Stretching The Imagination
For this megaproject, it’s all about what if. Yes, we’re going to need to stretch our imagination, because what we are dealing with here, would quite literally be out of this world. A structure bigger than anything ever built, in fact, if you added everything that has been constructed on earth, it still wouldn’t compare in size – not even anywhere even remotely close… But this wouldn’t simply be a structure, this would be the greatest leap forward humanity has ever seen – I’m talking about a Dyson Sphere.
Never heard of it? Well, unless you orbit among the theoretical physicists of this world, there’s a good chance this may have passed you by. But it is a theory that, however fantastical it may sound now, just might be the answer for humanities long term survival.
A Dyson Sphere is a hypothetical construction that would essentially enclose a star as a way of capturing solar radiation emanating from it and transferring into usable power that we could use. Sounds far fetched? Perhaps not as much as you’d think, but we’ll get to that later.
If we look through history we can see a clear progression in how we have gained energy. Once upon a time, we relied simply on our own bodies for warms, but then we discovered fire and found that wood, which conveniently grew in most areas of the world, was actually pretty useful for fire. This progressed to coal and then oil as our knowledge of Earth and its resources grew steadily. In 1932 Ernest Rutherford discovered that by splitting lithium protons enormous amounts of energy was released, and so kickstarting the nuclear age. Today, all of the talk is about renewable energy, including wind, water and of course, solar…
Here on Earth, we receive only a tiny fraction of the sun’s energy, but just imagine if we could harness more? The sun is 100 quintillion times more powerful than even the most efficient nuclear reactor on Earth – that’s 18 zeros if anybody is desperately trying to calculate that – and it shines with the power of a trillion nuclear bombs per second. In short, it’s incredibly powerful.
The Dyson Sphere takes its name from Freeman Dyson, an American-English Physicist who first formulated the theory in his 1960 paper, Search for Artificial Stellar Sources of Infrared Radiation. However, the idea had been put forward many years before, but in a much broader sense.
Olaf Stapledon’s 1937 science fiction novel Star Marker includes one telling sentence,
“every solar system… surrounded by a gauze of light traps, which focused the escaping solar energy for intelligent use.”
Freeman Dyson greatly expanded the idea, and the name stuck. He argued that this was the logical progression for a civilization whose energy needs had spiralled beyond their own planet. Considering how quickly Earth’s population and thirst for energy is increasing, it certainly makes sense. But while Dyson certainly considered this a possibility for humans in the future, he was particularly interested in whether these structures existed already somewhere in the galaxy, and he believed he knew what to look for.
He reasoned that according to the laws of thermodynamics any civilization out there using a large source of energy would be forced to get rid of waste energy by radiating it out into space in the form of infrared radiation. He concluded that by searching the universe for infrared radiation higher than natural levels, it could lead us to extraterrestrial life. This is something we have been doing as a way of studying planets and stars, but nothing of that magnitude has been found yet.
This theory is often discussed in conjunction with that put forth by Russian astrophysicist Nikolai Kardashev in 1962 in which he set out three stages of civilization advancement. Type 1 is to use and store all of the available energy on a planet. Humans are yet to reach this level, but we’re well on the way and may achieve it in a few hundred years. Type 2, also described at Stellar Civilization, can use and control all of the energy within its solar system, specifically from a star. This would be a Dyson Sphere. Type 3, also known as a galactic civilization, described a civilization which has essentially harnessed the power of its entire galaxy. Now, the power of this would be so extraordinary that it would be impossible for us on Earth not to have noticed because of the vast waste energy that would be produced… Theoretically.
It’s reasonable to say that a Dyson Sphere would transform a civilization beyond its wildest dreams. Not only would we have an effectively endless amount of energy on Earth to create what we wish, but it could also make advanced space travel a real possibility because, in theory of course, we would be able to use this energy to power spaceships that could travel faster and for longer than ever before with the increased energy. There are of course many aspects that would need to fall into place before this could happen, but while we’re letting our imagination run wild, why not push it to the extreme.
How Would It work?
