Thursday, April 30, 2009
biodiversity and entropy
biodiversity and entropy
One knows that entropy in a closed system moves in just one direction.
Is this true of biodiversity? and which way is it anyway?
The concept of closed system is somewhat difficult, since one probably has to have an energy input, ie light or similar.
I feel that there are forces both ways.
There are operations of gathering, concentrating and depositing ( ie herbivores) which will increase diversity.
There are static items such as geology which may reinforce diversity.
But there are also plenty of things like bracken that plain reduce diversity. and man of course.
cheers
martinW
Wednesday, April 29, 2009
planning flights to and from the nest
planning flights to and from the nest
I watched a robin today flying back and forth. It appeared as if the journey away from the nest was
done with speed over a long distance. A predator would not have long to use this for discovering the nest.
There was no apparent attempt to avoid predators on the way. Indeed the route always looked the same.
The journey to the nest was much more circumspect, and involved a number of intermediate landing sites,
presumably where a check was done on whether they were being watched or whether there was a predator in the
area. Were the hops something like halved each time?
All this makes sense, other than one can now tell in which direction and possibly how far away the nest is.
Maybe I only say this because I was not perceived as a predator.
I am not sure exactly how I would plan the journey.
cheers
martinW
Thursday, April 23, 2009
Does the circle minimise every measure?
Does the circle minimise every measure?
What shape minimises the perimeter for a given area. The Circle.
I was trying to work out what shape a birds territory should be given various
conditions for defending it against its neighbours. Average distance from a random point
inside to a random point on the perimeter. The maximum distance from a random point
to a random point of attack. etc etc.
I reckon all the answers are a circle. And probably the same is true for higher dimensional
objects as well.
what would the theorem look like, and what is its proof?
I leave as a short exercise for the student
cheers
martinw
shape of territories
shape of territories
In the theoretical situation of uniform terrain, and uniform population of, say, Robins, what would their
territories work out to be?
I guess the answer would be standard hexagons, filling the plane.
It fills the plane and minimises the boundary to be defended.
Of course, there is no such thing as a uniform terrain, and the presence of linear constraints
might lead to more of a square filling pattern at those edges.
Anyway each pair is likely to have 4 to 6 neighbours.
When they are singing I rarely hear that number of responses from their neighbours. Does
this mean that they rarely sing from the centre of their territory.
just some fun thoughts
cheers
martinw
Monday, April 06, 2009
How do you communicate with a nanomachine?
How do you communicate with a nanomachine?
I like the idea that one takes RNA, as an existing brilliant nanomachine, and modifies it to ones own purposes.
Perhaps one could get one to grab a piece of DNA, and then walk along it reading out the codes to us.
How would one communicate with this. It might be difficult to use our existing communication technology.
I suggest that we go back to something like semaphore, where the nanomachine sets a reflective
physical flag of some sort, and we then observe this with a laser beam(s).
I think the issue is one of energy and speed. We really want the nanomachine to read out the human
genome pretty smartish, so it has to have an incredible bandwidth with the one nanomachine.
just speculation
cheers
martinW
How do you communicate to other worlds?
How do you communicate to other worlds?
I think that communication to other worlds must be much more tricky than one might think. Otherwise other
civilisations would have already done it successfully.
If one thinks that it is going to be really diffiucult, maybe because one does not have
the time ( for whatever reason), then perhaps you just go ahead with colonisation anyway.
Now this is rather a long shot if you do it the traditional way.
But how about firing out, at great velocity, the smallest bits of 'life' that might survive the flight
and colonise? Would not one fire out the odd dna and rna strand. If one could direct this as well,
so much the better.
Fred Hoyles idea of life coming from outer space, would certainly speed up the process. But how
much more if the stuff was intentionally selected and directed at us.
Of course, it could be any sort of nanomachine, but RNA is currently about the best we have.
cheers
MartinW
we are average -- where are the early space travellers?
We are average -- where are the early space travellers?
There is always a bias to thinking that we ( earth, sun, man etc) must be special. However in most
cases we prove to be just average.
So there must be many civilisations that are far in advance of us. Where are they?
They must be around.
Our efforts must have been duplicated many times, many eons ago. One does wonder
why we bother. Well it is obvious -- we bother because we think we are the first. very unlikely!
In which case, one might conclude that things are a little more difficult than one might think.
Can we make use of this fact?
cheers
martinW
