Does Nuclear Pulse Propulsion—see previous post—solve the problem of travel between the stars? The Dyson paper proposes exploding H bombs behind a spacecraft at the rate of one every three seconds for ten days to achieve a speed of 10,000 km per second. At that speed, a ship would still take best part of 150 years to travel between the Sun and Proxima Centauri, the nearest star, a distance of four and a third lightyears. Even a one-way journey would require as much again propulsion to slow down at the other end, and the mass of this would have to be accelerated on the outward journey, nearly tripling the size of the craft and its cost. The legion questions regarding the practicalities of multi-generational crew survival in a very limited living area over such a long period are too obvious to need detailing.
It seems then that even nuclear pulse propulsion is impractical for the transport of biological species between the stars. But what about robots? The argument goes something like this: an advanced civilization would soon realize that interstellar travel is only possible for machines. Wishing to explore the galaxy, announce their presence, and proclaim their achievements, the civilization would conclude that the only way to do this would be to send out thousands of self-replicating ‘von Neumann’ machines on one-way journeys directed to different parts of the galaxy.
A von Neumann machine can build an exact copy of itself; in this case, a robot spacecraft capable of travelling to the stars. It uses built-in instructions and the raw materials that it finds on the planets it where it lands. The complete machine includes all the robotic paraphernalia needed for finding, mining and refining the minerals and other materials required, as well as setting up factories to manufacture the parts and fuel needed for the spaceship and new robot crew. It must also be able to construct a spaceship capable of lifting off from the planet and travelling to the nearest stars. It would be programmed to continue manufacturing copies of itself, each one to be directed to a different nearby star. Given enough time, and if such an advanced civilization really did exist, the Galaxy should be full of von Neumann machines.
Since Earth is not knee-deep in von Neumann machines, we can conclude that there are no advanced civilizations in the galaxy… Can’t we?
A few years ago I presented a course somewhat ambitiously titled A History of the Universe to a number of WEA groups. One of the most interesting sections (to me) was a discussion of the enormous number of stars and galaxies (and their ‘astronomical’ distances), and the fairly recent discovery that many—probably most—stars have a retinue of planets, including rocky Earth-like planets. Could we even find extra-terrestrial life out there, I wondered?
In one of the course modules, I considered the difficulties of travel to the stars. The great physicist Enrico Fermi suggested that life on Earth was unique. If it wasn’t, and considering the vast age and size of the universe, many other civilizations must have arisen millions of years before humanity, developed space travel, and have come to visit us. Since they have not done so, we can safely assume that they do not exist. A most interesting idea (I said), but it has one fatal flaw: the vast distances between the stars mean that manned (or creatured) spacecraft based on any known scientific principles would take many thousands of years even to travel from here to the nearest star.
And then, via good old Wikipedia, I came across a declassified Los Alamos paper from 1955 authored by C J Everett and S M Ulam. Stanislaw Ulam, along with Edward Teller, developed the thermo-nuclear ‘hydrogen’ bomb, and suggested the idea of Nuclear Pulse Propulsion. The paper with Everett developed the idea which was, quite seriously, to propel missiles to very high speeds by exploding a series of H bombs behind them…
Following the reference trail, I found an article in Physics Today from October 1968. The author was Freeman J Dyson, a renowned (originally English) mathematician from Princeton, who had worked on the defunct Orion project. Project Orion, funded in the US by DARPA, had examined the possibility of nuclear pulse propulsion as applied to a spaceship for travel to the stars. There is more detail on the Wikipedia page, but the basics can be condensed from Dyson’s paper.
Dyson proposed a starship propelled by sequentially exploding one megaton H bombs behind a ‘pusher’ plate connected to a shock-absorber. The bombs would detonate every three seconds over a period of ten days or so, requiring around 300,000 bombs. This would produce an average acceleration of one g, with a final velocity of 10,000 km per second—around one thirtieth of the speed of light. The cost of such a ship at 1968 prices would be 60,000 million dollars, around 0.1 US GNP. The shock absorber would ensure that the crew were not squashed by the force of the explosions, and suitable shielding would protect them from radiation from the bombs.
Dyson suggested that it would have been much cheaper to send a spacecraft to Mars powered by nuclear bombs, than it was costing to send the Apollo astronauts to the moon. For travel to Mars, only a few bombs would have been needed, so that’s a relief.
Tomorrow is the birthday of Emma Joan Brunel, the younger of Isambard's two sisters. Anyone loitering around the western portal of the Box Tunnel at around 5:30 in the morning, might be able to see the rising sun shine right through the tunnel.
