Before the Big Bang

Posted on December 16, 2008 1 Comment

Did our cosmos exist before the big bang?

The theory that the recycled universe was based on, called loop quantum cosmology (LQC), had managed to illuminate the very birth of the universe – something even Einstein’s general theory of relativity fails to do.

LQC is in fact the first tangible application of another theory called loop quantum gravity, which cunningly combines Einstein’s theory of gravity with quantum mechanics. We need theories like this to work out what happens when microscopic volumes experience an extreme gravitational force, as happened near the big bang, for example.

If LQC turns out to be right, our universe emerged from a pre-existing universe that had been expanding before contracting due to gravity. As all the matter squeezed into a microscopic volume, this universe approached the so-called Planck density, 5.1 × 1096 kilograms per cubic metre. At this stage, it stopped contracting and rebounded, giving us our universe.

In classical cosmology, a phenomenon called inflation caused the universe to expand at incredible speed in the first fractions of a second after the big bang. This inflationary phase is needed to explain why the temperature of faraway regions of the universe is almost identical, even though heat should not have had time to spread that far – the so-called horizon problem. It also explains why the universe is so finely balanced between expanding forever and contracting eventually under gravity – the flatness problem. Cosmologists invoke a particle called the inflaton to make inflation happen, but precious little is known about it.

Related: Cosmology Questions AnsweredQuantum Mechanics Made Relatively Simple Podcasts10 Most Beautiful Physics ExperimentsExtra-Universal Matter

Science Serving Society – Speech Australian Minister for Innovation

Posted on March 24, 2008 No Comments

Kim Carr, Minister for Innovation, Australia, speech to the National Press Club of Australia: Science meets Parliament

When societies invest in science, they are investing in their own future. They are entitled to expect a fair return on that investment.

They’re entitled to know we are using the country’s intellectual and technical capacity to deliver outcomes that matter to them – stronger communities, more good jobs, a cleaner environment, better public services, a richer culture, greater security for themselves and their children. Everybody here knows the rules of professional scientific conduct – think independently, put emotion aside, reject received authority, be faithful to the evidence, communicate openly.

These are good rules – rules I wholeheartedly endorse – but there’s one more I’d like to add – remember your humanity. Remember you’re part of a wider society – one that you have a special ability and therefore a special duty to serve. This doesn’t just apply in the physical sciences, but in the humanities and social sciences as well. When I say science I mean knowledge in all its forms.

Related: Engineering Economic BenefitsAuthors of Scientific Articles by CountryEconomic Strength Through Technology LeadershipScience and Engineering in Global EconomicsAussies Look to Finnish Innovation ModelInvest in Science for a Strong Economy
Read more

Laws of Physics May Need a Revision

Posted on March 8, 2008 No Comments

Something seems wrong with the laws of physics

Einstein’s general theory of relativity swept Newton away by showing that gravity operates by distorting space itself.

Even Einstein, however, may not have got it right. Modern instruments have shown a departure from his predictions, too. In 1990 mission controllers at the Jet Propulsion Laboratory (JPL) in Pasadena, California, which operates America’s unmanned interplanetary space probes, noticed something odd happen to a Jupiter-bound craft, called Galileo. As it was flung around the Earth in what is known as a slingshot manoeuvre (designed to speed it on its way to the outer solar system), Galileo picked up more velocity than expected. Not much. Four millimetres a second, to be precise. But well within the range that can reliably be detected.

Altogether, John Anderson and his colleagues analysed six slingshots involving five different spacecraft. Their paper on the matter is about to be published in Physical Review Letters. Crucially for the idea that there really is a systematic flaw in the laws of physics as they are understood today, their data can be described by a simple formula. It is therefore possible to predict what should happen on future occasions.

That is what Dr Anderson and his team have now done. They have worked out the exact amount of extra speed that should be observed when they analyse the data from a slingshot last November, which involved a craft called Rosetta. If their prediction is correct, it will confirm that the phenomenon is real and that their formula is capturing its essence. Although the cause would remain unknown, a likely explanation is that something in the laws of gravity needs radical revision.

An interesting puzzle that illustrates how scientists attempt to confirm our understanding and real world results. And those efforts include uncertainty and confusion. Too often, I think, people think science is only about absolute truth and facts without any room for questions. We understand gravity well, but that does not mean we have no mysteries yet to solve about gravity.

Research paper: The Anomalous Trajectories of the Pioneer Spacecraft

Related: NASA Baffled by Unexplained Force Acting on Space ProbesMysterious Effect May Influence Spacecraft TrajectoriesEarth’s rotation may account for wayward spacecraftPioneer anomaly put to the testUnderstanding EvolutionScientists Search for Clues To Bee Mystery

Pynchonverse Science

Posted on March 2, 2008 1 Comment

Mind-Bending Science in Thomas Pynchon’s Mind-Bending Novel Against The Day: Part I

Pynchon takes the science of this period and incorporates it deeply into the language and structure of Against the Day, more so perhaps than in any of his other novels. Against the Day is suffused with meditations on light, space, and time, and often plays with the tension between different perspectives in math and physics – classical physics versus relativity, Maxwell’s laws of electromagnetism described with the imaginary numbers of quaternions versus the real numbers of vector analysis. This material is not just filler – it’s critical to the core of Against the Day, a fact which has been underappreciated in early reviews of the novel.

One reviewer claimed that a new generation of writers has a “grasp of the systems that fascinate Pynchon — science, capitalism, religion, politics, technology — [that] is surer, more nuanced, more adult and inevitably yields more insight into how those systems work than Pynchon offers here.” When it comes to science at least, this claim is not true – Pynchon’s achievement in Against the Day proves that he is peerless as a poet who can mine science for gems of insight and set them into the context of the humanity that is the ultimate concern of his novels.

