Smashwords Ebook Discount

Until near the end of April, my ebooks at Smashwords will be discounted by 60%, The fictional ebooks include”

Puppeteer:  (Free!) A technothriller where governance is breaking down due to government debt, and where a terrorist attack threatens to kill tens to hundreds of millions of people and destroy billions of dollars worth of infrastructure.

http://www.smashwords.com/books/view/69696

‘Bot War:  A technothriller set about 8 years later, a more concerted series of terrorist attacks made by stolen drones lead to partial governance breaking down.

https://www.smashwords.com/books/view/677836

Troubles. Dystopian, set about 10 years later still, the world is emerging from anarchy, and there is a scramble to control the assets. Some are just plain greedy, some think corporate efficiency should rule, some think the individual should have the right to thrive, some think democracy should prevail as long as they can rig it, while the gun is the final arbiter.

https://www.smashwords.com/books/view/174203There is also the non-fictional “Biofuels”. This gives an overview of the issues involved in biofuels having an impact on climate change. Given that electric vehicles, over their lifetime probably have an environmental impact equivalent to or greater than the combustion motor, given that we might want to continue to fly, and given that the carbon from a combustion exhaust offers no increase in atmospheric carbon levels if it came from biofuel, you might be interested to see what potential this has. The author was involved in research on this intermittently (i.e. when there was a crisis and funding was available) for over thirty years. https://www.smashwords.com/books/view/454344

The Virus Strikes

By now it is impossible to be unaware of the presence of a certain coronavirus (SARS-Cov-2, causing COVID-19) that is sweeping around the world. (Wouldn’t it be better if some nit-pickers could stop changing the name and do something more constructive to deal with it?) Unfortunately, the time for containment has passed. It may have been that the only chance was early on in Wuhan because China can do things to stop the personal lack of consideration of others; the possibility of 5 years in a Chinese jail would inhibit most from personal stupidity, but the authorities did not get started quickly enough. This, in turn, may have been because the officials in Wuhan did no alert Beijing until it was impossible for Beijing not to notice. That golden opportunity was missed.

In New Zealand, we started with a law passed by which all people coming into the country had to self-isolate for two weeks. Within about two days a small number had been arrested for breaking that rule. In Wellington here we had someone fly in from Brisbane. He had been tested in Brisbane, but would he wait for the test results? No, he felt he wasn’t sick (so why was he tested?) Did he stay isolated until the test results? Of course not. When you are that self-centred, you do not suddenly become responsible. Wellington now has the second most cases in the country.

There was one woman who arrived in Auckland from overseas and was feeling ill.  At this stage she was advised to self-isolate but the law requiring her to had yet to come into play. So what did she do? She convinced herself she wasn’t so ill after all, so she flew to Palmerston North, where she discovered that maybe she really was sick so she flew back to Auckland. The net result of this is we shall get some idea of how easily this virus really does spread. So far, Palmerston North has three cases, but if there is an inexplicable surge over the next few days, we shall find out something. If, on the other hand, there are no such cases, we may be able to breathe a little easier. (It is not just the people sitting close on the aircraft; recall how people behave prior to boarding, during boarding, collecting luggage, and if using public transport, getting to and from the airport.)

While we were relying on voluntary compliance, the virus was actively spreading. The government has now required a complete lockdown, going out only for essential services. Will that work? In principle, if everyone on the entire planet stayed home for a month, all would be well. Those who had it would have to recover, but the virus would run out of people to transmit to. Simple? The problem there lies in everyone doing it at the same time. In the West, people want freedom of movement. Asking them to give this up seems to be beyond them. In New Zealand this might work. The police and if necessary the military are there to enforce it, and China appears to have shown this can work. We shall see.

As for me, I am self-isolating, only going out for groceries, but in my case, because I am retired it is no big deal. My day-time job used to be to do chemical research on contract for companies wanting to develop new products. That work has dried up completely. When potential clients are having problems staying open and paying their wages, research is the first to be stopped. As it happens, I was approached to write a chapter for an academic book on hydroliquefaction of algae, so writing that will keep me occupied. Searching the scientific literature can be done on-line these days.

The main tactic is not to get close to people. However, there is also the problem that the virus may land on something and you touch it. Staying at home is fine, but you still have to get groceries, and some people have to work.  Hand washing is important, but if you touch something after washing hands, that wash does nothing for what follows. The virus on the hand does no damage, but how often do you touch your face? What I intend to do is make a blocking gel to smear on my hands when visiting the supermarket. Two functions are desirable. One is to kill viruses. The second is to make the virus immobilized on the gel, like flies on flypaper. The coronavirus has a “crown” of protein so something that binds protein is called for. I won’t know for sure it works, but one advantage is that while I cannot get it tested for efficiency, I can back my own theoretical ability for myself.So, keep well, everyone. If all goes will and we all cooperate, this will pass. Finally, good luck all.

Can you Think like a Scientist?

Ever wondered how science works? Feel you know? If so, read this slowly. There is a puzzle to solve so don’t cheat and read past the question before trying to answer. 

