How to measure in feet,not meters.

[SailRN]

Originally Posted by rwidman

Now if I'm watching a documentary on TV (I live in the USA) and they keep using metric measurements, knowing that their audience thinks in inches and feet (and miles), I just change the channel.

I do just the opposite, if the documentary is using the old system I don't watch it. I grew up in the U.S.A. with feet, inches, cubits, etc., but made the switch long ago to the metric system, which I find preferable.

[nohal]

Originally Posted by P_Dub

NOHAL, why don't you add this in your next vesion, that should not be too complicated.Thanks in advance.

I of course will add it in the next version as it is certainly less work than surviving another thread like this...

[NevilleCat]

Originally Posted by nohal

I of course will add it in the next version as it is certainly less work than surviving another thread like this...

[Tehani]

What a mess you have in your head!
If we observe the system that you Anglo-Saxons have to measure the height of a person, we will see the mention of parts of the human body: foot, big toe (or inche) ... a whole poem.
In metric, you can move the decimal point without the risk of mixing units.

[Narfi]

1. buy an American size 12 shoe.......
2. ....
3. profit?

[Tehani]

1 light year = 361.350.000.000 feet. It is possible that some more ...

[StuM]

Originally Posted by Tehani

1 light year = 361.350.000.000 feet. It is possible that some more ...

You're several orders of magnitude out !

You'll find several different answers , some given to the nearest 1/100th of a foot around the place, but all the ones I've seen fall in the range
31 038 911 000 000 000
to
31 039 144 000 000 000



(Largely depending on how they define a "year"





BUT:
Taking
"year" to mean a Julain year of exactly 31 557 600 seconds as commonly used in astronomy and defined bu UCUM
Speed of light to be 299 792 458 metres per second
and 1 metre to be 3.28084 feet,


I'd go with 31 039 142 207 219 309 feet

[StuM]

Originally Posted by StuM

I'd go with 31 039 142 207 219 309 feet

Oops, insufficient precision in the calcluations
Make that 31 039 142 963 661 991.82

[Wotname]

Originally Posted by StuM

You're several orders of magnitude out !

You'll find several different answers , some given to the nearest 1/100th of a foot around the place, but all the ones I've seen fall in the range
31 038 911 000 000 000
to
31 039 144 000 000 000



(Largely depending on how they define a "year"





BUT:
Taking
"year" to mean a Julain year of exactly 31 557 600 seconds as commonly used in astronomy and defined bu UCUM
Speed of light to be 299 792 458 metres per second
and 1 metre to be 3.28084 feet,


I'd go with 31 039 142 207 219 309 feet

Close enough for government work

[goboatingnow]

Originally Posted by thomm225

meter



the SI base unit of length (equivalent to approximately 39.37 inches), first introduced as a unit of length in the metric system.

from the French unit mètre, from the Greek noun μέτρον, "measure") is the base unit of length in the International System of Units (SI). The SI unit symbol is m.

[Tehani]

Originally Posted by StuM

You're several orders of magnitude out !

You'll find several different answers , some given to the nearest 1/100th of a foot around the place, but all the ones I've seen fall in the range
31 038 911 000 000 000
to
31 039 144 000 000 000



(Largely depending on how they define a "year"




...

Yes, I missed 1 day to seconds. But it does not matter, it is clear that it is a lot of feet. What matters is that each unit of measure has an environment in which to use it.

For me, the use of nautical miles is justified because it is related to the angle in minutes on the great circle of the earth.

On the other hand, in the metric system, 1 kilometer is 1000 meters, 1 meter is 100 centimeters, and also 1000 millimeters. Round numbers, without complications in divisors and multiples. The justification for the existence of this unit of measurement (meter) was also related to the size of our planet. People's feet usually have very different sizes ... We do not know which man or woman imposed their foot as a unit of measurement.

Nor do statute miles have round dividers in feet or inches. It is a system that in old Europe we see complicated. Remember what happened to the Mars Climate Orbiter probe in 1999 ...

[SailRN]

1 light-year = 31 038 900 011 929 566.929 133 858 267 716 U.S. feet


(I'm not promoting the U.S. foot, it is mentioned as this to clarify it is not one of the other feet of different length. The definition of this foot is 1 U.S. foot = 0.3048 m exactly.)



Tropical year 2021-03 to 2022-03 is 365 d 5 h 55 min 54 s within a few s


= 365.247 152 777 777 777 777 777 777 777 777 ... d
www.TimeandDate.com


c= 299 792 458 m/s (exact), U.S. foot = 0.3048 m (exact)



( 299792458 × 60 × 60 × 24 × 365.24715277777777777777777777777 ) ÷ 0.3048 =‬ 31 038 900 011 929 566.929 133 858 267 716

[StuM]

Originally Posted by SailRN

1 light-year = 31 038 900 011 929 566.929 133 858 267 716 U.S. feet
...
Tropical year 2021-03 to 2022-03 is 365 d 5 h 55 min 54 s within a few s
...
U.S. foot = 0.3048 m (exact)

A few problems with that

Firstly:
A light year doesn't change in length according to when it is calculated.
Hence the use of the standard, astronomical UCUM year of 365.35 days (exactly 31 557 600 seconds) to define a light year and not some random changing value.
The speed of light in a vacuum is defined as exactly 299 792 458 metres per second.

So a Light Year is exactly 9 460 730 472 580 800 metres.

Secondly:
You say "within a few seconds" and then give a distance to a precision of 15 decimal places.
One light second is approximately 983 571 056 feet, so your calculation is only accurate to plus or minus about 3 billion feet
All you can say based on your numbers is that it is somewhere between 31 038 897 000 000 000 feet and 31 038 903 000 000 000 feet

Thirdly:
Unfortunately 1/0.3048 is a recurring decimal so there is no exact length of a light year in decimal feet.
(Even 1 foot canot be expressed as an exact decimal number of meters)

It actually evaluates to
31 039 141 970 409 448.¯818 897 637 795 275 590 551 181 102 362 204 724 409 448
(42 recurring decimal digits)


Note, niether of my previous calculations used sufficient precision to establish an accurate figure. The discrepancy resulted from using the approximation 3.28084 rather than the more accurate 1/0.3048


Feel free to round the about number of feet to whatever precision you require

[Cheechako]

Originally Posted by Lepke

Using 5.2.0.
Just discovered measure is giving distances in meters over 0.1 nautical mile.

I've been navigating for about 60 years and don't work in the metric system.
I own other electronic programs, but prefer OpenCPN most of the time.
Do I need to abandon Open CPN?

I'm not a huge proponent of the Metric system, but most conversions are easy once you get used to doing it.
Multiply meters by 3.3 for feet.

[SailRN]

Sarchasm (n): The gulf between the author of sarcastic wit and the person who doesn't get it.