Friday, September 29, 2023

 

black and white

I always liked the experiment where you filled a metal cube with hot water, and then measured the radiation coming from the surfaces.  The surfaces were alternately back and white, and now i think of it, probably a matt surface.

This of course was a set up, so people would think it was the bright white surface was radiating/reflecting more.  It was clearly radiating/reflecting more 'white' light, but less infra-red.

And then you were made to think about animals like mountain hares that changed their coat to white in the winter.

Now looking back at it, i think this had far too much magic, and really did not get one to think about equilibriums and spectrums, or the difference between reflection and 'absorption and radiation'. Nor whether camophlage was more important than warmth.

We certainly did not talk about internal reflections at the white surface, which is probably the key point.

I leave all that to the reader to worry about.  The only point i want to make is that the ability to change colour or reflectivity rapidly to maintain a constant internal temperature might be super way of cutting energy usage.  

Our cars should be all 'white in the winter'  and 'black in the summer',  or rather more optimised strategies, such as black in the sun, and white in the shade, if you are cold. the opposite if too hot.

Naturally this also links to how much energy can be shoved into a battery, as an alternative.

I guess camelions might be a better model rather than mountain hares.


M



# posted by martinW @ 10:44 pm 0 comments
 

strange 'decimal's

We are all used to the decimal representation of real numbers, and can imagine it with other integer bases, instead of 10.

But how about considering numbers represented to a strange non-integer base.  Particularly irrational numbers such as e or pi.

I think everything still works as before, though it takes a bit of time to get used to it.  The representation of e would be 10.0 .  Of 2 would be 2.0 

It is a little difficult to get you head round it.

M



# posted by martinW @ 10:38 pm 0 comments

Thursday, September 28, 2023

 

Not the first vandalism

 There is news today of the vandalism of cutting down a not very old sycamore on Hadrians wall, which had become a photographers icon apparently.

The image is of a single sycamore stump, though it might have been either two closely planted trees or a division just above ground.  It seemed not circular, but more eight shaped.

Anyway in classic fashion they failed to point out the the tree was obviously planted there, and not that long ago.  Less than 60 years would be my wild guess.  This planting of a tree near a historic monument is itself a clear act of vandalism.  And a sycamore could be seen at this latitude as being a non native species, I guess.

I think I might prefer to clap the cutter rather than the planter.  

It was a little inept though letting the tree fall on the wall itself.

I am sure  that the Roman legions would have worked out that having trees near this military structure was a very bad idea, and they certainly would have cut it down pronto.


Martin


Update.   People are still claiming the 300 years age.  It must be a very slow growing sycamore.  The trunk is not massive.  My neighbour has a specimen that could be up to a hundred years old that makes this look a toddler.  

The shape looks a little strange with the lowest couple of branches either side looking wider, than all those above it.  Perhaps it had a trauma or pruning at some stage.

One notes no obvious young sycamore around.  This is not my experience.  I therefore conclude it has no nearby neighbours, increasing my thought that this is not a natural native plant, and is not being pollinated successfully.


M

Update 2

on bbc news.  Well it sounds more like under 150 years old, which is a great deal more realistic....m

"The National Trust, which looks after the site with the Northumberland National Park Authority, said it was planted in the late 1800s."


# posted by martinW @ 2:20 pm 0 comments

Thursday, September 21, 2023

 

Is a number of dimensions really integer?

 It seems so obvious that the number of dimensions is an integer.  But I am never sure how one would ever measure it.  One thinks of 'flatland' and it just confuses one.

But at least flatland only ever had integer numbers of dimensions.

I also don't like the presentation of the 'laws' of gravity with a simple 2 as the exponent of the distance.  would it be more helpful to have "number of dimensions' -1".  Then at least one is forced to think about it.

Now I prefer a system that does not start with a euclidean space as its dominant structure.  I am happy with counting, points, distance, and 'spheres' .  I am happy with different sizes of spheres.  Now one can measure the dimensionality.  Basically  build a big sphere and then pack as many small spheres inside this as you can. See what the answer is for the smallest spheres you can create or imagine.  and from this you can work out the dimensionality of that bit of space.  

