Who moved our spacecraft?

Some spacecraft have trajectories that are slightly unexpected. Something has speeded them up or slowed them down - but what? Current methods of analysing and predicting spacecraft behaviour involve many factors, but the figures just don't add up. Something strange and unexpected is going on.

The major factors that affect spacecraft motion are gravity and rocket propulsion. Spacecraft and indeed all bodies in the solar system, from dust grains right up to the the largest planet Jupiter, move through a complex gravity field. Each body is tugged upon by every other, and the strength of pull depends on the masses involved. The mathematics is very complex and for more than two bodies involves iteration.

The second major factor comes into play whenever a manoevering engine is fired, this clearly changes the trajectory (which is the purpose of the engine of course).

The velocity of a spacecraft can be measured very accurately by examining its radio signals. Changes in velocity cause a change in frequency. But the calculated trajectories don't always match up with the measured ones.

There are many other subtle factors that affect a spacecraft. Pressure from solar radiation, loss of gas from the spacecraft's systems, impact by small particles, relativity effects, loss of speed due to passing through the outermost fringes of a planetary atmosphere, magnetic and electrostatic fields, and more.

But effects such as these are quite well known and can be allowed for. Yet the figures still don't quite add up. And nobody knows why.

The effect was first noticed decades ago as the Pioneer probes passed into the outer Solar System. They were travelling ever so slightly slower than they should have been. At the time this didn't cause much surprise, it was put down to some minor effect that nobody could identify and, like all these effects, it was far too small to affect the mission. Several possibilities were discussed at the time, none of them were accepted enthusiastically.

But it's happened again, and again, and again with other spacecraft.

At last a pattern is beginning to emerge. All the affected spacecraft have made close planetary passes to help shape their trajectory (gravity assists), while other spacecraft have not been affected. John D Anderson, Curator of Aerodynamics at the National Air and Space Museum in the USA, has been looking very carefully at the evidence. Anderson and others working with him have now come up with a mathematical formula which may enable them to predict the size and direction of the effect, it seems to work for all the effects seen in past spaceflights and they're waiting with bated breath to see if it accurately predicts the effect for Rosetta as it made its second fly-by of Earth last November (they haven't seen the data yet). There's another opportunity in November 2009. (John Anderson's scientific paper is "Anomolous orbital-energy changes observed during spaceflight fly-bys of Earth", John Anderson et al., Physical Review Letters, Vol 100, p 091102. There's also a report in New Scientist, 20th September 2008, pp 38-41).

All of this is quite fascinating, both to spacecraft engineers and to physicists; it really does seem as if something may be slightly wrong with our theory of gravity or there's some other effect at work that we are not yet aware of. Either way, prepare for a major new discovery in physics. But either way, don't hold your breath. Finding the underlying mechanism could take quite some time (years or decades, perhaps even longer).

Eaton Ford - Lazy or diligent?

We began with a hot drink and a chat about events during the last week. Once again the main topic was next year's youth camp, important aspects are to make sure that Father is glorified in all we do and say, to have some plans for earlier events that could help us meet young people and their parents in Eynesbury, and to consider how best to bring new believers into the church in St Neots. We have had one enthusiastic response and one unclear response from the two churches we have approached informally so far.

Jim mentioned that we are all supposed to feed the other sheep that belong to the Shepherd, we are not meant to feed our own organisation with a supply of his sheep. Sheep are not a commodity, we are a family.

Chris read Proverbs 10:4-5, he'd come across these verses while reading privately before the meeting. He said that in his own life he feels he's been a lazy son, but it's never too late to start and now is the time. Yahshua said the fields are full with the harvest (John 4:35), if we are diligent and wise we'll be busy gathering those crops.

Jim has been reading about the period of time between the old and new testaments, a time when Israel had no revelation and no real sense of the Lord's purpose. He thought how he would hate to have no revelation or purpose in his own life. But Jesus came and everything was changed, and his Spirit is with us and speaking to us daily. What a privilege we have!

