The first thing you see when you arrive at the $35m museum is very large toy dinosaur, right outside the main entrance. Inside, there are many more. Dinosaurs are a bit of a theme here. My guide, Mark Looy, one of the co-founders of the Museum (with Ken Ham and Mike Zovath) explains that dinosaurs were chosen as a key focus of the museum because they attract such intense media attention, interest children and young people, and illustrate some of the decisions about global history that need to be made by biblical Christians. And there hasn't been much of global history according the museum's young earth creationists: in essence, they agree with James Ussher, the 17th century Archbishop of Armagh, that the world was created just six thousand years ago (Ussher was more precise: 23 October, 4004BC). Which means that dinosaurs existed alongside human beings -- and they entered Noah's Ark two-by-two. (Maybe that's why one of the dinosaurs is wearing a saddle; visiting children can have their photograph taken sitting on its back.)

While ten full-time staff continue to work on the Ark project, more than 250 full-time staff are employed by Answers in Genesis in its various ministries, including the museum. Some of these are speakers and demonstrators, travelling to churches and schools across America (and sometimes across the world) to spread the young earth message.

Professional scientists, as you might expect, regard the whole thing as baloney: the Creation "Museum" is a pseudo-scientific theme park and the young earth theory is as far-fetched as astrology. But that dismissive attitude only seems to re-energise those working here in Petersburg: after all, the Bible they read tells them to expect the contempt of the world.

What struck me most about my visit to the Creation Museum was not the science (or pseudo-science, depending on your point of view), but the moral vision of this organisation. Part of the exhibit includes an alleyway covered in graffiti -- an image of a world that's lost its way. The narrative linking these exhibits tells a moral story: a world without the Bible will be plunged into moral chaos. In order to restore the world, the narrative tells us, we need to return to the Bible. And that Prodigal-like return involves us in a hermeneutical decision: do we take the Bible seriously (by which, they mean "literally") or not? Young earth creationists start with that commitment to read the Bible literally, as the inerrant Word of God; they then accommodate "science" to that a priori assumption.

When I talked to one of the Museum's educators, it wasn't long before she was linking their work to culture wars about abortion and homosexuality. This isn't surprising. Young earth creationists believe both are examples of the moral decay that results from an abandonment of biblical values. They fear a world in which non-biblical or post-biblical values might hold sway. That's why they resist modern evolutionary science so much: because it appears (to them) both to threaten the coherence and integrity of the biblical worldview and to devalue the explanatory power of the Bible in their hands. Since their faith is so fundamentally grounded in an inerrantist reading of the Bible, such a significant challenge to the Bible represents an existential and moral assault.

So far, I've been to Philadelphia (America's fifth largest city), Washington DC, Nashville and Dayton in Tennessee, Los Angeles and San Francisco. While in LA, I fell victim to that city's appalling air pollution: you can see the smog hanging over the streets. I caught a bout of acute bronchitis and had to spend eight hours in a downtown hospital's Emergency Department. It's nothing like "ER"; no, I wouldn't recommend it. LA isn't really a city; it's a clump of cities linked together by freeways. I visited Pasadena to meet Richard Mouw, president of Fuller Theological Seminary (now the world's largest seminary) and had lunch with three world-class historians of science at CalTech (the California Institute of Technology).

Also in LA and San Francisco, I met with lawyers and activists working on Proposition 8. That was the California plebiscite which introduced a constitutional ban on same-sex marriage. When it passed, it was a great surprise to everyone, because California is one of the most progressive (and Democrat) states in the Union. Now, two of America's best-known lawyers, Ted Olson and David Boies, are fighting to have the ban declared unconstitutional. Olson was George W Bush's solicitor general, so he's not regarded as a liberal voice in America's culture wars. But marriage equality, he says, is about American justice.

I leave the Grand Canyon tomorrow morning and make the six-hour journey to the airport at Phoenix, then travel to Kentucky for a visit to the Creation Museum to take a close-up look at another of America's culture was: the battle over intelligent design, creationism and the science curriculum.

Clarence Darrow and William Jennings Bryan chat in court during the Scopes Trial.

Scopes was convicted, though the verdict was eventually overturned on a legal technicality. The trial became the first to be nationally-broadcast via the new medium of radio. And Dayton soon became a byword for intellectual intolerance.