Though the idea was understandably light on specifics, Dyson’s theory called for a series of orbiting solar panels around the sun, connected loosely together and somehow transmitting the energy back to a planet or to an artificial object in space. Most versions that have come after present the sphere as a solid structure, but Dyson himself saw this as the least plausible option – the reasons for which I’ll get to shortly.
This is of course well past the technological know-how of humanity today. Considering it took us nearly 30 years to build the relatively small International Space Station, the length of time and technology to build a Dyson Sphere around the sun is difficult to comprehend. To put it into perspective, such a project would likely be over ten billion trillion times heavier than the International Space Station and if each satellite was 0.6 sq miles (1 sq km), we would need about 30 quadrillion to completely surround the sun. Yet despite sounding outlandish, physicists have long thought it at least possible.
In order to construct a Dyson Sphere, we would need to practically disassemble an entire planet. A little drastic I hear you say, but where do you think the raw metals are going to come from? If we were to do it on Earth, well, we wouldn’t have anything left to live on, so we need to look around our solar system. Mercury would be the best place to start for a number of reasons. It’s the closest to the sun which would require less travel time and has about a third of the gravity that we have on Earth, making it significantly easier to launch objects from. But importantly it is also mineral-rich, and we’re going to need a lot of it. Mercury in fact has a relatively similar composition to Earth and is thought to have the highest concentration of iron in our solar system.
But finding the right planet is just the start. Humans are fragile little things, so the idea of us shipping an enormous colony to Mercury is out of the question. No, we would need an army of self-sustaining robots to carry out almost every task. But once we actually had the technology to do it, the process could theoretically be completed in a series of steps laid out by Oxford University physicist Stuart Armstrong:
1 – Solar Collectors – In order to power this enormous project on Mercury we would need vast amounts of energy. We could launch a fleet of solar collectors to orbit Mercury and transfer the energy back down onto the planet.
2- Mining – As I’ve already said, we are going to need most of this planet, so we’ll require mines to strip the planet of its minerals, both on the surface and below it.
3 – Refineries – Now of course minerals coming out of the ground are not ready to be used on high tech solar panels, so they need to be sent to a refinery where the important elements can be extracted.
4 – Construction – The solar panels needed will be nothing like what is produced today, which are far too flimsy and short-lived. Scientists think that polished metal foil could be used, that would essentially create enormous mirrors once it was opened – perhaps as large as 0.6 square miles (1 square kilometre)
5 – Launch – We won’t be able to use rockets to take these solar panels into space, as they are far too costly and slow for what is needed. Ideas have been put forward of a rail gun that could rapidly fire the satellites into space.
6 – Sphere Assembly – Once the satellites are in space they would unfold and be manoeuvred closer to the sun to eventually form the sphere.
Easy, right?, But how long would all of this take? Well, actually less time than you would think. The most significant hold up is our lack of technology, and human will, on Earth. But once that was in place this project could effectively move at quite a pace. The most important aspect is energy. The more we have, the faster we can grow, and the project can quickly become self-expanding. The more solar collectors we have, the more energy available to create and work the mines on Mercury, as well as all of the other steps. The first solar collector launched would soon be joined by another, and together they would work to provide the energy for two more. At this rate, and if the number of solar collectors doubled each time – two becomes four, four becomes eights etc – we could effectively have a Dyson Sphere in 60 doubling times. If one solar collector took a month to build, we could theoretically complete a Dyson Sphere in a decade.That does not mean a solid structure, but more of a loose collection that could be further added to over time. The biggest issue regarding time is developing the technology first, and setting up the operation on Mercury, but once all of that was in place we could move quickly – well, sort of quickly.
While Freeman Dyson put forth the initial idea, it hasn’t stopped countless variations appearing over the years.
A Dyson Swarm
This is the closest to Dyson’s original design and would involve multiple solar power satellites packed closely together orbiting the sun, with the energy sent via wireless transfer back to Earth. The major advantage of this variation is that it could be added to incrementally, but because of orbital mechanics, this would be an enormously complex task – as if this wasn’t difficult enough…
There has been a variation, on the variation if you will. A Dyson ring would involve the same idea but where all of the satellites are orbiting together, funnily enough, in a ring shape.