Sean emphasised the importance of loving our neighbours. He read out Romans 13:8-14 where Paul writes that the time has come to wake up from our sleep. He had read this passage recently and it had been on his mind. Like Chris, he feels that he has been, if not lazy, then at least asleep. We talked for a while about how the church in the UK seems to have been asleep during our lifetimes. Christians seem to be mostly inactive in our day. It's as if night has come, everyone is asleep so it's natural for us to yawn and slumber too. But we need to wake up!

We talked about how everything must be done for Father's glory, we dare not take any of that glory for ourselves. Then Chris shared a picture of a house, it was like looking down at the plan of the house. He realised that the house is Father's living temple built of the living stones of his people. It's the house in which he lives, where his Presence rests. There were many rooms in the house and each room was like a different part of the church - the Baptists, The River, Open Door, the Methodists, St Mary's in Eaton Socon, and so on - each one like a separate room. As he looked, Chris saw that not all the rooms had internal doors. Sometimes a room had an external door, but no connection to the other rooms. And the Lord said, 'What an inconvenient house!' He also told us that he will open up doors between the rooms, he doesn't want a house like that, it needs to be changed to make it more useful.

Jim saw it a little differently, he was encouraged because we are going to go into the town and open up doors for young people to come in and have life in its fulness. We prayed for doors to open up right through the estate, doors to open for the Good News. We asked this in love.

Jim also mentioned that we need the Holy Spirit to give us openings on the estate that we can develop, ideas that can be presented to others as projects, at least four half or whole days of activity on the estate. And we need something for Brampton too.

We discussed this and jotted down six preliminary ideas, but Sean felt a little unsettled in his heart. He reminded us that the Lord will provide the things for us to do, they may not necessarily be the things we think up for ourselves. So as we go forward we need to be open and expectant.

Great Doddington - Our weakness, his strength

While we were chatting at the beginning of the meeting we thought that we often grow weary of our circumstances, but it's good to remember that we're only in the world, not of it. Sometimes life seems like being on a plane that flies round and round but never arrives at its destination.

Jody referred to Psalm 28, we read that his purpose is to bless us (v 8-9).

Chris mentioned that there's no hope in us, in the people who are in need, or in the financial system; there's only hope in Yahshua. He is our hope! Jody read Psalm 41 in which Yahweh protects and blesses the weak.

And then Jody shared a picture of a red velvet bag tied with a twisted silk cord. The top had opened and a very large pearl had fallen out. Jody told us that the Lord says, 'You are like that pearl - precious to me'.

Rachael thought about the plane flying around and said that it might seem to be going round and round when seen from above, but it might also be flying higher and higher if we could see it from the side.

Chris read two passages, Luke 6:20-26 and Luke 12:49-53. They contrast strongly with one another. Jesus came to bring comfort, peace and joy - but also division and distress. Which we receive depends, not on our circumstances, but on our hearts.

Rachael prophesied, 'Look, you know you can just reach out and touch me whenever you want. You don't have to join a long queue that winds round the corner and down the next street. You can just reach out and touch me.'

We also thought about the cycle of life. From a fruit come seeds, these fall and grow and produce trees. The trees produce more fruit, exactly the same so many more seeds fall and grow. Seeds change everything! One fruit can turn a grassy field into a whole forest.

Rachael shared a picture of a large bed with a beautifully embroidered cover. Father asks us, 'Why are you sleeping on that pile of straw covered with an old rag when you could be in the bed I've already provided?' She also thought of the words of an old Diana Ross song, 'Reach out and touch'.

Finally, we had the thought that we are privileged as his people, but there are so many unprivileged who don't know him. We are his body in the earth, we have to allow him to reach out through us - to the people all around us. This is also our prayer, to be used like this.

Rape and pillage

When a nation is defeated in war, the victors take whatever remains. In the last fifty years the human race has waged war on the environment, but the environment has pretty much lost the war and we're now taking what remains.

I assume you can see the terrible flaw in our thinking (or lack of it).

It was true of the ancient empires and city states and it's still true today - in all out war the victor takes anything that remains. Sometimes it's slaves, sometimes it's property, sometimes it's the lives and welfare of the defeated population, often it's all three, but when victory is complete it is always very bad news for the losers.

