BBC BLOGS - Today: Tom Feilden

Archives for July 2009

Celebrating 400 years of the telescope

Tom Feilden | 07:27 UK time, Saturday, 25 July 2009

Picture (Trinity College, Oxford) often said to be of Thomas Harriot
It's exactly 400 years since the Jacobean scientist and draftsman Thomas Harriot first turned his "Dutch Trunke" to the night sky to make a series of observations and drawings of the moon.

The telescope had been invented, probably in Holland, a few months earlier. But it had mainly been used as an amusing way of spying on one's neighbours, and by the navy to spot the colours of far off ships.

It was a profound moment in the history of science. The first time any sort of instrument had been used to augment one of the five senses.

Until then astronomy had been conducted with the naked eye. We saw the same starry sky as Aristotle and Plato, and although Copernicus had suggested that the planets orbited the sun rather than the earth, the geocentric Greek model of the universe still held sway.

But if Harriot was first, it was Galileo who cemented the telescope's place in history. His observations of the moons of Jupiter the following year proved that the earth was not the centre of the universe - and no end of trouble it caused him.

Since then of course the telescope, and the instruments mounted on it, have been refined and improved beyond Harriot's wildest expectations.

Today the biggest ground based telescopes, like those at the Keck Observatory on Mauna Kea in Hawaii, boast mirrors ten metres across. We can see further, and at greater resolution than ever before.

Artist's impression of the European Extremely Large Telescope

With a primary mirror some 42 metres across, and housed in a dome the size of Wembley stadium, the European Extremely Large Telescope, or ELT, will dwarf even the biggest existing instruments. At the moment it exists only in virtual space, but when it's finally built - probably by around 2018 - it will dramatically improve our understanding of the cosmos.

But telescopes enable us to do more than see far off objects in greater detail. Because light travels at a finite speed they're also time machines.

When Harriot pointed his telescope at the moon he was seeing it as it was a couple of seconds earlier. The light from the moons of Jupiter that Galileo observed the following year had taken a few minutes to reach him.

In order to see this content you need to have both Javascript enabled and Flash installed. Visit BBC Webwise for full instructions

By the same token the ELT will study the light emitted by some of the first galaxies to form more than 13 billion years ago.

According to Andy Martin, the author of Beware Invisible Cows, it means that nothing is ever really lost. If we want to know whether Lee Harvey Oswald acted alone, he says, all we need to do is get to a point some 46 light years from earth and train a powerful telescope on the grassy knoll.

It's somehow comforting to think that if there's an advanced civilisation out there inhabiting a planet some 400 light years from earth, and they happen to point their version of the Extremely Large Telescope this way on Sunday, they just might catch a glimpse of Thomas Harriot staring back at them through his Dutch Trunke.

Marking the lunar landings

Tom Feilden | 09:04 UK time, Tuesday, 21 July 2009

It's 40 years since Neil Armstrong, Buzz Aldrin and Mike Collins blasted off from Cape Canaveral on the first leg of a truly epic adventure.

For the first time in history a human being would set foot on another world.

To mark the achievement we've put together a series of pieces and interviews that have kept pace with the mission, from launch day on Thursday the 16th July to the landing and that fisrt small step on the 20th.

Buzz Aldrin on the MoonYou can hear them all here:
Apollo 11 you are go for TLI (16 July 2009)
The miracle of Apollo 11 landing (17 July 2009)
The cultural impact of Apollo era (18 July 2009)
Final preparations for first step (20 July 2009)
Nasa makes plans for Mars landing (21 July 2009)

We're often told - in a rather glib way - what a staggering feat of scientific and technical engineering the lunar landings were, and when president John F. Kennedy set the ball rolling in 1961, many of those involved thought it couldn't be done.

The consumer age had barely begun in the early 1960's, and the mobile phone and personal computer were still the stuff of science fiction. And yet the Apollo programme managed to fire 12 men - they were all men - more than 244,000 miles across the vast expanse of empty space, land on the moon, and bring them safely home in less than a decade.

Looking back the Apollo era does seem like a moment out of time. As the Astronaut Gene Cernan described a decade plucked from the 21st century and dragged - by sheer force of presidential will - into the 20th.

But like the sixties themselves, and the era of the counter culture it paralleled, the Apollo programme is marked by a strong sense of unfinished business.

Many of those who took part saw themselves as pioneers in the continuous exploration of space. By now there would be permanent bases on the moon, regular trips to near-earth objects like asteroids, and maybe even the first manned mission to Mars.

Today NASA's mantra is "the moon, Mars and beyond", but its still not clear whether President Obama will commit America to the astronomical sums involved.

The rare tale of the piggy-back heart

Tom Feilden | 11:33 UK time, Tuesday, 14 July 2009

Pick up almost any paper today and you'll see the shyly smiling face of Hannah Clark beaming back at you. (See the Sun, the Daily Mail and the Independent) And it's no wonder. Hannah's tale is that very rare thing: an unalloyed good news story.

