Monday, October 23, 2023
is the universe rational?
I am here thinking about the construction of spacetime. I am not too worried about whether it is infinite or not, but i do wonder if it is granular in some way or not. Do you really need to have more than rational numbers?
More thought necessary.
M
Sunday, October 15, 2023
number of facets
just putting this down as a project to think about.
if you have n points in space, how many potential flat surfaces have you got?
Any three points define a single surface. So the answer is n.(n-1).(n-2) / 3.2
So n=3 you have one surface defined.
n=4 you have 4.3.2 / (3.2) = 4
n=5 you have 5.4.3 / 6 = 10
n=6 you have 6.5.4 / 6 = 20
n=7 you have 7.6.5 / 6 = 35
n=8 you have 8.7.6 / 6 = 56
n=9 you have 9.8.7 / 6 = 84
The thing that intrigues me is that this does not depend on the dimensionality of the space. The dimensionality must come in somewhere surely. And I am currently guessing that it is more about how many you can 'see partially' if the surfaces are opaque. So in three dimensions
n most visible out of comment
4 4 4 go inside tetrahedron
3 4 go outside
5 6+ 10 go inside ( eg square pyramid )
6 10 go outside (eg triangle with two triangular pyramids)
I cannot cope with the difficulty of imagining these spaces at the moment, and the figures above may be wrong.
I am also intrigued by the thought of inside and outside. Where did that come from?
martin
Monday, October 09, 2023
bird audio radar
It occurred to me that you might be able to harness some of the features of mobile phones to monitor bird migration in a passive fashion without all the expense of using radar.
The main issue would be finding a reasonably quiet location. You would place your mobiles in some simple parabolic reflector pointing roughly to the same area of sky. This probably does not have to be very exact, as it main purpose is to cut out local noise.
Then just record sounds on your mobiles, after you have synced their clocks. This does not have to be hugely accurate, as you are only wanting to locate noises roughly in three dimensions.
You are looking for bird calls in a volume of space. So if all devises pick up a similar call within a second or two of each other, you can calculate its position in space from the recorded timings. Confirmation can come from comparing the sounds length, volume and shape.
Most of this can be done totally automatically. You can then manually investigate the interesting events, and see if they can be identified. If lucky you may have a number of records for the same object and see the speed and direction of flight.
This not much more complicated than a group of people hearing a bird call in flight, and then discussing where you thought it was. I think the amount of processing is quite within mobile phones ability to achieve in real time.
The info is not complete, in that you dont record silent birds, but would be interesting.
Food for thought. A student group project?
Martin
Thursday, October 05, 2023
options for sycamore tree
1. Screw it back on as leafless winter scene only.
2. Cut it up as momentos for sale
3. Let it dry out, and sell as firewood
4. Pulp it and print some 'in memoriam' on paper made from it. sell as souvenirs
5. Put it on top of some photographic peak, and let it rot
M
