In article <ham9e8$pq...@reader1.panix.com>, nos...@nospam.com (Paul Ciszek) wrote:
> In article <m36tc518u08ch48mg717ism5c8taeqv...@4ax.com>, > Bill Snyder <bsny...@airmail.net> wrote:
> >>Indeed it is. What kind of space did they construct?
> >Non-Euclidian. But, shhh, don't tell Shawn.
> Does Shawn have a thing about non-Euclidian geometry? I have encountered > Relativity deniers on the far right before, so I suppose that denial of > non-Euclidian geometry would go with that.
He has a thing about it being real. At one point, a discussion with him resulted in him (or his idiot think-alike friend) using "the interior angles of a triangle add up to 180 degrees" as something that was true by definition. When non-euclidean space was mentioned to him, he dismissed it as unreal. Mentions of relativity went unheeded.
-- Mike Ash Radio Free Earth Broadcasting from our climate-controlled studios deep inside the Moon
In article <mike-8DF896.13131009102...@news.eternal-september.org>, Mike Ash <m...@mikeash.com> writes:
>In article <ham9e8$pq...@reader1.panix.com>, nos...@nospam.com (Paul Ciszek) wrote: >> In article <m36tc518u08ch48mg717ism5c8taeqv...@4ax.com>, Bill Snyder <bsny...@airmail.net> wrote: >> >>Indeed it is. What kind of space did they construct?
>> >Non-Euclidian. But, shhh, don't tell Shawn.
>> Does Shawn have a thing about non-Euclidian geometry? I have encountered >> Relativity deniers on the far right before, so I suppose that denial of >> non-Euclidian geometry would go with that.
>He has a thing about it being real. At one point, a discussion with him >resulted in him (or his idiot think-alike friend) using "the interior >angles of a triangle add up to 180 degrees" as something that was true >by definition. When non-euclidean space was mentioned to him, he >dismissed it as unreal.
Ayn Rand had a similar tic, didn't she?
-- Michael F. Stemper #include <Standard_Disclaimer> You can lead a horse to water, but you can't make him talk like Mr. Ed by rubbing peanut butter on his gums.
Michael Stemper <mstem...@walkabout.empros.com> wrote: > In article <mike-8DF896.13131009102...@news.eternal-september.org>, Mike Ash <m...@mikeash.com> writes: >>In article <ham9e8$pq...@reader1.panix.com>, nos...@nospam.com (Paul Ciszek) wrote: >>> In article <m36tc518u08ch48mg717ism5c8taeqv...@4ax.com>, Bill Snyder <bsny...@airmail.net> wrote:
>>> >>Indeed it is. What kind of space did they construct?
>>> >Non-Euclidian. But, shhh, don't tell Shawn.
>>> Does Shawn have a thing about non-Euclidian geometry? I have encountered >>> Relativity deniers on the far right before, so I suppose that denial of >>> non-Euclidian geometry would go with that.
>>He has a thing about it being real. At one point, a discussion with him >>resulted in him (or his idiot think-alike friend) using "the interior >>angles of a triangle add up to 180 degrees" as something that was true >>by definition. When non-euclidean space was mentioned to him, he >>dismissed it as unreal.
> Ayn Rand had a similar tic, didn't she?
I don't know about Rand, but Marilyn vos Savant used the same tic to reject Wiles' proof of Fermat's Last Theorem. I think she backpedaled on that a few years alter, though.
Anthony Nance wrote: > Michael Stemper <mstem...@walkabout.empros.com> wrote: >> In article <mike-8DF896.13131009102...@news.eternal-september.org>, >> Mike Ash <m...@mikeash.com> writes: >>> In article <ham9e8$pq...@reader1.panix.com>, nos...@nospam.com >>> (Paul Ciszek) wrote: >>>> In article <m36tc518u08ch48mg717ism5c8taeqv...@4ax.com>, Bill >>>> Snyder <bsny...@airmail.net> wrote:
>>>>>> Indeed it is. What kind of space did they construct?
>>>>> Non-Euclidian. But, shhh, don't tell Shawn.
