would come to my apartment for tea and we’d talk physics and cosmology. In one of my favorite memories he leant across the table and said, “Keith – Einstein never actually understood relativity”. Quite a bold statement and remarkably, one that Chandra’s own brilliance could end up rebutting.

Space is big – mind-bogglingly so once you start to think about it, but we only know how big because of Chandra. When a giant sun ends its life, it goes supernova – an explosion so bright it outshines all the billions of stars in its home galaxy combined. Chandra deduced that certain supernovae (called “type 1a”) will blaze with near identical brightness. Comparing the actual brightness with however bright it appears through our telescopes tells us how far away it is. Measuring distances is one of the hardest things in astronomy, but Chandra gave us an ingenious yardstick for the Universe.

In 1998, astrophysicists were observing type 1a supernovae that were a very long way away. Everyone’s heard of the Big Bang, the moment of creation of the Universe; even today, more than 13 billion years later, galaxies continue to rush apart from each other. The purpose of this experiment was to determine how much this rate of expansion was slowing down, due to gravity pulling the Universe back together. It turns out that the expansion’s speeding up. The results stunned the scientific world, led to Nobel Prizes, and gave us an anti-gravitational “force” christened “dark energy”. It also proved Einstein right (sort of) and, perhaps for the only time in his life, Chandra wrong.

Why Chandra told me Einstein was wrong was because of something Einstein himself called his “greatest mistake”. When relativity was first conceived, it was before Edwin Hubble (after whom another space telescope is named) had discovered space itself was expanding. Seeing that the stable solution of his equations would inevitably mean the collapse of everything in the Universe into some “big crunch”, Einstein devised the “cosmological constant” to prevent this from happening – an anti-gravitational force to maintain the presumed status quo.

Once Hubble released his findings, Einstein felt he’d made a dreadful error, as did most astrophysicists. However, the discovery of dark energy has changed all that and Einstein’s greatest mistake could yet prove an accidental triumph.

Of course Chandra knew Einstein understood relativity better than almost anyone on the planet, but it frustrates me that many people have such little grasp of this most beautiful and brilliant temple of science. Well done Christopher Nolan for trying to put that right.

Interstellar is an ambitious movie – I’d call it “Nolan’s 2001” – and it educates as well as entertains. While Matthew McConaughey barely ages in the movie, his young daughter lives to a ripe old age, all based on what we know to be true. Some reviewers have criticized the ending – something I thought I wouldn’t spoil for Sir Roger. Can you get useful information back out of a black hole? Hawking has changed his mind, now believing such a thing is possible, whereas Penrose remains convinced it cannot be done.

We don’t have all the answers, but whichever one of these giants of the field is right, Nolan has produced a thought-provoking and visually spectacular film.

Image Credit: “Best-Ever Snapshot of a Black Hole’s Jets.” Photo by NASA Goddard Space Flight Center. CC by 2.0 via Flickr.

The post That’s relativity appeared first on OUPblog.

       

Although we rarely stop to think about the origin of the elements of our bodies, we are directly connected to the greater universe. In fact, we are literally made of stardust that was liberated from the interiors of dying stars in gigantic explosions, and then collected to form our Earth as the solar system took shape some 4.5 billion years ago. Until about two decades ago, however, we knew only of our own planetary system so that it was hard to know for certain how planets formed, and what the history of the matter in our bodies was.

Then, in 1995, the first planet to orbit a distant Sun-like star was discovered. In the 20 years since then, thousands of others have been found. Most planets cannot be detected with our present-day technologies, but estimates based on those that we have observed suggest that almost every star in the sky has at least one extrasolar planet (or exoplanet) orbiting it. That means that there are more than 100 billion planetary systems in our Milky Way Galaxy alone! Imagine that: astronomers have gone from knowing of 1 planetary system to some 100 billion, in the same decades in which human genome scientists sequenced the 6 billion base-pairs that lie at the foundation of our bodies. How many of these planetary systems could potentially support life, and would that life use a similar code?

Exoplanets are much too far away to be actually imaged, and they are way too faint to be directly observed next to the bright glow of the stars they orbit. Therefore, the first exoplanet discoveries were made through the gravitational tug on their central star during their orbits. This pull moves the star slightly back and forth. Only relatively heavy, close-in planets can be detected that way, using the repeating Doppler shifts of their central star’s light from red to blue and back. Another way to find planets is to measure how they block the light of their central star if they happen to cross in front of it as seen from Earth. If they are seen to do this twice or more, the temporary dimmings of their star’s light can disclose the planet’s size and distance to its star (basically using the local “year” – the time needed to orbit its star – for these calculations).  If both the gravitational tug and the dimming profile can be measured, then even the mass of the planet can be estimated. Size and mass together give an average density from which, in turn, knowledge of the chemical composition of that planet comes within reach.