A listener to BBC Radio Bristol wants to know: When was the tube in London built? What was the first tube station, and is it true it was designed by Isambard Kingdom Brunel’s father? What a lovely question!
The London Underground as an integrated system did not come into existence until 1933. Before then, the lines that form the network today were all privately financed and owned railways, some sharing stations and ticketing, and some not.
The ‘tube’ as it is generally known consists of two distinct types of train. The first line, which opened in 1863 was the Metropolitan Railway between Bishops Road—next door to Paddington Station—and Farringdon Street in the city. It did not use tunnels, but rather a method known as ‘cut and cover’; a trench was dug, usually along a street, the rails were laid along the bottom, and the roof was covered over. Essentially, the train travelled just below ground level covered by a series of arches with frequent openings for ventilation, because until the 1890s, it was operated using steam locomotives.
The first tube proper, where a tunnel was dug deep underground, was on part of what is now the Northern Line between a now defunct station King William Street—near London Bridge—and Stockwell. It was finished in 1890, and operated using electric locomotives, the first underground train to do so. Trains designed to run in the deep tunnels, ‘Tube trains’, are smaller than those on the Metropolitan and other cut and cover lines, and have a nearly circular cross-section. Metropolitan Line carriages are virtually indistinguishable—apart from seating—from suburban and main-line trains.
So where does Brunel senior come in? He was Sir Marc Brunel, a French ex naval officer, who fled the French Revolution for America because of his Royalist beliefs. He came to England in 1799 to be reunited with his sweetheart Sophia Kingdom, an English girl he had met in Rouen. Their son, Isambard, was born in 1806.
In 1825 Sir Marc started work on a tunnel under the Thames between Rotherhithe and Wapping. This was around a mile and a half downriver from London Bridge, which was at the time the last crossing on the river. Anyone wishing to cross further downstream was obliged to use a ferry. A bridge could not be built because of the height needed to accommodate the masts of the sailing ships, so Sir Marc opted for a tunnel to meet a substantial anticipated demand. The work was difficult because the ground consisted of gravel, sand, and mud, liberally laced with London sewage and other detritus… There were frequent cave-ins, when the river broke through and flooded the tunnel. Isambard was co-opted to the project, and very nearly drowned during one of the inundations. He was pulled unconscious from the water, and was very lucky to have survived.
In 1843 the tunnel was finally completed after eighteen years work, including seven years when the money ran out and work just stopped. It was opened for pedestrians only; the original plan had been to provide ramps for horse-drawn traffic, but these proved to be too expensive. Access was via two great spiral staircases. The toll was one old penny, and in the first year two million people made the crossing. As well as a river crossing, the tunnel was used for fairs and other entertainments, and soon earned a reputation for disgraceful goings-on…
The tunnel was finally sold for £200,000 to the East London Railway in 1865, and opened to rail traffic four years later using steam locomotives. The East London Railway became the East London Branch of the Metropolitan Line. Today, it takes the ‘London Overground’ under the river, and at Wapping Station it is possible to see parts of the original tunnel.
So, although Sir Marc Brunel did not design the first station, he did build the very first tunnel to be used on the London Underground system, many years before the next one was dug. Since he died in 1849, he had no idea at the time that he had done so.
And as a rather satisfying coda, the Paris 'Metro' is named after the Metropolitan Line on the London Underground, an extension to which ran through the very first tunnel on the system, a tunnel designed and constructed by a Frenchman, Sir Marc Isambard Brunel.
NB. Persons of a deeply masochistic temperament can hear me talking about this to John Darvall of BBC Radio Bristol, today, 31 March, just after 1:20 PM ...
An old quip that I still find amusing: the sun never set on the British Empire because God does not trust Englishmen in the dark. Nevertheless, one hears it said that Britain has a reputation around the world for honesty, probity, and adherence to the rule of law.
But every now and then, critics say, the government does something which rides roughshod over this alleged reputation, and risks Britain becoming a pariah state. A recent example would be the Internal Market Bill, where the UK planned to override the EU withdrawal treaty under certain circumstances, thus breaking international law. In the event, the contentious parts of the bill were withdrawn after talks with our ‘European partners’, as Johnson refers to them. I’m not sure whether many ‘partners’ would wish to continue that arrangement with a state planning to renege on an agreement not many months old .
And now, the government has unilaterally extended the grace period relating to the control of goods travelling across the Irish Sea to Northern Ireland because of difficulties with the new regulations. The Europeans were not consulted; they were not even told... As a result, the EU are preparing legal action.
