Feet Per Minute Conversion Question

[Steve B]

I think in Feet Per Minute... I must be from a different country.

How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
Feet per minute

Thanks

[JJ Sinclair]

feet per sec X 0.508 = meters per sec

This from the 1987 SSA MEMBERSHIP HANDBOOK.

Haven't seen an updated book in 20 years. It has lots of useful information,
like this in it.
JJ Sinclair

[Pete S]

Looks like they made the mistake of assuming that a nautical mile was 6000
feet when it's actually 6080 ft



"JJ Sinclair" > wrote in message
...
> feet per sec X 0.508 = meters per sec
>
> This from the 1987 SSA MEMBERSHIP HANDBOOK.
>
> Haven't seen an updated book in 20 years. It has lots of useful
information,
> like this in it.
> JJ Sinclair

[MikeYankee]

300 fpm = 3 knots
500 fpm = 5 knots

etc., etc., etc.


Mike Yankee

(Address is munged to thwart spammers.
To reply, delete everything after "com".)

[Dave Ellis]

1 Knot = 1 NM/Hr = 6080ft/Hr * 1Hr/60min = 101.3 Ft/min
For practical variometer purposes, equate 1 knot to 100 ft/min

Dave Ellis


"Steve B" > wrote in message
om...
> I think in Feet Per Minute... I must be from a different country.
>
> How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
> Feet per minute
>
> Thanks

[BTIZ]

1Knt equals approx 100feet per min..

BT
"Steve B" > wrote in message
om...
> I think in Feet Per Minute... I must be from a different country.
>
> How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
> Feet per minute
>
> Thanks

[Ralph Jones]

On Sat, 23 Aug 2003 23:09:17 +0100, "Pete S"
> wrote:

>Looks like they made the mistake of assuming that a nautical mile was 6000
>feet when it's actually 6080 ft
>
It's actually 6076.115 feet, but 1 knot=100 fpm is entirely precise
enough for glide computation purposes.

rj

[HL Falbaum]

For practical purposes in flight, 1 meter/Sec = 2 knots = 200 ft/Min
100 knots is about 185 Km/Hr
Not exactly but close enough for mental arithmetic.

--
Hartley Falbaum
"Steve B" > wrote in message
om...
> I think in Feet Per Minute... I must be from a different country.
>
> How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
> Feet per minute
>
> Thanks

[Martin Hellman]

(Steve B) wrote in message >...
> I think in Feet Per Minute... I must be from a different country.
>
> How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
> Feet per minute
>
> Thanks

While the other responses give the data, there is one point I'd like
to add. Within about 1% accuracy, 100 fpm = 1 kt = 1/2 m/sec. Forget
the 0.508. Who has the mental accuracy (or instrument accuracy) to
work to three significant figures?

It struck me as strange that, within this roughly 1% accuracy,
nautical miles make more sense than either statute miles or the metric
system. When they standardized on the metric system, it's interesting
that they did not decimalize time. We still have 60 sec/min and 60
min/hour. So m/sec and km/hr do not have any nice relation, at least
for those of us who think decimally. But converting fpm to kts is easy
because 6000 (the approximate number of feet in a nautical mile) is
divisible by 60. So, when I have a 1% upgrade on a takeoff runway and
take off at 60 kts, it knocks 60 fpm off my climb rate. Not too much.
But a 2% grade knocks 120 fpm off, getting to be a bit more of a
concern.

Too bad a nautical mile isn't exactly 6000 feet. Or that the metric
guys didn't change to 100,000 seconds per day (now there are 86,400)
and break the day into 10 hours, each with 100 minute, each with 100
seconds. I guess it says something about how deeply ingrained time is
in our culture that they didn't, or couldn't, mess with it. (See E T
Hall's "The Dance of Life" if you're interested in delving further.
It's at least as good in my opinion as his better known "Beyond
Culture.")

Martin

[John H. Campbell]

>When they standardized on the metric system, it's interesting
>that they did not decimalize time.

"They" (the revolutionary French in the late 18th C) did, including days and
months (which aren't arbitrary but relate to astronomical events). But it
wasn't popular or accurate and usage reverted to the old units after a few
years.

[John H. Campbell]

>How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
>Feet per minute

Look at a Winter brand vario. Full scale = 1,000fpm, 10 kt, or 5 m/s, as
the customer prefers. Only the face-plate is changed, it's the same unit
otherwise.

[JJ Sinclair]

Navigational question for the day;
One minute of latitude = 1 nautical mile. At what point on the earth does 1
minute of longatude = 1 nautical mile?
JJ Sinclair

[W.J. \(Bill\) Dean \(U.K.\).]