WASP 76b is a planet circulating the star known as WASP 76. (WASP stands for “wide angle search for planets” and is an international consortium searching for exoplanets by using robotic telescopes in both hemispheres, hence wide angle. It searches by looking for transits, i.e. a planet passing in front of the star and dimming it. The 76 presumably means the 76th star of interest, and the b means the first planet to be discovered around that particular star.) The star is an F7 class, with a mass of about 1.46 that of the sun, and an effective temperature of about 6,000 oC. So it is bigger, brighter and hotter than the sun.

This planet is weird, by any standards. It is about 0.92 times the size of Jupiter, which means it is a gas giant, and it is 0.033 AU from the centre of the star. (The Earth-Sun distance is defined as 1 AU.) That is close, especially since the star is bigger than the sun. The time taken to go around the star is 1.809886 days. That means a birthday every second day our time, not that there will be anyone having birthdays. The news media has got hold of this because being so close it is expected that the planet is tidally locked. That means, like the Moon going around the Earth, one side is always facing the star and the other side is always facing away. This means that if that is correct and it is tidally locked, the side facing the star will have a temperature of about 2,400 oC, but the side facing away would have a temperature about 1,000 degrees cooler.

When a planet transits in front of the star, the material in the atmosphere absorbs starlight, which gives slightly darker spectral lines, and these give clues as to what is in the atmosphere. In this case, lines corresponding to iron were seen in the gas. At first sight, that is not surprising at 2,400 C. The melting point of iron is 1538 oC, while the boiling point, at our atmospheric pressure, is 2862 oC.  It is not hot enough to boil iron, but then again Earth has temperatures that are nowhere near hot enough to boil water, but plenty of water gets into the atmosphere as clouds, and comes down as rain.

This is where the media have sat up and taken notice: it appears it might be raining iron on that planet. That is weird. More evidence was cited for the rain in that the iron signal was unevenly distributed. Recall the light has to go through the atmosphere, so what we see is the signal from the edges. That signal is not evenly distributed, and apparently present on the evening side, but not in the transition edge from night to day. This was interpreted as due to the iron condensing out as it entered the cold side, and there would be liquid iron droplets as rain during the night. Now, here is your test as a potential scientist. Stop reading and think, and answer this question: do you see anything inconsistent in the above description? This is a test for potential theorists. Theories are not developed by brilliant insights, but rather by thinking that something we think is right has an inconsistency.

Anyway, what struck me is the planet allegedly has a morning and an evening. It cannot have that if it is tidally locked, because the same parts always face the star the same way. The planet must be rotating. As an aside, it is hard to see how it could be tidally locked because the gas in the atmosphere will be travelling extremely fast – the winds and storms will be ferocious if there is a thousand degree difference between night and day. But if it is rotating, maybe the difference is not that much. We cannot measure the dayside from transits. Also, if it were tidally locked, we might expect the iron to rain out on the dark side, but then what? How would it get back to the dayside? After a while it would all be on the night side. There has to be some rotation somewhere.Another interesting point is how do you tidally lock gas? And what does rotation of a gas giant mean? In the case of Jupiter we know it rotates because characteristic storms mark the rotation, but Jupiter is far enough from the star that the temperature differences between night and day are trivial. The hot gas around WASP 76b must move. If it is always going the same way, is the planet rotating or merely the gas has a uniform wind?

Aircraft and Carbon Dioxide Emissions

Climate change requires significant changes to our lifestyle, and one of the more tricky problems to solve is air travel. Interestingly, you will find many environmentalists always telling everyone to cycle, but then spend tens of thousands of air miles going to environmental conferences. So, what can we do?

One solution is to reduce air travel. And there is no need in principle to adopt Greta Thunberg’s solution of sailing over the Atlantic. With a bit of investment, high speed rail can get you between the centres of reasonably close cities faster than aircraft, when you include the time taken to get to and from airports, and time wasted at airports. We can also reduce travel, but only so far. At first sight, things like conferences can be held online, but there are two difficulties: time-zone differences encourage doing something else, and second, the major benefit from conferences is not listening to set talks, but rather meeting people outside the formal program. For business, facing each other is a far improved way of negotiating because the real signals are unspoken. 

Some airlines are trying to improve their environmental credentials by planting trees to compensate for the carbon dioxide they emit. That is very noble of them, but apart from the fact it is their money doing it (and often it is not – it is the passengers who feel conscious stricken to donate more money for planting) it is something that should be done anyway. 

There has been talk of building electric aircraft. My personal opinion is this is not the solution. The problem is in terms of unit weight, jet fuel contains at least thirty times the energy density of the best batteries available. Even worse, for jet fuel, as you go further, you get lighter, but not with batteries. You could make a large aircraft fly, say, 1,000 to 2,000 km, as long as you did not want to carry much in the way of passengers or cargo. With thirty times the fuel weight for a long distance flight your aircraft would never get off the ground. However, the Israeli firm Eviation has developed a small electric aircraft for a load of 9 persons (plus two crew) powered by 920 kWh batteries with operating costs estimated at $200/hr. The range is about 540 nautical miles, or about 1,000 km. That could work for small regional flights, and it will be available soon.