>>>> Does Shawn have a thing about non-Euclidian geometry? I have >>>> encountered >>>> Relativity deniers on the far right before, so I suppose that >>>> denial of >>>> non-Euclidian geometry would go with that.
>>> He has a thing about it being real. At one point, a discussion with >>> him >>> resulted in him (or his idiot think-alike friend) using "the >>> interior >>> angles of a triangle add up to 180 degrees" as something that was >>> true >>> by definition. When non-euclidean space was mentioned to him, he >>> dismissed it as unreal.
>> Ayn Rand had a similar tic, didn't she?
> I don't know about Rand, but Marilyn vos Savant used the same tic to > reject Wiles' proof of Fermat's Last Theorem. I think she backpedaled > on that a few years alter, though.
Heinlein would sometimes do away with science and math he disliked. "Waldo" mentions that Heisenberg's unceertainty princple had been disproved, and one of his other works ("Gulf", perhaps?) insisted that Cantor's apprach to infinite sets was a fallacy. Neither pronouncement had much to do with the story.
> >>>> All right... I was thinking of a prior thread about when the moon was > >>>> visible during the day, and remembering from a distant science class > >>>> that the full moon rises at sunset at sets at dawn, and that got me to > >>>> thinking about how nights get longer and shorter through the year, so > >>>> I assume that that was just an approximation.
> >>>> And that got me to the real question I have... does the moon still go > >>>> through phases at the poles? If it's daylight 24 hours a day, and the > >>>> moon is full, would you see it? Is it in the sky 24 hours a day if > >>>> the sun is? I'm trying to visualize the geometry and failing > >>>> miserably. And I figure that there were good people on this group > >>>> that could answer this. > >>> The phase of the moon has nothing to do with where you are on the > >>> planet, it's where the moon is in relation to the planet. We see the > >>> moon because it's "lit up" by the sun, and we see phases because its in > >>> vacuum and has really sharp shadows.
> >> Let me clarify my question. I understand that the moon is > >> going to continue doing what it does, regardless of where I > >> am. But, if I am in sunny southern California, look out my > >> window in June and see a full moon, and instantaneously > >> teleport to the North Pole, would the moon still look like a > >> full moon? Or would it be washed out by the sunlight? It > >> wouldn't be night there, even though it was in California. > >> It appears, from other posts, that the answer is that it > >> would be below the horizon. Which makes a certain amount of > >> sense to me.
> > Maybe you can visualize it by imagining you're in a room lit by a > > single bulb. You're holding a ball in one hand. In this setup, > > the bulb is the Sun, the ball is the Moon, and you're the Earth.
> > Hold the ball up more or less directly between you and the bulb, > > and you're looking at the dark side of it; that's a new moon. Turn > > around so you're holding it away from the bulb (but not in an > > actual straight line with your shadow falling on it), and you're > > looking at the lit side; that's a full moon. Turn halfway back, > > so it's at right angles to the bulb, and you see it half lit and > > half dark.
> Oh, I get all that. It's the pole thing that is throwing > me. After all, my normal assumption is that at some point > the sun goes below the horizon, and then it comes back up > over the other horizon, and it does this once a day. If the > sun isn't doing what I expect daily, why should the moon be > doing what I expect? But if it's not, then I don't know > what it _is_ doing. I've heard about the White Nights and > the 6 months of daylight/6 months of darkness, but no one > ever bothers to say "during those 6 months that the sun > doesn't set, the moon is doing X." Or at least not that I > have ever heard of. And I'm not good at figuring out where > the moon is in relation to the sun if I am standing at the > pole. It's one thing to do the ball and light thing, it's > something entirely different to do that with all the > appropriate angles between the tilt of the earth, the orbit > of the moon, and the orbit of the earth, which is what I > would need in order to figure out exactly where the moon is > relative to the horizon of the earth when I'm standing at > the pole and the moon's half-full/waxing/waning/etc.
> Rebecca- Hide quoted text -
> - Show quoted text -
I've thought of a place to ask! http://www.heavens-above.com/ Very nice website, with lots of info (do try the FAQs before emailing the question).
