For a man who spends his days pondering the climatic catastrophes and geological disasters that will wipe out large chunks of the human population, this week's guest Prof Bill McGuire of the Benfield UCL Hazard Research Centre is a surprisingly cheery chap. James Randerson and the team discuss his latest book Seven Years to Save the Planet and ask whether it is already too late.

Welcome to Science Weekly, the show that combines chin-stroking discussions about the nature of free will with a rap about particle physics.

A fast and furious show from Alok Jha and the Science Weekly team this time around - and it has nothing to do with an octogenarian tortoise who may be about to become a father. Here's to an end to loneliness, George!

This week, Alok Jha and the Science Weekly team are joined by Jelena Bekvalac from the Museum of London and Emily Sargent, a curator from the Wellcome Collection. They're in the pod to talk about 'London's Buried Bones' - a new exhibition featuring a range of samples from over 17,000 skeletons. Can the study of ancient bones really reveal the story of an entire city?

You can see some of the skeletons in the Wellcome exhibition here, with an explanation of what they tell us about their former owners.

This week's special guest is Steve Miller, who's been looking at the often fractious relationship between scientists and journalists. He wanted to find out whether the stereotype - that scientists are unhappy with the way their research is presented in newspapers and on TV - is actually true.

This week, the Science Weekly team discuss dark energy and the even darker matter of the gender gap with astrophysicist Sarah Bridle - recipient of a Women in Science fellowship. It's sponsored by a well-known cosmetics company - is it worth it? Do awards like this actually help to de-beard science? And isn't this a wider societal problem anyway?

It's been a busy seven days in podland, and this week we have two programmes for your aural delectation.

This week, Alok Jha is joined by environmental campaigner Bryony Worthington. She's the founder of sandbag.org.uk - probably the most creative anti-climate change website around. Environment correspondent David Adam is on hand to lend his expertise to the discussions about energy policy, pollution and cleaner fuels.

Photograph: Carsten Koall/Getty

This week, the Science Weekly team discuss solar power, light conversion and clean power as we hear from Dan Nocera, the MIT professor who believes chemistry can solve the energy crisis. If you're interested in more of what he has to say, his full half hour conversation is this week's Science Extra podcast. Oh, and if you want to admire his beard, head here.

This week, Alok Jha is joined by science writer Piers Bizony to talk about the future of personal space travel. They ponder why, forty years after the Apollo missions, and even with near-miraculous advances in technology, it's taken us so long to get private individuals up into space. Piers' new book, How to Build Your Own Spaceship, is out now.

This week Alok Jha and the Science Weekly team hear from Lisa Jardine, the new head of the Human Fertilisation and Embryology Authority. She gives us her reaction to the recent embryology bill; tells us about battling with religious dogma; and explains why she thinks infertility should be taught as part of the sex education curriculum. You can read more of her thoughts in our health editor Sarah Boseley's article here.

This week, Alok Jha is joined by science writer Simon Singh, who has just co-authored a new book with Edzard Ernst - the world's first professor of complementary medicine - putting homeopathy, placebos and quackery in the dock. Have a listen to our full, half-hour conversation with Simon as this week's Science Extra.

Ahead of its grand re-opening later this summer, Alok Jha and the Science Weekly team this week celebrate 200 years of science communication at the Royal Institution as they are joined in the pod by two of the RI's most distinguished members - science historian Frank James and nanotechnologist Quentin Pankhurst .

We take a trip through the human head this week with scientist, philosopher and poet, Raymond Tallis. He thinks the brain gets too much of the attention whenever people talk abut the head and his new book, The Kingdom of Infinite Space, aims to put the story straight. Be warned: it's a story of vomiting, mucus, baldness, snogging and smoking. You can listen to our extended conversation with Prof Tallis as this week's Science Extra podcast.

What can the climate of the past tell us about the future? Chris Turney is in the pod to help us decipher the messages from extreme weather in the Earth's history. He's a professor of physical geography at Exeter University, where he researches past climate change and what it means for the future, and has recently published a new book, "Ice, mud and blood - lessons from climates past".

This week, Alok Jha and the Science Weekly team discard the hyperbole and headlines about creating artificial life to discuss the very real future of synthetic biology - unquestionably one of the most exciting fields in science today.

