Chris Lintott’s Universe

I went up to Birmingham to record the voiceover for the interview with Eugene Cernan, which included a sneak preview of the programme. I’m really pleased with it; the team have done a great job of cutting down nearly two hours of interview while keeping the best bits. There are a few surprising comments, and a couple of stories that send a shiver down your spine. As the modest man I am, I don’t always plug the programme on the blog, but this one really is required watching, if only for some of the shots that the team have pulled out of the archives.

BBC One : Sunday night (early Monday morning) 00:45
BBC Four EXTENDED EDITION (Watch this one if you can) : Monday evening 19:30

But what if you can’t wait until Sunday or Monday for your Sky at Night? If you have access to BBC4 you don’t have to! Tonight there’s a repeat of our meteor special (the filming for which was one of the more surreal nights of my life). That’s on at 19.30. Then this Sunday is satellite night on BBC4, and our contribution looks at the British contribution to the space age. That’s 20.30 on BBC 4.

Enjoy. (And if you’re not in the UK, remember all of these will end up on the magazine cover disc, and the Cernan interview will land on the website before too long.

In the fourth and final part of the guestblog from Alice Sheppard, we conclude our trip to CERN with a pictorial look round the ATLAS detector. If you’d rather start at the beginning, then part one is here, part two here and part three here. I’d like to thank Alice for assuaging somewhat my annoyance that I’ve never made it to CERN, apologise again for taking so long to put these up, and to invite anyone else who might fancy guestblogging to email me.

CERN – reception floor! “Cosmic Song”, 1986, Serge Moro. Apparently a detector recording cosmic rays, with a programme modulating light information and timing cycle, with 9 lighting circuits arranged under metal floor panels.

As you can probably tell, the walkway was halfway up the wall, which prevented any of us from taking a panoramic photo. Hence, it is impossible to reproduce what ATLAS – the detector – really looked like, which was a bit annoying. The “clock-face” thing was, the guide said, 40m high, though it looked an awful lot bigger.

I’m afraid the technical details of how the detector worked would probably have gone straight over my head even if the roar of machinery hadn’t been so loud; all I can tell you is that there is a lot of aluminium involved, and that they are especially concentrating on capturing muons and to do so are making lots of layers “like an onion”. In the shed-like area was a scary-looking instrument I would have ascribed to the torture trade: a sort of rectangular aluminium rod full of bits of wire, which apparently helps with detection . . . There were hundreds of feet below and above us in that room, and people hurrying back and forth everywhere and doing the most amazing gymnastics on and between machines!

We had finished by lunch time, though there were several hours of fun left in the Microcosm museum. There was something especially uplifting about the message of openness and international concerted effort. There was much emphasis on how CERN was founded by several nations who had recently been fighting each other in World War II, and how Palestinian and Israeli scientists now happily work together. It was also evident that students can come here and find the doors are open to them.

The only annoying thing about the visit was how very little I felt I’d learnt and seen in comparison to how much there actually was there. All the notes I didn’t take, all the times my mind had wandered while the guide might just have been saying something especially interesting! So I’ll end with one of my favourite quotes, by someone called Richard Jeffries:

“In the heart of most of us there is always a desire for something beyond experience. Hardly any of us but have thought, some day I will go on a long voyage, but the years go by and still we have not sailed.”

For more information, see the CERN website.

Seven of the Galaxy Zoo team are gathered in Portsmouth today for our first science meeting. The plan is to go through all of the hard work we’ve been doing to analyise the results and see what we agree on – and what we don’t. Sadly we can’t invite the more than 100,000 people who have contributed to the meeting, but we’ll try to keep you up to date here. I’ve turned off comment moderation, so feel free to join in.

10.07 : Typical organised start to a meeting; currently everyone is running around trying to connect their laptops to the internet while Steven is downstairs printing draft copies of the papers and Edd is making coffee for us visitors. Personally, three donuts have been consumed so I’m waking up. More soon.

