The Forgotten History of Project Orion
Question: What was Project Orion?
Freeman Dyson: This was in the year 1957 when the Russians sent up the first satellite, which they called Sputnik, which means companion. It was a companion for the earth. So this Sputnik was up there in space and it was making everybody nervous because if the Russians could send satellites into space they could also throw missiles at us and we at that time didn’t have any missiles which we could throw at them. So it was a scary moment and so it was a moment when you could get money very easily for crazy projects and so my friend, Ted Taylor, who was a young physicist, actually younger than me, he had this idea of building a spaceship with nuclear bombs, which sounds crazy and in a certain way it is crazy, but it could have actually… it could have worked and so I thought that would be exciting to do. I had never done anything like that. I had been always just a mathematician and working on paper, but so that gave me a chance to do something real, so I moved to San Diego in California and joined a company called General Atomic, which is still there and went to work on this spaceship and it looked as though we might even get the green light actually to go ahead and build it, but in the end of course we didn’t. The fatal flaw of that whole scheme is that it spreads radioactivity all around. You’re exploding bombs in big numbers, so you really do make a tremendous mess, and so in the end common sense prevailed and they decided to go ahead with ordinary rockets and not with nuclear bombs, but we had a great time. We studied the theory of this and the engineering. We had a lot of good engineers and we actually did little tests of chemical explosives building little model spacecraft, which would go pop, pop, pop, pop, just up in the sky and come down again and just to show that we knew how to do it, so we had every Saturday morning we didn’t get paid for that, but every Saturday morning we’d go and fly our little models. The rest of the week we’d do the serious stuff. So I spent a year and a half there and the project actually lasted for seven years, but by the end of the first year it was pretty clear that it wasn’t going to fly.
Question: What were the theoretical possibilities of the Orion mission?
Freeman Dyson: If it had been given the green light we could have gone to Mars in about five years. I mean the thing started in ’58 and we planned to have a Mars mission already within five years and we’d be scooting all around the solar system. I mean it was a very, very high performance ship, far better than anything we have today, and it would have easily gone to Mars and back and to Jupiter, the satellites of Saturn and all the interesting places in the solar system. We could have gone scooting around, and of course we intended to go ourselves. This was a big ship and it was with a crew. We imagined we would have a crew of about 40 people, so it was on the grand scale, and it would have been comparatively cheap because it was built like a submarine, not like an airplane. It was heavy engineering and so a lot cheaper than aerospace.
Question: Will we ever be able to accomplish those feats through some alternative technology?
Freeman Dyson: Well the joke is of course that we do such marvelous missions now with small payloads. I mean when we worked on Orion we were talking about 1,000 tons of payload just for one ship, and so we thought of ourselves as sort of like the Darwin on the Beagle going out for five years and with all our provisions and having to take along a squash court so that you could stay fit, and we could take along almost anything you wanted, and of course nowadays the whole way of operating in space is so totally different. Now you measure the payload in pounds, not in tons, and so we have a ship which is now orbiting around Saturn called Cassini, which of course doesn’t have people on board. It has wonderful instruments on board and the total payload of that thing is a few thousand pounds and it’s doing far more exploring than we could have done. So if we had a thousand tons of payload today we wouldn’t know what to do with it.
Question: Will humankind ever reach the stars?
Freeman Dyson: Yes, I think so, but of course my guess is no better than anybody else’s, but technically it could be done. Of course it’s much too expensive just for the next hundred years or maybe the next thousand years, but we have lots and lots of time, so I would imagine that we will be scooting around on a much grander scale, but it could… On the other hand, we could decide we’re not interested, so let’s not do it and that remains to be seen.
Recorded March 5th, 2010
Interviewed by Austin Allen
With NASA’s future in doubt, the physicist recalls designing an ingenious (and sadly, radioactive) rocket that could have had us "scooting all around the solar system" 50 years ago. Will we ever find a better way to reach the stars?
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For some reason, the bodies of deceased monks stay "fresh" for a long time.
- The bodies of some Tibetan monks remain "fresh" after what appears to be their death.
- Their fellow monks say they're not dead yet but in a deep, final meditative state called "thukdam."
- Science has not found any evidence of lingering EEG activity after death in thukdam monks.
It's definitely happening, and it's definitely weird. After the apparent death of some monks, their bodies remain in a meditating position without decaying for an extraordinary length of time, often as long as two or three weeks.