The BBC published an article today about the plight of the bluefin tuna, it's a good article, everyone should read it, but it's only the tip of the environmental iceberg. It seems the tuna is now in real danger of extinction, the very existence of the 'tiger of the sea' is precariously balanced and yet we are still overfishing it.

Big trouble - The fact is that the environment is in big trouble. The knowledge that we all depend upon it for our daily lives has not yet impacted us nearly enough. But it will do - you may depend upon it.

The air we breathe, the water we drink, the food we eat, even the very land we stand on is in danger. Mankind has won a great victory over nature, but has not properly considered that nature itself is our only provider. We have all but killed the goose, the supply of golden eggs is just about ended.

Cod - Here's another cautionary tale from the sea. Cod stocks on the Canadian Grand Banks off Newfoundland have been depleted, and despite measures to reduce catch levels or even ban fishing altogether, they have so far failed to recover (article section from Wikipedia).

But it's not just sea fishing that's at risk, here's a shortlist of some other factors to consider.

Climate - there's now strong evidence that the earth's climate is changing in response to rising levels of carbon-dioxide and other gases. Ice in the Arctic Ocean is vanishing year on year, sea levels are rising, glaciers are retreating all over the globe, storms are becoming more frequent and more violent, extremes of temperature and rainfall are more common.

Pollution - of the atmosphere, the oceans, and the land is better in some respects, but is worse in many others. The long term prospect remains poor.

Fresh water - sometimes too much (flash flooding) but often too little (droughts, dry reservoirs, falling levels in aquifers, spreading deserts).

Deforestation - there has been some recovery in north-west Europe, but much loss of tropical forest. This loss seems to be accelerating.

Easter Island - There is a stark warning in the story of this barren land in the Pacific. Once forested and fertile, it was home to the Rapanui people who carved the vast, stone heads or 'Moai'. The civilisation here was at one time advanced, writing was invented independently, farming technology was an important part of the economy, timber and stone were both in use for building and for artistic or ceremonial use. Yet now there are almost no trees and the civilisation has vanished. Why? Because they over-exploited their natural resources. This is the tragedy of the commons in action.

We also face the same tragedy. Genesis 1:26-28 calls on us to manage the earth and all that is in it. The Hebrew verb 'radah' can be translated 'dominate'. And although managing something involves taking charge, it also requires wisdom and stewardship. The Rapanui conquered and dominated their island but they did not care for it as good stewards. What will tomorrow's historians write about us? And in what sense did the Rapanui truly 'dominate' their island? They are certainly not dominant now.

Too many social networks!

There are too many social networking sites out there, each one different, many with interesting content.

Each one requires me to enter my profile details again, has a different menu structure, unique facilities, and specialist functions. We need something better.

Let me explain. For a while now I've been a member of Facebook (which I like and use regularly) and MySpace (which I don't like and rarely visit now). I'm also a member of various mailing lists and several specialist social networking sites, mostly to do with church.

For each one of these systems I have to enter my profile details all over again, but in a slightly different way. I have to learn a new and different way of working, a new set of menus and functions.

I was prompted to post this blog item when a friend emailed me details of a community building tool (Oikos) and asked me what I think about it.

There's a real problem here - it will be resolved eventually for sure, but meanwhile it will make life harder and harder for us all. The problem is that there are so many of these systems and the number is increasing dramatically all the time. There are even sites that offer 'roll your own' facilities (like Ning, and Oikos). I need more systems like I need a hole in the head!

What do we really need? - We need one system that lets us put in our user profile once, and then party with as many subgroups as we choose. In my case that might be a general organic church group, a local area christian group involving believers from every background and opinion, an astronomy group, a techie web software group, a history group, a group for my workmates, a photography group, and perhaps half a dozen others.

Facebook can do that already. And in a different way, so can Ning. We'll come back to Facebook and Ning later.

I predict that in the short term groups will proliferate, and they'll proliferate until people become heartily fed up with accessing so many. From then on a few will grow larger and larger at the expense of the smaller ones. The few are already growing in size, but we're still in the proliferation stage with new social networking sites coming on line daily - perhaps thousands of them daily, certainly hundreds.