On the Equator.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

>
> "JJ Sinclair" > wrote in message
> ...
>
> Navigational question for the day;
> One minute of latitude = 1 nautical mile.
> At what point on the earth does 1 minute of longitude = 1 nautical mile?
>
> JJ Sinclair.
>

[Gene Nygaard]

"Pete S" > wrote in message >...
> Looks like they made the mistake of assuming that a nautical mile was 6000
> feet when it's actually 6080 ft

No, it's actually 1852 m in today's world. Your 6080 ft is 1853.184
m, all around the world since an international agreement on the
definition of the yard (and thus feet, inches, etc.) over 40 years
ago.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Gene Nygaard]

(JJ Sinclair) wrote in message >...
> feet per sec X 0.508 = meters per sec
>
> This from the 1987 SSA MEMBERSHIP HANDBOOK.
>
> Haven't seen an updated book in 20 years. It has lots of useful information,
> like this in it.
> JJ Sinclair

Right number, for something. Unfortunately, not for the units you
have stated.

This illustrates quite well one of the many pitfalls of having to make
conversions. Get with it, get rid of the Fred Flintstone units and
use the interdisciplinary and International System of Units.

It is actually hectofeet per minute (a screwball unit) that you'd
multiply by 0.508 to get meters per second:

100 ft/min = 0.508 m/s

Note that 100 ft/min is not 1 ft/s, the units you claimed, since we
don't have 100 seconds in a minute.

--
Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/
"It's not the things you don't know
what gets you into trouble.

"It's the things you do know
that just ain't so."
Will Rogers

[Gene Nygaard]

On Sun, 24 Aug 2003 14:38:07 +0100, "W.J. \(Bill\) Dean \(U.K.\)."
> wrote:

>On the Equator.

Wrong.

There have been some geographical miles based on the equatorial
circumference, but I've never seen them called nautical miles. There
was one geographical mile equal to 4 minutes of arc on the equator, or
about 7.421 km; I have a copy of a map using these units.

Nautical miles have normally been defined to be some midrange,
midlatitude value for a minute of arc as you travel north-south along
a meridian.

At the equator, 1 minute of longitude is 1.001795 nmi.

But 1 minute of latitude (geodetic latitude, the kind normally used)
at the Equator is only about 0.9950 nmi.

>W.J. (Bill) Dean (U.K.).
>Remove "ic" to reply.
>
>>
>> "JJ Sinclair" > wrote in message
>> ...
>>
>> Navigational question for the day;
>> One minute of latitude = 1 nautical mile.
>> At what point on the earth does 1 minute of longitude = 1 nautical mile?
>>
>> JJ Sinclair.

It is at some place close to the equator, where the circumference of
the earth at that latitude is 40.0032 Mm, rather than the 40.007495 Mm
at the Equator (WGS-84 ellipsoid). A latitude close to the arccosine
of 40.0032/40.007495, or about 3½ degrees from the Equator either
north or south (a more exact value depends on which type of latitude
you use, as well as which ellipsoid you use to approximate this).

To help see this better, your "minute of longitude" at a latitude of
60 degrees would be about 0.50 nmi, and at the poles a
"minute of longitude" is 0 nmi. It is actually the minute of latitude
as you travel along a meridian (constant longitude) that most people
consider in evaluating the fit of a nautical mile to the Earth.

Now, at what point is one centigrade of latitude equal to one
kilometer?

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Gene Nygaard]

On Sun, 24 Aug 2003 02:28:58 GMT, Ralph Jones >
wrote:

>On 23 Aug 2003 12:54:18 -0700, (Steve B)
>wrote:
>
>>I think in Feet Per Minute... I must be from a different country.
>>
>>How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
>>Feet per minute
>>
>1 nautical mile = 6076.115 feet.

Actually, 1 nmi is defined as 1852 m, your feet figure is a conversion
accurate to that many places.

>1 knot = 1 nautical mile per hour = 1.1508 mph = 101.3 feet per
>minute.
>1 meter = 39.37 inches.

That was the U.S. definition from 1893 until 1959. Today, we have
units defined exactly as 1 yd = 0.9144 m or 1 ft = 0.3048 m or 1 in =
0.0254 m.

>1 kilometer = 1000 meters = 0.621 miles = 3281 feet.
>1 meter per second = 3.281 feet per second = 197 feet per minute.
>
>For practical purposes, 1 knot = 100 feet per minute is close enough
>for glide computations. Also, one minute of latitude covers one
>nautical mile on the ground, so the vertical lines on a chart make an
>excellent nautical mile scale.

Sure, but also 1 mm on those charts equals 1 km (regional charts) or 2
km (sectional charts). So, since you are using charts drawn to a
metric scale, an ordinary ruler in millimeters also makes an excellent
kilometer scale. Don't need one of those fancy, expensive plotters if
you use sensible units that fit the scale of the charts.


Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Doug Hoffman]

(Steve B) wrote in message >...

> How do you convert Kts per Sec / Meters per sec / Kilometers etc... to
> Feet per minute

Knots per second would be a unit of acceleration, since knots are
already a unit of velocity. One knot is one nautical mile per hour.

I have two "older" gliders, each with 2 varios (4 varios total). 1
vario reads in feet per second, another in meters per second, another
in knots, and the last one in 100's of feet per second...

I have settled on thinking in terms of "knots" because 1) that's what
everyone else uses where I fly (so I can easily decipher thermal
strength callouts on the radio and so forth) and 2) for all practical
purposes 100 fpm is one knot, as others have correctly pointed out.

-Doug

[Doug Hoffman]

Iwrote:
> I have two "older" gliders, each with 2 varios (4 varios total). 1
> vario reads in feet per second, another in meters per second, another
> in knots, and the last one in 100's of feet per second...

Pardon me, that should read "100's of feet per *minute*..."

-Doug

[Lennie the Lurker]

(JJ Sinclair) wrote in message >...
> feet per sec X 0.508 = meters per sec
>
> This from the 1987 SSA MEMBERSHIP HANDBOOK.
>
> Haven't seen an updated book in 20 years. It has lots of useful information,
> like this in it.
> JJ Sinclair

1 meter =39.37 inches. Methinks someone screwed up, like JJ. Maybe
try .3048, just seems to agree with fact, and good math, not new math,
not french math, either. Nautical mile 6080 feet, as against 5280 for
statute mile.

nautical mile -> statute mile =1.1515

statute mile -> nautical mile = .8684

[John Giddy]

"Lennie the Lurker" > wrote in
message
om...
| (JJ Sinclair) wrote in message
>...
| > feet per sec X 0.508 = meters per sec
| >
| > This from the 1987 SSA MEMBERSHIP HANDBOOK.
| >
| > Haven't seen an updated book in 20 years. It has lots of
useful information,
| > like this in it.
| > JJ Sinclair
|
| 1 meter =39.37 inches. Methinks someone screwed up, like
JJ. Maybe
| try .3048, just seems to agree with fact, and good math,
not new math,
| not french math, either. Nautical mile 6080 feet, as
against 5280 for
| statute mile.
|
| nautical mile -> statute mile =1.1515
|
| statute mile -> nautical mile = .8684

Lennie,
6080 feet is the United Kingdom Nautical Mile
6076.115 feet is the United States Nautical Mile
According to the conversion program I use (Prokon, by Harold
Schwartz, Jefferson City, MO)
Cheers, John G.

[Lennie the Lurker]

"John Giddy" > wrote in message >...
> "Lennie the Lurker" > wrote in
> message
> om...
> | (JJ Sinclair) wrote in message
> >...
> | > feet per sec X 0.508 = meters per sec
> | >
> | > This from the 1987 SSA MEMBERSHIP HANDBOOK.
> | >
> | > Haven't seen an updated book in 20 years. It has lots of
> useful information,
> | > like this in it.
> | > JJ Sinclair
> |
> | 1 meter =39.37 inches. Methinks someone screwed up, like
> JJ. Maybe
> | try .3048, just seems to agree with fact, and good math,
> not new math,
> | not french math, either. Nautical mile 6080 feet, as
> against 5280 for
> | statute mile.
> |
> | nautical mile -> statute mile =1.1515
> |
> | statute mile -> nautical mile = .8684
>
> Lennie,
> 6080 feet is the United Kingdom Nautical Mile
> 6076.115 feet is the United States Nautical Mile
> According to the conversion program I use (Prokon, by Harold
> Schwartz, Jefferson City, MO)
> Cheers, John G.

So change the last two digits to correct it. Then try to read that
off your VSI. I don't use converstion programs, just an old copy of
the math tables published by Industrial PRess, copyright 1929.
Sometimes factors applied with my old Post Versalog. Close enough for
most matters, except for nitpickers.

[JJ Sinclair]

Ups, make that;
Hundreds of feet per minute times 0.508 = meters per second.
JJ Sinclair

[Liam Finley]

How do I convert Meters/second to Leagues per Hour? I need the answer
to five significant digits.

I also need to convert wing loadings from Kg/square meter to
tons/acre.

Can I do the conversion in Winpilot?

[John Shelton]

You seem like a swell person. I have two tickets to the rodeo. Maybe you
would like to have some Chinese food and a couple of brewskis, then we can
go to rodeo together. You will really enjoy it. Try to rent some Levi's
though. I don't think a starched collar is appropriate.



