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Groups > comp.lang.forth > #15684 > unrolled thread
| Started by | "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> |
|---|---|
| First post | 2012-09-15 22:28 +0100 |
| Last post | 2012-10-15 18:00 -0400 |
| Articles | 20 on this page of 143 — 26 participants |
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Olympic Spririt for Forth "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2012-09-15 22:28 +0100
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-09-18 02:08 -0700
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-09-18 11:58 +0000
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-09-18 05:55 -0700
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-09-19 12:50 +0000
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-06 01:40 -0700
Re: Olympic Spririt for Forth "A. K." <akk@nospam.org> - 2012-10-06 11:18 +0200
Re: Olympic Spririt for Forth Spam@ControlQ.com - 2012-09-18 11:13 -0400
Re: Olympic Spririt for Forth Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-09-19 15:56 -0700
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-09-29 00:56 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-09-30 12:31 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-09-30 11:53 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-09-30 17:38 -0400
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-02 04:16 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-02 10:52 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-02 20:20 +0200
Re: Olympic Spririt for Forth Spam@ControlQ.com - 2012-10-02 15:58 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-02 13:31 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-03 02:59 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-02 19:08 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-03 15:50 +0200
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-03 14:04 +0000
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-03 10:29 -0700
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-04 16:07 +0000
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-03 20:27 +0200
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-04 16:11 +0000
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-04 20:12 +0200
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-05 13:08 +0000
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-05 17:48 +0200
Re: Olympic Spririt for Forth Pablo Hugo Reda <pabloreda@gmail.com> - 2012-10-03 07:39 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-03 20:24 +0200
Re: Olympic Spririt for Forth Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-03 18:13 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-03 12:05 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-03 22:20 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-04 12:41 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-04 22:40 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-04 18:11 -0700
Re: Olympic Spririt for Forth "Elizabeth D. Rather" <erather@forth.com> - 2012-10-04 15:26 -1000
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-04 18:54 -0700
Re: Olympic Spririt for Forth "A. K." <akk@nospam.org> - 2012-10-05 08:19 +0200
Re: Olympic Spririt for Forth "Elizabeth D. Rather" <erather@forth.com> - 2012-10-04 22:18 -1000
Re: Olympic Spririt for Forth Gerry Jackson <gerry@jackson9000.fsnet.co.uk> - 2012-10-05 08:20 +0100
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-05 11:08 +0000
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-07 08:32 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-07 21:39 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-07 21:03 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-08 19:09 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-08 21:57 -0700
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-09 01:10 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-09 14:12 -0400
Re: Olympic Spririt for Forth "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2012-10-10 09:29 +0100
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-10 21:13 -0400
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-10 02:02 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-10 21:23 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-10 18:24 -0700
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-11 17:21 +0000
Re: Olympic Spririt for Forth Mark Wills <markrobertwills@yahoo.co.uk> - 2012-10-11 12:33 -0700
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-11 13:42 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-11 18:59 -0400
Re: Olympic Spririt for Forth "Elizabeth D. Rather" <erather@forth.com> - 2012-10-11 13:49 -1000
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-12 03:27 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-12 19:18 -0700
Re: Olympic Spririt for Forth Elizabeth D Rather <erather@forth.com> - 2012-10-12 18:53 -1000
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-12 22:55 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-13 22:07 +0200
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-13 00:56 -0400
Re: Olympic Spririt for Forth Doug Hoffman <glidedog@gmail.com> - 2012-10-13 18:41 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-13 16:05 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-14 02:57 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-14 00:26 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-14 19:28 +0200