This great post offers a detailed explanation of some of the science related to Pynchon’s writing.

Related: Books by Thomas Pynchon (with online resource links)New Yorker Review of Against the Day

At the Heart of All Matter

Posted on February 27, 2008 2 Comments

Large Hadron Collider at CERN

The hunt for the God particle by Joel Achenbach

Physics underwent one revolution after another. Einstein’s special theory of relativity (1905) begat the general theory of relativity (1915), and suddenly even such reliable concepts as absolute space and absolute time had been discarded in favor of a mind-boggling space-time fabric in which two events can never be said to be simultaneous. Matter bends space; space directs how matter moves. Light is both a particle and a wave. Energy and mass are inter- changeable. Reality is probabilistic and not deterministic: Einstein didn’t believe that God plays dice with the universe, but that became the scientific orthodoxy.

Most physicists believe that there must be a Higgs field that pervades all space; the Higgs particle would be the carrier of the field and would interact with other particles, sort of the way a Jedi knight in Star Wars is the carrier of the “force.” The Higgs is a crucial part of the standard model of particle physics—but no one’s ever found it.

The Higgs boson is presumed to be massive compared with most subatomic particles. It might have 100 to 200 times the mass of a proton. That’s why you need a huge collider to produce a Higgs—the more energy in the collision, the more massive the particles in the debris. But a jumbo particle like the Higgs would also be, like all oversize particles, unstable. It’s not the kind of particle that sticks around in a manner that we can detect—in a fraction of a fraction of a fraction of a second it will decay into other particles. What the LHC can do is create a tiny, compact wad of energy from which a Higgs might spark into existence long enough and vivaciously enough to be recognized.

Previous posts on CERN and the Higgs boson: The god of small thingsCERN Prepares for LHC OperationsCERN Pressure Test FailureThe New Yorker on CERN’s Large Hadron Collider

Biggest Black Hole’s Mass = 18 Billion Suns

Posted on January 10, 2008 3 Comments

Biggest black hole in the cosmos discovered

The most massive known black hole in the universe has been discovered, weighing in with the mass of 18 billion Suns. Observing the orbit of a smaller black hole around this monster has allowed astronomers to test Einstein’s theory of general relativity with stronger gravitational fields than ever before.

The black hole is about six times as massive as the previous record holder and in fact weighs as much as a small galaxy. It lurks 3.5 billion light years away, and forms the heart of a quasar called OJ287.

The smaller black hole, which weighs about 100 million Suns, orbits the larger one on an oval-shaped path every 12 years. It comes close enough to punch through the disc of matter surrounding the larger black hole twice each orbit, causing a pair of outbursts that make OJ287 suddenly brighten.

Time

Posted on July 27, 2007 3 Comments

Newsflash: Time May Not Exist

Planck time—the smallest unit of time that has any physical meaning—is 10-43 second, less than a trillionth of a trillionth of an attosecond. Beyond that? Tempus incognito. At least for now. Efforts to understand time below the Planck scale have led to an exceedingly strange juncture in physics. The problem, in brief, is that time may not exist at the most fundamental level of physical reality.

Einstein’s theories also opened a rift in physics because the rules of general relativity (which describe gravity and the large-scale structure of the cosmos) seem incompatible with those of quantum physics (which govern the realm of the tiny). Some four decades ago, the renowned physicist John Wheeler, then at Princeton, and the late Bryce DeWitt, then at the University of North Carolina, developed an extraordinary equation that provides a possible framework for unifying relativity and quantum mechanics. But the Wheeler-­DeWitt equation has always been controversial, in part because it adds yet another, even more baffling twist to our understanding of time.

“One finds that time just disappears from the Wheeler-DeWitt equation,” says Carlo Rovelli, a physicist at the University of the Mediterranean in Marseille, France. “It is an issue that many theorists have puzzled about. It may be that the best way to think about quantum reality is to give up the notion of time—that the fundamental description of the universe must be timeless.”

Interesting. As usual, quantum actions seem bizarre. Related: Quantum Mechanics Made Relatively Simple PodcastsPhysicists Observe New Property of MatterParticles and WavesQuantum Theory Fails Reality ChecksPhysics Concepts in 60 Seconds

The Best Science Books

Posted on November 21, 2006 3 Comments

An interesting post from John Dupuis discusses several lists of the best and worst science books. Some of the best books from the lists, based on importance, what strikes my mood right now, what I enjoyed… (those I list could easily change on another day):

Please share your favorite science books.

Related: our science and engineering book page2005 Science book gift suggestions (from the list above The Selfish Gene, Chaos, A Brief History of Time and The Mismeasure of Man are likely the best gifts for the widest audiences).

20 Scientists Who Have Helped Shape Our World

Posted on August 16, 2006 2 Comments

20 Scientists Who Have Helped Shape Our World (pdf document) from the National Science Resources Center

Norman Borlaug, Plant Scientist”–Father of the Green Revolution”

The results of Dr. Borlaug’s work are encouraging: India, for example, harvests six times more wheat today than it did only 40 years ago. This increase in wheat production in poor countries has been called the “Green Revolution.” It has been written about Dr. Borlaug that he has saved more lives than anyone else who ever lived.

For his scientific achievements, Dr. Borlaug was awarded the 1970 Nobel Peace Prize. Today, at age 90, Dr. Borlaug remains active in science as a distinguished professor of international agriculture at Texas A&M University

Others include:

  • Tim Berners-Lee, Computer Scientist—Inventor of the World Wide Web
  • George Washington Carver, Inventor/Chemist (1861−1943)—Saving Agriculture in the South
  • Ayanna Howard, Engineer—Robotics Pioneer, and
  • Read more