Dayton residents today are all too aware of the reputation the town gained in 1925, and many regret the episode entirely -- though most, it would have to be said, are simply uninformed about what actually took place. Dayton's tiny economy benefitted from the two-week trial for about the duration of the media circus, which was very short-lived. Those who concocted the scheme to bring the trial of the century to the town are reported to have regretted their own legal ingenuity before the completion of the court's business. The minimal financial boost was short-lived, but the reputational damage has endured.

Bryan, one of America's best-known politicians at the time (a Democrat, he'd served as Secretary of State and was a two-time presidential nominee), died five days after the trial, while still in Dayton writing a pamphlet about the significance of the case. He was buried in Arlington Cemetary with full military honours. But his final legacy in Dayton itself is Bryan College, founded in 1930 as a Christian university. Today, Bryan is a small liberal arts college with some 800 undergraduates and a full-time faculty of about 50 professors. It employs about 200 local people, and contributes about $35m annually to the Dayton economy.

Outside the courthouse stands a statue of William Jennings Bryan -- the gift of the college on the 75th anniversary of the trial. In the basement of the court you can visit a small museum commemorating the biggest thing that's ever happened in this little town. There you'll find picture boards and artefacts from the event that rocked the Roaring 20s; you buy a copy of the full trial record, or a facsimile of the local newspaper reporting the conviction of the teacher who, we now know, may never have even read any Darwinian evolution, let alone taught It. Walk upstairs and you can sit in the actual seats used by the jury or sit behind the actual desk where Darrow and Bryan piled their science books and Bibles respectively.

The Dayton trial teaches us many things about religious culture wars. Perhaps its greatest lesson is this: it prompts us to dig under the surface of a purported "encounter" between science and religion to find out what was really going on. That's just as true with Dayton and John Scopes as it is with Rome and Galileo.

That said, while I've been visiting Tennessee, the state legislature has passed a new law dubbed by some "The Monkey Bill", which just goes to show that some of the issues in the air at the time of the Scopes trial are still issues for some today.

Land believes the media in the US, with the exception of Fox News, is Left-leaning and biased in favour of Obama. He regards the President as a "statist", indeed a "socialist"' who has massively expanded the federal government. He explains: since the end of World War II, the US federal government's spending has averaged about 20 per cent of GDP. When George W Bush left office, it was 20.8 per cent. Under Obama, it's 25.6. Moreover, under Obama the US national debt increased by 50 per cent in four years -- from $10 trillion to $15 trillion. This isn't just an economic issue for Land, it's also a moral concern. He regards that scale of debt as a form of "generational theft". That's why he believes this next presidential election will be the most important for the US since Lincoln's election in 1860.

He speaks positively about David Cameron, but parts company with him on gay marriage. Many socially conservative Republicans here are struggling to understand why a conservative government in the UK would be campaigning in favour of same-sex marriage. Marriage is open to gay couples in a few US states but 31 others have already passed state-wide constitutional bans on non-heterosexual marriage (while, in a few cases, permitting civil partnerships). Land expects North Carolina to become the 32nd state to do so next month. He also disputes the new polling suggesting that more than 50 per cent of Americans are now in favour of gay marriage: people don't give honest answers to pollsters, he says.

Land will be supporting Romney, the likely Republican candidate, in the presidential election and tells me he believes most evangelicals will do the same. They may regard Mormonism as a cult,as Land does ("it's a cult, but they don't act like a cult"), but when the alternative is Obama their vote will go to Romney.

One of the chapters in Land's book The Divided States of America deals with America's special status in the world. America, he says, is not like any other country: it's less a piece of geography and more like a cause ("and that cause is freedom"). Land believes that "America's particular fortune has not been fortuitous; it is a sign of divine blessing". God, he says, has a particular and special interest in the American project: America is called to be a beacon of freedom in the world and God is personally looking out for it. Many in Europe will see that attitude (sometimes called "American Exceptionalism" or the doctrine of "manifest destiny") as part of the problem. Jim Wallis, founder of Sojourners, equates it with a "theology of empire". But Land dismisses those critiques: just look at the history of the United States, he says, and you'll find all the evidence you need that God is unusually interested in the progress of this place.

Rep. Pete Stark, America's first openly-atheist congressman

Religion is politically important in the US because this is a society with high levels of religiosity, at least by European standards. When asked how important religion is to them, 56 per cent of Americans say it's very important. The British figure is only 17 per cent. It would, however, be a mistake to conclude from this that America is unusually religious. By global standards, religiosity in the US Is mid-range; secularisation in Europe is the exception to the general pattern across the world.