"Gene Nygaard" > wrote in message
m...
> "Pete S" > wrote in message
>...
> > Looks like they made the mistake of assuming that a nautical mile was
6000
> > feet when it's actually 6080 ft
>
> No, it's actually 1852 m in today's world. Your 6080 ft is 1853.184
> m, all around the world since an international agreement on the
> definition of the yard (and thus feet, inches, etc.) over 40 years
> ago.
>
> Gene Nygaard
> http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Jonathan Gogan]

tons/acre = Cos( furlongs/ weekend)
Jon.



"Liam Finley" > wrote in message
om...
How do I convert Meters/second to Leagues per Hour? I need the answer
to five significant digits.

I also need to convert wing loadings from Kg/square meter to
tons/acre.

Can I do the conversion in Winpilot?

[Doug Hoffman]

Nygaard is a troll. He is *not* a glider person. He gets his jollies
by trying to "show off" his supposedly superior knowledge of units of
measure. Ignore him.


(Gene Nygaard) wrote in message >...
> "Pete S" > wrote in message >...
> > Looks like they made the mistake of assuming that a nautical mile was 6000
> > feet when it's actually 6080 ft
>
> No, it's actually 1852 m in today's world. Your 6080 ft is 1853.184
> m, all around the world since an international agreement on the
> definition of the yard (and thus feet, inches, etc.) over 40 years
> ago.
>
> Gene Nygaard
> http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Doug Hoffman]

Hey Gene, What kind of glider do you fly? Methinks you are a troll
and should leave this newsgroup alone with your misguided "superior"
knowledge of weights and measure. This is a newsgroup for soaring.

Gene Nygaard > wrote in message >...
> On Sun, 24 Aug 2003 14:38:07 +0100, "W.J. \(Bill\) Dean \(U.K.\)."
> > wrote:
>
> >On the Equator.
>
> Wrong.
>
> There have been some geographical miles based on the equatorial
> circumference, but I've never seen them called nautical miles. There
> was one geographical mile equal to 4 minutes of arc on the equator, or
> about 7.421 km; I have a copy of a map using these units.
>
> Nautical miles have normally been defined to be some midrange,
> midlatitude value for a minute of arc as you travel north-south along
> a meridian.
>
> At the equator, 1 minute of longitude is 1.001795 nmi.
>
> But 1 minute of latitude (geodetic latitude, the kind normally used)
> at the Equator is only about 0.9950 nmi.
>
> >W.J. (Bill) Dean (U.K.).
> >Remove "ic" to reply.
> >
> >>
> >> "JJ Sinclair" > wrote in message
> >> ...
> >>
> >> Navigational question for the day;
> >> One minute of latitude = 1 nautical mile.
> >> At what point on the earth does 1 minute of longitude = 1 nautical mile?
> >>
> >> JJ Sinclair.
>
> It is at some place close to the equator, where the circumference of
> the earth at that latitude is 40.0032 Mm, rather than the 40.007495 Mm
> at the Equator (WGS-84 ellipsoid). A latitude close to the arccosine
> of 40.0032/40.007495, or about 3½ degrees from the Equator either
> north or south (a more exact value depends on which type of latitude
> you use, as well as which ellipsoid you use to approximate this).
>
> To help see this better, your "minute of longitude" at a latitude of
> 60 degrees would be about 0.50 nmi, and at the poles a
> "minute of longitude" is 0 nmi. It is actually the minute of latitude
> as you travel along a meridian (constant longitude) that most people
> consider in evaluating the fit of a nautical mile to the Earth.
>
> Now, at what point is one centigrade of latitude equal to one
> kilometer?
>
> Gene Nygaard
> http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Pat Russell]

My vario is calibrated in megaparsecs per millenium. Very
handy.

[George William Peter Reinhart]

Troll = Ugly devil liviin' under a bridge, (see also motorcycle cops with
radar guns (usually under a bridge)).
Trolls = More than one ugly devil (also found in newsgroups)
Trolling = Fishin' with fake bait from a slow boat.
Cheers!

[Doug Hoffman]

Gene Nygaard > wrote in message >...
> On 26 Aug 2003 02:26:21 -0700, (Doug Hoffman)
> wrote:
>
> >Nygaard is a troll. He is *not* a glider person. He gets his jollies
> >by trying to "show off" his supposedly superior knowledge of units of
> >measure. Ignore him.
>
> "A" troll? Can't even get your metaphors right, can you?
>
> http://w0rli.home.att.net/youare.swf
>
> This is even better than _trolling_ (verb). This place has fools like
> like you who just jump into my boat, you're so anxious to show off
> your stupidity.

I rest my case.

