It may be unfashionable to says such things, but I am rather impressed with the way my water company, Severn Trent, handled a reported leak. I reported a small leak (oozing not gushing) down by the road a few days ago, using their web form. ...
Jim Simons
@pippinsboss.bsky.social
Mathematician, tutor of A level maths, bridge player, father, grandfather and dog lover. Maker of mathematical videos, mostly at the level of A levels youtube.com/channel/UCnYszOhEIIdIMYyNx2yjwfg
It's baking hot. There is plenty of shade in the garden, but the dog decides to lie in full sun. He loves to have warm fur!
Out with the dog, we were walking towards the setting Sun. It occured to me that there would come a point in time when the shadow of my head would move backward, whilst I was still walking forwards. There would be a point on my body whose shadow would be stationary. That point would move downwards
Also what is your oldest consumable? Mine is a tub of grease I bought for my first car about 60 years ago!
Pookleblinky@pookleblinky.bsky.social · last mo.I always like thinking about: what is the oldest object you regularly use, the oldest thing you're using in your normal everyday life
I inherited my G&T glasses from my grandfather who rather half-heartedly collected antique glass. They are well over 200 years old.
Pookleblinky@pookleblinky.bsky.social · last mo.I always like thinking about: what is the oldest object you regularly use, the oldest thing you're using in your normal everyday life
Following up on my video introduction to tansfinite cardinals, here is an introduction to transfinite ordinals - a much richer structure, with a fascinating arithmetic. youtu.be/pi7B8mn_N_E
Making Sense of Infinity: Part 2, Ordering
YouTube video by Jim Simons
youtu.be
Pruned the enormous bay tree a bit to net the blueberries. Took off about 10,000 leaves. Bay leaves cost about 5p each in a supermarket. We literally can't give most of ours away. After a few hundred to friends and a restaurant chef we know, the rest are compost. Delicious smelling compost!
Please can the round of 32 be called the semihemidemisemifinals?
Later this year the day will come when my wife will be exactly twice as old as our youngest. That day will be (drum roll) our oldest's birthday. I missed the day earlier in the year when I was twice as old as the youngest. It was 3 days after the the middle one's birthday.
In #mathstoday introducing linear opetators, spent a fruitful half hour investigating the non-linear operator (x, y) -> (x, y)/||(x, y)||. Transforms the unit square into the unit circle.
I like the proof using complex numbers, which is how Van Aubel himself proved it (using the strange notation where √ as a stand-alone symbol means what we call i). You might enjoy my video on the subject. youtu.be/pUSI91Mo7LU
Three pretty geometric theorems, proved by complex numbers
YouTube video by Jim Simons
youtu.be
ProfSmudge@profsmudge.bsky.social · 2mo agoVan Aubel's Theorem (mentioned in Paul's report): the purple lines are equal and at right angles. The diagram, based on an article by Yutaka Nishiyama, provides the skeleton of a proof (nicer than Paul's proof based on vectors (in my view!)).
My latest video: Making Sense of Infinity: Part 1, Counting. Nothing here for anyone who has met transfinite cardinals before, but if you have been puzzled by the infinite, this video gives a simple introduction to one way of thinking about it avoiding paradoxes. youtu.be/uST3nnU5UnE
Making Sense of Infinity: Part 1, Counting
YouTube video by Jim Simons
youtu.be
We've done no mow May for three or four years (actually for rather longer than just May). The first year a couple of bee orchids emerged apparently from nowhere. This year we have eleven! Of course we also have lots of other wild flowers. It's wonderful.
I've always been interested in numbers that are not counting or measuring, like telephone numbers or bus route numbers. The internet tells me they are called nominal numbers, like cardinal and ordinal numbers. Is that standard usage in the UK or elsewhere? I feel there ought to be word for them.
It was blowing half a gale when the puppy went out for a pee. He cocked his leg, but he has only just learnt to do this, so he's not very good at it. He blew right over! Poor pup. Nothing hurt but his dignity.
I've been reading the output of the solar powerstation on my roof every quarter for 15 years. Here is a summary (in kWH) Q1 Q2 Q3 Q4 Mean 488 1082 911 229 St Dev'n 198 161 103 63 What do you notice? What surprises you?
Has anyone got any idea what the top left group of symbols in a lift in a hotel in Malta means? My family has only managed scatalogical explanations. That squiggly thing looks like an 8 on its side, but elsewhere it says the max capacity is 13 persons.
And of course the right angle was Euclid's unit of angle, before the degree became standard. I was puzzled at school to learn that the sum of the angles in a triangle is 2 right angles. Why not 180°? Because that's how Euclid had it.
Andrew Stacey@mathforge.org · 5mo agoSeems a good day to remark that π isn't something to get all bothered about, but then neither is τ. At least, not *that* τ. loopspace.mathforge.org/CountingOnMy... #mathsky #UKMathsChat
Here's the third of my videos on "How Far Away is the Sun?". We look at how the transits of Venus in 1761 and 1796 were predicted 50 years earlier and then observed from all around the world to find out how far away Venus is. Starring intrepid Yorkshireman James Cook. youtu.be/QazkPvqo_cw
How Far Away is the Sun? Part 3
YouTube video by Jim Simons
youtu.be
Here's the second part of my video series "How Far Away is the Sun?" This covers the amazingly brilliant work that got us from the terrible ancient Greek estimate to being able to make an accurate measurement. Particularly Kepler's astonishing work on elliptical orbits. youtu.be/-Fe0am6M-Uk
How Far Away is the Sun? Part 2
YouTube video by Jim Simons
youtu.be
How far away is the Sun? The story of how we answered this question includes lots of fascinating mathematics and science. Here's the first part: how the ancient Greeks got a pretty good estimate of how far away the Moon is, and a terrible estimate of how far away the Sun is. youtu.be/xCqPZ7o0ad4
How Far Away is the Sun? Part 1
YouTube video by Jim Simons
youtu.be
Indeed, some scholars have argued that some early Homo species should be reclassified as Australopithecus.
New-Cleckit Dominie@ncdominie.bsky.social · 7mo agoPick up the nearest book. Turn to page 42, and post the second sentence. "Here p is rational, although it will be shown in Problem P of Chapter 2 that the results hold for all real p in the ranges stated." (Books round here do not tend to have a strong narrative drive.)
I'm self-employed, so I have to fill in a tax form every year, and I have a guilty secret - because it is all numbers and spreadsheets, I rather enjoy doing it.
In #Mathstoday, we explored 2D linear transformations. I made this geogebra thingy, but the coordinates of the transformed points only seem to be right to about 2sf, even when the matrix is the identity. Am I doing something silly? www.geogebra.org/m/regvfyr2
Transforming with a 2D Matrix
Demo of 2D Linear Transforms
geogebra.org
#ukmathschat calculator hack. My calculator app can convert between units, such as gallons and litres. To convert pence per litre to pence per gallon, convert from gallons to litres.
As a programmer back in the day, I sometimes faced the "come from" problem. A program crashed executing code it should never have reached: how did it get there? Today I have a different come from problem. We have been sent flowers by Margaret. We know many Margarets ...