One approach might be an agreed system for syndicating profiles around different systems. That would certainly help, but the navigation and feel of the systems would still be different and we'd have to learn our way around each one. There is at least one standard out there already and some systems are supporting it.

So - back to Facebook and Ning. Both systems offer a solution but they do it in very different ways.

The Facebook model - here we see an overall system that lets you join, select friends, and also select groups.

In practice most users will have a circle of friends composed of work colleagues, family, college friends, large or small geographical groups (my town, my state, my street - whatever), and people who share a common interest.

Many users will join groups on specific interests (I'm a member of several local groups, church groups, astronomy groups and so forth). These will include some Facebook friends but also many Facebook 'strangers'. The shared interest will normally be enough to keep the group buzz going, the conversations and shared resources will always be of interest providing they remain on topic.

All the groups work in the same way, use the same navigation, and have the same sort of arrangement on the page. As a user I can navigate very easily from a group to a friend's page, to my messages, to a group on another topic, all pretty much seamlessly and without having to login to a different website or learn a new style of operation. Joining a new group is not a big deal.

This is good!

The Ning model - Here the emphasis is on the groups, not on the friends. Using Ning, you or I can roll our own social networking site and invite interested parties to join up. We can run our own 'Facebook'.

At first sight this merely makes the proliferation of online social networks even more severe, it's easier than ever to create a new one!

But Ning has a real advantage here, if you sign up to several Ning-based systems your personal profile is shared between them. What's more, they all work in the same way. They may look a little different (colour, graphics, and to some extent layout), but they all share structure, navigation, and features. Ning sites are like Lego models, they look different but they're made of the same kind of parts. If you know how Lego works you'll have no problem recognising a Lego construction, using it, or altering it.

This is good too!

Ning or Facebook? - Which is best? In the end they're pretty similar. Ning is Facebook groups. Facebook groups are Ning social networks. If Ning added a feature to let you choose and interact with specific people outside the social networks it would be just like Facebook. And if Facebook allowed you to access a group as a separate website it would be just like Ning.

The two systems emphasise slightly different aspects but could so easily grow to be much more alike. One underlying difference is that you don't need to be a Ning member to join a Ning-built social network. Anyone with internet access can join in. But not everyone is on Facebook, not everyone wants to join Facebook. So a Facebook group is inaccessible to a whole section of the internet community. From an individual's perspective this may not appear to be a problem, but for someone planning to build a social network it may be a serious issue.

Which of the two will win out? It's much too early to say. Both have grown very fast indeed and show no sign of stopping. Both make it easy to set up a social space for a specific purpose. There are plenty of other systems and organisations out there, Yahoo, Google, or Microsoft in particular could muscle in on the act very quickly if they chose to stake a claim.

What does the future hold? - Here's my best guess.

• In the short term, more proliferation but with continuing market share going to Facebook and to a lesser degree Ning. Facebook has, I think, more mass-market appeal than Ning.
  
• In three years time expect to see more and more of the small players fall by the wayside, while Facebook, Ning, and one or more of Yahoo, Google, and Microsoft clean up.
• Long term, expect two or three dominant players to emerge. One will take 75% to 95% of the share, one or two others will fight over the rest.
• Expect the unexpected. There might be a major corporate takeover or two. One of the smaller players might come out with something innovative and grow from less than 1% share to become the major force in this space.
• A major open source contribution is likely. This has happened in other areas of computing with Linux, Apache, Open Office, MediaWiki, and the GIMP.

There will be a shakeout, that much is certain. It will make life easier for everyone but at the same time restrict our choices. We've seen the same process with operating systems, word processors, spreadsheets, web browsers and more. History repeats itself. The end result is always one major player and a small number of niche alternatives.

Eaton Ford - Camp planning

Jim was unable to make it this evening, but Sean and Chris spent some time talking about church in a general way, and then Pete arrived to join us.

We were able to make some progress with planning for the youth camp next year, and Donna sat with us to listen and contribute some useful thoughts and questions.

We prayed briefly at the end of the meeting, and agreed to meet again next Thursday when Pete will bring some of his helpers so we can meet, discuss, and pray about the coming camp in much more detail.