[John Lee]

On 27 Aug 2003 10:54:05 GMT, John Lee
wrote:

>>Navigational question for the day;
>>One minute of latitude = 1 nautical mile. At what point
>>on the >earth does 1
>>minute of longatude = 1 nautical mile?
>>JJ Sinclair
>
>Nowhere! However on the equator 1 second of longitude
>equals 1 nautical mile

T>hat isn't any more correct now than when Bill Dean
>claimed >that
>earlier in this thread. See my reply to his message.

>Gene Nygaard
>http://ourworld.compuserve.com/homepages/Gene_Nygaard/

Still looking Gene...... the other stuff is interesting
though

[Jonathan Gere]

(JJ Sinclair) wrote in message >...
> Navigational question for the day;
> One minute of latitude = 1 nautical mile. At what point on the earth does 1
> minute of longatude = 1 nautical mile?
> JJ Sinclair

8-9 degrees north or south LAT where EW radius of curvature = NS
radius of curvature.

With screwy "geodetic" latitude that gps uses, FAI 6371km sphere
errors are even worse than if using geocentric latitude on ellipsoid.
I think pythagorean theorum with scale factors below would match
ellipsoid better than sphere does for gliding distances.

Someone please check these equations. The instrument display makers
may want to use an ellipsoid some day:

dist = pi/180*[delta Lat or Long in deg]*radius of curvature

radius of curvature NS:
a^2*b^2/(a^2*cos^2(Lat)+b^2*sin^2(Lat))^(3/2)

radius of curvature EW:
a^2/sqrt(a^2+b^2*tan^2(Lat))

Jonathan

p.s. check my equations against tiny EW or NS distances at various
lats using the FAI java calculator.

[Jonathan Gere]

(JJ Sinclair) wrote in message >...
> Navigational question for the day;
> One minute of latitude = 1 nautical mile. At what point on the earth does 1
> minute of longatude = 1 nautical mile?
> JJ Sinclair

(Didn't read the question the first time, and answered "When does a
minute of lat = a minute of long?" instead.)

Second guess:

One minute of latitude equals 1.000000000 nm only at a single latitude
somewhere between 44° and 45° N (or S) latitude. (Don't expect it to
fall on an even minute.)
One minute of longitude equals 1.000000000 nm only at a single
latitude somewhere between 3° and 4° (N or S) latitude. (Don't expect
it to fall on an even minute.)

Morals:
1) Don't count on those ticks on the chart - you'll fall short : )
2) Don't move to the equator to find square lat/long grids.

Jonathan Gere

[Tom Claffey]

Interesting reading all this cr@# about units,
for gliding varios [the oridinal question I think!] all you need
is 1 knot / 100 feet per minute
and 1 metre per sec / 2 knots.
IT REALLY IS THAT SIMPLE!!!!!!

[tango4]

And at what altitude would that be?

Just messin with you!

:-)

Ian

"Tom Claffey" > wrote in message
om...
> Interesting reading all this cr@# about units,
> for gliding varios [the oridinal question I think!] all you need
> is 1 knot / 100 feet per minute
> and 1 metre per sec / 2 knots.
> IT REALLY IS THAT SIMPLE!!!!!!

[root]

Pat Russell wrote:
>
> My vario is calibrated in megaparsecs per millenium. Very
> handy.

According to my calculations, this should be near 0.5 mm/s.
You need a very big scale.

[Gene Nygaard]

On Thu, 28 Aug 2003 12:49:30 +0000, root >
wrote:

>Pat Russell wrote:
>>
>> My vario is calibrated in megaparsecs per millenium. Very
>> handy.
>
>According to my calculations, this should be near 0.5 mm/s.
>You need a very big scale.

Try again. What do you think a millennium is? A parsec? The prefix
mega-?

1 Mpc/ka = 978 Gm/s, or about 3262 times the speed of light. He's got
bigger problems than you thought.

In other words, even one parsec (without the prefix) per millenium is
nearly 1 Mm/s (978 km/s). Thus 1 microparsec per millennium is equal
to a meter per second, within the precision many of you accept with
knots and the like.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Gene Nygaard]

On 27 Aug 2003 20:30:05 GMT, (JJ Sinclair) wrote:

>John Lee wrote>>>>>>>>>>>>>.>
>>>Nowhere! However on the equator 1 second of longitude
>>>equals 1 nautical mile
>>
>
>Hmmmm? When I went to navigation school, 1 degree of latitude anywhere in the
>world and 1 degree of longitude (on the equator) was made up of 60 minutes and
>each minute was 1 nautical mile. A second would be 6080 devided by 60 or 101
>feet. Please don't tell me they have changed all that. I'm not talking about
>the nit-pickers that want to say there is an + or - a foot or two in a nautical
>mile, but I would like to believe we still have 360 degrees around the equator
>and 90 degrees north and 90 degrees south latitude.
>JJ Sinclair

Maybe Eratosthenes still thought the Earth was a near-perfect sphere,
when he made a fairly reasonable calculation of its diameter Maybe
Columbus wasn't even aware of the true shape of the poles.