The Catholic population remains stable (mostly due to Hispanic migration) at about a quarter of the population, and the 'other' quarter is made up of smaller religious denominations such as Jews (roughly 2 per cent), Muslims (0.8 per cent) and Mormons (just under 2 per cent). Statistically, the most interesting section of the other quarter is the 'unaffiliated'. This category is one to watch: it's growing significantly, and currently adds up to just under 20 per cent of the entire US population.

'Unaffiliated' includes non-denominational yet spiritually minded people (about 4 per cent), atheists and agnostics (about 4 per cent) and those who happily describe themselves as 'nothing in particular'. These figures come courtesy of the Pew Forum on Religion and Public Life; I spent a very valuable few hours this week visiting the Pew Forum at their headquarters in Washington, DC, and I'm immensely grateful to Alan Cooperman and his team their for their extremely helpful briefing.

Not that these religious 'blocks' are fixed and unchanging. There is considerable switching: one in every ten Americans is a former Catholic, and 44 per cent of US adults have changed their religious affiliation from their original group membership. Migration, as I say, is bolstering the Catholic population, but it is not significantly challenging America's overwhelmingly Christian identity. Contrary to what some culturally paranoid Americans may believe about how immigration is a threat to those values, it turns out that 78 per cent of migrants are in fact Christian.

It's always dangerous to try to predict the future on the basis of trends, but we might risk a few educated guesses. We can expect the Protestant population to continue to drop, and the unaffiliated category to grow. We already have evidence to show that the 'next generation' of evangelicals will differ significantly from previous generations in terms of the values that matter most to them -- which may mean an end to some traditional culture war issues such as gay marriage (which is now supported by more than 50 per cent of the American population). Contrastingly, recent polls suggest that abortion will continue to be a focused issue of concern, both for many Christians, both also, increasingly, as a mainstream concern.

New research from Pew also shows a statistically significant increase in the number of Americans becoming uncomfortable with politicians talking about religion, so future candidates for president or congress may feel less inclined to invent a religious history for themselves or to draw on their own religious narrative in elections.

One politician who is already down-playing his obviously very genuine religious narrative is Mitt Romney. He is clearly worried that his Mormon faith could alienate many voters, particularly evangelicals. I spoke to one leading evangelical this week who speculated that 25 per cent of US evangelicals would never vote for a Mormon (since they regard the church as a cult). But that speculation is challenged by other research which suggests that Romney's so-called 'Mormon Moment' is an issue for the Primaries which will recede in importance once we enter the general election, which will be dominated by domestic economic issues rather than religiously-based culture wars. Another evangelical told me, earlier this week, that he'd probably vote for Romney 'with a heavy heart'. If I had to make a prediction, I'd say that Romney's faith will not ultimately prove to be a deal-breaker for those evangelicals who typically vote Republican.

Instead, this new generation of Christian leader advocates a kind of 'principled pluralism', where difference is protected and respected under the law. That means that you don't outlaw another person's perspective or life-choices simply because they fail to comply with your own theological perspective.

The consequence of this is that the issues that matter to many of those I met today are not the issues that defined evangelicalism in the past. Creationism is not their concern, nor are they particularly animated about homosexuality or climate-change denial. Instead, they care deeply about defeating poverty, extending rights to minority groups (such as illegal immigrants), and taking a stand against human trafficking.

It will be fascinating to see how this new kind of evangelicalism finds its voice during what many predict will be the ugliest and most partisan presidential election in living memory.

This week, I've been meeting the other Fellows here in Philadelphia and attending briefings on American politics, foreign policy and learning more about the meetings that have been scheduled for me during my visit to the US. A highlight so far was our off-the-record seminar with Ambassador William J Burns, who is the US Deputy Secretary of State. A career foreign service official, Ambassador Burns walked us through US foreign policy in various global regions in an extraordinarily insightful session. He took questions and offered us an impressive descriptive analysis of America's place in the world today.

We continue our briefings tomorrow at City Hall: we'll be meeting local councillors, state representatives and federal level politicians, including a current senatorial candidate. Please suggest any questions or topics you think I can helpfully explore in my many meetings, or indeed suggest anyone you recommend I should meet. I'll be recording some interviews as I go for eventual broadcast.

'Big Build 12' will see the first hammer come down on a Roma integration project that will deliver 50 homes over the next three years for families trapped in the cycle of poverty in the town of Caransebes, Romania.

