Fly Me to the Moon

Barcodes are everywhere, to the point where you probably don't notice them...until you're stuck with a nasty bill, or you have to find them on an item you want to scan yourself. But, this week, a pioneer of barcode technology, George Laurer died at age 94. Reflecting on how lines of black and white equate to a loaf of bread and George Laurer’s world-changing invention, angel investigator and tech commentator Peter Cowley joined Adam Murphy and Chris Smith...

Peter - We all know what a barcode looks like, because we see that on retail products and they're basically a set of vertical lines. They're black lines of varying widths and they're actually, if you look closely at it, you'll see the white lines and also of varying widths. There's four different widths of black and white and that together they make up a code. That code is on a retail product, the variety of barcodes from a linear one dimensional barcode here, the variety they make, there's 100 billion combinations here, so that's obviously a great deal. Some of that'll be the manufacturer or the distributor, but it'll be the product code as well. So a device actually looks at this and converts it to a number which is also printed on anyway in case a barcode is not readable. So a checkout operator potentially could type that in. So, basically encoding a set of numeric digits or possibly alphanumeric characters into a set of vertical lines.

Adam - How did we end up with these set of lines? How do they get invented and how did they end up in shops?

Peter - Yes, George Laurer, and in fact a guy called Joe Woodland who died a few years ago, in the early fifties produced something loosely based on Morse code. If you think about it, on off, on off, if you know Morse code. And, apparently, he was walking along a beach at one point and he drew lines in the sand and from that he decided that's a great way of doing it. The initial barcodes actually were circular, but they found that the printers in those days, in the early seventies, weren't good enough, so they just turned into the linear ones. What happened was the national association of food chains in the States decided they want to encode somehow and so they put out a tender and a number of people went in there and in fact in the end it was IBM that won this and these two people, George and Joe, worked for that. The first retail barcode was scanned in in 1974 - it was a packet of chewing gum, apparently!

Adam - Wow, now, you can't scan a barcode without a barcode scanner? How do those work?

Peter - Actually you can. I've been around barcodes for 35 years and there is something which I think sent to lead to a five which you can actually read. Super geeky, but generally, have you looked at the UPC in front of me here? Which UPC Universal product code, I can't read that. The original reading was done and I have, I go back long enough, I remember buying these things; there was a wand and the end of the wand was a light source and there was a receptor and you pulled it across with your hand across it, it would read light, dark, light, dark and the timing which would give you the width of the whites and the width of the blacks and that's then your code, you send it back to some sort of computer system that's worked it out.

Chris - Didn't you have to therefore make sure you drew it at a very standard rate, then, Peter? If it was the timing?

Peter - No, it worked it out - I mean obviously if you'd stop, start, stop, start, it wouldn't work - but, generally, the hand, it's only an inch or so, you know, across 32 millimetres. And so that was possible. That would damage of course damage the paper, because you were actually pressing on it. So the CCD - charged coupled device - arrived, which read the whole lot at once, either with ambient light or with its own LED. And the ones we see in the supermarkets now, have a laser diode, and it's got a rotating mirror or prism, which then scans it very rapidly.

Chris - And, sorry to interrupt, but, I'm fascinated by that. So in there, basically, that laser beam is scanning backwards and forwards. How is it reading? Is it that the laser bounces off of the white bits but not the black bits?

Peter - Exactly, exactly. And then there's the face receptor. Exactly. Yeah.

Adam - And now, you mentioned there were circular barcodes, but what other kinds of barcodes can you have?

Peter - Well, the linear ones, these are the one dimensional ones, there are about 30 odd and they store usually 20 or maximum 30 characters, sometimes less than that. But of course many of us have now seen the 2D barcodes. There are about 40 different types of two D barcodes. These are the ones that look like a dot matrix and matrix with lots of dots and these can store several thousand characters. They've got much greater resilience, and I've got a barcode here, which you won't see on the radio with a picture of my face, which is actually a link to my LinkedIn profile. My face takes up a lot of the middle of the thing and it still reads perfectly because there's a lot of resilience and redundancy in a 2D barcode.

Adam - I remember when I was walking around Dublin on Sunday at a literary festival, they had copies that would let you link to James Joyce's Ulysses that you could download. But I didn't because I was suspicious of how safe they were.

Peter - Absolutely, there are all kinds of ways of sending you to the wrong website, which could be malicious, could be a phishing website. There's a potential there of premium rate texts being sent from that. There's also, there's not really the possibility of executing illegal code. That's okay. But certainly, I would never recommend scanning something that, unless you know what it is. It's like putting something in your mouth when you don't know what it is, isn't it? You wouldn't do that. Can I just very briefly mention RFID? That's the next stage. So this is where there's a chip. These things are obviously more expensive because there's some technology there. They actually put them in Japanese bank notes. So there's a chip in each one in the metal Stripe. So they have to be very cheap. But generally that is probably the future of bar codes, when the price can be got right.