But we've known about the flattening at the poles for about four
centuries at least, probably longer than nautical miles have existed.
Certainly since long before the French scientists in the 1790s
designed the meter to be 1/10000000 of the distance from the equator
to the North Pole.

We do, of course, have 360 degrees around the equator. When we agree
on a starting point (e.g., the point where it crosses the meridian
through Greenwich, England, the one most often used now), any
particular place will always be the same number of degrees from it.

We also have 90 degrees between the equator and either pole. The
equator is always 0 degrees and the poles 90 degrees. But in between,
there are at least three different ways of measuring latitude:
geocentric latitude (the angle formed at the center of the Earth),
geodetic latitude (the one normally used, the angle formed between the
line normal to the tangent of the ellipsoid and the axis of rotation),
and the angles used in the parametric formulas representing an
ellipse. These don't agree with each other at any place not on the
equator or the poles.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Robert Ehrlich]

Gene Nygaard wrote:
>
> On Thu, 28 Aug 2003 12:49:30 +0000, root >
> wrote:
>
> >Pat Russell wrote:
> >>
> >> My vario is calibrated in megaparsecs per millenium. Very
> >> handy.
> >
> >According to my calculations, this should be near 0.5 mm/s.
> >You need a very big scale.
>
> Try again. What do you think a millennium is? A parsec? The prefix
> mega-?
>
> 1 Mpc/ka = 978 Gm/s, or about 3262 times the speed of light. He's got
> bigger problems than you thought.
>
> In other words, even one parsec (without the prefix) per millenium is
> nearly 1 Mm/s (978 km/s). Thus 1 microparsec per millennium is equal
> to a meter per second, within the precision many of you accept with
> knots and the like.
>
> Gene Nygaard
> http://ourworld.compuserve.com/homepages/Gene_Nygaard/

I just forgot the mega, I computed a parsec/millenium. Here is what I
did:

1 parsec is the distance of something having a parallax of 1 second, i.e.
the distance (from the sun) where the diameter of the orbit of the earth
is seen with an angle of 1 second. I don't remember this diameter but I
remember that the light coming from the sun needs 8 minutes to do that,
so the diameter should be 8*2*60*3*10^8 (diameter = 2*radius, 60 seconds
in a minute, speed of light 3*10^8 m/s) = 4800000000 m. 1 second is PI/(180*60*60)
radians, so 1 parsec is 4800000000/(PI/(180*60*60)), this is roughly 10^15 m.
A year is nearly 365.25 days, i.e. 365.25*24*60*60 seconds = 1980281535681600 s.
A millenium is 1980281535681600*1000 = 1980281535681600000 seconds or roughly
2*10^18 s. So a parsec/millenium is 10^15/(2*10^18) = 0.5*10^-3 m/s. A megaparsec
per millenium should be ~ 500 m/s. A huge unit for a vario in a glider, although
well under the speed of the light.

Well I was never good in calculations, so if there is a error, please point where.

[Nyal Williams]

Gene, we aren't doing ballistics here; we only want
to get close enough for the eyeballs to do the proper
adjustments. For badge flights we try to exceed the
minimums enough to make up for instrument errors; for
record flights we must exceed the current record by
a percentage that should account for these relatively
minor distances.

It's nice that someone is turned on by all this precision;
in my mind it has all the usefulness of train spotting
with respect to practicality in soaring.

At 15:12 28 August 2003, Gene Nygaard wrote:
>Maybe Eratosthenes still thought the Earth was a near-perfect
>sphere,
>when he made a fairly reasonable calculation of its
>diameter Maybe
>Columbus wasn't even aware of the true shape of the
>poles.
>
>But we've known about the flattening at the poles for
>about four
>centuries at least, probably longer than nautical miles
>have existed.
>Certainly since long before the French scientists in
>the 1790s
>designed the meter to be 1/10000000 of the distance
>from the equator
>to the North Pole.
>
>We do, of course, have 360 degrees around the equator.
> When we agree
>on a starting point (e.g., the point where it crosses
>the meridian
>through Greenwich, England, the one most often used
>now), any
>particular place will always be the same number of
>degrees from it.
>
>We also have 90 degrees between the equator and either
>pole. The
>equator is always 0 degrees and the poles 90 degrees.
> But in between,
>there are at least three different ways of measuring
>latitude:
>geocentric latitude (the angle formed at the center
>of the Earth),
>geodetic latitude (the one normally used, the angle
>formed between the
>line normal to the tangent of the ellipsoid and the
>axis of rotation),
>and the angles used in the parametric formulas representing
>an
>ellipse. These don't agree with each other at any
>place not on the
>equator or the poles.
>
>Gene Nygaard
>http://ourworld.compuserve.com/homepages/Gene_Nygaard/
>