In order to see this content you need to have both Javascript enabled and Flash installed. Visit BBC Webwise for full instructions. If you're reading via RSS, you'll need to visit the blog to access this content.

Born with cardiomyopathy, a relatively rare condition which effects the muscle of the heart, Hannah's prognosis was poor to say the least. Her only real hope was for a heart transplant, and in 1995 aged just 2, that's what happened.

Hannah ClarkeBut as the Lancet reports in its online edition this week this was no ordinary heart transplant operation.

In a revolutionary new procedure nicknamed "piggy-backing", the team - lead by pioneering heart surgeon Sir Magdi Yacoub - grafted the donor organ onto Hannah's own heart, so that it took over much of the function of circulating blood around her body.

That gave Hannah's heart some respite, and the chance to slowly recover from its diseased state.

Ten years later Sir Magdi came out of retirement to oversee a second - reverse - transplant operation to remove the donated heart.

The problem with all transplant operations is the issue of immune rejection - the patient's own natural defences identifying the transplanted organ as alien, and attempting to destroy it. Hannah could have had a conventional heart transplant, but that would have condemned her to a lifetime on immuno-suppressant drugs and all the consequential illness that goes with it.

As it was Hannah was very ill for much of the time her donor heart was in place. She had problems with her lungs and spinal chord, and suffered from a particular form of cancer associated with transplant patients known as Epstein Barr Virus or EBV.

Illustration of the "piggy-back" donor heartGiven her age, Sir Magdi wanted to give Hannah the chance of a normal life. Implanting a donor heart to take the pressure off her own while it recovered, and then removing it at a later date, offered that possibility.

The benefits of that far-sighted decision were only too clear in the bashful, giggling - but healthy - 16-year-old who came into the studio this morning.

Is swine flu targeting the young?

Tom Feilden | 10:45 UK time, Tuesday, 14 July 2009

In order to see this content you need to have both Javascript enabled and Flash installed. Visit BBC Webwise for full instructions. If you're reading via RSS, you'll need to visit the blog to access this content.

Here's the graph showing the breakdown for swine flu cases by age that we were talking about on the programme this morning. It was put together by QSurveillance and used in the latest HPA report on the virus in the UK.

QSurveillance® flu-like illness weekly rate for week 27 (week ending 5 July) by age band

As you can see the normal bell curve distribution is strongly skewed to the younger end of the range, with 5 -14 year olds apparently worst affected.

There's still no clear explanation for why that might be. The latest research published in the journal Nature this week does show some striking similarities between swine flu and the virus responsible for the 1918 influenza pandemic.

That could explain why people born before 1920 have stronger immunity, but doesn't really account for the lower incidence of infection amongst those aged 45 and over. It could equally be that school classrooms and the playground simply offer a better environment for the transmission of infection.

One more point for the statisticians amongst you. The graph may inadvertently give a slightly false impression of the distribution by age because the bands are not all of the same duration. There were, for instance, 38 cases amongst children aged up to one year, but later columns cover longer periods.

If anything, the real bias towards the younger end of the spectrum is even more pronounced.

The true scale of swine flu

Tom Feilden | 10:32 UK time, Wednesday, 1 July 2009

The official figure for the number of people who've contracted swine flu stands at 6,538.

But it seems increasingly likely that this "official statistic" significantly underestimates the true scale of the problem.

The figures are compiled by the Health Protection Agency, and are based on the number of laboratory confirmed cases - that's people who have undergone a swab-test for the virus that has proved positive for infection.

But if you ring your GP today and try to make an appointment complaining of flu-like symptoms, the chances are you'll be told to stay at home, try and get your fever down, and get some rest.

A man blowing his noseIn the vast majority of cases, where the infection is proving to be quite mild, that's good, sensible advice. It certainly helps to minimise the spread of infection around the doctor's surgery, but obviously if no test is conducted no report is forwarded to the Health Protection Agency and the case doesn't show up in the official statistics.

The result is that there's really no way to be sure exactly how many people have contracted the swine flu virus. Although it seems likely that the true scale of the epidemic is significantly higher than the official estimate.

So does that matter?

It should be stressed that in most cases a bout of swine flu seems to produce only mild illness - fever, fatigue, lack of appetite and coughing. In only a very small number of cases the symptoms have been more serious, requiring admission to hospital, and there have been three deaths across the UK.

Anyone experiencing more serious symptoms, including prolonged high fever, nausea and vomiting, or who may be in a high risk category or suffering from an underlying medical condition, is still being urged to seek medical attention.

But for most people it seems, a bout of swine flu may result in less serious illness than traditional seasonal flu.

BBC © 2014 The BBC is not responsible for the content of external sites. Read more.

This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.