The full Moon will not be concealed by the Sun; within a day or so of new Moon, the crescent is visible in daytime. But the Moon may well dip below the horizon, I think -- depending. The Moon does not describe a fine line around the Earth, but a line within a band; this month's line will not be exactly last month's line. The ecliptic band of constellations is tilted; it is not parallel to the equator nor normal to the axis. I can't visualize in three dimensions well enough to know how much of the constelllation band is above the horizon at the North Pole, nor do I know how far up and down the Moon's path goes. But I bet Chris Peat can figure it out!
>Anthony Nance wrote: >> Michael Stemper <mstem...@walkabout.empros.com> wrote: >>>> by definition. When non-euclidean space was mentioned to him, he >>>> dismissed it as unreal.
>>> Ayn Rand had a similar tic, didn't she?
>> I don't know about Rand, but Marilyn vos Savant used the same tic to >> reject Wiles' proof of Fermat's Last Theorem. I think she backpedaled >> on that a few years alter, though.
>Heinlein would sometimes do away with science and math he disliked. "Waldo" >mentions that Heisenberg's unceertainty princple had been disproved, and one >of his other works ("Gulf", perhaps?) insisted that Cantor's apprach to >infinite sets was a fallacy. Neither pronouncement had much to do with the >story.
I know that in one of his stories, possibly TNotB, one of the characters decries the "fallacy of treating infinity as a number". However, in another story, somebody explains why two line segments of different lengths still have the same 'number' of points, with apparent authorial approval.
-- Michael F. Stemper #include <Standard_Disclaimer> A bad day sailing is better than a good day at the office.
> In article <hao1et$ub...@news.eternal-september.org>, "Mike Schilling" > <mscottschill...@hotmail.com> writes: >> Anthony Nance wrote: >>> Michael Stemper <mstem...@walkabout.empros.com> wrote:
>>>>> by definition. When non-euclidean space was mentioned to him, he >>>>> dismissed it as unreal.
>>>> Ayn Rand had a similar tic, didn't she?
>>> I don't know about Rand, but Marilyn vos Savant used the same tic to >>> reject Wiles' proof of Fermat's Last Theorem. I think she backpedaled >>> on that a few years alter, though.
>> Heinlein would sometimes do away with science and math he disliked. "Waldo" >> mentions that Heisenberg's unceertainty princple had been disproved, and one >> of his other works ("Gulf", perhaps?) insisted that Cantor's apprach to >> infinite sets was a fallacy. Neither pronouncement had much to do with the >> story.
> I know that in one of his stories, possibly TNotB, one of the characters > decries the "fallacy of treating infinity as a number". However, in another > story, somebody explains why two line segments of different lengths still > have the same 'number' of points, with apparent authorial approval.
But they probably both sounded good and did their job of presenting the speaker in a way that Heinlein wanted him presented, I'd guess.
I doubt either was meant as a math lecture, but rather as a bit of worldbuilding. Heinlein's characters disagreed with each other, depending on what approach served the story he was telling. He presented the stories so forcefully and confidently that many readers assume that if a Heinlein Wise Man says it, it must be what he himself believed -- but his Wise Men didn't all agree with each other, because he was telling different stories.
In article <hao8oa$pb...@news.eternal-september.org>,
Michael Stemper <mstem...@siemens-emis.com> wrote:
>I know that in one of his stories, possibly TNotB, one of the characters >decries the "fallacy of treating infinity as a number". However, in another
There are paradoxes and contradicitons that you run into if you try to treat infinity as a number, especially if you try to do any arithmetic with it as if it were a specific number.
-- Please reply to: | "Any sufficiently advanced incompetence is pciszek at panix dot com | indistinguishable from malice." Autoreply is disabled |
Paul Ciszek wrote: > In article <hao8oa$pb...@news.eternal-september.org>, > Michael Stemper <mstem...@siemens-emis.com> wrote:
>> I know that in one of his stories, possibly TNotB, one of the >> characters decries the "fallacy of treating infinity as a number". >> However, in another
> There are paradoxes and contradicitons that you run into if you try to > treat infinity as a number, especially if you try to do any arithmetic > with it as if it were a specific number.
