May 15th, 2007 by Stephen
In the news this week, as Tony Blair plans to step down from his role as Prime Minister of the UK, he has indulged in one final round of constitutional change and agreed to move parliament to Aberystwyth. See News Biscuit for the full story. 
May 3rd, 2007 by spk
Should children be present in the communion service? This was a question recently on MInTheGap’s weblog. It is also a question I have come across before regarding practices in churches where infant baptism is practiced. The question is asked, “if baptism is the mark of a Christian, what right do we have to refuse communion to children?”
As I understand it, membership of the Christian Church is through baptism. This is, I think, a subtlety that is important to protestant congregations that practice infant baptism. Because those who believe in baptising children too young to answer for themselves, do so on the belief that there is some special benefit of so being a part of the Church, whilst not actually a believer. c.f. 1 Cor 7:14 (which is talking about marriage partners, but it perhaps conveys the same idea).
Now if this accepted, then it follows that when one comes to faith, the promises made for them at baptism are now owned by them. Their membership of the church is confirmed in some sense by their faith.
On the other hand, those of us who hold to believers baptism say that faith should precede the baptism, and the baptism itself is the symbolic or sacramental enactment of our new birth. But even so, we can still hold to a view that the children present in our church are in a priveleged position, benefiting from teaching and nurture and the love of our community. Churches that practice believer’s baptism usually have some kind of dedication ceremony symbolising the special responsibility of the church to that child.
Now communion is a feast for the believer, and only for them. If people are baptised into the Church, and properly instructed as to the purpose and meaning of communion, then the act of taking communion itself is a declaration of faith. Thus, someone who might say that the eucharist defines the church is quite right. The true Church, the body of baptised believers is self defined by the very act of taking communion.
This being so, it seems to me that any age limit applied by us on the taking of communion simply says that we do not believe anyone under that age can be a true believer, or sufficiently capable of making a declaration of faith.
Now we might argue that this is so, but I wonder how this differs from the argument that is thrown against “believer’s baptism”, which argues that very young children are either unjustly denied baptism, or else the believers baptism is virtually infant baptism in any case.
One minister I spoke to recently suggested we don’t baptise the children until they are eight, but this still suggests we do not believe the statement of faith of a seven year old, if they should make one.
It is all something of a knotty issue, but I think the key issues are flexibility, a good understanding of grace, and the ability to believe the testimony of young children, without falling into gullibility.
But one thing is clear: if we don’t allow children at the communion table - if we just ship them off to their own age specific activities - then we are making a statement that these people are not believers.
The solution, as practiced in many churches, is to allow children to take part in the communion service but suggest that they receive a special prayer rather than the bread and the wine.
Now in churches with believer’s baptism, we have a good date for when they first take communion - at the first opportunity after their baptism. Churches that have infant baptism, or believer’s baptism only after a certain age have a thornier problem. But if children are really to benefit from the worship of a communion service, and if they are to understand how deeply we feel about Christ’s sacrifice, and the glorious hope that we will one day drink from the fruit of the vine with Christ in His Father’s kingdom, then however we deal with this issue, we are wrong to take them out of the service altogether.
May 2nd, 2007 by Stephen
You may not have known it, but Moore’s law appears to have reached its limits.
If you don’t know what Moore’s law is, it is a law proposed by Gordon Moore (a co-founder of Intel) that the number of transistors on an integrated circuit would double every two years. Double the number of transistors on a chip and you essentially double the speed by halving distance between transistors. This he predicted in 1965.
And he was right! What a star!!!
So essentially since 1965 we have seen chip speeds (including, of course, processor speeds) doubling every two years (or less). And now we have processors that run … well .. very fast.
There have been some problems on the way. The technique of etching a circuit into silicon is based essentially on a photographic technique, but at some point the transistors got so small that the wavelength of photographic light required was so tiny that it was in the X-ray spectrum. The result - the X-rays passed right through the silicon. But clever people solved these and other problems.
But now there is a new problem. Each transistor gives off a tiny bit of heat, and all those transistors working together are running the chips too hot. Heat dissipation is a major issue, and of late we have not seen the big increases in chip speeds - which is why we are going to parallel multi-core designs.