Chris - They work a bit different, don't they, in that the way they work is that there's a signal sent from a device which then effectively gives energy to the thing that's in the product, which then does a bit of processing and sends back a signal which is unique to that product.

Peter - Yeah, exactly. Yeah, but that's hidden and also, you can write to that device as well.

Chris - And obviously, the power of that is, unlike the barcode you've got in front of you, which someone's physically got to scan, these things basically they'll respond whenever their wake up call is transmitted anywhere near them.

Peter - There's a problem with people's privacy and the fact that you supposedly can read them into your pocket from a distance across the road.

Chris - And the problem I have, which is I always seem to set these things off when leaving shops, despite the fact I have not stolen anything.

Peter - Well, exactly, let's talk about that later, Chris.

Chris - No comment!

Adam Murphy has been speaking with Christopher Chen about new papers published in Nature, which shed some light what the Parker Solar Probe has been up to...

Adam - in August of 2018, NASA launched the Parker Solar Probe, and sent it hurtling off towards the Sun to further our understanding of the source of our sunlight. The probe is about the size of a car, with a heat shield covering one side so that it can withstand the enormously high temperatures. The other side has a suite of instruments on it, like magnetic field detectors to help us probe into the Sun. The probe is currently orbiting the Sun, getting closer and closer to its atmosphere, which is known as the corona. Now as it approaches, it's discovered something unusual in the Sun's magnetic field, which may help to explain some of the deepest mysteries about the Sun, like how the atmosphere surrounding it is hundreds of times hotter than the surface. I heard how from Christopher Chen at Queen Mary University London, who was involved with interpreting the data from one of the solar probe’s instruments.

Christopher - We found several new and unexpected discoveries. So one of these is the fact that we found these big folds in the magnetic field near the Sun. So the spacecraft has a magnetic field sensor, and what it found was that within the period of a few seconds, the magnetic field flips direction entirely. So at one moment it's pointing away from the Sun and then in a few seconds later, it flips to be pointing towards the Sun, and then it flips again and is pointing away from the Sun again. And this is sort of unexpected. It's not been seen further out and we don't know exactly what is causing these large flips in the magnetic field.

Adam - And that kind of thing doesn't happen here on Earth, does it?

Christopher - In the solar wind at earth, there are large amplitude fluctuations in the magnetic field, but these flips are certainly not as clear and pronounced as we're seeing up close to the Sun. It looks like a different type of structure that's occurring. Yeah.

Adam - And as it's getting closer, is it changing those flips, or how static are they?

Christopher - So they are getting more intermittent and more bursty. What is seen is that, as we're going closer to the Sun,  there are these periods where the solar wind is very, very quiet and the magnetic field is not flipping at all. But then there are these periods where it's flipping all over the place, and really rapidly, and at all kinds of timescales as well. So some of these, so we call them switch backs, so some of these switchbacks last for just a couple of seconds. Some of them last for minutes. So it's really much more bursty and much more, sort of, complex and dynamic up close to the Sun.

Adam - Given how big the Sun is, given the scale of it, the idea that the magnetic field can flip over the course of seconds seems really, really intense to me.

Christopher - Yeah, so when I say the magnetic field's flipping, it's not the entire magnetic field of the Sun, but it's the magnetic field in the solar wind where the spacecraft is measuring. So if you think of the magnetic field around the Sun, it's not as simple shape that you'd get from a bar magnet, but it's actually a really complex, intricate structure. So there's loops of magnetic field on the Sun. There are these long striations of magnetic field lines that that stretch far out into solar wind. So it's really the flips within this structure of the magnetic field as it points away from the Sun.

Adam - And what other kinds of things is the Solar Probe measuring?

Christopher - So for example, there's an instrument which measures the solar wind velocity as it travels away from the Sun. And what that found was that as we're going in closer, the solar wind is not flowing just radially away from the Sun in straight line, the solar wind is spinning around in a circle as it's traveling away from the Sun. But this speed of the spin is much faster than we expected from our models. So we say that things that are spinning have angular momentum, and the solar wind is something which can transport angular momentum away from the Sun. So what that's really causing is the Sun to be spinning at a slower rate than it otherwise would be. So the solar wind is carrying away the spin from the Sun.

Adam - And what implications do these results have for our understanding of the Sun?

