So, yesterday we were discussing when it’ll still be light before we leave work again - the conclusion being that it just about looks like it should be light just as the clocks change… so it’ll be the monday after clock-change day.

But that led on to other discussions culminating in the question: How fast do you have to approach a red traffic light for the doppler effect to make it appear green?

After a few sums, I came up with the following results…

To make red look green, assuming a red wavelength of 685nm and green wavelength of 532nm, you need to approach at 28.8% of the speed of light - that’s 192 million miles per hour.

Note that at that speed you could reach the sun from the earth in just 29 minutes.

If you have a less powerful car and can’t quite manage that one, it’s a lot easier to make a green light look red - by travelling away from it at just 22.3% of the speed of light… a mere 148 million miles per hour.

The real bonus is that if the red light camera catches you going through the light, and you’re driving a yellow car, it’ll look purple and they’ll never be able to find you.

Oh, and I practised conscious countersteering for the first time. It absolutely blew my mind… I hope it starts to feel more normal soon… sure I can do it… but it just feels, um, wrong.

If you haven’t tried it yet, do it.

I’ve been considering the question of evolution after seeing the Strange Maps evolution thing, linked by Henry.

It seems that in the US, one in three adults believes firmly in creationism as opposed to evolution (according to this bit of literature from the pro-creation lobby). There are a couple of things I find interesting there… firstly, the question:

Why do so few Americans accept evolution when so many people in Iceland do?

My initial response to this is that a proportion of Americans tend to be nutjobs, whereas Icelanders, while terminal alcoholics, certainly seem to be more together on the whole ‘reality’ thing.

But that led to a thought… I wonder if Americans have a propensity for not believing in evolution because they can’t imagine a time-span long enough. Icelanders have their epics and their sagas and their old types of writing and their runes and ice ages and thousands if not millions of years of history to think about. Perhaps a young whippersnapper like America just can’t imagine themselves far enough into the past to give evolution enough time to work.

I had to laugh on the Strange Maps site, one of the pro-creation comments was:

There is a junkyard across the street, I don’t see it turning into an airplane.

That is one of the worst cases of analogy I have ever seen in my life*. Junkyards don’t reproduce. The commenter hasn’t watched the junkyard reproducing over millions of years. The junkyard (assuming the two previous points were ok) may not evolve into an airplane, if that’s not the best survival tactic. It’s more likely to sit there and just evolve a plastic roof to stop it rusting so quickly.

But what would I know? I only have a science background to degree level. They must have brainwashed me, the pinko lefty liberal higher education monkey boys.

(* except maybe this one)

Bristol Airport invents new ‘negative friction’ material.

“I’ve landed in wet weather, put the brakes on and come to the bit that is being re-surfaced, and just skated across it - we actually speeded up. When it is wet, you have no grip.”

Now, either Bristol Airport is built on a steep hill (unlikely), or someone is exaggerating. See the story here.

I am happy to have my opinion on this story swayed.

There’s a flaw in my previous blog about dimension folding - and possibly in the link mentioned, too.

You see, in each of the low-dimension cases, I’ve written such as ’start at A and move towards B along the line’. The problem here is that in our one-dimensional world, movement is not possible. For movement to be possible, time is required. So we require one spatial dimension to move along, one spatial dimension to fold in PLUS a dimension of time.

So any theories we construct based on n dimensions + 1 folding dimension + time will probably not hold water when time is one of the n dimensions or the folding dimension.

If I thought my brain hurt before, well… it hurts significantly more now.

(*I think that’s the correct plural form of Tardis)

I’ve been mulling over the site Imagining the Tenth Dimension which Rich linked on Friday. I’ve drawn pictures and built models, and it’s absolutely fascinating to discover and confirm for myself that time travel and teleportation are both trivial tasks.

Of course, it’s not going to be that easy, is it? However all we have to do is gain control of the 4th dimension and learn how to fold it to achieve teleportation. Time travel is a little more difficult requiring folding of the 5th dimension.

Let me attempt to explain, taking the simplest case… one dimension.

In a one-dimensional world, you exist on a line. The only thing you can say about your position is how far along that line you are. Now - gain control of the second dimension and you can bend the line around so that it crosses itself (try drawing a simple ‘christian’ type fish, or greek letter alpha). Now by walking to the crossing point, you can appear instantaneously at a different point on the line.

For example, start at one of the points of the line and start walking. When you reach the crossroads, turn towards the other point. You have just done the full journey along the line, but have succeeded in missing out the whole of the loop. If you like, you have teleported from a position 20% of the way along the line to a position 80% of the way along the line.