But wait a minute! Does an increase in the clock rate really increase the speed of the chip? Perhaps we could keep the clock speed static with more intelligent chip designs.
Why? Because of pipelining. One instruction is not executed each clock cycle any more. Instead, processor pipelines are created and in a clock cycle, one part of one instruction and another part of another instruction is executed.
Consider a launderette which opens with just one washing machine, spin tub thing (whatever that bit is called) and one dryer. I go in and wash my clothes in the first wash cycle. In the second wash cycle I use the spinner thing and Fred washes his clothes. In the third was cycle I dry my clothes, Fred spins, and Mary washes her clothes.
This is the way processor pipelines work.
And Apple made an excellent point about processor speeds and pipelines here:
Their point - run the chips slower with shorter pipelines and you could improve performance.
But I guess the question is: if PowerPC architecture is so much better than the Intel arhitecture, why did Apple switch to Intel chips?
Hmmm.
April 29th, 2007 by Stephen
The media is working itself up into a feeding frenzy again. This week’s issue: the alleged dangers of WiFi radiation. First BBC Radio news, then Newsnight, now the Daily Telegraph have all had articles from quoting from people who believe that there might be health risks from WiFi. The BBC programmes at least balanced the sillier claims by noting that WiFi power output is far lower than that from mobile phones.
The Daily Telegraph, on the other hand, had this nonsense:
However it is believed that a classroom containing 20 laptops and two routers could combine and be equivalent to the emission from a mobile phone.
Notice the use of passive voice: “it is believed”. Who believes this?
It turns out that no-one does, although the Telegraph quotes from the “Powerwatch” web site. On this site, there is a calculation designed to show that a room full of 20 computers and an access point (or two) is approaching the power output of a mobile phone call.
But this is arrant nonsense. It is nonsense because of the silly assumptions being made about average distance from antennae. It is nonsense because they first make an assumption of low power output from the phone, and it is especially nonsense because it makes no difference whether you have one computer or fifty in a room. The maximum power output is the same - capped in the UK at 100mw (but usually less than this).
Let me explain: WiFi stations are receiving a radio signal when they receive data. But if two stations transmit a signal at the same time then what occurs is a collision - the signal is garbled and not received. The solution is that WiFi uses a collision avoidance scheme to try to ensure that packets are never sent out whilst another station is already transmitting. A couple of carrier sense mechanisms are used to do this, and the result is a very low collision rate. Essentially, if one station is talking, all the other stations are quiet. Click on the thumbnail image to see how this looks in practice. Each wireless station waits a random amount of time before transmitting, and if another station transmits first, the wireless station will quietly defer to it.
Therefore the maximum power output from a room of 20 computers remains capped at 100mw. What is more, no one station is transmitting all the time. For the majority of the time, even on a congested network, each station is actually transmitting nothing.
And that brings us to the next bit of nonsense - the assumption of the amount of traffic in transit. The powerwatch page assumes more than 100% usage for periods of two hours or more in its calculations. Note that if a single wireless station on an IEEE 802.11g network were downloading constantly (and that the downstream network could maintain the same throughput), then even assuming protocol overheads reduce the actual throughput to a mere 30 Mbps, over a course of two hours, that station would download some 26 Gigabytes of data.
To put this in perspective, fairly heavy Internet users download about this quantity of data in a month. Light users (people just browsing the web, using email and similar) would not get close to this figure.
26 Gigabytes is the equivalent of about 44 CD images, or several thousand podcasts. It is a guge quantity of data - not the kind of thing people will be downloading in one sitting - and certainly not regularly.
Ah, you say - but spread between 20 computers? What classroom environment is encouraging pupils to download over a gigabyte of data per computer? None!
So the assumption of 100% utilisation is nonsense.
Next problem: The assumption is made that people are - on average - a metre from the transmitting antenna.
This is just silly. The writers seem to know that magnetic fields decrease by the square of the distance from the antenna, but they assume that on average, people are a metre from the emitted radiation. Based on the fact this is a classroom, and 20 stations are variously transmitting, the fact that some of these transmitters will be many metres away only really makes this assumption if the pupils have swallowed the transmitter.