[Bob Korves]

In my line of work we speak of "measuring it with a micrometer, marking it
with a crayon, and then cutting it off with an axe".
Bob Korves

"Nyal Williams" > wrote in message
...
> Gene, we aren't doing ballistics here; we only want
> to get close enough for the eyeballs to do the proper
> adjustments. For badge flights we try to exceed the
> minimums enough to make up for instrument errors; for
> record flights we must exceed the current record by
> a percentage that should account for these relatively
> minor distances.
>
> It's nice that someone is turned on by all this precision;
> in my mind it has all the usefulness of train spotting
> with respect to practicality in soaring.
>
> At 15:12 28 August 2003, Gene Nygaard wrote:
> >Maybe Eratosthenes still thought the Earth was a near-perfect
> >sphere,
> >when he made a fairly reasonable calculation of its
> >diameter Maybe
> >Columbus wasn't even aware of the true shape of the
> >poles.
> >
> >But we've known about the flattening at the poles for
> >about four
> >centuries at least, probably longer than nautical miles
> >have existed.
> >Certainly since long before the French scientists in
> >the 1790s
> >designed the meter to be 1/10000000 of the distance
> >from the equator
> >to the North Pole.
> >
> >We do, of course, have 360 degrees around the equator.
> > When we agree
> >on a starting point (e.g., the point where it crosses
> >the meridian
> >through Greenwich, England, the one most often used
> >now), any
> >particular place will always be the same number of
> >degrees from it.
> >
> >We also have 90 degrees between the equator and either
> >pole. The
> >equator is always 0 degrees and the poles 90 degrees.
> > But in between,
> >there are at least three different ways of measuring
> >latitude:
> >geocentric latitude (the angle formed at the center
> >of the Earth),
> >geodetic latitude (the one normally used, the angle
> >formed between the
> >line normal to the tangent of the ellipsoid and the
> >axis of rotation),
> >and the angles used in the parametric formulas representing
> >an
> >ellipse. These don't agree with each other at any
> >place not on the
> >equator or the poles.
> >
> >Gene Nygaard
> >http://ourworld.compuserve.com/homepages/Gene_Nygaard/
> >
>
>
>

[Lennie the Lurker]

(Bob Kuykendall) wrote in message >...
> Earlier, Pat Russell wrote:
>
> > My vario is calibrated in megaparsecs
> > per millenium. Very handy.
>
> I prefer cubits per jiffy for the vario, and furlongs per fortnight for the ASI.
>
> :)
>
Your altimeter is in fathoms?

[JJ Sinclair]

Add one more, Bob.

Measure with a micrometer,

Mark with a crayon,

Cut on the safe side, with an axe,

Grind to fit!
JJ Sinclair

[clay thomas]

(Bob Kuykendall) wrote in message >...
> Earlier, Pat Russell wrote:
>
> > My vario is calibrated in megaparsecs
> > per millenium. Very handy.
>
> I prefer cubits per jiffy for the vario, and furlongs per fortnight for the ASI.
>
> :)
>
> Bob "" K.

Angstroms per picoseconds anyone?

[Gene Nygaard]

On 28 Aug 2003 19:10:17 -0700, (Lennie the
Lurker) wrote:

>Robert Ehrlich > wrote in message >...
>> Gene Nygaard wrote:
>> >
>> > On Thu, 28 Aug 2003 12:49:30 +0000, root >
>> > wrote:
>> >
>> > >Pat Russell wrote:
>> > >>
>> > >> My vario is calibrated in megaparsecs per millenium. Very
>> > >> handy.
>> > >
>> > >According to my calculations, this should be near 0.5 mm/s.
>> > >You need a very big scale.
>> >
>> > Try again. What do you think a millennium is? A parsec? The prefix
>> > mega-?
>> >
>> > 1 Mpc/ka = 978 Gm/s, or about 3262 times the speed of light. He's got
>> > bigger problems than you thought.
>> >
>> > In other words, even one parsec (without the prefix) per millenium is
>> > nearly 1 Mm/s (978 km/s). Thus 1 microparsec per millennium is equal
>> > to a meter per second, within the precision many of you accept with
>> > knots and the like.
>> >
>> > Gene Nygaard
>> > http://ourworld.compuserve.com/homepages/Gene_Nygaard/
>>
>> I just forgot the mega, I computed a parsec/millenium. Here is what I
>> did:
>>
>> 1 parsec is the distance of something having a parallax of 1 second, i.e.
>> the distance (from the sun) where the diameter of the orbit of the earth
>> is seen with an angle of 1 second. I don't remember this diameter but I
>> remember that the light coming from the sun needs 8 minutes to do that,
>> so the diameter should be 8*2*60*3*10^8 (diameter = 2*radius, 60 seconds
>> in a minute, speed of light 3*10^8 m/s) = 4800000000 m. 1 second is PI/(180*60*60)
>> radians, so 1 parsec is 4800000000/(PI/(180*60*60)), this is roughly 10^15 m.
>> A year is nearly 365.25 days, i.e. 365.25*24*60*60 seconds = 1980281535681600 s.
>> A millenium is 1980281535681600*1000 = 1980281535681600000 seconds or roughly
>> 2*10^18 s. So a parsec/millenium is 10^15/(2*10^18) = 0.5*10^-3 m/s. A megaparsec
>> per millenium should be ~ 500 m/s. A huge unit for a vario in a glider, although
>> well under the speed of the light.
>>
>> Well I was never good in calculations, so if there is a error, please point where.
>
>the speed of light is 299759.6 km/s. the orbital radius is 149668992
>km. Not exact, but close enough.

Wrong.

The speed of light is 299.792458 Mm/s. Exactly. That is
299792.458000000000000000... km/s, with as many zeros as you care to
add.

The astronomical unit is about 149.597870 Gm. Not exact, but close
enough--and different from your value by .05% or 1 part in 2100.
Yours is wrong in the 5th digit, and all the following ones are
garbage.




Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/

[Lennie the Lurker]

Gene Nygaard > wrote in message >...
>
> Yours is wrong in the 5th digit, and all the following ones are
> garbage.
>
Once you go past the fourth digit, everything else in astronomy is
speculation. Ask me if I give a ****.

[Doug Hoffman]

"George William Peter Reinhart" > wrote in message >...
> Troll = Ugly devil liviin' under a bridge, (see also motorcycle cops with
> radar guns (usually under a bridge)).
> Trolls = More than one ugly devil (also found in newsgroups)
> Trolling = Fishin' with fake bait from a slow boat.
> Cheers!


As used on the Internet (source = Whatis?com):

2) As a verb, the practice of trying to lure other Internet users
into sending responses to carefully-designed statements or similar
"bait."


I suspect that unless one's dictionary is very recent that the words
"hacker" and "spam" would also not be defined as they are now used on
the Internet, if they are defined at all.


-Doug Hoffman

[JJ Sinclair]

Gene wrote>>>>>>>>>>>>>>>>>the
>line normal to the tangent of the ellipsoid and the axis of rotation),
>and the angles used in the parametric formulas representing an
>ellipse.

I got a little lost in all that, Gene, but I figure it all amounts to about
half a mile (statute) in a 1000K flight. Anyone that doesn't plan their long
flight with at least a 5 mile cushion, is asking for trouble.
JJ Sinclair

[Gene Nygaard]

On Sat, 30 Aug 2003 19:13:47 +0100, Mike Lindsay
> wrote:

>In article >, Gene Nygaard
> writes
>>On 27 Aug 2003 20:30:05 GMT, (JJ Sinclair) wrote:
>>
>>>John Lee wrote>>>>>>>>>>>>>.>
>>>>>Nowhere! However on the equator 1 second of longitude
>>>>>equals 1 nautical mileWe also have 90 degrees between the equator and either pole. The
>>equator is always 0 degrees and the poles 90 degrees. But in between,
>>there are at least three different ways of measuring latitude:
>>geocentric latitude (the angle formed at the center of the Earth),
>>geodetic latitude (the one normally used, the angle formed between the
>>line normal to the tangent of the ellipsoid and the axis of rotation),
>>and the angles used in the parametric formulas representing an
>>ellipse. These don't agree with each other at any place not on the
>>equator or the poles.
>>
>>Gene Nygaard
>>http://ourworld.compuserve.com/homepages/Gene_Nygaard/
>
>Hmm, interesting...
>
>What would the error be over, say 500km, if you used geocentric instead
>of geodetic measurement?
>
>In other words, does it matter?

If you are measuring the difference between two points, it will make
no difference whatsoever--assuming that you do the calculations
properly for the angles you are using. It's just that those two end
points will be at different latitudes, depending how you measure that
latitude.

That assumption has no guarantee of likelihood, if you are unaware
that there are different ways to measure latitude. It's sort of like
the Mars Climate Orbiter-turned-Crash-Lander. Those NASA engineers
could have converted pound force seconds to newton seconds--only
problem was, they didn't realize that they should be doing so.

Gene Nygaard
http://ourworld.compuserve.com/homepages/Gene_Nygaard/