With the discoveries of so many planets, we have realized that an astonishing diversity exists: hot Jupiter-sized planets that orbit closer to their star than Mercury orbits the Sun, quasi-Earth-sized planets that may have rain showers of molten iron or glass, frozen planets around faintly-glowing red dwarf stars, and possibly some billions of Earth-sized planets at distances from their host stars where liquid water could exist on the surface, possibly supporting life in a form that we might recognize if we saw it.

Guided by these recent observations, mega-computers programmed with the laws of physics give us insight into how these exo-worlds are formed, from their initial dusty disks to the eventual complement of star-orbiting planets. We can image the disks directly by focusing on the faint infrared glow of their gas and dust that is warmed by their proximity to their star. We cannot, however, directly see these far-away planets, at least not yet. But now, for the first time, we can at least see what forming planets do to the gas and dust around them in the process of becoming a mature heavenly body.

A new observatory, called ALMA, working with microwaves that lie even beyond the infrared color range, has been built in the dry Atacama desert in Chili. ALMA was pointed at a young star, hundreds of light years away. Its image of that target star, LH Tauri, not only shows the star itself and the disk around it, but also a series of dark rings that are most likely created as the newly forming planets pull in the gas and dust around them. The image is of stunning quality: it shows details down to a resolution equivalent to the width of a finger seen at a distance of 50 km (30 miles).

At the distance of LH Tauri, even that stunning imaging capability means that we can see structures only if these are larger than about the distance of the Sun out to Jupiter, so there is a long way yet to go before we see anything like the planet directly. But we will observe more of these juvenile planetary systems just past the phase of their birth. And images like that give us a glimpse of what happened in our own planetary system over 4.5 billion years ago, before the planets were fully formed, pulling in the gases and dust that we now live on, and that ultimately made their way to the cycles of our own planet, to constitute all living beings on Earth.

What a stunning revolution: from being part of the only planetary system we knew of, we have been put among billions and billions of neighbors. We remember Galileo Galilei for showing us that the Sun and not the Earth was the center of the solar system. Will our society remember the names of those who proved that billions of planets exist all over the Galaxy?

Headline image credit: Star shower, by c@rljones. CC-BY-NC-2.0 via Flickr.

The post Stardust making homes in space appeared first on OUPblog.

        

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As soon as I hear any news about new cuddly toys, you can bet I’ll let you all know about it! And I’ve already got one such announcement for you already, you lucky cuddlers of the Internet. StylinOnline have unveiled a set of San Diego Exclusive Big Bang Theory plush figures today, available both at their SDCC booth and online, as part of a combo pack.

You have your pick of either Leonard or Sheldon, as presumably people were worried about making a cuddly Penny figure. Each doll comes with a T-Shirt so you can dress up like your nerdy cuddle-buddy. Sheldon, who isn’t afraid of who he is and what he loves, wears a Flash shirt. Leonard, the perpetual worrier/one who looks suspiciously like a male model whenever he takes his glasses off on the show, wears a hoodie.

To the booth, cuddly toy fans! To the booooothh!!!

This Day in World History

April 1, 1948

Scientists Propose Big Bang Theory

Poet T.S. Eliot might still be right — the world might end with a whimper. But on April 1, 1948, physicists George Gamow and Ralph Alpher first proposed the now prevailing idea of how the universe began — with a big bang.

Gamow worked closely in the 1930s and 1940s with Edward Teller to understand beta decay — a kind of nuclear decay that results in the loss of electrons — and to understand the makeup of red giant stars.

From this work, Gamow and Alpher — one of his students — developed the idea that the universe was highly compressed until a vast thermonuclear explosion occurred. The explosion released neutrons, protons, and electrons. As the universe cooled, it became possible for neutrons to combine with other neutrons or with protons to form chemical elements.

Time Line of the Universe. Source: NASA/WMAP Science Team.

Gamow and Alpher published their findings in the journal Physical Review on April 1, 1948. The title of the paper — “The Origin of Chemical Elements” — suggests the link between cosmology and particle physics that the big-bang theory represents.

The paper’s authorship showed a bit of Gamow’s whimsy. Thinking it wrong to have a paper on particle physics written by one author whose name began with A (as in positively charged alpha particles) and G (as in gamma rays) without having a B (as in negatively charged beta particles), Gamow asked friend Hans Bethe to add his name to the byline. Bethe agreed, and thereby became part of history.