Admittedly, I wouldn’t put this past some children - but if they have done so, they probably have worse problems to deal with than the emitted signal from the station!
No, in fact the vast majority of the transmissions come from the access point. (Remember, we download much morethan we upload) this may not even be in the class, but if it is, it will probably be several metres from even the nearest child. The law of squares tells us that these signals will be far lower than the silly assumption made on the powerwatch page and repeated uncritically by the Daily Telegraph.
As one commentator on the Telegraph page says:
“Can there ever be a better example of why the current decline of Physics teaching in schools and universities is so worrying?”
Let’s give the last word to Mike Clark, senior spokesperson for the Health Protection Agency. He has run the figures rather more intelligently than the Powerwatch pressure group, and tells us that 1 year of exposure to WiFi radiation in a classroom is equivalent to 20 minutes on a mobile phone.
Maybe we could quibble and bring that down to a month or so. So what? The worry with mobile phones is that the radiation causes excitation of water molecules in the brain near where the phone is held to the head. This causes a slight warming effect which could theoretically be a cause for concern, although there is no proof of harmful effects.
WiFi radiation - if it causes any warming at all - is so slight as to be unmeasurable.
April 27th, 2007 by Stephen
Following the server crash yesterday, I have now replaced all the postings that went missing over the last month. As far as possible, I have also replaced the missing comments. These are posted with original attribution but under my name. Apologies that this will put the frequent commentator list out - but it was the easiest way.
Still to do:
If anyone else loses data in this way, remember - Google is your friend! (Particularly the Google cached text).
Please note that a few of the most recent comments were lost, as Google had not cached these.
April 27th, 2007 by Stephen
“In my view, the Christian religion is the most important and one of the first things in which all children, under a free government ought to be instructed…No truth is more evident to my mind than that the Christian religion must be the basis of any government intended to secure the rights and privileges of a free people.”
Noah Webster (Preface to the 1828 edition of Webster’s American Dictionary of the English Language)
April 27th, 2007 by Stephen
Selahv mentioned in a comment the disdain of the world for America - but there are in fact two distinct types of anti-Americanism. There is one kind which is just prejudice. There are people who disdain Americans simply because they are in a different “in group”, and it is fallen human nature to disdain out groups. Therefore every bad thing from America (fast food and sugary drinks for instance) is held against them. Every good thing (Clam chowder for instance) is ignored.
Such prejudice is hard to battle against, but it really is not Americans that need worry about this. The same people that hate Americans because of this prejudice probably have similar prejudices about any out group they care to consider.
However, there is another kind of anti-Americanism which is really anti-American policy, rather than the nation or its people. This is the feeling expressed in surveys that suggest people across the world believe that America is the biggest threat to world peace. This feeling comes around because of the gun boat diplomacy of one or other American administrations.
Note that America is no different from other nations here. In the 19th Century, the UK fought two wars against China to force them to accept the trade in opium. The drug was legal in the UK at the time - used as a seditive - particularly for gripey babies! But China banned the drug, citing public morals as the reason. After an incident when Chinese authorities boarded British ships and confiscated smuggled opium, a contingent of the British navy, including the new “iron clads” steamed into China. The fleet was larger than anything the Chinese had expected, and the first opium war was quickly lost. The peace treaty opened up a number of Chinese ports and ceded a lease on Hong Kong island to the British.
If you asked at that time who was the biggest threat to world piece, the answer in Shanghai would no doubt have been “the British”.
All countries act out of self interest most of the time. The thing that people dislike about American policy is its willingness to flout international law and order to pursue its self interest. Failure to become signatories to the ICC, arming of Israel as they kill people in Lebanon, The invasion of Iraq, support of regimes that persecute their own people, the arms trade, sidelining the UN and excessive use of the veto when the issue concerns client states, failure to ratify the Kyoto protocol - the list goes on (and these are just the recent examples).
But whilst I personally have a problem with all of these policies, I am not personally against Americans. (Indeed I am opposed to much UK policy for very similar reasons, but I am not anti-British).
Selahv was speaking about Iraq, so the question is: how does this help Iraq?
