I like the #flowers of this #plant but it is growing out of a gap in #concrete by the porch and garage. I think it must have propagated from a neighbour’s #garden many years ago. I tried to take a cutting and plant it in some soil in the back garden but it withered away. Evidently, it only likes rocky conditions. Can anybody tell me the species?
Our immediate neighbour, who moved in a year ago or so, keeps #bees. Sometimes, they swarm in our #garden. I don’t think there’s any danger but I think it’s wise to keep a safe distance from them. They eventually disperse on their daily foraging. Here, they’ve commandeered the #vine#plant.
Forgive the recent apparent obsession (I’d call it a fascination) with the #cycloid but I’ve just discovered something I’d not heard of before. It is also called a #TautochroneCurve or #Isochrone curve, which means that a particle starting from any location on the curve will get to the #MinimumPoint at precisely the same time as a particle starting at any other point.
After lunch yesterday, we went to the #HistoryOfScienceMuseum in #Oxford. It’s not very big but contains some really fascinating exhibits. It is right next to the #SheldonianTheatre and well worth a visit.
To this day, trainee pilots have to master the #CircularSlideRule in order to do calculations for various tasks. Before flying was ever developed, such #SlideRules were in common use.
Yesterday, we went on a day trip to #Oxford by #train. No other means of powered transport was used as we #cycled to and from our local #RailwayStation.
Here is the #countryside zooming past the train window.
@necrosis Yes, I went to Kew Gardens in London not that long ago. Actually, this time, we didn't enter them as we went to a couple of museums instead. More photos coming up.
Die Seiten sind aktuell noch nicht perfekt aufeinanderliegend, weil pdfcrop unterschiedliche Ergebnisse lieferte. Für den heimischen Drucker funktionieren sie aber gut:
A couple of weeks ago, I posted an #animation of a point on a circle generating a #cycloid.
If you turn the curve "upside down", you get the #BrachistochroneCurve. This curve provides the shortest travel time starting from one cusp to any other point on the curve for a ball rolling under uniform #gravity. It is always faster than the straight-line travel time.
Anyway, the #animation took a bit of thought as it requires a bit of #Mechanics, some #Integration and is made a bit more tricky as the curve is multi-valued and so you need to treat different branches separately. The #AnimatedGif was produce with #WxMaxima.
Nothing too remarkable about tonight’s #sunset. I just happen to like the three parallel #contrails. We live under two orthogonal #airways here, one running north-south and the other east-west. The latter is usually busier as it includes transatlantic air traffic.
Imagine a circular wheel rolling, without skidding, on a flat, horizontal surface. The #locus of any given point on its #circumference is called a #cycloid. It is a #periodic#curve with #period over the #circle's circumference and has #cusps whenever the point is in contact with the surface (the two sides of the curve are tangentially vertical at that point).
Interestingly, it is also the curve that solves the #Brachistochrone problem, which means that starting at a cusp on the inverted curve (maximum height), a frictionless ball will roll under uniform gravity in minimum time from the start to any other point on the curve, even beating the straight line path.
Interestingly, the length of the path that a point on the circumference takes during one whole revolution of the circle is precisely equal to the length of the perimeter of the smallest square that contains the circle.
It’s #spring and the #flowers are blooming, which means that #Bees have got a good supply of food. They particularly seem to like the small flowers of the #Cotoneaster plant in the front #garden and throughout a #SunnyDay, there are always several dozen on it.