Tag Archives | Physics

In the Beginning was the Code: Juergen Schmidhuber at TEDxUHasselt

The universe seems incredibly complex. But could its rules be dead simple? Juergen Schmidhuber’s fascinating story will convince you that this universe and your own life are just by-products of a very simple and fast program computing all logically possible universes.

Juergen Schmidhuber is Director of the Swiss Artificial Intelligence Lab IDSIA (since 1995), Professor of Artificial Intelligence at the University of Lugano, Switzerland (since 2009), and Professor SUPSI (since 2003).

He helped to transform IDSIA into one of the world’s top ten AI labs (the smallest!), according to the ranking of Business Week Magazine. His group pioneered the field of mathematically optimal universal AI and universal problem solvers. The algorithms developed in his lab won seven first prizes in international pattern recognition competitions, as well as several best paper awards.
Since 1990 he has developed a formal theory of fun and curiosity and creativity to build artificial scientists and artists.… Read the rest

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Is String Theory About to Unravel?

trailfan (CC BY 2.0)

trailfan (CC BY 2.0)

via Smithsonian:

In October 1984 I arrived at Oxford University, trailing a large steamer trunk containing a couple of changes of clothing and about five dozen textbooks. I had a freshly minted bachelor’s degree in physics from Harvard, and I was raring to launch into graduate study. But within a couple of weeks, the more advanced students had sucked the wind from my sails. Change fields now while you still can, many said. There’s nothing happening in fundamental physics.

Then, just a couple of months later, the prestigious (if tamely titled) journal Physics Letters B published an article that ignited the first superstring revolution, a sweeping movement that inspired thousands of physicists worldwide to drop their research in progress and chase Einstein’s long-sought dream of a unified theory. The field was young, the terrain fertile and the atmosphere electric. The only thing I needed to drop was a neophyte’s inhibition to run with the world’s leading physicists.

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2 Futures Can Explain Time’s Mysterious Past

In the evolution of cosmic structure, is entropy or gravity the more dominant force? The answer to this question has deep implications for the universe's future, as well as its past.  Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team

In the evolution of cosmic structure, is entropy or gravity the more dominant force? The answer to this question has deep implications for the universe’s future, as well as its past.
Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team

via Scientific American:

Physicists have a problem with time.

Whether through Newton’s gravitation, Maxwell’s electrodynamics, Einstein’s special and general relativity or quantum mechanics, all the equations that best describe our universe work perfectly if time flows forward or backward.

Of course the world we experience is entirely different. The universe is expanding, not contracting. Stars emit light rather than absorb it, and radioactive atoms decay rather than reassemble. Omelets don’t transform back to unbroken eggs and cigarettes never coalesce from smoke and ashes. We remember the past, not the future, and we grow old and decrepit, not young and rejuvenated.

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Researchers use real data rather than theory to measure the cosmos

Incase (CC BY 2.0)

Incase (CC BY 2.0)

via Phys.org:

For the first time researchers have measured large distances in the Universe using data, rather than calculations related to general relativity.

A research team from Imperial College London and the University of Barcelona has used data from astronomical surveys to measure a standard distance that is central to our understanding of the expansion of the .

Previously the size of this ‘standard ruler’ has only been predicted from theoretical models that rely on general relativity to explain gravity at large scales. The new study is the first to measure it using observed data. A standard ruler is an object which consistently has the same physical size so that a comparison of its actual size to its size in the sky will provide a measurement of its distance to earth.

“Our research suggests that current methods for measuring distance in the Universe are more complicated than they need to be,” said Professor Alan Heavens from the Department of Physics, Imperial College London who led the study.

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The Strangeness of Force [Debate]

The laws of science were founded on the idea of force. But Newton’s critics argued it was a mystical idea and the Standard model has replaced force with ‘interactions’. Does an account of force elude us because it doesn’t exist, or are forces essential if we are to explain why anything happens?

The Panel 

Philosopher of physics Eleanor Knox, eminent mathematician Peter Cameron and post-postmodern metaphysician Hilary Lawson untangle cause and effect.

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Bohm’s Gnosis: The Implicate Order

Original uploader was Karol Langner at en.wikipedia.

Original uploader was Karol Langner at en.wikipedia.

