BBC BLOGS - Gregory's First Law

Archives for April 2011

What the Cadbury Creme Egg teaches us about science

David Gregory | 09:13 UK time, Saturday, 23 April 2011

I found this via @maggiephilbin and @loudmouthman on Twitter. Who knew our local chocolate maker could contribute so much to science?

Happy Easter! You can stay up to date with this blogs RSS feed or by following me on Twitter too! @davidacgregory And a tip o' the hat to the University of Nottingham too.

Wildlife survey details

David Gregory | 10:18 UK time, Thursday, 21 April 2011

Narrow boat

Today I've been reporting on the British Waterways Wildlife Survey. This is an annual event that relies on the Great British Public keeping their eyes peeled and making a note of what wildlife they see around our canals and rivers.

Our waterways provide very useful uninterrupted routes for wildlife that allows easy movement between habitat rich areas. This year the survey is particularly interested in bats who often make a home in the roofs of canal tunnels and feed on the insects attracted to water.

You can find a guide on what to look for here as well as a survey form here. Although the focus is on bats all wildlife sightings are useful. Genelle tells me the weather for the Easter Weekend is looking great so it's a great chance to enjoy the sun and help our Midlands wildlife.

How to survive digital tv switchover

David Gregory | 17:07 UK time, Wednesday, 13 April 2011

So the countdown begins to September and the remaining part of the Midlands switching off the analogue tv signal and going totally digital. Here is what I learned from the first stage of the switchover which will pretty much answer any questions you may have come autumn.

"Help! BBC Two has disappeared!"

You are watching analogue tv and you need to buy a new digital tv or set top box as you are about to lose all four or five tv channels you watch.


"Help! I can't get ITV/Channel 4/Ch5/other channels on my Freeview box!"

You have to retune your digital tv or set top box as part of the switchover. If you only "add channels" then the process doesn't always work you need to do a "full retune"


"Help! I can't get ITV/Channel 4/Ch5/other channels on my BRAND NEW Freeview box!"

If you get your TV via a smaller television transmitter linked to a larger main transmitter then switchover is the first time you will get a digital signal. But it takes two weeks to complete the switchover and the BBC channels go digital first followed by the commercial ones. So for two weeks you'll have to switch between analogue and digital to get the BBC and ITV for example.


"Help! Do I need to worry if I have satellite or cable?"



"Do I still need my ariel booster?"

No. The new digital signal is much stronger so keeping the booster may well no longer solve problems but actually cause them. Try switching it off. In the end it seems to be freeview/top-up tv or BT Vision viewers that are caught out by digital switchover. Not realising they will have to retune their set top boxes and tvs. The advice that seemed to solve the most problems for the first half of switchover? Turn off ariel boosters, turn the box on and off and do a FULL retune. If that doesn't work call 08456 50 50 50 or click

Read the rest of this entry

Behind the scenes of digital tv switchover

David Gregory | 17:20 UK time, Tuesday, 5 April 2011

The radiator powered by tv signals

This is a radiator but it doesn't use electricity or hot water to produce heat. Instead this radiator produces warmth using television. That's because the people running the Wrekin television transmitter are testing the new digital television systems. But since they're not being broadcast yet they have to go somewhere and all the energy is dumped into this piece of kit, turning it into a very unusual radiator.

Discussing digital switchover means I don't always get into just how much is involved behind the scenes in making it all work. Apart from this rather special radiator the teams have also used helicopters to lift new digital components into place on the existing transmitters. The one on the Wrekin weighed four tonnes. And tonight those teams will begin the disconnecting, turning off and reconnecting to start digital switchover. They have a big list to make sure they do everything in the right order.

Tomorrow morning if all has gone well then analogue viewers will find BBC Two has gone and BBC One is now in it's place. Meanwhile Freeview viewers will have to retune their tvs and boxes. That's because the BBC digital signal will be turned up to high power. So far digital tv has been broadcast at a lower power level to avoid interfering with the analogue signal.

Then after two weeks all the analogue tv channels will be turned off and the rest of the digital channels will also have their power turned up. Freeview viewers will also have to retune for a second time. And then the whole process starts again in September when the remaining Midlands transmitters, including Sutton Coldfield, make the switch.

Viewers who need to prepare for digital switchover will see a caption like this one

If you are still unsure when your transmitter will be going digital there's one final obvious clue to look out for. Analogue tv signals now carry an onscreen caption, like the one shown in this picture, to warn you what is about to happen. And on Freeview there's an onscreen caption warning you you will have to retune. If you can't see a caption there's no need to worry just yet.

In the meantime if you have any questions do call the help line on 08456 50 50 50. They can help with anything you might be worried about. They even have all the manuals for all the tvs, recorders and set top boxes to explain how to go about returning them.

Don't forget there is free help and equipment for those that qualify and you can learn more about that scheme from this earlier blogpost and leave any other questions or thoughts in the comments and we'll do our best to answer them.

Hawkear. The future of bell ringing

Post categories:

David Gregory | 16:02 UK time, Friday, 1 April 2011

The bells of Birmingham cathedral

It turns out when the twelve bells of Birmingham Cathedral are being rung the whole tower sways to the rhythm of the bells themselves. I only noticed as I was wedging myself in a corner to stay out of the way of the ringers. And as the circle of bell ringers reversed their direction so too did the motion of the tower. I dread to think what it was like for my poor cameraman above me filming the bells themselves. I've been told at the top of the tower you can get quite seasick.

We were here to report on "Hawkear" a new technical aid for judges in bell ringing competitions. It's been in development in Birmingham for five years now. Microphones are positioned in the top of the bell tower and they record every time a bell is struck. The data is fed into a computer which can then work out the accuracy achieved by each team of bell ringers.

One of the

The end result is a simple number, the error rate for each competing team. I assumed that a perfect result for a team would be to achieve an error rate as close to zero as possible. But in fact as bell captain Richard Grimmett explained to me that would produce a soulless sounding peal of bells that would be pretty unappealing to listen to.

The aim isn't to replace judges but rather to supply extra back-up. On Saturday there will be seven teams playing the same twelve minute peal ("Cambridge Surprise Maximus") in competition and each team will play 3456 notes. It's not surprising that the judges might lose focus during the three and a half hour competition. That's where hawkear comes in.

For the teams the system produces reams of data that the teams can take away with them. But as Richard pointed out you wouldn't want to achieve a perfect hawkear score because bell ringing is not just a science it's also an art.


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