10.18 : Starting 18 minutes late is probably a record. Bob has just announced he’s paying for lunch.

10.57 : I’ve just presented my paper, which will be an introduction to the project. The bottom line is that there are many different ways to go from clicks on a website to a final catalogue, and that understanding the biases in each is difficult. In particular, the fraction of galaxies which are classified as elliptical is very sensitive to what decisions we make. However, if we require a high level of agreement we get results that agree with other professional data. Other people can then use the results to do interesting science – over to Steven.

11.07 : Steven’s job has been to work out where ellipticals and spirals live. We know that you’re more likely to find ellipticals in the heart of clusters, but quantifying that in the nearby Universe is hard because you have to look across large regions of sky, which is exactly what Sloan and hence Galaxy Zoo does.

11.18 : …it turns out that comparing to high redshift results is difficult. If I’m understanding the discussion correctly, the problem is defining how dense an environment actually is. Is it enough to count how many neighbours, or do we need to something more complicated?

11:42 : If you take the data at face value, the fraction of galaxies which are classified as elliptical changes rapidly with redshift (distance). This isn’t true if you only look at the brightest galaxies, suggesting it’s just the tendency of people to see faint fuzzy things as elliptical. However, Steven can account for this by correcting to match the results from the closest galaxies of a particular brightness.

12.15 : We’ve moved on from talking about the main population of galaxies to the weird and wonderful. Kevin has been collecting the bluest ellipticals in the sample; remember this was one of the main points of Galaxy Zoo. Most elliptical galaxies formed their stars in the early Universe and are now ‘red and dead’. Elliptical galaxies which are blue might be late developers, allowing us to see stars forming in elliptical galaxies today.

12:39 : Yey, we find lots of blue ellipticals. Many more than anyone else has, and lots of them are pretty close (so we can be sure that we’re not confusing faint fuzzy spirals with ellipticals again). We immediately plunge into an argument as to what these strange objects actually are.

12.45 : I may be becoming flippant (blood sugar from donuts is all but gone) but I think we agree we don’t know what these are, and that that’s what we’re excited about. Bob’s talking next but has run away.

12.47 : He’s back, but we’re back to arguing about what these blue ellipticals are, particularly about how to compare to computer simulations. Bob’ll be talking about our other set of weird galaxies – red spirals.

12.57 : Bob’s now standing up, and we’re still arguing about what the blue ellipticals are. It’s his own fault, though. OK, he’s now moved on.

13.04 : Here there’s more confusion – distinguishing between true spirals, and galaxies which have no spiral arms but do have a disc – is all important. Not all of them can be explained away by this, though.

13.11 : Off to lunch to argue about those results. Back about 2.

14.14 : Back from lunch, and just setting up conference calls to other team members who couldn’t be in Portsmouth today. – Edd

14.18 : One of the other interesting parts to the Zoo is the social science side – looking at the users rather than the galaxies, user demographics, motivations and so on. Jordan’s giving us a rundown. – Edd

14.37 : Jordan’s telling us his plans for surveys of users. It’s not only sounding interesting, but also useful in keeping the Zoo something everyone enjoys using. – Edd

14.43 : And moving on to talk about our plans for the next phase of Galaxy Zoo – Edd

As a who’s who – the last pic, Chris has is back to you all, with Kate on the left. Then it’s Kevin, Daniel and me on the far right. The middle one’s from the other side, and you can see Steven at the back on the left. Bob’s not pictured – he’s the man with the camera. – Edd

15.25 : And Kate is now telling us about the mysteries of spiral handedness… – Edd

16:25 : Which caused a huge argument – all good fun. Some of us have to head home, others to the pub. Thanks for joining us. Chris

This is part 3 of Alice Sheppard’s trip to CERN, our first guest blog. Part 1 is here, and Part 2 here.

