Wreckless Rat wrote: Thu Jul 13, 2023 7:26 pm
Electricity doesn’t actually flow in the wires, it flows in the gaps, the insulation or the air in an electric field… it doesn’t actually flow in the wire itself.
Really? So how/why do different material wires have different resistances etc? Not sure I understand this interesting little fact.
Wreckless Rat wrote: Thu Jul 13, 2023 7:26 pm
Electricity doesn’t actually flow in the wires, it flows in the gaps, the insulation or the air in an electric field… it doesn’t actually flow in the wire itself.
Really? So how/why do different material wires have different resistances etc? Not sure I understand this interesting little fact.
Over the last year or so (I think?) there's been a whole series of (good natured) YouTube videos/rebuttals on it.
Wreckless Rat wrote: Thu Jul 13, 2023 7:26 pm
Electricity doesn’t actually flow in the wires, it flows in the gaps, the insulation or the air in an electric field… it doesn’t actually flow in the wire itself.
Really? So how/why do different material wires have different resistances etc? Not sure I understand this interesting little fact.
Mr. Dazzle wrote: Thu Jul 13, 2023 9:00 pm
Have you seen the clip of Richard Feynman explaining how magnets work?
His point is, you can get deeper and deeper into the physics but at some point you always reach a level where you have to accept "they just do".
It's the same with electricity IME
In my head, I can hear him now. He is one of my favourite physicists ever, bar none.
An extraordinary chap greatly missed.
The man who, while dealing with terminal cancer, dug down and discovered the real reason why the Challenger failed so catastrophically, and even managed to produce a demonstration of the failure cause for the panel. One of the 20th century greats.
The very definition of "do your own research" and a level of simple clarity most people who cry "sheep" can only aspire to (which of course, they don't).
for those who don't know, the root (technical) cause of the Challenger shuttle disaster was O ring seals not sealing at low temperatures. 'Everyone' said they would, Feynman does a simple demo during the inquiry with ice water to demonstrate that's BS. Obviously quite a lot more to that story, worth reading up on it.
Mr. Dazzle wrote: Thu Jul 13, 2023 10:00 pm
The very definition of "do your own research" and a level of simple clarity most people who cry "sheep" can only aspire to (which of course, they don't).
for those who don't know, the root (technical) cause of the Challenger shuttle disaster was O ring seals not sealing at low temperatures. 'Everyone' said they would, Feynman does a simple demo during the inquiry with ice water to demonstrate that's BS. Obviously quite a lot more to that story, worth reading up on it.
His books are well worth a read, fascinating stories from Challenger back to his involvement in the Manhattan Project. He and his first wife would write letters to each other in code to challenge each other whilst he was based on the secret site building the A Bomb until the sites security dept. asked him not to encode the letters as it was taking far too much time to crack them.
"Of all the stories you told me, which ones were true and which ones weren't?"
"My dear Doctor, they're all true."
"Even the lies?"
"Especially the lies."
Trinity765 wrote: Thu Jul 27, 2023 5:44 am
There is a growing number of bears (Ursus arctos arctos), a population of at least 70 in the Pyrenees and more in the Pico's/north Galicia
And from the linked article, word of the day: clade
In biological phylogenetics, a clade (from Ancient Greek κλάδος (kládos) 'branch'), also known as a monophyletic group or natural group,[1] is a grouping of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree.
Friends live near the Pyrenees. Apparently the government compensate farmers for livestock taken by the bears. Going by the level of claims, the bears must be obese.
Cousin Jack wrote: Thu Jul 27, 2023 8:35 am
Do they eat motorcyclists? I need to know soon, I am off to Spain in September and may need to upgrade my insurance.
Not a whole one in a single sitting.
I was prompted to look it up as I saw a motorbike being mauled by a bear on a FB European motorcycle tour group. It looked like it was trying to get at something in a pannier so my advice would be don't carry snacks if you're wandering off the beaten track.
Trinity765 wrote: Thu Jul 27, 2023 8:44 am
I was prompted to look it up as I saw a motorbike being mauled by a bear on a FB European motorcycle tour group. It looked like it was trying to get at something in a pannier so my advice would be don't carry snacks if you're wandering off the beaten track.
That makes sense. In most of the NPs in the USA they tell you not to leave food, or even food wrappings in cars overnight. We saw one 4x4 that had not heeded the advice, a grizzly can and will rip a car door open just to get to some sweets.
Cousin Jack wrote: Thu Jul 27, 2023 8:35 am
Do they eat motorcyclists? I need to know soon, I am off to Spain in September and may need to upgrade my insurance.
If you're going hiking while there, the best things you can do is to deter them and also learn to recognise that they're possibly in the area so you can avoid disturbing them.
Deter: use noise to warn them, so they're not surprised, by hanging small bells on your clothes. Apply peppermint oil too.
Recognise: identify their droppings. Easily recognised as it smells of peppermint and contains small bells.
Went for a hike up one of the cross-country ski trails in Banff and happened upon a toilet block (why it was out there in the woods I dunno) - on the door was a sign suggesting you don't just charge in....
(I can't really remember but there was probably a door latch of some sort but they're pretty canny them bears. They were all over the place, small ones not grizzlys, even sat in small groups on the grass verges at the roadside. I assume people would throw 'treats' out of the car window Did a hike around an old/historic site of interest - an old mining settlement - and you really had to keep your eyes open and make a bit of noise.They're supposed to be mainly nocturnal but they seemed pretty wide awake during the day and definitely not all hibernating!).
Did a hike around an old/historic site of interest - an old mining settlement - and you really had to keep your eyes open and make a bit of noise.They're supposed to be mainly nocturnal but they seemed pretty wide awake during the day and definitely not all hibernating!).