Christopher - So they're really sort of changing our view of what's happening. One of the big mysteries of the Sun, and solar physics is something known as the coronal heating problem. So the corona is at a temperature of more than a million degrees, whereas the surface of the Sun is at a few thousand degrees. So it's really the atmosphere of the Sun is hundreds of times hotter than its surface. And this has been a long standing mystery in solar physics. So one of the things we're finding is that the amplitude of the fluctuations are getting much larger as we're going in closer. So as I said, we have these big folds in the magnetic field, and they contain a lot of energy in them. So we're thinking that these are involved somehow in the process which is causing the corona to be heated to such high temperatures. And another thing is the existence of the solar wind itself, the solar wind, by the time it gets to the Earth is traveling at around a million miles per hour or so. And it's again another open question as to how the solar wind comes to be traveling so fast. We think again that these large amplitude fluctuations, and this sort of complex, chaotic dynamic environment is providing the energy to push the solar wind and cause it to be accelerated to these large speeds.

Adam - Lastly, what's next for the solar probe? What's it going to start measuring now?

Christopher - So over the next few years, it's going to be getting gradually closer and closer to the Sun. And one thing that we expect to happen, within perhaps the next year or two, is it to cross within the solar corona itself. So it has not got within the corona yet, but we're expecting it to do so within the next few years. And then it's really going to be in a completely new, unexplored area of space. Right up close to the Sun.

What exactly is the Moon, and what’s up there for us in the first place? Adam Murphy spoke to Lewis Dartnell from the University of Westminster about our nearest celestial neighbour...

Adam - The moon has fascinated us since time immemorial. Formed as leftover debris from a primordial collision, our biggest natural satellite holds a special place in all our hearts. But we haven't been back since Apollo 17 in 1972. However, new missions are sending humanity back to the moon. But what's there for us? I spoke with Lewis Dartnell from the University of Westminster about what is actually up there for humanity.

Lewis - Well what we've learnt from the Apollo missions in the late 1960s and early 70s, when we're able to go to specific locations on the moon surface and bring back rocks, bring back geological samples back to the earth that we can study, is the astonishing thing is that the rocks on the moon are very, very similar to the rocks on earth. At least their composition of different elements and isotopes is very, very similar to the earth. So that's why we think, that's one of the best pieces of evidence we have, that the earth and moon have both come from the same basic mixing pot, as it were. Although the exact kind of rocks and minerals we find on the moon are exceedingly bone dry, far drier than any of the rocks we find on earth, because earth is covered with this lovely thick atmosphere and deep oceans; the moon is exceedingly dry in comparison.

Adam - So if moon rocks are like earth rocks - and we've got plenty of earth rocks down here - what's up there we might want?

Lewis - The sort of things that we talk about, in terms of in situ resource utilisation - which is just kind of space talk, that's kind of nerd talk for living off the land - if we're trying to send humans to survive on the moon in lunar colonies or lunar habitats, we're going to have to find things on the moon that we need to help us survive there. So things like water ice near the poles will be very useful in the moon for not just drinking water for astronauts and a moon base, but also splitting that water, spitting that H2O to give off oxygen, which you can use for breathing. But we also think there are things which have an inherent value on the moon that we could export from the moon back to the earth. And these sort of resources would be metals which are either rare or hard to mine effectively on the earth, things like platinum or tungsten, or they might be other resources which we haven't started using on the earth. And one of these resources would be something like Helium-3. And we think that Helium-3, one of the isotopes of helium, would be the ideal fuel for nuclear fusion reactors.

Adam - But what is it that's bringing us up there again? And why now?

Lewis - Another very good reason to go back to the moon would be effectively as a stepping stone on our journey, on humanity's path out to the planets. And the next logical step would be to start sending humans to Mars and perhaps trying to establish some kind of human presence there. But Mars is just so much further away than the moon is. And if you are an astronaut in a human colony on Mars and you have some kind of emergency, maybe some of your technology on the base keeping you alive starts malfunctioning, maybe you have some kind of medical emergency, you would have to wait perhaps several months before the Earth and Mars start lining up in their orbits so you could launch to come back home. And what we would therefore want to do before we start attempting a long-term human habitation on Mars is to learn all of our lessons and make sure we can get things right on what is effectively our own front doorstep, on the moon. So the moon in that sense represents a much closer, safer place - a test bed, if you like - for all the technologies and tools we'd need for exploring Mars and then out through the rest of the solar system.

Adam - And does Lewis see a future in which humans are living on the moon long-term?

Lewis - I do. It's something that, within my own research of astrobiology and space exploration, it's something I think would be very, very exciting and something very important for humanity to do. To start spreading beyond our own planet, look beyond into new horizons, start establishing a permanent human presence on the moon, possibly Mars, possibly out through the asteroid belt, maybe mine these places for useful stuff to support human civilization back on our home world.