The main tunnel is 100m underground, and 27km in circumference, with detectors at various intervals like beads on a bracelet. The circular tunnel lies under both France and Switzerland, so, as someone commented, sub-atomic particles must have very fast passport controls. The building work underway at the moment has to be done with precision of micrometres, and has to be flexible in accordance with the effect of the Moon’s gravity on the mountains. The temperature stays fairly constant down there; however, they shut down from November-March when it is coldest – which seemed interesting and contradictory to me, since the infrastructure needs to be kept cold. That just goes to show that natural conditions are never good enough for sophisticated experiments.

The experiment we are currently waiting for is the same principle as an earlier one, when electrons and positrons were accelerated around the tunnel and made to collide close to the speed of light, thus, as we heard, “recreating the conditions of the Big Bang”. A positron is an antielectron. When a particle meets its antiparticle, they annihilate each other, releasing energy. CERN’s proton/antiproton smasher releases so much energy that new particles are created – and discovering what these are is what the detectors are for. The experiments have to be timed to unbelievable precision, given that the newly created particles break up in, for example, a millionth of a second. Even neutrons have a half-life of only about 15 minutes if left on their own – that is, not in a neutron star, where they are held together by gravity, or in an atom, where the strong nuclear force stabilises them.

Anyway, the Large Hadron Collider, the new experiment, works on the same principle, but with protons and antiprotons not electrons and positrons. This is much more ambitious, as protons are composed of three quarks each, and are a thousand times heavier than electrons. One thing struck me and has stayed in my mind: the speed at which they will be accelerated around the circuit – 11,000 times per second. As the tunnel’s circumference is 27,000m, this does indeed come very close indeed to the speed of light – 297,000,000 m s-1 as opposed to 299,000,000.

And it will be double this speed at which they collide . . . presumably their time will have to slow down quite a lot relative to our own to make sure that from their perspective, the other is not travelling faster than the speed of light !

This was also the first time I heard about relativity causing an increase in mass rather than weight. I had always heard about increases in weight when travelling at relativistic speeds, and my very basic physics background had given me the idea that this was not the same as an increase in mass – so hearing about these particles gaining mass made me realise how much I still have to learn. The lecturer also said the temperature would reach several billion Kelvin, much hotter than the Sun, and indeed would be the hottest temperature in the Universe since just after the Big Bang. I wondered how they could contain such heat. Someone I asked shrugged off this question on the grounds that they would be putting in more energy than they would be getting out, but I thought that the same could be said of a radiator, or indeed any energy transfer . . . I don’t know how much matter they’ll be sending around; it’s not as if it’s a massive power station doing this to millions of tonnes of protons and anti-protons, of course. Thus musing, we then headed towards two little buses for the tour to Atlas, one of the detectors around the tunnel.

After what’s possibly the longest summer break in recorded history, Living Space – the podcast I do with Harriet Scott – has relaunched over at Livingspaceonline.com. It’s taken a while to get to this point partly because we were trying to control as much of the process ourselves as possible without compromising on the quality of the sound. I think we’ve managed that, so please do come and catch up. The programme will be fortnightly, and the best way to keep in touch and get the usual mix of interviews and news is to subscribe to our rss feed (this is different from the old feed, so update your bookmarks).

Continuing our first set of guest blogs at Chris Lintott’s Universe, this is the second
part of Alice’s trip around CERN. The first part is here.

The talk began with a description of the international co-operation involved, the 20 member states, and the Big Question they are investigating: “How Nature Really Works”. The lecturer described their branch of science as “Astro-Particle Physics”, or the origin of matter. The list of topics he put up at the beginning sounded so interesting that I just have to put up a list: particle physics, neutrino oscillation, lead nuclei collisions, anti-hydrogen radiation and spectroscopy, radioactive isotopes and neutron beams, accelerators and detectors.