Tibetan Buddhists, who view death as a process rather than an event, might assert that the spirit has not yet finished with the physical body. For them, thukdam begins with a "clear light" meditation that allows the mind to gradually unspool, eventually dissipating into a state of universal consciousness no longer attached to the body. Only at that time is the body free to die.
Whether you believe this or not, it is a fascinating phenomenon: the fact remains that their bodies don't decompose like other bodies. (There have been a handful of other unexplained instances of delayed decomposition elsewhere in the world.)
The scientific inquiry into just what is going on with thukdam has attracted the attention and support of the Dalai Lama, the highest monk in Tibetan Buddhism. He has reportedly been looking for scientists to solve the riddle for about 20 years. He is a supporter of science, writing, "Buddhism and science are not conflicting perspectives on the world, but rather differing approaches to the same end: seeking the truth."
The most serious study of the phenomenon so far is being undertaken by The Thukdam Project of the University of Wisconsin-Madison's Center for Healthy Minds. Neuroscientist Richard Davidson is one of the founders of the center and has published hundreds of articles about mindfulness.
Davidson first encountered thukdam after his Tibetan monk friend Geshe Lhundub Sopa died, officially on August 28, 2014. Davidson last saw him five days later: "There was absolutely no change. It was really quite remarkable."
The science so far
Credit: GrafiStart / Adobe Stock
The Thukdam Project published its first annual report this winter. It discussed a recent study in which electroencephalograms failed to detect any brain activity in 13 monks who had practiced thukdam and had been dead for at least 26 hours. Davidson was senior author of the study.
While some might be inclined to say, well, that's that, Davidson sees the research as just a first step on a longer road. Philosopher Evan Thompson, who is not involved in The Thukdam Project, tells Tricycle, "If the thinking was that thukdam is something we can measure in the brain, this study suggests that's not the right place to look."
In any event, the question remains: why are these apparently deceased monks so slow to begin decomposition? While environmental factors can slow or speed up the process a bit, usually decomposition begins about four minutes after death and becomes quite obvious over the course of the next day or so.
As the Dalai Lama said:
"What science finds to be nonexistent we should all accept as nonexistent, but what science merely does not find is a completely different matter. An example is consciousness itself. Although sentient beings, including humans, have experienced consciousness for centuries, we still do not know what consciousness actually is: its complete nature and how it functions."
As thukdam researchers continue to seek a signal of post-mortem consciousness of some sort, it's fair to ask what — and where — consciousness is in the first place. It is a question with which Big Think readers are familiar. We write about new theories all the time: consciousness happens on a quantum level; consciousness is everywhere.
So far, though, says Tibetan medical doctor Tawni Tidwell, also a Thukdam Project member, searches beyond the brain for signs of consciousness have gone nowhere. She is encouraged, however, that a number of Tibetan monks have come to the U.S. for medical knowledge that they can take home. When they arrive back in Tibet, she says, "It's not the Westerners who are doing the measuring and poking and prodding. It's the monastics who trained at Emory."
When Olympic athletes perform dazzling feats of athletic prowess, they are using the same principles of physics that gave birth to stars and planets.
- Much of the beauty of gymnastics comes from the physics principle called the conservation of angular momentum.
- Conservation of angular momentum tells us that when a spinning object changes how its matter is distributed, it changes its rate of spin.
- Conservation of angular momentum links the formation of planets in star-forming clouds to the beauty of a gymnast's spinning dismount from the uneven bars.
It is that time again when we watch in awe as Olympic athletes perform dazzling feats of athletic prowess. But as we stare in rapt attention at the speed, grace, and strength they exhibit, it is also a good time to pay attention to how they embody, literally, fundamental principles that shape the entire universe. Yes, I'm talking about physics. On our screens, these athletes are giving us lessons in the principles that giants like Isaac Newton struggled mightily to articulate.
Naturally, there are many Olympic events from which we could learn some basic principles of physics. Swimming shows us hydrodynamic drag. Boxing teaches us about force and impulse. (Ouch!) But today, we will focus on gymnastics and the cosmic importance of the conservation of angular momentum.
The conservation of angular momentum
Much of the beauty of gymnastics comes from the spins and flips athletes perform as they launch themselves into the air from the vault or uneven bars. These are all examples of rotations — and so much of the structure and history of the universe, from planets to galaxies, comes down to the physics of rotating objects. And so much of the physics of rotating objects comes down to the conservation of angular momentum.