What are we to make of this? Undoubtedly, Europhobes will applaud the government for ‘sticking it’ to the bullying and unreasonable EU, who are, by the way, simply expecting the UK to adhere to the terms of an agreement freely entered into.
Of all things in the exit from the EU, the issue of the Irish border was always the circle that could never be squared. If there are different standards, regulations etc. on either side of an international border, the unrestricted movement of goods is not possible. So in order to preserve free movement between the North and the South of Ireland—per the Good Friday Agreement—the only solution, no matter how unpalatable, is to set the ‘border’ in the Irish Sea and perform the checks there. That was agreed and signed up to by both sides, but now the UK appears to be in denial.
The real villains of this affair, whose behaviour in my view borders on criminality, are Messrs Johnson and Gove. They and others assured us that the issue of movement of goods across the Irish border would be no problem at all, and would all be dealt with using technology. This has proved to be about as credible as the ‘easiest and quickest trade deal in history’... Johnson and his cronies were the architects of the current mess, but it is all of us who will pay for their gross stupidity and incompetence, as the reputation of this country continues to slide.
It is very sad to see the row that has broken out between AstraZeneca and the EU about supply issues with the vaccine. Also to read about Macron wading in with ill-considered—and ill-informed—comments about the vaccine. Clearly the situation is complex, and more than just the simple contractual issue of ‘first come, first served’, but the implementation of export controls is absolutely not the way to proceed. If the UK can’t get the Pfizer vaccine from Belgium, then guess what the reaction to making up the EU AstraZeneca shortfall from UK sources is going to be? Already the right-wing press in the UK has gone into overdrive, particularly after the insane decision—fortunately reversed within a few hours—of the EU to impose restrictions on the Irish border. That was the sort of nonsense we’ve come to expect from the Prime Minister of the United Kingdom.
However, I shall relate a story that might throw some light on matters. Following the importation of dunderheads into the highest levels of management of the company for which I had given twenty years of loyal service, I suffered a fairly major demotion. This was some time ago, and both persons having long since left the employ of the company in question, I can say that two of them, my boss, and my boss’s boss, resembled Laurel and Hardy. And the comedic resemblance did not end there … But I digress; the Hardy lookalike was my boss, and talking to him was like chewing a brick. But again, I digress. I was demoted at least two—possibly three—levels of management down, plus a kick sideways, and ended up project managing the design, build, test, and packaging of CCD devices. Needless to say, I knew nothing about CCDs—charge coupled devices—and absolutely nothing about project management.
These were special CCDs for use in space probes, and the one thing about space probes, is that if anything goes wrong you can’t send in a bloke with a spanner to sort things out. Consequently, the devices have to be super-reliable, and the way to ensure that is to make lots of them and test the bejesus out of them. Yet again, I digress. Dumping me, who knew absolutely sod all about either the product or the process, into the management of the production of a device that was to be blasted into space sounds like another insane decision. Fortunately, my new colleagues were splendid and most supportive, and I ended up greatly enjoying the new challenge. If I say so myself, I didn’t make too bad a fist of it.
I was involved in a number of projects, but two stand out. Both were for devices that had a similar resolution. One was for a major European manufacturer, the other was for an American company. The specification for the European device was tortuous in the extreme, and required an enormous amount of testing. The mandatory paper-trail occupied a small library, and the complexity of the device caused a legion of technical problems. In addition to this, there were endless review meetings and telephone conferences involving the customer, the customer’s customer, and the customer’s customer’s customer. Eventually the device was completed, the satellite was launched, and the system is currently working admirably.
The specification for the American device was not onerous, the testing requirements were modest, and the paperwork constituted around one tenth of that needed for the European device. It too was completed, the satellite launched, and the unit functions still, having preformed now for about five times its original design life.
As I have said, there were many technical problems with the European device. On one memorable occasion I visited the customer, along with one of our engineers, to try and sort out some difficulty or another. (I gave a talk on this project to an assembly of our engineers and technicians, prefacing it with the famous legend over Dante's gates of Hell: “Abandon hope all ye who enter here”; that comment was greeted with thunderous applause.) One of the senior engineers of our European customer had seen a paper published on our American device—which had been completed and delivered, and was readying for launch—and demanded to know when we had started the project. He was somewhat taken aback to discover that we had started it considerably after commencing his project.