The lecturer went on to focus on one of these: the accelerators and decectors. He claimed that the antihydrogen produced is the first that exists in the Universe since the “grand shoot-out” between matter and antimatter that occurred in the first minutes after the Big Bang, and that it is not yet confirmed whether it will show the same spectroscopic lines as hydrogen. This made us all sit up and frown because we’d had a lecture claiming that antimatter is exactly the same as matter, just with the charges reversed – that a galaxy we see through our telescopes could be antimatter, that the person sitting next to us could be antimatter; the only way we could tell is if we touched these things. Unfortunately all the antihydrogen so far created has far too much kinetic energy for it to be useful, and research is currently underway to see how to cool it. (We all wanted to know how it can be contained before it meets matter and they annihilate each other! I am still wondering. I also wonder if aliens have ever created antimatter or recreated the Big Bang, too, in a galaxy far, far away . . .)

We then focussed on one major experiment to come in 2008, the Large Hadron Collider. Particle accelerators such as the LHC were compared to electron microscopes: both can “see” smaller things than visible light. The particles they accelerate gain kinetic energy up until a point at which the kinetic energy can be interpreted as an increase in mass (E = mc2). Electrons accelerated by CERN, for example, have reached 20,000 times the mass of an ordinary electron. They then hit He(l) nuclei. This generates new particles – so new matter is created out of kinetic energy.

Energy and momentum have to be conserved. If very big particles are created, they may just “flip away” little ones, so it is necessary to make the heavy ones collide with each other. One method of detection is Cherenkov radiation – distorted atoms left behind a trail, like a visual sonic boom. In the LEP detector, the only thing that is not absorbed is muons. They can see them falling down like rain. The tour guide, later, talked a lot about muons . . .

In a previous CERN experiment, when an electron and a positron, they created a new pair of quarks. The lecturer spoke about quarks changing ‘flavour’ from up to down, for example in the creation of C14 in the Earth’s upper atmosphere, and the weak nuclear force and how it allows changes of particle (quark) identity, and the sizes of neutrinos and generations of matter which literature can describe better than I can. This was given as an explanation for matter rather than antimatter surviving in the Universe. (I’ve heard quite a few of those, most of which were stated to be the established truth! The most intriguing to date claimed that Dirac’s equation suggests that, for antimatter, time runs backwards*, and that antimatter decays faster than matter, hence the one in a billion matter particles left over after all the annihilations . . .)

* Someone told me two weeks ago that that’s tachyons, not antimatter.

Coming up over the weekend : The experiment itself

Alice Sheppard will be well known to any of you who’ve been to the Galaxy Zoo forum where she does a sterling job as moderator. Not content with putting her to work there, when I heard she was going to particle physics lab CERN in Geneva along with her cohort of trainee teachers, I insisted that she write up her experiences for this site. I’m afraid this is long delayed – and that’s my fault, for which I apologise – but here’s the first installment of her trip diary. The rest will follow daily.

It was one end result of a stimulating and memorable six months for twenty-six future Chemistry teachers – an Enhancement Course at Sussex University for those whose degrees were a long time ago, or did not contain quite enough chemistry, to immediately qualify as a teacher of that subject. “I’ll bet you’ve all been told that matter is just protons, neutrons and electrons,” said Tim, our course leader. Well, science is never that simple, is it? Many of us now know about neutrinos, streaming out in their billions from the Sun and other stars. What few of us knew was quite how many fundamental particles can exist (if only for a few millionths of a second at a time), and just how much has been discovered 100m underground around the mountains of France and Switzerland.

Anyone can go to CERN. It’s a few minutes on the no. 9 bus from Geneva, and it’s easy to find your way around. You can visit the reception, shop and Microcosm (their museum); or groups can book a lecture and tour. We were able to do so, and in English – they are prepared for a range of nationalities. They even have a restaurant, but mind out for the small pieces of octopus in the salads.