This week we hear from Colin Blakemore, one of the most powerful scientists in the country, who recently stepped down from his position as chief executive of the Medical Research Council. He tells us about his experiences as the bête noire of the animal rights lobby, and highlights the big scientific and technological challenges that will face the UK in the coming years.

When did the western world start to think scientifically? That's the question we're asking as science writer Phillip Ball joins Alok Jha and the Science Weekly team in the pod to shed light on a crucial but hidden story in the history of rationalism.

In a week that sees the inaugural conference of the UK National Stem Cell Network, the latest edition of Science Weekly features Doug Melton, co-director of the Harvard Stem Cell Institute and one of the world's leading researchers in the field.

Helping Science Weekly to celebrate its second birthday this week, environment writer Fred Pearce joins Alok Jha and James Randerson in the studio. Fred's latest book concerns his mission to find out where all of our 'stuff' comes from. But if you think you're about to be subjected to an aural assault of environmental worthiness, fear not. As Fred says, 'I'm not a tree-hugger. I'm a humanist. I just want solutions that place people at the centre of things.'

Education should, in my view, be lifelong, writes AC Grayling. We should be seeking to learn and re- learn, to keep up to date, to challenge our own assumptions, to reflect, and to change our minds when logic and the evidence compel. Few disagree with this sentiment, but few act on it either: an odd anomaly, given the pressure that rapid and complex change applies to us all in our speeded-up phase of history.

This week, James Randerson and the Science Weekly team get a tour through biodiversity and conservationism with EO Wilson, one of the world's most influential living biologists.

What is the point of studying English or most of the social sciences. I wasted most of educational life reading novels and nodding at poetry, does it really mean I comprehend beauty with a keener eye than a biochemist?

We're all for blurring the lines between science and the arts, and this week James Randerson and the Science Weekly team discuss science, fiction and 'lablit' with our special guest, Dr Jennifer Rohn.

This week, James Randerson is joined by brain and cognition scientist Dr Martin Monti to discuss the computerised mind-reading technique that, one day, raises the possibility of being able to visualise a person's thoughts or even their dreams.

Prof Alan Sokal, the man whose spoof paper arguing that gravity is a social construct made it into a respectable journal of postmodern cultural studies in 1996, gave this year's Sense About Science annual lecture. The lecture is introduced by the science writer Matt Ridley and you can hear it as a Guardian exclusive podcast here.

This week, James Randerson is joined in the pod by Ian Sample and Nell Boase to discuss placebos and panaceas, including the new evidence that Prozac and other SSRI antidepressants are little better than sugar pills.

Physics professor Alan Sokal in 1997, a year after his hoax social sciences paper "Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity" was published (Photograph: Najlah Feanny/CORBIS SABA)

This week, Alok Jha speaks to Alan Sokal, the controversial physicist who, in 1996, published an infamous paper that rocked the science world and kick-started the so-called Science Wars.

Welcome to the first international edition of Science Weekly. Podcasting live - sort of - from Toscanini's ice cream store in Boston, Alok Jha and James Randerson round up all the news from this year's annual meeting of the American Association for the Advancement of Science (AAAS).

Despite numerous international agreements on every conceivable aspect of the global environment, eco problems are getting worse not better. According to Prof Larry Susskind - a distinguished expert on disputes between governments over the environment - this is because the way international treaties are put together is fundamentally flawed.

The US public is at a tipping point (to use that favourite journalese cliche) in its attitude to climate change. That's according to Prof John Holdren at Harvard University, who is chairman of the American Association for the Advancement of Science and a passionate advocate for more robust action to curb greenhouse gas emissions.

February 12 is Darwin Day, celebrating the life and influence of the grandfather of evolution, Charles Darwin, who was born 199 years ago. On Saturday the Guardian published the definitive guide to On the Origin of Species, with extracts from key chapters and essays from leading scientists and thinkers including Richard Dawkins and former Bishop of Oxford Richard Harries.

We also mark the occasion by welcoming Cambridge University philosopher Tim Lewens and Nature magazine's Adam Rutherford to the pod. Tim will be giving this year's keynote Darwin Day lecture, while Adam is blogging about On the Origin of the Species on Comment is Free.