The build will be helping families who are currently living in cramped, unhealthy conditions with no running water or proper sanitation facilities.

No skills are needed just a big heart and the determination to help transform lives! If you would like further information about Big Build you can go along to an information session on Wednesday 28th March, 7-8pm, Common Grounds Cafe, Belfast or visit Habitat for Humanity NI's website (here).

Archbishop of Dublin Diarmuid Martin, Cardinal Sean Brady and papal nuncio to Ireland Archbishop Charles Brown

The Visitation also calls on Irish Catholics to "establish a proper relationship" with the media. Many public commentators have expressed criticism, over many years, of the official Church's media strategy (or lack thereof) in dealing with the abuse crisis in particular. Some priests have, in the past year, expressed concern that the Visitation would turn into a heresy hunt, with the focus on rooting out non-orthodox, radical or progressive ideas: they will no doubt find some comments in these findings to confirm their fears. This sentence in particular will raise some concerns: "It must be stressed that dissent from the fundamental teachings of the Church is not the authentic path to renewal."

Significantly, the findings also comment on the lack of a "common line of action" by bishops in responding the the abuse crisis.

Read the Summary of the Apostolic Visitation here.

The church even offered amendments to the Covenant, which were accepted by the Unionist leaders, and participated in a campaign which took Britain and Ireland to the brink of civil war, with the emergence of the UVF and a provisional Unionist government.

On today's Sunday Sequence, we debated the morality of the church's involvement in the Ulster Covenant. What's your view?

Titanic under construction at Harland and Wolff

The question we asked this week was this: why was this shipbuilding feat completed by an overwhelmingly Protestant workforce? This answer to that question, our guests were agreed, remains a deeply troubling one: Catholic workers were very often excluded from the workforce because of their religion. Some spoke of "clear outs" of those Catholics who were employed at the shipyard. One even said the clear out was so comprehensive that we might properly regard Titanic as itself Protestant. You can listen again to this week's programme here and join the debate yourself.

Have we airbrushed the history of Titanic in this centenary year to make the story more acceptable to tourists?

It was the same with audiences. Other comedians might pause after a well-delivered one-liner and allow the audience a chance to respond, or at least to breathe. Not Frank. The gags came thick and fast, as if he wanted to pummel you into laughter. He was relentless.

In fact, he didn't need an audience to laugh - he provided his own laughter track with every joke. He was never crude, but he had a filthy laugh. His enjoyment of laughter for its own sake was so genuine, so innocent, that you couldn't help but join him. And when he thought you really did need a break, he'd deploy one of his signature catchphrases: "It's a cracker!", or "It's the way I tell 'em".

He was one of those rare comedians who walked on stage to the sound of laughter, the audience half anticipating the experience ahead of them, half remembering the last time they'd hurt themselves because of him.

He came from a city that had experienced a different kind of pummeling through the Troubles, and he saw laughter as respite - an antidote, a distraction, and a bridge between communities. Catholics and Protestants, loyalists and republicans all creased-up when Frank came on, and they've been lining up this week at Belfast City Hall to add their names to a special book of condolence - still laughing. Try to picture that: complete strangers standing in a queue exchanging his best lines, nodding with recognition, groaning, giggling, and sighing just a little. Frank would have loved that.

He became a household name, but it was his Northern Irish audience he cherished above all others. When they laughed together, it was a sign of hope. Some of the jokes were cheesy, some were even cringe-worthy, but they were never cruel. And when they came from Frank, we went from falling out to falling about. You can read scores of tributes to him in the papers this week, but you really need to be in Belfast to feel the depth of our affection for him.

It shouldn't surprise us that one of the causes closest to his heart was the campaign for integrated education in Northern Ireland. He gave his time, his money, and brought his many friends from show-business to make the case for building a shared future for children in a society where people still lead segregated lives.

Frank's first audience wasn't a comedy club. It was Saint Patrick's parish church in north Belfast, where he was a choirboy. He remained a devout Catholic all his life, and the accolade he most cherished came in 1987, when Pope John Paul II awarded him a papal knighthood for his tireless commitment to charity, he was given a private audience lasting 17 minutes. I can only suppose that the Vatican planned a five-minute audience, but they couldn't get Frank to stop talking.

This tribute to Frank Carson was broadcast on BBC Radio 4's Last Word on Friday 24 February (listen here).