Sunday, February 21, 2010

living with offence

Kindly Inquisitors: The new attacks on free thought (1993) by Jonathan Rauch

Frances Widdowson (Offended by Offence) has recently reviewed this book on her blog. I liked her review and also the Kirkus review at amazon books. I haven't read the book. These brief notes are based on the reviews.

In our civilised democratic society (not Iran, China, etc.), the modern day equivalent of the Inquisition are the philosophies of egalitarianism and humanitarianism

ie. the principle of the Inquisition was that people with wrong or hurtful opinions ought to be punished for the good of society

egalitarianism - the beliefs of all sincere people deserve equal respect
humanitarianism - one must never offend

Taken separately and in particular when combined these outlooks undermine the pursuit of scientific truth by introducing a variety of mental and ideological barriers to free and open discussion. This is explained more in the reviews.

It is essential to learn the hard discipline of living with offence that will inevitably follow from this approach rather than fudging the quest for truth out of fear of offending others or being offended ourselves. Words might offend but as long it remains just words then we need to accept it and either argue back or move on, not try to censor it and to reject philosophies which attempt to censure open, vigorous discussion

Previous: This book reminds me of Frank Furedi's book, "Where have all the intellectuals gone?" which I did read and review
truth slips from view in the sea of post modern knowledge
how the left became conservative

Wednesday, February 17, 2010

economics of nuclear energy

Irrespective of other concerns (safety, disposal, proliferation of weapons) the generally accepted wisdom about the cost of nuclear generated electricity is that it is more expensive than electricity from coal or other fossil fuels.

I thought this as well until I researched it. Here are some notes

France is the number one country in the world which generates electricity from nuclear power. France derives over 75% of its electricity from nuclear energy. Their electricity costs are very competitive in Europe. France is the world's largest net exporter of electricity and gains over EUR 3 billion per year from this. (Nuclear Power in France)

In the 1970s in the USA electricity from nuclear power was sometimes cheaper than coal. But this situation reversed itself in the 1980s which led to many planned nuclear power stations being abandoned. The reasons for this are clearly documented in an online book, published in 1990, The Nuclear Energy Option, by Bernard Cohen. Here is a brief summary of his Chapter 9:
  • construction time for nuclear plants doubled from 1971 (7 yrs) to 1980 (12 yrs), which in turn doubled the costs
  • labour costs also doubled with the biggest increases being professional labour
(these figures corrected for inflation)

So, the cost of nuclear plants quadrupled in 10 years and as a result they were no longer built. The main reason for these increases were regulatory ratcheting (excessive) and regulatory turbulence (the latter being having to change things after the project has started and hence more expensive)

According to Cohen it was accepted wisdom by the utilities in the USA before the over regulation of the 1980s that nuclear would be cheaper than coal and would replace coal.
"Many utilities seek cost analyses from economics consulting firms, some utilities have their own in-house economists to make estimates, and banking organizations maintain expertise to aid in decisions on investments. From the early 1970s until the early 1980s, all of their reports found that nuclear power was the cheaper of the two. For example, the Tennessee Valley Authority (TVA) is the largest electric utility in the United States. Its profits, if any, are turned back to the U.S. Treasury. It maintained a large and active effort for many years in analyzing the relative cost advantages of nuclear versus coal-burning power plants, consistently finding that nuclear power was cheaper. The 1982 analysis by the Energy Information Administration, a branch of the U.S. Department of Energy, was the first to find that coal and nuclear were equal in cost; their previous analyses found nuclear to be cheaper. By 1982, these analyses were mostly discontinued, since it seemed unrealistic for a utility to consider building a nuclear power station, or even to hope that it could be done without regulatory turbulence"
- Ch. 10, The Nuclear Energy Option by Bernard Cohen
Tom Blees also discusses and updates answers to these questions in his book Prescription for the Planet. One of the important points he makes is that the modern reactor designs (Gen III and Gen IV) employ passive safety using molten sodium as a coolant and consequently do not have to operate under high pressure, except for the steam portion of the system in the turbine room. This means that significantly fewer valves, pumps and tanks are required compared with the older reactors. This lowers construction costs.

The other main point made by Blees about high costs in the USA (compared with France and some other countries) is that the nuclear industry there has yet to agree on a standard design and each new design has to jump many regulatory hurdles all of which pushes the cost of the process higher.

Thanks to Barry Brook's blog I recently attended a debate in which Tom Blees participated. Subsequently, I bought a few copies of his book and have distributed them to friends who are interested in discussing these questions.

I notice that the Obama administration has just announced a loan guarantee intended to underwrite construction of two nuclear reactors in Georgia. If the project goes forward, the reactors would be the first begun in the United States since the 1970s.