But that is not all. Prior to my ignominious demotion, I spent many years servicing a supply contract to CERN in Geneva for high power switches for their many high-energy particle accelerators. The success of our devices at CERN led to sales to many other accelerator centres all over the world. Naturally, several of these were in the USA, and I made regular visits to Brookhaven (long Island), Fermi Lab (near Chicago), SLAC, (Palo Alto, California) and one or two others that I have forgotten. In visiting their labs, it was impossible not to notice that whereas the various (international) groups at CERN built their equipment positively earthquake proof, the Americans were far more relaxed and laid-back. String and sealing-wax is an exaggeration, but there was definitely a feeling at the American laboratories of ‘best effort’, and ‘just make it work’, rather than write a Library of Congress specification and spend the next three years in a procurement process.
The point I am trying to make, albeit very long-windedly but based on hard-won first-hand experience, is that sometimes the European view gets bogged down in the process, and loses sight of the objective and the imperatives associated with it. One country suffers particularly from this, and I have already mentioned its president.
Italy and Spain suffered Covid infections significantly earlier than the UK—the UK government was criticised for not realizing that the same would happen here a few weeks later, as it did. Why then was the EU so slow off the mark to place vaccine orders? One of the few, the very few things this government has done in the pandemic with exemplary speed, is to get contracts in place for the supply of vaccine—well before it was known whether the vaccine would even work. It seems a pity that our supply should be endangered by export controls put in place after the event.
The B****t argument is lost, but it maddens me to see the ‘I told you sos’ bandying about, and this does not bode well for the future. Poorly done Europe, poorly done ...
Very little has made me feel my age more than Monday night’s TV. First off there was University Challenge. Neither the team from Balliol College, Oxford, average age 26, nor King’s College, London, average age 23, were able to identify the Everly Brothers singing Bye Bye Love. Admittedly it was the Everlys' first hit and dated from 1957, but they had such a characteristic and unique sound, it seems incredible that not one of the eight in the teams was able to recognize them.
It got worse. The team from King’s who won the bonus then failed to identify Roy Orbison—admittedly a trick question, because he was singing an Everly Brothers' song—but then no-one could identify Buddy Holly singing Raining in my Heart. Of all the iconic sounds of pop music from the late ‘Fifties and early ‘Sixties, surely the Everly Brothers, Roy Orbison and Buddy Holly must be at the top. Still, probably even the teams’ parents had not been born by the time Buddy Holly died.
Then, Mark Kermode’s Secrets of the Cinema—Pop Music Movies, compounded my misery when I found that not even half way through the timeline, I had little or no knowledge of the bands he was showcasing.
Finally, following Mark Kermode the BBC repeated A Hard Day’s Night. I remember being up in the West End and coming out of a music shop where I had been ogling a Gretsch guitar of the type George Harrison used. There was a primeval scream of fans who had caught sight of one or other of the Beatles who were in town for a London Palladium performance. It thrilled me to the core, and the film brought it all back; it was 1964, fifty-seven years ago …
There cannot be much left to say about Trump. He lacks any sense of the dignity of his office, and his overweening hubris is just breathtaking. He is an unashamed populist who aims for the lowest common denominator, and yet the majority of his enthusiastic supporters—interviewed on TV at and around the Capitol—were not loonies with KKK tattoos, or barely coherent rednecks, but looked and sounded like regular and decent-looking articulate citizens. This, to me, is the real worry of Trump. How is it that this ignorant, narcissistic, bullying clown is able to garner so much support from apparently ‘normal’ people?
For five years I have been toiling on this new book, Reverend Duke and the Amesbury Oliver. The last six months have been spent just editing the final version for print. It has been the most difficult thing I have done, but now it is published.
I recount the quite extraordinary behaviour of the Reverend Edward Duke, 1779-1852, antiquary, magistrate, and guardian of the Amesbury Union Workhouse. The introduction to the book can be read here.
The new book is available directly from me via this website, or from all reputable online booksellers, including the one named after a South American river, and high-street shops—if any of them are still trading. A short account extracted from the book will be published in Genealogists’ Magazine in due course. A summary of Mr Duke’s bizarre theory concerning the origin of Stonehenge, Avebury and Silbury Hill can be found here.
Keen observers may note that my appearance has undergone a subtle change over the last few months. I blame general indolence and shortages of razor blades due to panic-buying.
I suspect that the phrase ‘UK Energy Policy’ might well be an oxymoron. With the exception of subsidies given to wind farms, there is little to suggest any sort of comprehensive plan.
Here are some statistics that I find uncomfortable. Yesterday at various times, natural gas provided more than 50% of UK electricity power generation. Since the demise of coal, combined cycle gas turbine (CCGT) generators provide the lion’s share of UK power needs. They are efficient—up to 60% is claimed; the gas turbine exhaust heat is used to generate steam, which drives steam turbine generators—and notwithstanding the CO2 emissions, CCGT is relatively clean. They can also be started up in half an hour or so in order to meet rapid variations in demand.