A Dyson Bubble
Unlike the Dyson Swarm, the bubble would be composed of multiple statites, which is a hypothetical satellite that uses a solar sail to effectively hover in space. A huge grouping of these statites would create a stationary bubble around the sun. The major problem with this theory is that we simply don’t have the technology to do it. The lightest solar sail that we can currently produce is still about four times heavier than what would be needed.
A Dyson Shell
When a Dyson Sphere appears in science fiction, it’s almost always portrayed a Dyson Shell. A uniformed solid mass that entirely envelopes the star. Let’s imagine that such a structure existed around the sun. It would be around 550 million times the surface of the Earth and would gather the full 384.6 yottawatts of the sun’s energy each year. Never heard of a yotta? You’re probably not alone, because it is almost too large to even fathom. But it is the largest decimal unit prefix in the metric system and denotes a factor of 10(24). This energy capture every second would be enough to power the current earth’s needs for a million years.
The problems with this design are extensive. Such a structure wouldn’t have any gravitational interaction with the sun, and would simply drift in relation to it. If the structure were to actually come into contact with the sun, or simply closer than it was designed to, it would be catastrophic. It would, therefore, need its own propulsion system to regulate distance.
The structure would also need to be made of something that simply doesn’t exist to withstand the enormous gravitation pressure exerted by the sun. Even if we did have something that could be used, imagine how much of it would be needed. It’s debatable whether there is enough material in the solar system to even do this.
Lastly, the shell would be vulnerable to impacts from comets, meteorites and even solar flares coming off the sun. This may look good in Star Trek but is also the least likely.
Do They Already Exist?
Now, hear me out here. While we tend to think of Dyson Spheres as our own future invention, is it not therefore possible that this technology is already in use somewhere in the universe? Of course, there is no proof of this, but there have been a number of oddities recorded that have led some to ask the question, do they already exist?
The most famous of these has come to be known as Tabetha’s Star. In September 2015, a group of astronomers, led by Tabetha Boyajian, announced a baffling discovery. A star, with the rather catchy name KIC 8462852 and about 1,500 light-years from Earth, had dimmed dramatically over a number of years. It’s not unusual for a star to dim slightly when a planet moves in front of it, but this is usually only around 1%. This particular star had dimmed as much as 22%, meaning almost a quarter of it was covered by something, far too large to be a planet.
Tabetha Boyajian and her colleagues initially stated it could be caused by a comet cloud or planetary building blocks such as gases or dust, but others argued that this could be consistent with an alien megastructure.
The mystery deepened over the following year as astronomers from around the world began training their attention on Tabetha’s star. Bradley Schaefer, a professor of physics and astronomy at Louisiana State University, stated that the star had appeared to have dimmed by 20% between 1890 and 1989, while another study found it had decreased by 3% between 2009 and 2013, including an enormous 2% over one 200 day period. To put that into context, other stars were studied as a comparison. Out of 355 stars with similar parameters, only 0.6% showed a dimming with a maximum of 0.06% per year. Quite simply nothing came close to the fading light from Tabetha’s star. To this day, the mystery as to what is happening 1,500 light-years away remains unsolved.
To Infinity, And Beyond
It’s easy to just label the Dyson Sphere as science-fiction, but the mathematical figures, however vast they may be, do add up. The greatest obstacle humanity faces in terms of a Sphere is not about physics, it’s about us as a species. As long as we squabble on our planet over resources and ideologies we cannot possibly hope to make the next enormous leap forward. The only other discovery that humanity has made that can compare would be fire. The discovery of fire enabled our species to launch forward rapidly. It changed how we ate, it separated us from other mammals, it eventually led to countless other startling discoveries. If we are to fulfil our potential as a species, and perhaps reach that illustrious Type 2 civilisation, we will need unparalleled cooperation – something that sadly still feels like a distant dream.
But what is life without dreams? Since the early days of humanity, we have looked to the stars in wonder. We have debated, analysed, explored and dreamt about what lies above us. We have gained vast knowledge of mathematics, astronomy and physicists – the question now is, what are we going to do with it?