From what I have read I conclude that electricity from nuclear power could be as cheap as electricity from coal.

update 4th March: After a fair bit of discussion on threads at Strange Times (Technology, development and c... c... c... climate change) and Brave NewClimate (Do climate sceptics and anti nukes matter?) I have changed my mind again. In general nuclear is not cheaper than coal unless extra costs such as a carbon tax are (in the future) added to coal.

Monday, February 15, 2010

our energy rich future

The importance of numbers, from John McCarthy's sustainability of human progress site

The fission of an atom of uranium liberates about 10 million times as much energy as does the combustion of an atom of carbon from coal. I fear that to many people, the impression made by saying 10 million is about the same as if I had said 10 thousand or 10 billion.

One cannot understand policy issues without taking numbers seriously. If the number were 10 thousand, we probably could not afford nuclear energy. If the number were 10 billion, there would be no need for a significant uranium mining industry, and the waste problem would be trivial.
In another part of his site McCarthy quotes figures from Bernard Cohen demonstrating that nuclear energy can supply human needs for billions of years into the future. Although there is no reference to Bartlett type exponential growth here (which is not maintained in real life indefinitely, anyway) the calculations do demonstrate that there is no scientific reason to fear an energy deprived future.

Wednesday, February 10, 2010

david mackay: do the arithmetic

John McCarthy: He who refuses to do arithmetic is doomed to talk nonsense. (Progress and its Sustainability)

I'd forgotten a lot of my basic physics, so here is a refresher.

Power is the rate of energy conversion, or, the rate of doing work. This applies to both mechanical power, measured in joules / sec and electrical power, measured in watts

Work is done when a force is moved through a distance (W=F*D)

Mechanical force = mass * acceleration, the UNITS are kg.metre/sec/sec or Newtons
Mechanical work = force * distance, the UNITS are newton.metres or N.m or Joules
Mechanical power is work divided by time, or, Work / time, the UNITS are N.m /s or Joules / sec

Electrical power is measured in Watts. 1 Watt = 1 Joule / sec. A watt is also a volt.amp. Watts= Volts * amps

To obtain electrical energy then multiply the power * time. The UNITS here could be joules or watt.seconds. The normal units for larger amounts of electrical energy are KW.hrs. To convert watts to kilowatts divide by 1000, to convert seconds to hours divide by 3600 or 60*60.

We need to have an internalised way of having a feel for these values. A joule is the energy or work required to lift a small apple one meter straight up. If you perform that action in one second then that is equivalent to a watt or joule/sec of electrical power.

The small apple weighs 0.1 kg
The acceleration caused by the earth's gravity is roughly 10 m/sec/sec (9.8 m/s/s more accurately)
The distance we move the apple through is 1 metre
Work = force * distance
Work = mass * acceleration * distance
Work = 0.1 * 10 * 1
Work = 1 joule or 1 Newton.metre or 1 kg. metre ^2 / sec ^2, where ^2 means squared

Some other joule practical examples at the wikipedia joule page

A 40 watt incandescent light bulb produces forty joules of energy per second or the equivalent of lifting 4kg of apples 1 metre in one second. Fluorescent or LED lights achieve a similar effect with much less energy.

How much energy does a 40 watt incandescent light bulb use in one day?
40 * 24 / 1000 = 1 energy used in one day

How much energy does the average person in an industrialised country use? The figures here are for the UK

Answer: The equivalent of 125 of these light bulbs running all the time

How many wind turbines would it require to meet the energy needs of everyone in the UK?
Answer = 600,000, which would cover half of the UK. The UK currently has 2408 wind turbines

How many nuclear power stations would it require to meet the energy needs of everyone in the UK?
Answer = 300. The UK currently has 10 nuclear power stations.

Here is a video from David MacKay illustrating the need to do the arithmetic. Irrespective of whether you are an alarmist, denier or somewhere in between you still need to do the arithmetic and basic physics to intelligently discuss these issues:

David MacKay is the author of Sustainable energy - without the hot air. He has recently been appointed the UK's Department of Energy and Climate Change Chief Scientific Advisor.

Saturday, February 06, 2010

thoughts on the nuclear debate

Debate: "Should we consider Nuclear Power as a response to climate change?"


Professor Barry Brook, Sir Hubert Wilkins Chair of Climate Change, University of Adelaide, and author of the blog Brave New Climate

Tom Blees, President, Science Council for Global Initiatives and author of the book "Prescription for the Planet."

For the Negative:

David Noonan, Australian Conservation Foundation

Dr Mark Diesendorf, Deputy Director, Institute of Environmental Studies, University of New South Wales".