I have no idea how one would do such an experiment, particularly on the grand scale.  Sounds a bit like measuring gravity waves, and how many can fit in a box.  Or measuring the volume of a black hole, which might be zero for all I know.

The formula for the normalised number is  effectively pi.r.r  for the plane.  pi.r.r.r/3 or 2.pi.r.r.r/3!  for 3 dimensional space and 2.pi.r^n/n! for n dimensional space.  Now one can obviously generalise to a continuous variable for dimensionality, and then do the experiment and find the dimensionality, which I will label d.  One should not worry about how things are actually squashed in.  This is not euclidean space.

This probably gives one the formula for gravity ( or whatever) as f = G.m1.m2.r^(d-1).

I guess that the best way of thinking about fractional dimensions is to think of them as not independent of others. Indeed that some space has an integer dimensionality of n, does not imply that there are n independent dimensions.  Again black holes might be worth consideration as one seems to be able to pour a considerable mass into such small spaces.

have fun trying to think about it

martin




# posted by martinW @ 3:30 pm 0 comments

Saturday, September 09, 2023

 

changing to being eco

These are just some thoughts to drive home that the attitudes are so different that it will be very difficult for some gardeners to go eco.  I don't have a good name for the 'uneco' gardener that sums up the siutation, but here I use the label 'Imposing gardener'

Imposing Gardener     ecologically friendly            Comment
------------------------------      -------------------------------

Order                                    chaos                        give nature plenty of opportunity to do its own                                                                                         thing

Routines                              random                   "   and at its own times

Planned                               whim                         allow time to take on opportunities that occur
    
Thorough                            casual                     in case you are actually doing the wrong thing for                                                                                     some species

Tidy                                      messy                      don't waste time on your human view
 

Complete                            patchy                                        "

Methodical                         short cuts                                  "

Segregated/sorted            Just leave                  maximise variety of opportunities for 'waste'

Uniform                               Patchy                        a mixture might be more productive

Calendar                             Feeling                        Don't impose anything too strict as you have lots                                                                                      of different demands

Dispose of waste              Value waste                Nature comes with its own systems

Select                                   Leave alone               Let nature make the decisions on viability

Rules                                    Personal choice        duplication is not evolution, add variability

Hygene                                Ignore                          It is all nature

Designed                             Evolve                          Don't get personally involved, it is probably                                                                                               suboptimal

Broken things                     Re-purpose                 Nature does not have a disposal system

Targets                                Discovery                    Don't add human bias

Renewal/ Replacement    Variety                         Things change, go with it

Attention to detail              Slap-dash                   randomness is needed in evolution

Money                                  Miser                           Money implies your selection, not evolution

Obviousy  I exaggerate for effect, but this is necessary as it is very difficult to make the change to being eco.

read Dave Goulson  "gardening to save the planet  ....Garden Jungle"

martin


# posted by martinW @ 2:43 pm 0 comments

Tuesday, September 05, 2023

 

what is a real source of randomness?

Just listening to Sean Carrol's podcast on crisis in physics, and wondering what a source of randomness might be as a physical entity.

Would it have mass for instance? lets just assume it is a particle, which cannot interact other than gravity and providing a random state change to other systems.

 It would have to be observable in some way, by at least having a random effect on something else, which was observable.

There would have to be vast quantities of such randomness to support quantum machanical effects, and be distributed in all regions where such effects take place.

Now this does not have to be actually random, but would appear so if we cannot observe anything other than the mass and changes in other systems states.  Indeed it begs the question whether there need be any true randomness anyway, provided the individual particles don't leave any identifiable trail.

Now given this hidden mechanism, it does not need there to be any multi-world interpretation.  It could be purely mechanistic, but also mostly hidden other than its mass.  But internally it would appear totally random and strange

Of course there would be a whole lot of dark matter floating around that nobody could see, other than in large scale observations.  So that is what it is doing.

This is all rather chicken and egg.  

Martin





# posted by martinW @ 11:38 pm 0 comments

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