David Joseph Bohm was an American theoretical physicist who contributed innovative and unorthodox ideas to quantum theory, philosophy of mind, and neuropsychology. He is considered to be one of the most significant theoretical physicists of the 20th century.”

via Bizcharts:

The Cosmic Plenum: Bohm’s Gnosis: The Implicate Order

This article discusses the vision David Bohm intuited from his insight (gnosis) into the quantum world. This vision discerns the characteristics of an evolving cosmos in process; and, also, it ponders upon the implications for humanity. Bohm’s scientific presentations are not in this article; however, they can be found in his books listed in the Reference Section at the end of these series of articles.

BOHM AND THE IMPLICATE ORDER: AN INTRODUCTION

David Bohm, an American, was one of the leading quantum physicists of our age. He died recently. Following a venerable career at the University of California (Berkeley) and at Princeton’s Institute of Advanced Studies, he moved to become Professor of Theoretical Physics at Birkbeck College of the University of London.

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Learn physics with CERN’s John Ellis in ‘A Brief Guide to Everything’

iai-academy

Last month, The Institute of Art and Ideas (IAI), an organization committed to spreading “a progressive and vibrant intellectual culture in the UK,” launched IAI Academy — a new online educational platform that features free courses in everything from theoretical physics to the future of feminism. Get up to speed with what physicists do and don’t know with CERN physicist John Ellis’ ‘A Brief Guide to Everything’ or discover the meaning of life with sociologist Steve Fuller.

The initial lineup has 12 courses – here’s the list:

  • A Brief Guide to Everything – Web Video – John Ellis, King’s College London, CBE 
  • The Meaning of Life – Web Video – Steve Fuller, University of Warwick
  • New Adventures in Spacetime – Web Video – Eleanor Knox, King’s College London
  • Minds, Morality and Agency – Web Video – Mark Rowlands, University of Miami
  • Nine Myths About Schizophrenia – Web Video – Richard Bentall, University of Liverpool
  • The History of Fear – Web Video – Frank Furedi, University of Kent
  • Physics: What We Still Don’t Know – Web Video – David Tong, Cambridge
  • Science vs.
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Your Food Is Always Outside Of You: Some Ideas About Space But Definitely Not Time

via Ian Kilgore’s blog:

Here’s the original abstract of the talk:

YOUR FOOD IS ALWAYS OUTSIDE OF YOU

(Some Ideas About Space But Definitely Not Time)

ABSTRACT:

I’m going to, in an accessible way, cover some mathematical and physical ideas that I think are important or at least pretty cool. (CHILL. OUT.) You probably spent a lot of time in grade school factoring polynomials or whatever. I don’t care about that. I want to talk about why orbits work, what happens in 5-D, why the World Series is slightly better than a coin toss, databases are broken forever, truth itself is wrong, and what happens if an infinite number of buses roll up at your house. Or some subset of that.

I’ll cover three or four discrete topics, so don’t worry if you get lost; you’ll be following along again in a few slides. Any equations will be supplementary only- you won’t have to understand them to get the general idea.

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An infinite multiverse: a bad idea or inescapable?

Stanislav Sedov (CC by 2.0)

Stanislav Sedov (CC by 2.0)

via Ars Technica:

Earlier this week, a cultural center in Red Hook, Brooklyn played host to the sort of debate that’s usually reserved for smoke-filled dorm rooms: do we live in a multiverse and, if so, is there another you out there?

But rather than mind-altered undergrads, the debate took place among three physicists, one of whom happens to have a Nobel Prize sitting back home.

The debate was held at Pioneer Works, a nonprofit center that places artists’ studios next to a space for scientists-in-residence, mixing in a high-tech microscopy company and 3D printers for good measure. It’s mostly known for the classes it offers, which range from crafts from lockpicking and programming to learning how to play a theramin. But Pioneer Works is starting a series on controversial scientific topics, and the multiverse is the first one it chose to tackle.

It made some excellent choices to handle it.

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Dreams of the Universe: Is Particle Physics Unscientific?

From string theory to the multiverse, the theories of modern physics look increasingly exotic and untestable. But while they may be good for selling books, are they bad science? Do we need a return to empirical experiment, or should imagination be allowed its playground?

The Panel
Cambridge string theorist David Tong, experimental physicist Tara Shears, and author of The End of Science John Horgan seek the place where facts and fantasy collide.

This lecture was submitted via the Disinfo contact page.

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