Let's start with the conservation of regular or "linear" momentum. Momentum is the product of mass and velocity. Way back in the age of Galileo and Newton, physicists came to understand that in the interactions between bodies, the sum of their momentums had to be conserved (which really means "does not change"). This is a familiar idea to anyone who has played billiards: when a moving pool ball strikes a stationary one, the first ball stops while the second scoots away. The total momentum of the system (the mass times velocity of both balls taken together) is conserved, leaving the originally moving ball unmoving and the originally stationary ball carrying all the system's momentum.
Credit: Sergey Nivens and Victoria VIAR PRO via Adobe Stock
Rotating objects also obey a conservation law, but now it is not just the mass of an object that matters. The distribution of mass — that is, where the mass is located relative to the center of the rotation — is also a factor. Conservation of angular momentum tells us that if a spinning object is not subject to any forces, then any changes in how its matter is distributed must lead to a change in its rate of spin. Comparing the conservation of angular momentum to the conservation of linear momentum, the "distribution of mass" is analogous to mass, and the "rate of spin" is analogous to velocity.
There are many places in cosmic physics where this conservation of angular momentum is key. My favorite example is the formation of stars. Every star begins its life as a giant cloud of slowly spinning interstellar gas. The clouds are usually supported against their own gravitational weight by gas pressure, but sometimes a small nudge from, say, a passing supernova blast wave will force the cloud to begin gravitational collapse. As the cloud begins to shrink, the conservation of angular momentum forces the spin rate of material in the cloud to speed up. As material is falling inward, it also rotates around the cloud's center at ever higher rates. Eventually, some of that gas is going so fast that a balance between the gravity of the newly forming star and what is called centrifugal force is achieved. That stuff then stops moving inward and goes into orbit around the young star, forming a disk, some material of which eventually becomes planets. So, the conservation of angular momentum is, literally, why we have planets in the universe!
Gymnastics, a cosmic sport
How does this appear in gymnastics? When athletes hurl themselves into the air to perform a flip, the only force acting on them is gravity. But since gravity only affects their "center of mass," it cannot apply forces in a way that changes the athlete's spin. But the gymnasts can do that for themselves by using the conservation of angular momentum.
By changing how their mass is arranged, gymnasts can change how fast they spin. You can see this in the dismount phase of the uneven bar competitions. When a gymnast comes off the bars and performs a flip by tucking their legs inward, they can quickly increase their rotation rate in midair. The sudden dramatic increase in the speed of their flip is what makes us gasp in astonishment. It is both scary and a beautiful testament to the athletes' ability to intuitively control the physics of their bodies. And it is also the exact same physics that controls the birth of planets.
"As above so below," goes the old saying. You should keep that in mind as you watch the glory that is the Olympics. That is because it is not just athletes that have this intuitive understanding of physics. We all have it, and we use it every day, from walking down the stairs to swinging a hammer. So, it is no exaggeration to claim that the first place we came to understand the deepest principles of physics was not in contemplating the heavens but moving through the world in our own earthbound flesh.
The eastern inner core located beneath Indonesia's Banda Sea is growing faster than the western side beneath Brazil.
More than 5,000 kilometres beneath us, Earth's solid metal inner core wasn't discovered until 1936.
Almost a century later, we're still struggling to answer basic questions about when and how it first formed.
These aren't easy puzzles to solve. We can't directly sample the inner core, so the key to unravelling its mysteries lies in collaboration between seismologists, who indirectly sample it with seismic waves, geodynamicists, who create models of its dynamics, and mineral physicists, who study the behaviour of iron alloys at high pressures and temperatures.
Combining these disciplines, scientists have delivered an important clue about what's happening miles beneath our feet. In a new study, they reveal how Earth's inner core is growing faster on one side than the other, which could help explain how old the inner core is, and the intriguing history of Earth's magnetic field.
Earth's core was formed very early in our planet's 4.5 billion-year history, within the first 200 million years. Gravity pulled the heavier iron to the centre of the young planet, leaving the rocky, silicate minerals to make up the mantle and crust.