We are where we are, and Iraq is suffering. What can we do? Cut and run? That would cause the disintegration of the nation. Stay the course? There is no sign that this strategy will ever succeed.
We pray for peace in Iraq - and we pray for wisdom and humility in our leaders. Particularly the humility to go to the United Nations and ask for help. If the occupying force could be replaced with a peace keeping force, and if we gave up our claims to Iraqi assets, just as we forced Russia and France to give up their claims, then there may yet be a hope for this country.
It would take a miracle for the US to willingly humble themselves and pursue this problem through the UN. It would take another miracle to see the policy succeed, and peace finally come to the nation of Iraq.
But fortunately, I believe in miracles.
if my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then will I hear from heaven and will forgive their sin and will heal their land.
2 Chronicles 7:14
April 27th, 2007 by Stephen
When Mr Spock says something is logical in Star Trek, what he often seems to mean is that something is common sense in som ultilitarian way of thinking. Thus “The needs of the many outweigh the needs of the few” is a clear utilitarian statement.
What he does not do is couch everything he says in terms of formal logic. And there is one very good reason why that may be a good thing! There is a principle in logic known as “ex falso sequitur quodlibet” - from a contradiction, everything follows. What this principle tells us is that if there is a single inconsistency of the form “P is both true and false” (a negation inconsistency), then every other proposition can be validly implied. If such a contradiction is allowed, then essentially everything is true.
Here is the proof:
P and P’ (that is, P is both true and false)
P (therefore P is true)
P or Q (Either P is true or Q is true)
P’ (P is false from 1. above)
Q (from 3. If P is false, Q is true).
But that is nonsense, you say - because perhaps Q has nothing to do with P. Hold that thought, because the other problem is what propositions are actually both true and false?
Well let us suppose that I am standing in the doorway of a room. One foot is in the room, and one foot is out. Am I in the room or not? You could argue that it is both true and false that I am in the room. Let us apply the proposition to the proof above:
I am in the room AND I am not in the room
I am in the room
It is therefore true that either I am in the room or black is white.
But I am not in the room
Therefore, from 3 and 4 I can see that black is white.
(And, as Douglas Adams pointed out, I shall now go and get myself killed on a zebra crossing).
But the point here is not that we can really prove anything, but that we don’t instinctively think logically. We allow that some things can be kind of true and kind of false, and we don’t actuall accept step 3 in the above argument. If a proposition has nothing to do with another, then why should its negation inconsistency imply the truth (and simultanously the falsehood) of the other proposition?
Human brains are wired up to be “paraconsistent”. Paraconsistency is a type of logic that ignores or removes the ex falso proof, often by insisting on the relevance of conjoined propositions. Whether we strictly need paraconsistent logic is a whole larger debate, but we need to bear in mind that our own thinking is more relevance based than strictly logical. And that is, perhaps, a good thing.
April 27th, 2007 by Stephen
Over several months of last year I reposted some essays I had written on the book of Joel. These formed a series which you can find using the “Joel” tag on this site, but now for the first time here is a table of contents for the whole series:
April 26th, 2007 by Stephen
“We have no interest in oppressing other people. We are not moved by hatred against any other nation. We bear no grudge. I know how grave a thing war is. I wanted to spare our people such an evil. It is not so much the country; it is rather its leader. He has led a reign of terror. He has hurled countless people into the profoundest misery. Through his continuous terrorism, he has succeeded in reducing millions of his people to silence. The maintenance of a tremendous military arsenal can only be regarded as a focus of danger. We have displayed a truly unexampled patience, but I am no longer willing to remain inactive while this madman ill-treats millions of human beings.”
In hindsight we may argue that some of these threats regarding the military arsenal were over-estimated. But who can deny that the case for war was adequately made in this speach?
I will leave it as an exercise for someone to work out which great world leader said it, but in the same vein, he also said the following:
“By the most brutal methods of terrorism, a regime sought to maintain an existence that was condemned by the overwhelming majority of its people…I have tried to persuade the responsible authorities that it is impossible for a great nation, because it is unworthy of it, to stand by and watch millions belonging to a great, an ancient civilized people be denied rights by their government