I bought Tom Blee's book Prescription for the Planet. Tom was a very effective presenter due to his extensive research and personal contact with a wide range of people deeply involved in these issues allowed him to communicate telling and interesting anecdotes - and he has a wicked sense of humour, which was much needed on the night

The majority of the audience was anti nuclear (2/3rds or 3/4) but thanks to the work done by Barry Brook on his blog, Brave New Climate, there was a significant pro nuclear presence

Mark Diesendorf was energetically aggressive in his attack on nuclear power as an "idealistic fantasy". He argued that renewables could completely replace fossil fuels by 2030 and presented a slide showing the growth of various renewables illustrating how this could be done.

I felt this slide was dodgy but didn't know enough to refute it. Mark also made a big issue of his expertise and criticised Barry for pronouncing outside his field of primary expertise.

Aspects of this slide were challenged by Barry Brook. How could geothermal grow so quickly when on another slide Mark had shown geothermal at the R&D stage in Australia and that new technologies took 40 years or so to reach large scale commercial stage. Mark had used this to argue that IFR (Integral Fast Reactors) was pie in the sky, so Barry's counter was quite effective.

There was other to and fro along these lines, some of it amusing. Barry pointed out that renewables only made up 1% of the world's energy. Mark responded that it was unfair to take a world average because some European countries had a much higher percentage. But Mark had earlier criticised Tom Blee's example of ineffective solar panels in Germany as "cherry picking" because Germany had a cold climate. This sort of exchange confirmed my belief that you need to have a firm grasp of the arithmetic to engage intelligently in this debate. I've read this page (Renewable energy cannot sustain an energy intensive society) of Barry's site and downloaded Ted Trainer's pdf from that page to improve my own knowledge here

David and Mark were unreasonably dogmatic in their anti-IFR stance. The issue of urgency was used in an irrational way, given the reality of the failure in Copenhagen and the certainty of developing countries like China and India to continue using massive amounts of fossil fuels. Even if IFR does take 50 years to develop on a large scale (in itself debatable) then that is not a reason not to develop it. There is a can do and a can't do mentality and wrt IFR their attitude was totally can't do on technical grounds alone. They want a total roadblock on nuclear power. They spent quite a bit of time on this, irrespective of their other objections.

Barry took a realistic economic approach that coal would not be replaced by alternatives until a cheaper alternative emerged - and the best shot for that was nuclear.

Mark disputed that but admitted that his renewable futures would be more expensive. For me this was the real "idealistic fantasy", his repeated statement along the lines that people power would convince governments to change.

The other main objection from the anti-nuclear side was proliferation. What emerged here was that IFR reactors do not produce weapons grade plutonium and there are other more effective means of producing weapons grade plutonium, such as high-speed centrifuge technology. I felt the pro-nuclear side was on shakier ground here since more IFR reactors will lead to more transport around the world of weapons grade plutonium (as a start up fuel) and so the probability of it falling into the hands of terrorists will probably increase.

Mark said that nuclear power was 14% of the world's electricity production and declining. Barry offered a bet that the nuclear percentage would increase but Mark declined to accept it. Good move, Barry!

So, it boiled down to who was living in the "real world" and who was living in "fantasy world"

Thursday, February 04, 2010

scratch challenges update

Numbers 12-14 are new. Scratch is a free download

1) Use the Letter shapes to write your first name on the page. Then introduce some special effects such as making the letters wobble and change their appearance.

2) Point, click and move
Make an object both point and glide towards the mouse position when you click on the stage
Hint: Motion > point towards
Hint: Sensing > mouse down?

3) Make Dan or Anjuli or Cassy or ballerina dance to a beat, using all of their dance shapes. Include a suitable background that changes colours as the lights flash.

4a) Make two animals have a forwards and backwards conversation
Hint: Use broadcast, (ask for help if you don’t know how broadcast works)
4b) Make it an interesting conversation with each animal speaking at least 3 times and making gestures too

5) Make a sprite gradually grow in size and then shrink

6) Make 2 different balls move around on the stage
a) the first ball moves in straight lines but bounces randomly whenever it hits the edge
b) the second moves randomly, gliding from one position to a new random position continually

7a) One sprite chases another sprite around the stage. The first sprite moves in straight line but bounces off the edge randomly. The chasing sprite chases the first sprite but is moving slower.
b) Extension – if the chasing sprite catches the other sprite then it says something sensible and makes a suitable sound

8a) Play all the different drum sounds automatically
Hint: create a variable for the drum number
b) Extension – keep recycling through all the drum sounds automatically

9a) Count down on a timer. A rocket takes off when you reach zero
Hint: Use the number icons in the letters folder
9b) Your rocket has pulsating exhaust and disappears at the top of the screen

10) Add, multiply or subtract two variable numbers
Hint: Just to do addition only you will need 4 variables: firstNum, secondNum, answer (computer calculated) and myAnswer (human calculated)

11) Variable coloured squares
a) Write a script that can draw a square of any size
Hint: Make a variable for the side length
b) Use the variable square script to draw a series of square with variable sides, with a single click
c) Now add variable pen colour and pen shade to the variable square script and use it to draw a variety of different coloured squares, with a single click

12) Draw lines of random thickness in random directions with random colours. The pen must be lifted up and moved for each new line.
Hint: pen group contains set pen color, set pen size, pen up, pen down
Hint: colours range across the spectrum (ROY G BIV) starting with red = 0. There are about 190 colours in total and you need to display them all!