In two dimensions, what you just achieved wasn’t a particularly clever move, but to anyone trapped in the single dimension of the line, they will bow down to you as a deity, or at least a good magician.

So, now let’s extend this concept to a two-dimensional world. A sheet of paper, or a map is probably the best example of position in two dimensions. Take your map book and start driving along one of the roads. Now, by folding this map through the third dimension, you can make a different road line up with the one you’re currently travelling along. In the two-dimensional world you just teleported from one location to another completely different location.

Now, as we move into three dimensions, it becomes more complicated to visualise. The reason for this is that we live in a three-dimensional world, so we find it more difficult to grasp the idea of folding the fourth dimension (time), but we can probably manage something as follows…

Draw a straight line, label the points A and B. The line represents time, and the points represent complete three-dimensional states. At point A you are in Aberdeen, while by the time we reach point B, you have travelled to Bristol. The line, therefore, represents many hours of travel.

But who says we have to actually use any of that time? If we can fold the fourth dimension, as we did with our line in the first example, let’s see what can happen.

So draw your fish again, and label the points A and B. Start at point A, in Aberdeen and walk (in time) towards the crossroads. When you reach the crossroads, turn towards point B and continue to walk. Hey presto! You’ve just travelled the journey while hardly using up any time.

What I find interesting here is that the journey will not be instantaneous. It seems you will still lose the amount of time that it would have taken to make the journey - you just won’t experience that time passing. I believe you will also age appropriately, too, since the timeline we’re walking along is a representation of the state of the three-dimensional world. During the loop of the fish, the world will continue to exist and go about its business, and you won’t exist in it because you’ve walked off into the folded fourth dimension.

Extend once again, and we start to get really interesting, and even more difficult to visualise. Now, the start and end points of our line represent four-dimensional points in space-time. By folding the fifth dimension, we can now travel anywhere in space-time. We can’t jump between the ‘trousers of time’ though - that requires sixth-dimensional folding. I haven’t yet worked out the implications of the length of the loop in these higher-dimension folds and whether aging takes place. My brain hurts too much.

Last year I watched with interest the BBC series “The Monastery” where five men spent forty days in, can you guess? Yes, well done - a monastery. Worth Abbey in West Sussex to be precise. It really was a fascinating program and I gained a huge respect for the monks there.

Well, a new series has started called “The Convent”. You can probably tell where this is going - four ladies this time staying with some Poor Clares, also in West Sussex.

Now, I’ve always had a bias against nuns - I’m not sure if it’s reasonable, but growing up and going to school in the vicinity of a teaching convent and hearing horror stories from the young ladies who attended has probably not helped. I thought I’d better give them a fair chance.

As it happens, the program made me feel uncomfortable. Unfortunately, it’s hard to tell why - there were too many variables between The Monastery and The Convent to determine the cause. Strangely, though, there were also differences I just couldn’t put my finger on.

The major differences stem from the fact that Worth Abbey houses a Benedictine order, while Poor Clares are Franciscans. The monks are used to outsiders joining them for retreats whereas the nuns have had no outsiders in their convent for 800 years so they were obviously more put out.

Additionally, the ladies entering the convent just seem to be more desperate for salvation. Or something like that. The guys certainly had their problems, but they didn’t “tell their story” as part of their group session. They delved a little in one-to-one chats with the monks, but it was very different. I also don’t think we heard any of the background of any of the monks - it seems their ‘life’ started when they entered the monastery to the exclusion of their life before, whereas the nuns were telling all about their previous lives, loves, marriages.

So - I can’t tell if the differences are simply the difference between men and women, or Benedictines and Franciscans or something else. My scientific brain wants the ladies to visit a Benedictine nunnery, and then also they should all visit Franciscan equivalents. Of course, the guys on The Monastery did also visit a Carthusian charterhouse, so maybe I just need a little patience to see if they will compare and contrast.

Watch this space…

Well, the clocks changed again, and my server went weird again. I’ve always had problems with Linux and the time due to the number of different places the time is held - usually at least the hardware clock on the computer motherboard and the system clock running within Linux.

Well, I found a page at LinuxSA which finally describes a whole lot of clock-based information in one place. It doesn’t cover NTP, which I use to keep my clock synchronized to the US Navy or whichever other atomic clock my server finds on its travels around the intermagoogle. However, the basics on UTC, timezones and the like are all there.

Oh, and I’ve decided to follow in the footsteps of a family friend who refuses to switch his watch from GMT to BST and back every year. Although I’ve only done it to the server, and I picked UTC as the time zone. So posts and comments will appear an hour out for half of the year.

Here’s a fascinating article I found about religion and science. It’s perhaps a bit heavy, but puts forward some interesting arguments.