On Monday 30th July, amid a bit of a shoe crisis (somebody’s shoes had broken and her feet were very painful; a few more were later momentarily floored to discover that open shoes are not allowed – until we discovered CERN has shoes visitors can borrow), we made our way into Room 33, the reception area. We had been preceded by a flurry of excited questions along the lines of, “You mean it’s true, that Dan Brown book?” and jokes such as “Have a smashing time.” At nine o’clock we had a superb lecture and video – though I recommend a little reading up on particle physics first! The few posts that follow are a mixture of the lecture notes I took and my additions, speculations and random ramblings.

There are some days that you just know are going to stand out in the memory for years to come. Yesterday, the final filming day of our trip through the US was one of those. We were at the Johnson space center in Houston and the first task was to interview none other than the last man to set foot on the Moon, Eugene Cernan. Now, I don’t normally get nervous about interviewing people (except, strangely, Simon White) but I’d been worrying about this one since it was arranged months ago. What could I say to one of the six men who walked on the Moon? What could I ask that he won’t have answered thousands and thousands of times before? I’ve asked almost everyone I’ve talked to in the last three months what I should say, and noone came up with anything particularly useful. I know Patrick still rates the interview he did with the same guest in the 70s as one of his best, and the Moon is definitely his territory so for once I felt I was trespassing, albeit at his invitation.
Now, suddenly, Captain Cernan was standing in front of me, complaining that even he had to go through NASA security. Then suddenly he was sitting in front of me, waiting for the first question, and we talked. And talked. And talked. Then – just as he was describing the lunar surface – the tape in the camera ran out, and somehow it didn’t seem right to say anything. Normally I’d relax a bit and chat to the interviewee in the couple of minutes it takes to change tapes over, but this time I didn’t want to break the spell. So I stared at the floor, and then we talked on. In the end, I think we got 100 minutes of interview (for what is – at most – a 30 minute program). I hope we can get the uncut version onto the magazine disc, because I for one want to hear it again – there’s lots more I could have asked, but there’s loads of good stuff. I won’t spoil the highlights just yet, but watch December’s program.

The rest of the day was pretty good too;  we filmed one of the three remaining Saturn V rockets (main conclusion – they’re huge), and then got to wander round the building where the astronauts do their training. Then the final interview of the day was with Dr Andy Thomas, an astronaut who’s flown three shuttle missions and spent more than three months on the Russian space station, Mir.
Suddenly we were being taken out to their rover testing ground, and ran into their prototype Chariot rover, which just made me laugh out loud. What a fantastic, cleverly designed beast…seeing it on the ground somehow brought home how seriously NASA are taking their return to the Moon, more about which tomorrow.

The main point of our visit to the Goddard Space Centre a day or two ago was to catch up with the team behind the Lunar Reconnaissance Orbiter, which is now less than a year from launch. Obviously we were following some more prestigious British visitors, but they were extremely nice to us anyway. It’s a shock to realise that the Apollo era data just isn’t good enough to plan for a manned return to the Moon, and so LRO’s task is to create the ultimate lunar map from an orbit just 50km above the lunar surface. The impact of these pictures should be spectacular; they’ll show such fine detail that we should be able to see the tracks left by the lunar rovers the Apollo astronauts used. The spacecraft parts are being assembled at Goddard now, and we were allowed to get up close and personal with the spacecraft bus (the chassis, essentially). I’m now paranoid my jinx will strike, but they do seem to know what they’re doing. I promised I’d plug their website, which is here.

Andy has an interesting take on the Gemini crisis. It’s essentially a salient reminder that it’s the government and not the STFC that’s responsible for the loss of funding. That’s true, but the thing that scares me about the Gemini decision is that the apparent lack of consultation. Instead of asking the astronomical community to save £4 million, they’re just planning to shut of access to one of our major facilities. That isn’t how these decisions are supposed to be made.

There’s a response from Gemini themselves, which is best summarized as ‘putting a brave face on it’. It’s so depressing to be writing about such things instead of results like these.