Horizon and I are old buddies. Both of us have been on this earth for roughly the same length of time -- although the programme still has two years to go before it hits 50, while my big Hawaii Five-O is sadly no longer a shimmering line on the, erm, horizon.
The BBC4 special The Final Frontier? was a sort of rehearsal for that significant birthday. Guided by Dallas Campbell, from Bang Goes the Theory, it started with some audio from John F Kennedy's 1961 speech about putting a man on the Moon by the end of the decade and ended, bang up to date, with Nasa landing the Curiosity rover on Mars.
In between those two points was a kind of compilation of Horizon's greatest hits -- or at least those that related directly to our understanding of the universe. People who accuse Horizon, largely unfairly, of dumbing down over the decades (there's nothing stupid about making hard science accessible to the common people) will have found little to quibble about here.
The 1969 Apollo 11 Moon landing remains "the greatest voyage of discovery we humans have ever undertaken", said Campbell, but while the desire to explore and enquire is as strong as ever, what's been most notable is that the major discoveries about the universe we live in have all happened right here on Earth.
Isaac Newton came up with his Law of Gravity, which proved that the movement of everything in the universe can be predicted with clockwork-like precision, when an apple fell on his head in a Lincolnshire garden.
Cue a clip of Professor Brian Cox wandering around an orchard (in search of a Cox's pippin, perhaps).
Three centuries later, Albert Einstein posited his mind-bending, time-bending, space-curving Theory of Relativity. now there's a hard one to explain and Horizon has tried damn hard over the years to do so. As a wonderful montage showed, it's gamely used everything from marbles on a cloth, to knicker elastic with little stars sewn on, to a block of jelly -- which, like the universe, is wobbly.
In a lovely clip from 1978, a steam train and eight trumpeters were employed to demonstrate the Doppler Shift, which lets us know, via pitch, whether a sound is moving towards or away from us.
Astronomer Edwin Hubble discovered, from peering through the Hooker telescope, then the largest in the world, that you could measure light the same way and set out to discover the age of the universe. But the world would have to wait until the invention of the space telescope named in Hubble's honour -- which, as we were reminded, initially didn't work because of a tiny flaw in its mirror -- before we learned that the universe is 13.7 billion years old.
The big question science has been striving to answer is whether there is life on other planets, yet The Final Frontier? ended by posing one just as intriguing: if the Big Bang created the universe, what created the Big Bang? I expect Horizon will still be around in 50 years' time when someone finds out, even if I won't.
Emmerdale celebrated its 40th birthday with, as seems to be the norm in British soaps these days, an hour-long live episode. You watch this kind of thing waiting for something to go wrong -- an exploding light, a collapsing prop, an actor fluffing their dialogue.
In the event it went well, with nothing more disastrous than boring busybody Betty briefly stumbling over a line.
The plot was heady stuff: two weddings, two births and evil Carl King being battered to death by two different characters using the same polystyrene brick.
It was a complicated and challenging feat of TV production graced by some energetic, above-par performances from the regulars. There was a time when all TV dramas went out live, but I'm not so sure there's much to be gained from doing it that way now.
the final frontier? A Horizon guide to the universe HHHHI Emmerdale live HHHII