You're OK so long as you don't treat an infinite number as a finite one. There's no paradox in notiing that
aleph-null + 1 = aleph-null
unless you try to delete aleph-null from both sides.
> Paul Ciszek wrote: > > In article <hao8oa$pb...@news.eternal-september.org>, > > Michael Stemper <mstem...@siemens-emis.com> wrote:
> >> I know that in one of his stories, possibly TNotB, one of the > >> characters decries the "fallacy of treating infinity as a number". > >> However, in another
> > There are paradoxes and contradicitons that you run into if you try to > > treat infinity as a number, especially if you try to do any arithmetic > > with it as if it were a specific number.
> You're OK so long as you don't treat an infinite number as a finite one. > There's no paradox in notiing that
> aleph-null + 1 = aleph-null
> unless you try to delete aleph-null from both sides.
There are, of course, similar problems with zero. For example, 5*0=3*0, but don't divide both sides by zero to get 5=3, and with algebra this can be hidden, so one has to be careful.
I have sung all the verses of Aleph Null bottles of beer on the wall.
-- A computer without Microsoft is like a chocolate cake without mustard.
> >I suspect a goodly proportion of urban people don't know whether the > >moon rises earlier or later each day.
> >Or even whether today it is waxing or waning.
> "The moon is a liar. When you see a "D", it is not decreasing."
I believe that our Southern Hemisphere correspondents disagree, but us Northerners out vote them.
> I never remember how it compares to yesterday's moon, but reading the > shape tells you which way it's going.
As long as you remember which side of the equator you are on (and actually, the moon orientation is ambiguous in the tropics). It is much better to determine if the moon is in the sky when the sun sets or when it rises.
: "Robert A. Woodward" <rober...@drizzle.com> : As long as you remember which side of the equator you are on (and : actually, the moon orientation is ambiguous in the tropics). It is : much better to determine if the moon is in the sky when the sun : sets or when it rises.
Pfft. Don't really have to look at the *shape* of the (illuminated part of the) moon. Just compare the direction of the moon with the direction of the sun. Granted, the shape of the moon tells you where the sun is, but you also know that by time of day. So... knowing the time of day, just see where in the sky the moon is. Of course, if it's not up when you look, you'll have to check back later, but that's true of "check its shape" also.
If the sun is leading the moon (eg, it's sunset and the moon is overhead), it's waxing. If the moon is leading the sun (eg, it's sunrise and the moon is overhead), it's waning. The shape, and which hemisphere you're in, will take care of themselves.
And no, you can't call "leading by 90 degrees" the same as "trailing by 270 degrees"; you reckon it only up to 180 degrees, which is the full moon, which is the cusp between waxing and waning.
On Sat, 10 Oct 2009 14:13:36 -0400, Sean O'Hara <seanoh...@gmail.com> wrote: >the Great and Powerful Michael Stemper declared: >> Sometimes, >> the right half of the moon is lit, sometimes the left half. This happens >> no matter what hemisphere you're in.
>Equatorial regions aren't in either hemisphere?
Depends. Are they close to the West Pole?
Dave -- \/David DeLaney posting from d...@vic.com "It's not the pot that grows the flower It's not the clock that slows the hour The definition's plain for anyone to see Love is all it takes to make a family" - R&P. VISUALIZE HAPPYNET VRbeable<BLINK> http://www.vic.com/~dbd/ - net.legends FAQ & Magic / I WUV you in all CAPS! --K.
> In article <nebusj.1255024...@vcmr-86.server.rpi.edu>, nebu...@-rpi-.edu > (Joseph Nebus) writes: >>mstem...@walkabout.empros.com (Michael Stemper) writes: >>>In article <74iqc5pnadvk5h1lr3852ubrm3hrmn2...@4ax.com>, Howard Brazee >>><how...@brazee.net> writes:
>>>>At the Denver WorldCon we took some Kiwis ((two parents and a son) on >>>>a drive in the mountains. They pointed out that the half moon looked >>>>backwards to them.