Just five years later, Gamow made a brilliant addition to a wholly different field. After learning of James Watson and Francis Crick’s discovery of the double helical structure of DNA, Gamow wrote Crick suggesting that the genetic code was made up of three-part segments. Gamow’s suggestion set Watson, Crick, and other researchers to investigate the possibility, which turned out — in essence (though not in the details Gamow had suggested) — to be true.

“This Day in World History” is brought to you by USA Higher Education.
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Maybe it should be called Google++++ (considering the fledgling social network managed to post a whopping 1269% increase in traffic over the previous week. What drove the huge leap? The network is now open to everyone and no longer requires invites.... Read the rest of this post

I have taken a vow of silence. A week back, I received a ticket to attend an advance screening of a big Hollywood film that premieres later this summer. I went to the film and signed some piece of paper saying I wouldn’t release information about it and I plan to hold true to that pledge. I know first hand how advance reviews can occasionally sour enthusiasm. All I will say is that during the screening, people cheered and clapped and I was absolutely flumoxed. It wasn’t the worst film I’d ever seen, but it was, to put it lightly, rather awful. And yet clapping. Cheering even. For one liners and kisses and such.

I’m going to attribute it to peoples’ excitement at being the first to see something. They were so invested in believing that they saw the next colossal hit, that they whooped and whistled their doubts away and went home and updated their Facebook profiles with something along the lines of “Guess who went to a big Hollywood premiere? I probably won’t respond to any messages for a while, cause I’m guessing I’ll be grabbing cocktails with Matthew Lillard and Eddie Furlong later. So suck it, zeroes.” Now consider this. No one was cheering when I went to see Avatar, and that movie’s box office dwarfs the GDP of many a nation. The Navi need not get their braids in a twist. I doubt the film I just saw will challenge their record.

Then again, maybe I’ve completely lost touch with the public. Maybe it will be the hit the world’s been waiting for. I’ve been wrong before. There are a few things I was sure would bomb, but went on to be wild successes:

Middlesex by Jeffrey Euginedes – I read this book months before it was released and while I could appreciate the scope, I was sure it would derided for being a blatant rip-off of Salman Rushdie’s Midnight’s Children. Homage is one thing, but I felt Euginedes took the ideas, the form, even certain plot points of Rushdie and transplanted them with far less elegance and wonder to Greeks in the upper Midwest. I didn’t think Euginedes would be run out town with pitchforks, but I thought more than a few critics would wag a finger at him. But no. Oprah pick. Pulitzer winner. Modern classic. And no Greek equivalent of a fatwa to deal with. Go figure.

The Big Bang Theory - Not the actual theory, which I knew the kids would love. I’m talking about the television show. I think I watched the first episode or two of this sitcom and wrote it off as formulaic tripe. Virgin nerds fumble around a pretty lady while trading Star Wars metaphors. Insert laughter. I figured it would last a couple seasons with a “well, nothing else is on,” viewership, but it has become a verified hit. And critics dig it. I’ve poked my head back in to see if it’s changed. It hasn’t.

Communism – My buddy Karl assured me he was onto something. I thought it was some hippie BS. “Go back to the drum circle, Karl. Go date a girl who wears skirts and jeans at the same time, Karl.” But one toppled tsar, a shining path, and an arms race later, and it’s still kicking around. Even in our White House, at least according to my most trusted news source: Victoria Jackson.

We have just returned home from a week in London, exploring the city to dropping point! One place we visited was the National Gallery, where we followed the Chinese Zodiac Trail. We knew which animals to look for from retellings of the legendary selection process, such as The Great Race: The Story of the Chinese Zodiac. While looking at the paintings, we learnt a great deal about the differences and similarities in the symbolism attached to the animals in Chinese and Western cultures; and Little Brother, who is passionate about dragons, was overjoyed to discover that his birth sign, the Snake, is also known as the Little Dragon!
In the gallery shop afterwards, we found a delightful picture-book called Pablo the Artist by Satoshi Kitamura, which is an enigmatic exploration of the artistic process and where inspiration comes from – I agree with The Magic of Books‘ review, where PJ Librarian says “you really aren’t sure at this point if Pablo is dreaming or if these landscape characters are actually real” – it’s one of those books which grows with each re-reading as new details are discovered and absorbed. We especially loved the glimpse of infinity provided at the end, having read The Mouse and His Child so recently, where the picture of the dog carrying a tray with a tin of dog food with the picture of the dog carrying a tray etc. etc. was such a recurrent and pivotal theme.
Not Just for Kids recommends Pablo the Artist and some other picture-books which “introduce young readers to some of the world’s masterpieces”, as does Rhyming Mom.