Earth's formation captured a lot of heat within the planet. The loss of this heat, and heating by ongoing radioactive decay, have since driven our planet's evolution. Heat loss in Earth's interior drives the vigorous flow in the liquid iron outer core, which creates Earth's magnetic field. Meanwhile, cooling within Earth's deep interior helps power plate tectonics, which shape the surface of our planet.
As Earth cooled over time, the temperature at the centre of the planet eventually dropped below the melting point of iron at extreme pressures, and the inner core started to crystallise. Today, the inner core continues to grow at roughly 1mm in radius each year, which equates to the solidification of 8,000 tonnes of molten iron every second. In billions of years, this cooling will eventually lead to the whole core becoming solid, leaving Earth without its protective magnetic field.
One might assume that this solidification creates a homogeneous solid sphere, but this isn't the case. In the 1990s, scientists realised that the speed of seismic waves travelling through the inner core varied unexpectedly. This suggested that something asymmetrical was happening in the inner core.
Specifically, the eastern and western halves of the inner core showed different seismic wavespeed variations. The eastern part of the inner core is beneath Asia, the Indian Ocean and the western Pacific Ocean, and the west lies under the Americas, the Atlantic Ocean and the eastern Pacific.
Sanne Cottaar, Author provided
The new study probed this mystery, using new seismic observations combined with geodynamic modelling and estimates of how iron alloys behave at high pressure. They found that the eastern inner core located beneath Indonesia's Banda Sea is growing faster than the western side beneath Brazil.
You can think of this uneven growth as like trying to make ice cream in a freezer that's only working on one side: ice crystals form only on the side of the ice cream where the cooling is effective. In the Earth, the uneven growth is caused by the rest of the planet sucking heat more quickly from some parts of the inner core than others.
But unlike the ice cream, the solid inner core is subject to gravitational forces which distribute the new growth evenly through a process of creeping interior flow, which maintains the inner core's spherical shape. This means that Earth is in no danger of tipping, though this uneven growth does get recorded in the seismic wavespeeds in our planet's inner core.
Dating the core
So does this approach help us understand how old the inner core might be? When the researchers matched their seismic observations with their flow models, they found that it's likely that the inner core – at the centre of the entire core which formed much earlier – is between 500 million and 1,500 million years old.
The study reports that the younger end of this age range is the better match, although the older end matches an estimate made by measuring changes in the strength of Earth's magnetic field. Whichever number turns out to be correct, it's clear that the inner core is a relative youngster, somewhere between a ninth and a third as old as Earth itself.
This new work presents a powerful new model of the inner core. However, a number of physical assumptions the authors made would have to be true for this to be correct. For example, the model only works if the inner core consists of one specific crystalline phase of iron, about which there is some uncertainty.
And does our uneven inner core make the Earth unusual? It turns out that many planetary bodies have two halves which are somehow different to each other. On Mars, the surface of the northern half is lower-lying while the southern half is more mountainous. The Moon's near-side crust is chemically different to the far-side one. On Mercury and Jupiter it's not the surface which is uneven but the magnetic field, which doesn't form a mirror image between north and south.
So while the causes for all of these asymmetries vary, Earth appears to be in good company as a slightly asymmetrical planet in a solar system of lopsided celestial bodies.
How the British obsession with tea triggered wars, led to bizarre espionage, and changed the world — many times.
- Today, tea is the single most popular drink worldwide, with a global market that outstrips all the nearest rivals combined.
- The British Empire went to war over tea, ultimately losing its American colonies and twice beating the Chinese in the "Opium Wars."
- The British desire to secure homegrown tea resulted in their sending botanist Robert Fortune on a Hollywood-worthy mission to secure Chinese tea plants and steal horticultural secrets.
After water, tea is the most common drink in the world. It is more popular than coffee, soft drinks, and alcohol combined. 84 percent of Brits enjoy a daily "cuppa," but this is a mere bagatelle against the Turks, who drink on average three to four cups every day. The tea industry is worth $200 billion worldwide and is set to grow by half by 2025.
Tea is such a huge part of many cultures, that it even has origin myths. For instance, one involves the Buddha waking up after falling asleep during his meditation. Disgusted at his lack of self-discipline, he cut off his eyelids and threw them to the ground. These lids then grew into tea plants to help future meditators stay awake.
Tea really matters to a lot of people. And, it mattered so much to the British and their empire that it directed their entire foreign policy. It also inspired one of the most incredible and ridiculous tales of 19th century espionage.
