Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
Terry Reedy wrote: For the most part, there are no bears within a mile of the North Pole either. they are rare north of 88° (ie, 140 miles from pole). https://en.wikipedia.org/wiki/Polar_bears They mostly hunt in or near open water, near the coastlines. The way things are going, the coastline might be within a mile of the north pole quite soon. -- Greg -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
2014-05-01 3:57 GMT+02:00 Chris Angelico ros...@gmail.com: On Thu, May 1, 2014 at 9:46 AM, Ian Kelly ian.g.ke...@gmail.com wrote: It also works if your starting point is (precisely) the north pole. I believe that's the canonical answer to the riddle, since there are no bears in Antarctica. Yeah but that's way too obvious! Anyway, it's rather hard to navigate due south from the north pole. Which way do you go? How do you know you're still going due south? Will the rocket even light in that climate? Important questions must be answered! ChrisA -- https://mail.python.org/mailman/listinfo/python-list Well, after having been following the discussion, I couldn't resist but post the relevant sketch from the famous Czech play The Conquest of the North Pole by the Czech Karel Němec on 5th April 1909 by Jara Cimrman [as dicovered and presented by Z. Sverak and L. Smoljak] (translated by Craig Cravens) http://jaracimrman.files.wordpress.com/2010/04/north_pole.pdf (pp. 38-39) Teacher: And now, friends, I’d like to draw your attention to a certain geographical peculiarity. If I stand next to the chief and step off in any direction, I always go south. Pharmacist: No! Teacher: Yes, yes! Watch! (stands next to the chief and steps off.) I’m going south. (He returns and sets off in another direction.) And now I’m going south again. And now —once again south. Pharmacist: That’s unbelievable! Teacher: Hold on, you haven’t seen anything yet. Richard, stand here with your back to the chief. And now both of you, step forward. (Schwarzenegger and the chief, with their backs to each other, step forward.) Did you see that? They’re both going south! Pharmacist: That’s really something else! Teacher: And I’ve saved the best for last. Now, you’ll really see something. Vojtěch, mark the Pole with an X and step aside. (Vojtěch obeys. The teacher sets off toward the mark.) Watch this. I’m going north (he crosses the mark and continues walking) and now I’m going south! And now back: north … and now south. Pharmacist: That’s impossible! Teacher: Try it yourself. Pharmacist: This I’ve got to see. (He walks towards the pole and them moment he crosses it his face lights up with joy.) Wow! Friends, this was worth it! On the verge of death from hypothermia, from hunger, and from exhaustion, but it was worth it! = regards, vbr -- https://mail.python.org/mailman/listinfo/python-list
Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On 04/29/2014 03:51 PM, Chris Angelico wrote: On Wed, Apr 30, 2014 at 8:42 AM, emile em...@fenx.com wrote: On 04/29/2014 01:16 PM, Adam Funk wrote: A man pitches his tent, walks 1 km south, walks 1 km east, kills a bear, walks 1 km north, where he's back at his tent. What color is the bear? ;-) From how many locations on Earth can someone walk one mile south, one mile east, and one mile north and end up at their starting point? Any point where the mile east takes you an exact number of times around the globe. So, anywhere exactly one mile north of that, which is a number of circles not far from the south pole. It is my contention, completely unbacked by actual research, that if you find such a spot (heading a mile east takes you an integral number of times around the pole), that there is not enough Earth left to walk a mile north so that you could then turn-around a walk a mile south to get back to such a location. -- ~Ethan~ -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On 04/30/2014 06:14 AM, Ethan Furman wrote: On 04/29/2014 03:51 PM, Chris Angelico wrote: On Wed, Apr 30, 2014 at 8:42 AM, emile em...@fenx.com wrote: On 04/29/2014 01:16 PM, Adam Funk wrote: A man pitches his tent, walks 1 km south, walks 1 km east, kills a bear, walks 1 km north, where he's back at his tent. What color is the bear? ;-) From how many locations on Earth can someone walk one mile south, one mile east, and one mile north and end up at their starting point? Any point where the mile east takes you an exact number of times around the globe. So, anywhere exactly one mile north of that, which is a number of circles not far from the south pole. It is my contention, completely unbacked by actual research, that if you find such a spot (heading a mile east takes you an integral number of times around the pole), that there is not enough Earth left to walk a mile north so that you could then turn-around a walk a mile south to get back to such a location. Wow. It's amazing how writing something down, wrongly (I originally had north and south reversed), correcting it, letting some time pass (enough to post the message so one can be properly embarrassed ;), and then rereading it later can make something so much clearer! Or maybe it was the morning caffeine. Hmmm. At any rate, I withdraw my contention, it is clear to me now (at least until the caffeine wears off). -- ~Ethan~ -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On Wed, Apr 30, 2014 at 11:14 PM, Ethan Furman et...@stoneleaf.us wrote: Any point where the mile east takes you an exact number of times around the globe. So, anywhere exactly one mile north of that, which is a number of circles not far from the south pole. It is my contention, completely unbacked by actual research, that if you find such a spot (heading a mile east takes you an integral number of times around the pole), that there is not enough Earth left to walk a mile north so that you could then turn-around a walk a mile south to get back to such a location. The circle where the distance is exactly one mile will be fairly near the south pole. There should be plenty of planet a mile to the north of that. If the earth were a perfect sphere, the place we're looking for is the place where cutting across the sphere is 1/π miles. The radius of the earth is approximately 4000 miles (give or take). So we're looking for the place where the chord across a radius 4000 circle is 1/π; that means the triangle formed by a radius of the earth and half of 1/π and an unknown side (the distance from the centre of the earth to the point where the chord meets it - a smidge less than 4000, but the exact distance is immaterial) is a right triangle. Trig functions to the rescue! We want latitude 90°-(asin 1/8000π). It's practically at the south pole: 89.9977° south (89°59'52). Are my calculations correct? ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On Thu, May 1, 2014 at 12:02 AM, Ethan Furman et...@stoneleaf.us wrote: Wow. It's amazing how writing something down, wrongly (I originally had north and south reversed), correcting it, letting some time pass (enough to post the message so one can be properly embarrassed ;), and then rereading it later can make something so much clearer! Or maybe it was the morning caffeine. Hmmm. At any rate, I withdraw my contention, it is clear to me now (at least until the caffeine wears off). It's also amazing how much fun it can be to dig into the actual mathematics, as a means of dispelling a perceived error :) So, thank you for posting that, because it forced me to actually map things out (in my head - didn't feel like using pen-and-paper geometry, even though this is the most literal form of geo-metry possible) and figure out exactly how many degrees of latitude it takes. Good fun! ChrisA -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On Wed, Apr 30, 2014 at 9:02 AM, Ethan Furman et...@stoneleaf.us wrote: On 04/30/2014 06:14 AM, Ethan Furman wrote: On 04/29/2014 03:51 PM, Chris Angelico wrote: On Wed, Apr 30, 2014 at 8:42 AM, emile em...@fenx.com wrote: On 04/29/2014 01:16 PM, Adam Funk wrote: A man pitches his tent, walks 1 km south, walks 1 km east, kills a bear, walks 1 km north, where he's back at his tent. What color is the bear? ;-) From how many locations on Earth can someone walk one mile south, one mile east, and one mile north and end up at their starting point? Any point where the mile east takes you an exact number of times around the globe. So, anywhere exactly one mile north of that, which is a number of circles not far from the south pole. It is my contention, completely unbacked by actual research, that if you find such a spot (heading a mile east takes you an integral number of times around the pole), that there is not enough Earth left to walk a mile north so that you could then turn-around a walk a mile south to get back to such a location. Wow. It's amazing how writing something down, wrongly (I originally had north and south reversed), correcting it, letting some time pass (enough to post the message so one can be properly embarrassed ;), and then rereading it later can make something so much clearer! Or maybe it was the morning caffeine. Hmmm. At any rate, I withdraw my contention, it is clear to me now (at least until the caffeine wears off). Sure, but that still leaves the nagging problem that there aren't any Polar Bears in Antarctica (as someone else pointed out). This man must have brought a bear with him. Perhaps the story is something like this: A man near the south pole takes his dear friend and pet bear for a walk. He'd gone to great lengths to bring his pet bear with him to his Antarctic expedition, and his bear is his best friend, and sole companion, save for the constant, biting cold. They walk toward the pole, then begin their excursion eastward, encircling the pole. As the man grows weary, and decides to head back, a legion of penguins collaborate with a host of Weddell seals to be rid of their uninvited guests. It isn't clear what the man did to cause those seals to rise against him, but it must have been some dire feat, for Weddell seals are not easily frightened. After a fierce battle, the man and his bear (well, mostly the bear) manage to defend themselves against the attacking throng. However, the new peace realizes a terrible fate: his bear is mortally wounded, and is suffering immensely. The man, loving his friend dearly, shoots his solitary compatriot, and weeps as he watches the blood turn his dear bear's fur an ominous red. Overcome with grief, he heads back north to his tent to mourn his loss, and to arrange his trip north to the populated tropics, where he hopes to forget his troubles, and the place where he lost his closet pal, a bear. -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On Wed, Apr 30, 2014 at 7:14 AM, Ethan Furman et...@stoneleaf.us wrote: On 04/29/2014 03:51 PM, Chris Angelico wrote: On Wed, Apr 30, 2014 at 8:42 AM, emile em...@fenx.com wrote: On 04/29/2014 01:16 PM, Adam Funk wrote: A man pitches his tent, walks 1 km south, walks 1 km east, kills a bear, walks 1 km north, where he's back at his tent. What color is the bear? ;-) From how many locations on Earth can someone walk one mile south, one mile east, and one mile north and end up at their starting point? Any point where the mile east takes you an exact number of times around the globe. So, anywhere exactly one mile north of that, which is a number of circles not far from the south pole. It also works if your starting point is (precisely) the north pole. I believe that's the canonical answer to the riddle, since there are no bears in Antarctica. -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On 4/30/2014 7:46 PM, Ian Kelly wrote: It also works if your starting point is (precisely) the north pole. I believe that's the canonical answer to the riddle, since there are no bears in Antarctica. For the most part, there are no bears within a mile of the North Pole either. they are rare north of 88° (ie, 140 miles from pole). https://en.wikipedia.org/wiki/Polar_bears They mostly hunt in or near open water, near the coastlines. I find it amusing that someone noticed and posted an alternate, non-canonical solution. How might a bear be near the south pole? As long as we are being creative, suppose some jokester mounts a near life-size stuffed black bear, made of cold-tolerant artificial materials, near but not at the South Pole. The intent is to give fright to naive newcomers. Someone walking in a radius 1/2pi circle about the pole might easily see it. -- Terry Jan Reedy -- https://mail.python.org/mailman/listinfo/python-list
Re: Off-topic circumnavigating the earth in a mile or less [was Re: Significant digits in a float?]
On Thu, May 1, 2014 at 9:46 AM, Ian Kelly ian.g.ke...@gmail.com wrote: It also works if your starting point is (precisely) the north pole. I believe that's the canonical answer to the riddle, since there are no bears in Antarctica. Yeah but that's way too obvious! Anyway, it's rather hard to navigate due south from the north pole. Which way do you go? How do you know you're still going due south? Will the rocket even light in that climate? Important questions must be answered! ChrisA -- https://mail.python.org/mailman/listinfo/python-list