>>>"Backwards?" I could see "wrong phase", but not "backwards". Sometimes, >>>the right half of the moon is lit, sometimes the left half. This happens >>>no matter what hemisphere you're in.
>> You need to try life in another hemisphere (or near enough the >>equator). This northerner found it extremely disquieting to see what >>has always and correctly been the upper half of the moon pointed down >>at the horizon instead.
> Oh, upside-down! I hadn't thought of that definition of "backwards".
> -- > Michael F. Stemper > #include <Standard_Disclaimer> > Life's too important to take seriously.
And in the southern hemisphere, if you face the pole of the sky, the sun appears to rise to your left, not your right. Equatorial drives on telescopes have to run in the opposite direction from the northern hemisphere. So maybe that's what they meant by "backwards" as well as upside down for constellations like Orion, and the "Man in the Moon".
> All right... I was thinking of a prior thread about when themoonwas visible during the day, and remembering from a > distant science class that the fullmoonrises at sunset at > sets at dawn, and that got me to thinking about how nights > get longer and shorter through the year, so I assume that > that was just an approximation.
> And that got me to the real question I have... does themoon > still go through phases at the poles? If it's daylight 24 > hours a day, and themoonis full, would you see it? Is it > in the sky 24 hours a day if the sun is? I'm trying to > visualize the geometry and failing miserably. And I figure > that there were good people on this group that could answer > this.
> Thanks!
> Rebecca
Figuring out how to explain this has been bugging me for a month!
So, visualize the section of the globe that is the Arctic. Visualize the axis of rotation sticking straight up to point at Polaris. Visualize a bowl-shaped cap sitting crooked over it -- tilted at an angle of about 23 deg. Imagine that the edge of that bowl is decorated with constellations -- those of the zodiac. Remember that the Sun spends a month in each of those signs, and the Moon spends two or three days in each.
Right at this moment, the Sun is in Libra and the Moon (within a day of being full) is in Aries.
Take a look at this star chart, set for 90N: http://www.heavens-above.com/skychart.aspx?SL=1&SN=1&lat=90&lng=0&loc... There's the Moon, near the horizon; the Sun is nowhere to be seen. The only zodiacal constellations visible are Pisces, Aries, Taurus, Gemini, Cancer, Leo, and part of Virgo.
At that site, you can turn the constellation names on and off, and change the times and dates of the charts. So you can check noon or midnight, today or two weeks from today. Click on home to find out all the other things that site can do (change the place on Earth you're looking up from; see when the Moon is new or full this month -- all sorts of stuff.
Anyway, from the Pole during its very long term of daylight, you won't see the full Moon.
Cece wrote: > On Oct 7, 1:17 am, Rebecca Rice <rebecca_r...@att.net> wrote: >> All right... I was thinking of a prior thread about when themoonwas visible during the day, and remembering from a >> distant science class that the fullmoonrises at sunset at >> sets at dawn, and that got me to thinking about how nights >> get longer and shorter through the year, so I assume that >> that was just an approximation.
>> And that got me to the real question I have... does themoon >> still go through phases at the poles? If it's daylight 24 >> hours a day, and themoonis full, would you see it? Is it >> in the sky 24 hours a day if the sun is? I'm trying to >> visualize the geometry and failing miserably. And I figure >> that there were good people on this group that could answer >> this.
>> Thanks!
>> Rebecca
> Figuring out how to explain this has been bugging me for a month!
> So, visualize the section of the globe that is the Arctic. Visualize > the axis of rotation sticking straight up to point at Polaris. > Visualize a bowl-shaped cap sitting crooked over it -- tilted at an > angle of about 23 deg. Imagine that the edge of that bowl is > decorated with constellations -- those of the zodiac. Remember that > the Sun spends a month in each of those signs, and the Moon spends two > or three days in each.
> Right at this moment, the Sun is in Libra and the Moon (within a day > of being full) is in Aries.