A spot of tea
When the European powers of the 16th century first traded with, then militarily colonized, various East Asian nations, it was impossible not to come across tea. Since the 9th century, the Tang Dynasty of China had already popularized tea across the region. Tea was already firmly entrenched when the Portuguese became the first Europeans to sample it (in 1557), followed by the Dutch, who first shipped a batch back to mainland Europe.
Britain was relatively late to the tea party, not arriving until well into the 17th century. In fact, in Samuel Pepys' 1660 diaries, he makes reference to "a cup of tee (a China drink) of which I had never drunk before." It was only after King Charles II's Portuguese wife popularized it at court that tea became a fashionable societal drink.
After the Brits got going, there was no stopping them. Tea became a huge business. However, since tea was monopolized by the East India Company and the government imposed a whopping 120 percent tax on it, an army of smuggler gangs opened back channels to get tea to the poorer masses. Eventually, in 1784, Prime Minister William Pitt the Younger got wise to the popular cry for tea. To stamp out the black market, he slashed the tax on the leaf to just 12.5 percent. From then on, tea became the everyman's drink — marketed as medicinal, invigorating, and tasty.
A cup, a cup, my kingdom for a cup!
Tea became so important to the British that it even sparked wars across the empire.
Most famously, when the British imposed a three pennies per pound tax on all tea the East India Company exported to America, it led to the outraged destruction of an entire ship's tea cargo. The "Boston Tea Party" was the first major defiant act of the American colonies and led ultimately to ham-fisted and insensitive countermeasures from the London government. These, in turn, sparked the U.S. War of Independence.
Less well known is how Britain went to war with China over tea. Twice.
Credit: Ingo Doerrie via Unsplash
Back then, tea was only being grown and exported from China to British India and then around the empire. As such, it led to a massive trade imbalance, where the largely self-sufficient China only wanted British silver in return for their famous and delicious homegrown tea leaves. This sort of economic policy, known as mercantilism, made Britain really mad.
In retaliation, Britain grew opium and flooded China with the drug. When China (quite understandably) objected to this, Britain sent in the gunboats. The subsequent "Opium Wars" were only ever going to go one way, and when China sued for peace, they were lumped with $20 million worth of reparations — and had to cede Hong Kong to Britain (which only returned in 1997).
The tea spy: on her majesty's secret service
But even these wars did not resolve the trade deficit with China. The attempts to make tea in British India resulted in insipid rubbish, and the British needed the good stuff. So, they turned to a Scottish botanist named Robert Fortune, whose mission was simple: cross the border into China, integrate himself amongst Chinese tea farmers, and smuggle out both their expertise and preferably their tea plants.
Fortune accepted the mission, even though he could not speak a word of Chinese and had barely left his native Britain. (A forefather of 007 he was not.) But not one to let these details get in the way, he shaved his hair, plaited a pigtail that resembled those worn by the Chinese, and then set off on his adventure.
And what an adventure it was. He came under attack by bandits and brigands, his ship was bombarded by pirates, and he had to endure fever, tropical storms, and typhoons. In spite of all this, Fortune not only managed to learn Chinese and travel around the forbidden City of Suzhou and its surrounding tea-farming land, but he also integrated himself into secluded peasant communities. When the skeptical tea farmers challenged Fortune on why he was so tall, he fooled them by claiming that he was a very important state official — all of whom were tall, apparently.
An Indian speciali-tea
Amazingly, Fortune had good fortune and got away with it. Over the course of his three-year mission, he secreted out several shipments of new tea plants to Britain as well as the art of bonsai (previously, a closely held secret). Most of the smuggled tea leaves died from mold and moisture in transit, but Fortune persisted, and eventually the British began to cultivate their own tea plants using Chinese tea farming techniques in their colonial Indian soils.
It was not long until an Indian variant, almost indistinguishable from the stolen Chinese one, began to dominate the market, not least for Britain's huge and growing empire. Within 20 years of Fortune's remarkable mission, the East India Company had more than fifty contractors pumping out tea worldwide.
Today, things have reverted back. China now produces not only substantially more than India (in second place) but more than the top ten countries combined. In total, 40 percent of the world's tea comes from China. But it was British tea — and Robert Fortune's incredible and unlikely mission — which catalyzed the huge global market. Without this overly confident Scottish plant-lover, the world's love of tea might look very different.