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- Welsh kings: Gruffud ap Llywelyn
- Listen over lunch: Three interesting things
- Gravitational waves: a short reading list
- Enduring love
With Valentines Day round the corner, what better time than now to dip into an extract of the book Enduring Love, by the OU's Meg Barker and Jacqui Gabb?
There’s a lot of advice out there about relationships: self-help books, problem pages, and websites all promising you ‘the secret of staying together’, the rules for keeping your love alive’, or ‘the answer to overcoming relationship problems’. But not much of the advice is based on real-life experience. That’s why we carried out a research study with over five thousand people in long-term relationships. We wanted to find out what they were actually doing to make their relationships work, so that we could share their secrets with you.
An exciting day to be a physicist, as the existence of gravitational waves has been proved as a team finds evidence of their long-postulated existence. Here's a quick reading list:
Nature reports on the discovery:
One hundred years after Albert Einstein predicted the existence of gravitational waves, scientists have finally spotted these elusive ripples in space-time.
In a highly anticipated announcement, physicists with the Advanced Laser Interferometer Gravitational-Wave Observatory (LIGO) revealed on 11 February that their twin detectors have heard the gravitational 'ringing' produced by the collision of two black holes about 400 megaparsecs (1.3 billion light-years) from Earth.
“Ladies and gentlemen, we have detected gravitational waves,” David Reitze, the executive director of the LIGO Laboratory, said at a Washington DC press conference. “We did it!”
One of the team who made the discovery, Martin Hendry, explains how the discovery was made:
The discovery dates back to last September, when two giant measuring devices in different parts of the US called LIGO [External link] (Laser Interferometer Gravitational-Wave Observatory) caught a passing gravitational wave from the collision of two massive black holes in a faraway galaxy. LIGO is what we call an interferometer, consisting of two 4km “arms” set at right angles to each other, protected by concrete tubes, and a laser beam which is shone and reflected back and forth by mirrors at each end.
When a gravitational wave passes by, the stretching and squashing of space causes these arms alternately to lengthen and shrink, one getting longer while the other gets shorter and then vice versa. As the arms change lengths, the laser beams take a different time to travel through them. This means that the two beams are no longer “in step” and what we call an interference pattern is produced – hence the name interferometer.
If you're not a physicist, you might be wondering why you should be getting excited. A physicist explains:
Given that these ripples are so small and so difficult to detect, why have we made such an effort to find them – and why should we care about spotting them? Two immediate reasons come to mind (I’ll leave aside my own interest in simply wanting to know). One is that they were predicted by Einstein 100 years ago. Confirming the existence of gravitational waves therefore provides further strong observational support for his general theory of relativity.
In addition, the confirmation could open up new areas of physics such as gravitational-wave astronomy [External link] . By studying gravitational waves from the processes that emitted them – in this case two merging black holes – we could see intimate details of violent events in the cosmos.
Some alarming news this morning for fans of listening to things, as the growing losses at Soundcloud have put that platform at risk of closure. It seems like today might be a day to celebrate the service while it still exists - so here's three interesting things drawn from the hundreds of thousands hosted on Soundcloud:
First, from the British Library, Richard Nixon's deputy assistant shares his memories of the only President to resign, and life in the White House at a time of scandal:
Second: From The Guardian, food writer Bee Wilson explains why we've lost the art of eating - and why regaining that might be more valuable than detoxing:
Finally, in this rummage through what's on offer - The OU's Chancellor Martha Lane Fox talks about personal confidence and facing your fears, in this feature from the Telegraph's Wonder Women team:
This week we're exploring some of the rulers who exercised power over one or more of the kingdoms which are part of modern-day Wales. Yesterday, we focused on Cadwallon Lawhir ap Einion; today, we're meeting Gruffydd ap Llwyelyn.
Gruffydd ap Llywelyn was king of Wales. Indeed, he was king of the Britons, ruling between 1055CE and 1063CE. (Every schoolboy will note that this is before the Battle of Hastings.)
His first powerbase, though, was Powys, a realm to which he added Gwynned in 1039. From here, he fought an aggressive campaign to add the other parts of Wales to his kingdom. Hywel ap Edwin was the first to fall, with Deheubarth coming under Gruffydd's control in the same year.
It would take a further fifteen years before the other princes and leaders were defeated, crushed or cajoled, but by 1055 Gruffyd was ruling over an area more-or-less the shape of modern Wales - the first time all these areas had been unified under a single leader.
Now, his attention would turn to the border with the English. Aa alliance with the disgruntled Aelfgar, scion of the earls of Mercia, led to a fight with the English in Herefordshire. Harold - the soon-to-be King Harold, still a decade away from his painful starring role on the Bayeux Tapestry - intervened personally and peace was restored for a while. But only until Loefgar was appointed Bishop of Hereford.
Loefgar is notable for two reasons - one, tales of his exploits have been cut and pasted into a document which is used in a bid to hide unlicenced media files from copyright holders; two, he was very warlike. Even by the standards of bishops of the time, he had an unnatural desire to command armies. He launched an attack on the Welsh; again Harold was drawn in; but this time it was no quick affair. Although the Welsh were eventually repulsed, it was at the cost of heavy losts for Harold's army.
The conflict bubbled for a while, flaring up first in 1058, and then again in 1063. By now, Aelfgar had become Earl of Mercia, and had developed a personal beef with Harold into which Wales was drawn. When the English attacked in 1063, Gruffudd couldn't escape; he was caught, and killed.
With him went the united kingdom; Wales again split into small, constituent kingdomlets and principalities. It was a terrible weakening at a time when Norman might was about to overwhelm their neighbours to the east.