So we know what might be on the Moon for us, and the potentials that await us if can manage it. But is that enough in itself for a full set of missions to the Moon, and why does it have to be humans, and not robots? To find out more about the state of technology the moment, and what it’s going to take to blast us onto the Moon, Nadeem Gabbani spoke to Torsten Kriening of Spacewatch Global, and Phillipe Schoonejans of the European Space Agency...

Torsten -  What is in it for us? I mean that's the big question when you talk with people which are not like me, space geeks. What's in it for me, why should we spend these euros, these dollars on space programs? What comes back? First of all, it's the innovation, it's the inspiration, it's the imagination when we do really the next big thing. It's not just nations/agencies that are behind it and finance these endeavours. There are also private companies such as Blue Origin run by by the Amazon boss, Jeff Bezos, or SpaceX with their lunar ambitions, and that's Elon Musk. Many of the companies that came out of the Google Lunar X prize, the commercial offerings ranging around a million US dollar per kilogram payload to the surface of the moon.

Nadeem - So that gets us to the moon, but what's going to keep us there? Phillipe Schoonejans, Robotics and Future Projects Team Leader in the Human and Robotic Exploration Division at ESA gives us an insight.

Phillipe - There is a whole scale of things that we need to be on the Moon. Definitely shelter against radiation. It's one thing if we go for very very short, we have computed that it's sort of allowable, but if we want to stay for any length of stay, we have to look at the radiation. So we've also been looking at having a cylindrical element, like exactly what fits in a rocket, and to put it and to cover it completely with moon dust as protection against radiation. Definitely this is one area that we need, the shelter we need. We need water. Of course the Chandrayaan have already demonstrated that there definitely is water on the south pole of the Moon. So that's something that we have to be able to recover from the ice, but also that is something that we need for a bit longer stay. For one or two days you would never do that, you would just take the water. We need power. There's 14 days of day and then 14 days of night on the Moon. So we always are struggling with what to do with the 14 days of night. It can get like freezing cold and minus couple of hundred degrees. Then what do you do there? And then with no sunshine. So definitely we have to look at power. I think during the day it's okay, the solar rays would work, but during the night we need something else. We need a less clumsy EVA suit. If you look at the old movies from the past, from the Apollo missions, you see how incredibly clumsy they were. You could not pick up anything from the surface. You'd need some tool to do that. If they fell over they had immense trouble getting back up again, and NASA has now presented the new suits, I think a couple of weeks ago, a couple of months ago, which are way more flexible, but they are not yet at the end of their development.

Nadeem - And why are we even sending humans to the moon anyway? Can't we just send some robots?

Phillipe - My very clear view is that we should not speak of humans or robots. We should always speak of humans and robots. They have qualities that are definitely synergetic and it's clear that humans are, they're more flexible. A lot of things that they still do better, like image recognition or re-planning if your conditions change or something unexpected happens, and then they can take more rocks with them then you could do with the robot. On the other hand the robots, they are better for anything which is either boring or dangerous or repetitive, it's obviously still cheaper to put robots on the Moon. So we look at tele-operation, also to see whether we could put a robot on a small rover on the Moon's surface and tele-operate it from this lunar station. We've been doing a lot of experiments lately to develop the technology for it. So I think we have, we need to actually do both, but also if you look at our inspiration objective, then it is definitely still the case that one human on the Moon is way more inspirational than 10 robots.

Nadeem - So it seems as if not an awful lot has changed. We have rockets, we have space stations, and we have had landers, where do we struggle?

Torsten - We need proper sustainable rocket technology. Really a leap in the development for guidance and navigation that is from the technology side, the big issue. But I'm talking here about precise landing. I'm talking about avoiding craters or areas of eternal darkness. So that is something, I mean on the software development, I mean what led to the two mistakes earlier this year when Israel as well as India showed a hard landing on the Moon. Sounds much better than to crash it, but at the end it was a crash. So what happened were human mistakes and technical issues.

Nadeem - But despite difficulties and expensive failures, the race continues. So what's the next small step for mankind?

Torsten - We do have multiple approaches to return to the Moon. We have the NASA approach, the Artemis program, to put boots on the ground by 2024. At that stage, potentially, a one off mission, and then building an infrastructure later on. It is these ambitious goals within the next four, five years to get humans down on the Moon, again. On the other side, we have ESA, as you mentioned, with their programs, and I'm very happy that ESA just agreed to the highest budget ever, namely 40.4 billion Euros within the next five years.