Mathematician and author Marcus du Sautoy joins Alok Jha and the Science Weekly team in the pod this week to discuss super symmetries, mathematical mysteries and code-cracking.

The ancient Greek and Renaissance periods are lauded in the history of science, but what about the influence of the Arabic world, writes theoretical nuclear physicist, Jim Al-Khalili:

Last week, Pope Benedict cancelled his visit to Rome's La Sapienza University, where he'd been invited to give the inaugural address.

In a previous speech at the university before he became Pope, he gave his support to the astronomer Galileo's conviction for heresy in 1633 - which, suffice to say, didn't go down well with the students or academics at La Sapienza. Caspar Melville takes up the story:

Seventeen years ago at Rome's La Sapienza University, when he was just plain old Cardinal Ratzinger head of the Catholic Church's Congregation for the Doctrine of the Faith, the modern version of the inquisition, the Pope made a speech which argued that Galileo's' conviction for heresy in 1633 had been just and reasonable given the context of the time.

In the latest Science Weekly podcast Alok Jha and the team are joined by science writer Gabrielle Walker, who tells us about her latest book The Hot Topic: How to Tackle Global Warming and Still Keep the Lights On.

Comedian Adam Bloom joins us to discuss his appearance on a forthcoming Horizon TV documentary about what happens when you are deprived of all your senses. Find out how Adam coped with being locked up for 48 hours in a dark, silent nuclear bunker.

In the latest Science Weekly podcast, Alok Jha and the team are joined by Caspar Melville, editor of the New Humanist magazine, who tells us about a fictional dinner party hosted by Charles Darwin, with scientists Steve Jones and Jerry Coyle in attendance. The other guests are the noted historian John Van Wyhe and our very own James Randerson. Who would you invite to such an occasion and why?

There are big themes and grand ideas this week as Alok Jha and the Science Weekly team address the Edge question for 2008: What have you changed your mind about and why?

Welcome to the first Science Weekly of 2008. Alok Jha and the team are on hand to gaze into their quasi-mystical balls and speculate on what will be the biggest scientific happenings over the next 12 months

Is it that time of year already?

Clearly the answer is yes, so why not spend half an hour in the company of Alok Jha and the Science Weekly team as we look back on the Science Weekly highlights of 2007.

As Sir David King prepares to step down from his position as the UK government's chief scientist at the end of the month, he tells Alok Jha about his legacy and the advice he has for his successor, John Beddington.

This week we discuss the science of nothingness with our guest Oxford physicist Professor Frank Close. Prepare to have your mind blown by such questions as: what is the universe expanding into? What was there before the big bang? And why didn't the big bang happen sooner? Professor Close's new book The Void tackles these brain-teasers and more.

The solution to many scientific mysteries, from the Turin shroud to the identity of the fossilised 'Hobbit' found in Indonesia in 2003, often hangs on dating objects accurately. Dr Chris Turney of Exeter University joins host James Randerson and the team to talk about his new book Bones, Rocks and Stars, which explains how geologists tell the time and the part Turney played in discovering how special the 'Hobbit' really was.

We spend a third of our lives doing it. Going without it will kill you faster than going without food. It has led to some of the seminal moments of human creativity. Sleep is vital to our existence, yet scientists know very little about it. Ken Arnold joins James Randerson and the Science Weekly team to talk about the Wellcome Collection's new exhibition of sleep and dreaming.
(Dreamy harpsichord sound effect, some rights reserved)

Over the past 18 months, we've brought you guests from around the world of science and technology. We've spoken to everyone from Nobel prize winners to air guitar champions; from flirting experts to astronauts. Whilst they've all done amazing things, none of them can lay claim to having climbed mount Everest - and performing scientific experiments whilst they were there. At least not til now.

On the latest Science Weekly podcast, we get a vision of the future by speaking with theoretical physicist Michio Kaku.

On this week's show, the great Steven Pinker comes to the pod to tell us how our use of language reflects our inner- and outer-most thoughts.

This week, we welcome Chris Riley and Duncan Copp to the pod. They're the producers of the extraordinary new documentary, In The Shadow Of The Moon, which tells the story of the Apollo space programme.