So far, so good. But natural gas is a fossil fuel, and there are proven world-wide reserves of gas that will last for only slightly more than 50 years at current consumption rates. Undoubtedly more will be discovered, but the bad news is that more than 40% of known reserves lie in Russia and Iran, with Russia holding more than 24%.
Even the most liberal of observers could hardly claim that either country is a friend of the UK, so there must be a major question of security of supply; more than 50% of our gas is imported and our own natural reserves are now substantially depleted. As I remember well during the oil crisis of 1973, the OPEC countries increased the price of oil by 400% and the price of petrol at the pumps more than doubled within a few months.
It seems to me that natural gas may well be a strategic weapon of the future. Economies are based on the availability of electricity, and without gas to heat our homes and offices … True, there is a plan to phase out domestic heating with natural gas, and 30-40% of consumption is used for that purpose. I do wonder though at the reality and cost of replacing 22 million gas boilers over the next ten years. I suspect that, with a few exceptions, only new homes will be fitted with alternatives.
Nuclear power will not come to the rescue either. Hinkley Point C is enormously expensive although it is planned to provide 7 - 10% of our ‘current’ power needs, and there has been a shambles over financing and planning. Frustrations with financing have caused Hitachi to pull out of two new UK nuclear projects in the last few months. It is tragic that the UK, which produced the world’s very first commercial nuclear-powered electricity generation, is now not only dependent on imported technology, but seems unwilling to pay for it. And there is always the problem of security against hostile action. In these days of state-sponsored terrorism, anything is possible. A single, well-placed, air to ground missile could easily take a nuclear power plant off line for months, years, or for ever. Not even a missile would be needed. Remembering Chernobyl, what manager would risk operating a nuclear plant that had been damaged, no matter how slightly.
There is one more problem for future electricity generation that I suspect might be the elephant in the room. Within ten years no new petrol or diesel cars will be sold in the UK. All those new electric cars and other vehicles will need electricity. Apparently there are now in excess of 40 million cars, vans, busses, and lorries on UK roads. That is potentially a lot of extra electrical power needed in coming years.
The answer seems so burningly-obvious to me, that I wonder why we are not doing it already. One of the real successes of green energy policy, has been the proliferation of wind turbines. People moan that they are unsightly, although most are situated offshore. Others moan that the operators are sometimes paid not to generate electricity, but if that is the case, it is because they are flexible, and no-one yet has come up with an effective way of storing large amounts of electrical energy when generation exceeds demand. The main drawback of wind turbines is uncertainty in the wind. The website gridwatch.co.uk indicates how different technologies—nuclear, wind, solar, hydroelectric, CCGT etc.—contribute to UK power demand. Over the last few months, I have seen wind power provide from 40% of the country’s entire electricity needs, to just a few percent, entirely depending on the weather.
The one resource, untapped, eminently renewable, entirely predictable, distributed all around the country, and needing technology that has been mature for decades, is tidal power. The tides rise and fall twice every day. There is a monthly variation according to the disposition of the sun and moon, but that amounts to only 30% or so, and can be predicted with a high degree of precision. Furthermore, the time of high tide varies around the country.
The process is simplicity itself—and has been used for hundreds of years to power the milling of corn. Build a lagoon, and install turbine generators in the wall of the lagoon. As the tide rises, the water flows into the lagoon through the turbines and generates electricity. As it falls, the water flows out of the lagoon and generates electricity. In practice, sluices are closed at the beginning of the rise and fall to allow a head of water to build up; this reduces the availability of power generation to around 14 hours in every 24. But since there is always high or low water somewhere around the coast, careful positioning of generator sites could provide full, uninterrupted coverage.
There could be a further benefit. Much of the east of England, particularly Essex and Suffolk, is sinking into the sea. Since I lived at Wivenhoe on the Colne estuary in Essex in the 1970s, the sea-level has risen there by 40 mm. The cost of coastal protection is high and some say ultimately a waste of effort, since eventually the sea will overtop any man-made defences. But a tidal lagoon doubling as coastal defence would change the economics completely. Might this be an answer to the east-coast problem?
No-doubt there are some defects in these arguments, but I am certain that the basic principle is sound: renewable, relatively low tech, and distributed power generation, with added benefits, as part of future energy policy. Isn’t this exactly what the country wants right now? A massive infrastructure project providing employment for tens of thousands, and a real strategic asset for the whole country.
Welcome to the Mirli Books blog written by Peter Maggs