f national newspapers through News International such as the most popular tabloid The Sun and the longest-established daily "broadsheet" The Times, as well as holding a large stake in satellite broadcaster British Sky Broadcasting. London dominates the media sector in the UK: national newspapers and television and radio are largely based there, although Manchester is also a significant national media centre. Edinburgh and Glasgow, and Cardiff, are important centres of newspaper and broadcasting production in Scotland and Wales respectively. The UK publishing sector, including books, directories and databases, journals, magazines and business media, newspapers and news agencies, has a combined turnover of around £20 billion and employs around 167,000 people.
In 2009 it was estimated that individuals viewed a mean of 3.75 hours of television per day and 2.81 hours of radio. In that year the main BBC public service broadcasting channels accounted for an estimated 28.4% of all television viewing; the three main independent channels accounted for 29.5% and the increasingly important other satellite and digital channels for the remaining 42.1%. Sales of newspapers have fallen since the 1970s and in 2009 42% of people reported reading a daily national newspaper. In 2010 82.5% of the UK population were Internet users, the highest proportion amongst the 20 countries with the largest total number of users in that year.
The United Kingdom is famous for the tradition of 'British Empiricism', a branch of the philosophy of knowledge that states that only knowledge verified by experience is valid, and 'Scottish Philosophy', sometimes referred to as the 'Scottish School of Common Sense'. The most famous philosophers of British Empiricism are John Locke, George Berkeley and David Hume; while Dugald Stewart, Thomas Reid and William Hamilton were major exponents of the Scottish "common sense" school. Two Britons are also notable for a theory of