DNA pioneer Jim Watson is the subject of much of our show today - he's been raising hackles by making comments on race and genetics and we pick over the bones of last week's furore with Imperial College geneticist, Armand Leroi.

We meet the "warriors against claptrap" who are taking household names such as Pret a Manger and Champney's health resorts to task over their misleading use of scientific language. In the pod and armoured up against the forces of pseudoscience are Tom Sheldon and Alice Tuff of the Voice of Young Science.

Craig Venter is unquestionably one of the most brilliant and controversial characters in the world of genetics. Known by many as the 'Bad Boy of Science', he famously raced an international team of publicly funded researchers to sequence the human genome. Last month, he unveiled his own six-billion letter DNA sequence. In this week's Science Weekly, we hear exclusively about whether he had any fears mapping his own genetic code - and getting a glimpse into his own future. You can hear the rest of the interview as this week's Science Extra - and over the rest of this month, we'll be podcasting more of Ed Pilkington's intimate and insightful conversations with Venter.

It's a space special this week as, on the fiftieth anniversary of the Sputnik 1 launch, we're joined by Dr Chris Welch from Kingston University's Spaceweb programme to discuss the past, present and future of the space race.

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It is quite literally a festival of science on this week's show as we look back on the BA's, er, Festival of Science.

Human chromosomes/AAAS

Philosopher and bioethicist Janet Radcliffe Richards is our special guest this week as we discuss the problems thrown up by the rapid advances in understanding our genes. What use is your personal genome? Should scientists try to create synthetic life-forms, or experiment with hybrid embryos? And just what are the consequences of discovering the so-called skinny gene?

This week Alok Jha and the gang brave the long arm of the law to find two computer geeks from Sweden who are at the top of Hollywood's hitlist. Peter Sunde and Frederik Neij, are two of the founders of Pirate Bay - the biggest destination on the web for anyone looking to download copyrighted content such as movies and TV shows - and let's face it, they are not making much of a secret of what they are up to.

This week, Alok Jha and the Science Weekly team are joined by Simon Lewis, a Royal Society research fellow at the University of Leeds' Earth & Biosphere Institute to discuss the week of eco-protests at Heathrow.

Do you think you're safe posting comments in the Blogosphere? writes Tristan Farrow

Chat rooms monitored. Blogs deleted. Websites blocked. Search engines restricted. People imprisoned for simply posting and sharing information. That's the bleak prospect facing millions of internet users around the globe according to Kate Allen, director of Amnesty International UK, who joined this week's Science Weekly.

Photograph: Domenico Stinellis/AP

This week's Science Weekly has a treat for literary fans: Ian McEwan. The award-winning novelist tells us what draws him to science and revels in the genius of some of his scientific heroes, including E.O. Wilson, Voltaire and Charles Darwin.

Imagine sitting by a California swimming pool surrounded by flowers and hummingbirds and trying to interview the great biologist Francis Crick, writes Sue Blackmore. If it sounds peaceful, it wasn't. At the age of 78 and in failing health, Francis was more than a match for me.

"Now let me say why I think all that's nonsense," he said at one point, and "You ask that only because you're interested in Buddhism". But what a treat it was to be able to delve into his theories of consciousness and discover the reasons why he thinks we'll one day find the neural basis for consciousness.

Our guest in this week's Science Weekly podcast is the nuclear physicist, Jim Al-Khalili. He has a neat sideline in science communication too and was recently awarded the Royal Society's Michael Faraday Prize. This week he'll be presenting a new series called 'Atom' as part of the BBC's 'Science You Can't See' season. (There's a book that goes with the documentary by the way.)

This week's Science Extra podcast is an exclusive interview with the legendary natural history film-maker Sir David Attenborough in which he talks about wildlife documentaries and climate change - the subject of his lecture at this year's Hay Festival earlier this month.

Even some of Sir David's greatest admirers have been critical of his apparently rather ambivalent attitude - until recently - to the problem of global warming. His two-part documentary last year entitled 'Are We Changing Planet Earth?' strongly made the case that man-made climate change is a serious problem. But some were disappointed that he had not been more vocal on the subject earlier.

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