13A) Make a race
a) choose two suitable sprites, they must have at least 2 costumes to simulate motion
b) the sprites move at random speeds, you can’t predict the winner
c) make a finish line, using a new sprite is best
d) suitable background music
e) when the winner crosses the finish line it announces that it won
f) reset scripts to start again

13B) Extension: Make it a multi-lap race, the number of laps can vary
g) make a variable to set and count the laps (use this on just one of the sprites otherwise you will be counting the laps twice)
h) use “x position” with an if tile rather than “if on edge bounce” to manage the turning and lap increase value
i) hide the finish line so that it only appears for the final lap

14A) Play the scales on a piano
a) Check out the sound > play note tile
b) Teacher has supplies a graphic of a keyboard. Import it to your scratch project.
c) Program the computer keyboard so that it plays a series of notes on the piano keyboard
d) As the notes are played alter the keyboard graphic to make it appear they are being pressed and they revert back to blank when the key is released
e) Add some suitable background graphics

14B) Extension
f) As the notes are played a sprite dances to the tune created by the notes, ie. each note triggers a particular movement
g) The names of the notes are spoken by a new sprite as they are played
h) Find a way to play ALL the notes on the keyboard

Wednesday, February 03, 2010

We don't deserve this, Julia Gillard

source of graphic

OK, I spent 6 years or so teaching at a School in one of the most disadvantaged socio-economic areas in metropolitan Australia. And so I can empathise strongly with how teachers at that school would feel about the new Australian government MySchool site when they see how their low NAPLAN results (Paralowie) are prominently in RED when compared with ALL schools , even though the similar so called like school results are displayed in far lighter shades.

Just let me say that Paralowie had the most enlightened administration and the most creative teachers I have ever had the privilege to work with. Teachers who understood that the main source of educational disadvantage was socio-economic and worked very hard to turn things around for as many students as they could.

And guess what. It will be the same long after Julia Gilliard has left politics and has retired on her parliamentary pension to some upper class suburb somewhere.

Further reading: League Tables Increase Social Segregation and Inequality by Trevor Cobbold, pdf

Previous blog: sbs-insight: should-schools-test-results-be-made-public

Previous article:

More temperate but well researched blogs, even though I have no idea where Darcy gets the thought that Gillard and Rudd are well intentioned:
MySchool: Part I
MySchool: Part II

is it nuclear or newclear?

I like this approach to the global warming climate debate:

1) Rapid human economic development is good (not argued here) and inevitable (you aren't going to stop China, India etc. from developing)

2) The only valid alternative to fossil fuels for our energy needs is nuclear power. This is really a matter of doing the arithmetic. According to The Integral Fast Reactor – Summary for Policy Makers (IFR Summary article) , which is written from the POV of keeping CO2 under 450ppm, then we will need to produce 1 GWe per day of new clean power every single day for the next 25 years.

3) The integral fast reactor (IFR) is the safest and most efficient form of nuclear power about. It was invented by Charles Till in 1965 (Plentiful Energy and the IFR Story) who led a team which produced a small (non commercial) fast reactor which ran for 30 years without incident. Unfortunately, this program was shut down by Bill Clinton’s administration in 1994 for political reasons. In Congress, the main argument against (by John Kerry) was civilian nuclear proliferation (which I suppose is a valid concern today as well – although the end product of IFR is not suitable for weapon production I’m less certain about the fuel inputs, still researching)

4) So if you are a climate alarmist then you should support IFR (as James Hansen does, see Science Council for Global Initiatives)

5) If you are not an alarmist but support future human development then you should also support IFR, not so urgently but essential for the future.

There is a debate happening in Adelaide, Australia, this Friday presented by The Australian Solar Energy Society, Sustainable Populations Australia and The Zero Carbon Network, will see a debate on “Should we consider Nuclear Power as a response to climate change?” with Mark Diesendorf and Helen Caldicott for the negative and Barry Brook and Tom Blees for the affirmitive (The Nuclear Debate). I've booked a seat.

For more information about IFR do some reading from this page of Barry Brooks blog, Brave New Climate.

Tom Blees video, part 2 of 3: