Time travel makes great science fiction, but can it really be done? Travel into the future is already a reality, but visiting the past is a much tougher proposition, and may require fantastic resources such as a wormhole in space. Nevertheless, if going back in time is allowed, even in principle, then what about all those paradoxes that make time travel stories so intriguing?
Paul Davies is a physicist, cosmologist and astrobiologist at Arizona State University, where is Director of the Beyond Center for Fundamental Concepts in Science. He is the author of many books, including “How to Build a Time Machine” and, most recently, “The Eerie Silence: are we alone in the universe?”
The visual system has developed to allow us to navigate in a complex and dangerous world in order to find food and to avoid danger.
This survival system works by building a complex three-dimensional model based on two-dimensional data from the retina.
This model is tested against “reality” and checked with information from other senses and updated if needed. The brain suppresses the complexity of this processing and we believe that vision is instantaneous, real and effortless.
But is seeing just an illusion?
This is a part of Professor William Ayliffe‘s 2010/2011 series of lectures as Gresham Professor of Physics. The other lectures in this series include:
Via Gresham College a lecture by Professor Ian Morison on the violent universe:
A look at the most violent events that occur in our Universe, from supernovae and hypernovae to the cause of gamma ray bursts and what was the biggest explosion of all – the Big Bang origin of the Universe itself.
Ian Morison began his love of astronomy when, at the age of 12, he made a telescope out of lenses given to him by his optician. He attended Chichester High School and then went on to study Physics, Mathematics and Astronomy at Hertford College, Oxford. In September 1965, he became a research student at the University of Manchester’s Jodrell Bank Observatory. In 1970 he was appointed to the staff of the Observatory and teaches astronomy at the University of Manchester.
In 1990 he helped found the Macclesfield Astronomy Society which meets at the Observatory and later became president of the Society for Popular Astronomy, the UK’s largest astronomical society. He remains on the Society’s Council and holds the post of instrument advisor helping members with their choice and use of Telescopes.
He lectures widely on astronomy, has co-authored books for amateur astronomers and writes regularly for the UK astronomy magazines Astronomy Now and Sky at Night. He also writes a monthly sky guide for the Observatory’s web site and produces an audio version as part of the Jodrell Bank Podcast. He has contributed to many television programmes and is a regular astronomy commentator on local and national radio. Another activity he greatly enjoys is to take amateur astronomers on observing trips such as those to Lapland to see the Aurora Borealis and, last year, to Turkey to observe a total eclipse of the Sun.
In 2003 the Minor Planets Committee of the International Astronomical Union named asteroid 15,727 in his honour citing his work with MERLIN, the world’s largest linked array of radio telescopes, and that in searching for intelligent life beyond our Solar System in Project Phoenix.
You can find a transcript and Powerpoint of the lecture here.
A 6-part documentary series from the UK’s Channel Four in which Niall Ferguson asks why it was that Western civilization, from inauspicious roots in the 15th century, came to dominate the rest of the world; and if the West is about to be overtaken by the rest. It accompanies his book Civilization: The West and the Rest.
Ferguson reveals the killer apps of the West’s success – competition, science, the property owning democracy, modern medicine, the consumer society and the Protestant work ethic – the real explanation of how, for five centuries, a clear minority of mankind managed to secure the lion’s share of the earth’s resources.
Competition: The first programme in the series begins in 1420 when Ming China had a credible claim to be the most advanced civilization in the world: ‘All Under Heaven’. England on the eve of the Wars of the Roses would have seemed quite primitive by contrast.
Science: In 1683 the Ottoman army laid siege to Vienna, the capital of Europe’s most powerful empire. Domination of West by East was an alarmingly plausible scenario. But Islam was defeated: not so much by firepower as by science.
Property: Professor Ferguson asks why North America succeeded while South America for so many centuries lagged behind. The two had much in common (not least the subjugation of indigenous peoples and the use of slavery by European immigrants), but they differed profoundly on individual property rights, the rule of law and representative government.
Medicine: The French Empire consciously set out to civilize West Africa by improving public health as well as building a modern infrastructure. Yet in other European empires – notably Germany’s in southwest Africa – colonial rule led to genocide. What was the link from medical science to racial pseudo-science?
Consumerism: Today the world is becoming more homogenous and, with increasingly few exceptions, big-name brands dominate main streets, high streets and shopping malls all over the globe.
Work: The sixth element that enabled the West to dominate the rest was the work ethic. Max Weber famously linked it to Protestantism, but the reality is that any culture, regardless of religion, is capable of embracing the spirit of capitalism by working hard, saving, and accumulating capital.
ABC: For many, the arguments surrounding global warming and the ways to combat it can be convoluted and confusing. Delivering the first of the Sydney Ideas lectures for 2010, world renowned climate scientist Michael Oppenheimer outlined the evidence for global warming and explained how it was gathered.
Michael Oppenheimer is a Professor of Geosciences and International Affairs at Princeton University. He was the Lead Author on the third and fourth assessment reports of the Intergovernmental Panel on Climate Change, published in 2001 and 2007 respectively. Before joining the faculty at Princeton, he spent 20 years as chief scientist at The Environmental Defence Fund.
Also available on fora.tv. Length: 95 minutes 31 seconds (intro until 6:40, Q&A starts around 70 minutes).
The amazing Voyager spacecraft have been in the news again recently as they are about to leave the solar system. NPR’s Science Friday today had an interview with former Voyager chief scientist Ed Stone:
The Voyager 1 spacecraft is now 11 billion miles from Earth, speeding along at 38,000 miles per hour towards the edge of the heliosphere, the bubble that surrounds the solar system. Voyager chief scientist Ed Stone discusses the craft’s discoveries about the environment at the edge of the solar bubble.
Imagine a world where disease could be eradicated by an injection of tiny robots the size of molecules. That is the hope offered by nanotechnology – the science of microscopically small machines. But others fear nanotechnology could lead to a non-biological cancer – where swarms of tiny nanobots come together and literally devour human flesh.
Sounds like science fiction? It certainly did until a brilliant young scientist called Hendrik Schön seemed to bring it a step closer.
Schön’s great breakthrough was to make a computer transistor out of a single organic molecule. It was an achievement of almost incalculable brilliance. Some speculated this technology could spell the end of the entire silicon chip industry.
Crucially, Schön’s transistor was organic. Suddenly, this seemed to be the first step towards true nanotechnology, where minute computers could grow as living cells.
Scientists speculated about how these tiny machines could be used to target diseases with astonishing precision. Others wondered – could the military use them as a new weapon? Others, including Prince Charles, were terrified. If these machines can grow by themselves, how do we stop them from growing?
“The amazing thing about Hendrik was that everything he touched seemed to work.”
~ Professor Paul McEeun, Cornell University
What happened next would destroy reputations and shatter lives – because there was more to Hendrik Schön’s discovery than anyone knew.
Via 
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