Another option to be offered by Airbus is the E-Fan-X project. They will take a BAe 146 craft, which usually carries about 100 passengers, and which usually is powered by four Honeywell turbofan engines, and replace one of the inner ones with an electric-driven 2 MW propulsion fan motor. The idea is the takeoff, where the most power is required will use the normal jets, but the electric motor can manage the cruise. 

An alternative is to reduce fuel consumption. One possibility is the so-called blended wing, which is being looked at by NASA. This works; an example is the B2 bomber, however while it reduces fuel consumption by 20% it is most unlikely to come into commercial use any time soon. One reason is that there is probably no commercial airport that could accommodate the radically different design. It would also have to have extensive examination because so far the design has only had military applications, in which only very specific loads are involved. In principle, this, and other designs can reduce kerosene usage, but only by so much. Maybe overall, 25% is achievable, which does not solve anything.

Uranium 235 has an energy density that leaves kerosene for cold, but which airport wants it, and would you board it anyway? It could presumably be made to work, but I can’t see it happening anytime soon because nobody will take the associated political risk.

That leaves hydrogen. 1 kg of liquid hydrogen can provide the same energy as 3 kg of kerosene, so weight is not the problem, but keeping it cold enough and maintaining pressure will add weight. It cannot be stored in the aircraft wings because of the volatility. To keep it cold it is desirable to have minimum surface area of the tank. However, it is reasonably clean burning, giving only water and some nitrogen oxides. For a Boeing 747-400 aircraft, the full fuel load is 90 tonne less, but because the tanks have to be in the fuselage, they occupy about 30% of the passenger space.

That may work for the future, but the only real way to power current aircraft is to burn hydrocarbon fuel. More on that next week.

Molten Salt Nuclear Reactors

In the previous post, I outlined two reasons why nuclear power is overlooked, if not shunned, despite the fact it will clearly reduce greenhouse gas emissions. I discussed wastes as a problem, and while they are a problem, as I tried to show they are in principle reasonably easily dealt with. There is a need for more work and there are difficulties, but there is no reason this problem cannot be overcome. The other reason is the danger of the Chernobyl/Fukushima type explosion. In the case of Chernobyl, it needed a frightening number of totally stupid decisions to be made, and you might expect that since it was a training exercise there would be people there who knew what they were doing to supervise. But no, and worse, the operating instructions were unintelligible, having been amended with strike-outs and hand-written “corrections” that nobody could understand. You might have thought the supervisor would check to see everything was available and correct before starting, but as I noted, there has never been a shortage of stupidity.

The nuclear reaction, which generates the heat, is initiated by a fissile nucleus absorbing a neutron and splitting, and then keeping going by providing more neutrons. These neutrons either split further fissile nuclei, such as 235U, or they get absorbed by something else, such as 238U, which converts that nucleus to something else, in this case eventually 239Pu. The splitting of nuclei produces the heat, and to run at constant temperature, it is necessary to have a means of removing that amount of heat continuously. The rate of neutron absorption is determined by the “concentration” of fissile material and the amount of neutrons absorbed by something else, such as water, graphite and a number of other materials. The disaster happens when the reaction goes too quickly, and there is too much heat generated for the cooling medium. The metal melts and drips to the bottom of the reactor, where it flows together to form a large blob that is out of the cooling circuit. As the amount builds up it gets hotter and hotter, and we have a disaster.

The idea of the molten salt reactor is there are no metal rods. The material can be put in as a salt in solution, so the concentration automatically determines the operating temperature. The reactor can be moderated with graphite, beryllium oxide, or a number of others, or it can be run unmoderated. Temperatures can get up to 1400 degrees C, which, from basic thermodynamics, gives exceptional power efficiency, and finally, reactors can be relatively small. The initial design was apparently for aircraft propulsion, and you guessed it: bombers. The salts are usually fluorides because low-valence fluorides boil at very high temperatures, they are poor neutron absorbers, and their chemical bonds are exceptionally strong, which limits corrosion, and they are exceptionally inert chemically. In one sense they are extremely safe, although since beryllium fluoride is often used, its extreme toxicity requires careful handling. But the big main advantage of this sort of reactor, besides avoiding the meltdown, is it burns actinides and so if it makes plutonium, that is added to the fuel. More energy! It also burns some of the fission wastes, and such burning of wastes also releases energy. It can be powered by thorium (with some uranium to get the starting neutrons) which does not make anything suitable for making bombs. Further, the fission products in the thorium cycle have far shorter half-lives. Research on this started in the 1960s and essentially stopped. Guess why! There are other fourth generation reactors being designed, and some nuclear engineers may well disagree with my preference, but it is imperative, in my opinion, that we adopt some. We badly need some means of generating large amounts of electricity without burning fossil fuels. Whatever we decide to do, while the physics is well understood, the engineering may not be, and this must be solved if we are to avoid a planet-wide overheating. The politicians have to ensure this job gets done.