> Take a look at this star chart, set for 90N: > http://www.heavens-above.com/skychart.aspx?SL=1&SN=1&lat=90&lng=0&loc... > There's the Moon, near the horizon; the Sun is nowhere to be seen. > The only zodiacal constellations visible are Pisces, Aries, Taurus, > Gemini, Cancer, Leo, and part of Virgo.
> Now try this one, set for 90S: > http://www.heavens-above.com/skychart.aspx?SL=1&SN=1&lat=-90&lng=0&lo... > There's the Sun, near the horizon; the full Moon is out of sight. > Visible zodiacal constellations are part of Virgo, Libra, Scorpio, > Sagittarius, Capricorn, and most of Aquarius.
> At that site, you can turn the constellation names on and off, and > change the times and dates of the charts. So you can check noon or > midnight, today or two weeks from today. Click on home to find out > all the other things that site can do (change the place on Earth > you're looking up from; see when the Moon is new or full this month -- > all sorts of stuff.
> Anyway, from the Pole during its very long term of daylight, you won't > see the full Moon.
> Cece wrote: > > On Oct 7, 1:17 am, Rebecca Rice <rebecca_r...@att.net> wrote: > >> All right... I was thinking of a prior thread about when themoonwas visible during the day, and remembering from a > >> distant science class that the fullmoonrises at sunset at > >> sets at dawn, and that got me to thinking about how nights > >> get longer and shorter through the year, so I assume that > >> that was just an approximation.
> >> And that got me to the real question I have... does themoon > >> still go through phases at the poles? If it's daylight 24 > >> hours a day, and themoonis full, would you see it? Is it > >> in the sky 24 hours a day if the sun is? I'm trying to > >> visualize the geometry and failing miserably. And I figure > >> that there were good people on this group that could answer > >> this.
> >> Thanks!
> >> Rebecca
> > Figuring out how to explain this has been bugging me for a month!
> > So, visualize the section of the globe that is the Arctic. Visualize > > the axis of rotation sticking straight up to point at Polaris. > > Visualize a bowl-shaped cap sitting crooked over it -- tilted at an > > angle of about 23 deg. Imagine that the edge of that bowl is > > decorated with constellations -- those of the zodiac. Remember that > > the Sun spends a month in each of those signs, and the Moon spends two > > or three days in each.
> > Right at this moment, the Sun is in Libra and the Moon (within a day > > of being full) is in Aries.
> > Take a look at this star chart, set for 90N: > >http://www.heavens-above.com/skychart.aspx?SL=1&SN=1&lat=90&lng=0&loc... > > There's the Moon, near the horizon; the Sun is nowhere to be seen. > > The only zodiacal constellations visible are Pisces, Aries, Taurus, > > Gemini, Cancer, Leo, and part of Virgo.
> > Now try this one, set for 90S: > >http://www.heavens-above.com/skychart.aspx?SL=1&SN=1&lat=-90&lng=0&lo... > > There's the Sun, near the horizon; the full Moon is out of sight. > > Visible zodiacal constellations are part of Virgo, Libra, Scorpio, > > Sagittarius, Capricorn, and most of Aquarius.
> > At that site, you can turn the constellation names on and off, and > > change the times and dates of the charts. So you can check noon or > > midnight, today or two weeks from today. Click on home to find out > > all the other things that site can do (change the place on Earth > > you're looking up from; see when the Moon is new or full this month -- > > all sorts of stuff.
> > Anyway, from the Pole during its very long term of daylight, you won't > > see the full Moon.
> > How's that?
> Cool! Thanks!
> Rebecca- Hide quoted text -
> - Show quoted text -
When the Pole is in unending sunlight, you will see the Moon every month, from Last Quarter to First Quarter (except when it is (more or less) in line with the Sun so that its dark side is toward us) -- approximately! Depending on where you are inside the Artic (Antarctic) Circle, and the orbital wobble(s), it may rise (or set) a little early (or a little late). If you have a particular date in mind, and want to know exactly, you'll need to consult lots of astronomical tables, or someone with a command of astronomical math (a good amateur could help, or a university or planetarium). I can't help with this; after 50 years, I still can't use right ascension and declination and I sure can't calculate them.
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