Re: Olympic Spririt for Forth kenney@cix.compulink.co.uk - 2012-10-15 04:21 -0500
Re: Olympic Spririt for Forth Mark Wills <markrobertwills@yahoo.co.uk> - 2012-10-14 03:17 -0700
Re: Olympic Spririt for Forth Alex McDonald <blog@rivadpm.com> - 2012-10-14 15:43 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-14 21:18 -0400
Re: Olympic Spririt for Forth kenney@cix.compulink.co.uk - 2012-10-15 04:21 -0500
Re: Olympic Spririt for Forth anton@mips.complang.tuwien.ac.at (Anton Ertl) - 2012-10-15 10:03 +0000
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-15 04:04 -0700
Re: Olympic Spririt for Forth "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2012-10-15 21:34 +0100
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-15 17:51 -0400
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-16 01:09 -0700
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-16 02:15 -0700
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-16 02:30 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-16 15:18 -0400
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-14 21:05 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-14 18:19 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-15 17:58 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-15 15:21 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-15 18:51 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-15 17:20 -0700
Re: Olympic Spririt for Forth "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2012-10-12 22:41 +0100
Re: Olympic Spririt for Forth "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2012-10-12 22:24 +0100
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-09 01:20 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-09 08:56 -0700
Re: Olympic Spririt for Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-09 11:14 -0500
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-09 22:47 +0200
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-09 18:31 -0700
Re: Olympic Spririt for Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-09 22:55 -0500
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-09 01:04 -0700
Re: Olympic Spririt for Forth Bernd Paysan <bernd.paysan@gmx.de> - 2012-10-09 17:30 +0200
Re: Olympic Spririt for Forth "Elizabeth D. Rather" <erather@forth.com> - 2012-10-04 11:31 -1000
Re: Olympic Spririt for Forth kenney@cix.compulink.co.uk - 2012-10-03 16:53 -0500
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-03 16:50 -0700
Re: Olympic Spririt for Forth Hugh Aguilar <hughaguilar96@yahoo.com> - 2012-10-03 18:06 -0700
Re: Olympic Spririt for Forth kenney@cix.compulink.co.uk - 2012-10-03 16:53 -0500
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-03 00:38 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-03 02:06 -0700
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-03 03:38 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-03 13:40 -0700
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-04 01:00 -0700
Re: Olympic Spririt for Forth "Elizabeth D. Rather" <erather@forth.com> - 2012-10-03 22:32 -1000
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-04 04:49 -0700
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-04 01:35 -0700
Re: Olympic Spririt for Forth Howerd <howerdo@yahoo.co.uk> - 2012-10-06 06:17 -0700
Re: Olympic Spririt for Forth arc <arc.deletethis@vorsicht-bissig.de> - 2012-10-07 23:45 +1300
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-10 09:34 -0700
Re: Olympic Spririt for Forth Mark Wills <forthfreak@gmail.com> - 2012-10-10 12:16 -0700
Re: Olympic Spririt for Forth Andrew Haley <andrew29@littlepinkcloud.invalid> - 2012-10-10 20:04 -0500
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-04 11:41 -0700
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-05 12:29 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-06 19:26 -0700
Re: Olympic Spririt for Forth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2012-10-05 19:09 +0000
Re: Olympic Spririt for Forth "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2012-10-02 22:03 +0100
Re: Olympic Spririt for Forth Ilya Tarasov <ilya74.tarasov@gmail.com> - 2012-10-06 08:30 -0700
Re: Olympic Spririt for Forth ilya74.tarasov@gmail.com - 2012-09-29 07:09 -0700
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-09 14:30 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-09 18:27 -0400
Re: Olympic Spririt for Forth "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> - 2012-10-10 09:46 +0100
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-10 03:52 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-10 06:01 -0700
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-10 07:42 -0700
Re: Olympic Spririt for Forth theoriginalsnial@gmail.com - 2012-10-10 09:10 -0700
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-10 10:34 -0700
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-11 17:17 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-13 01:03 -0400
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-10 21:59 -0400
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-10 20:57 -0700
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-11 02:05 -0700
Re: Olympic Spririt for Forth Matthias Koch <koch@pci.uni-hannover.de> - 2012-10-15 11:20 +0200
Re: Olympic Spririt for Forth albert@spenarnc.xs4all.nl (Albert van der Horst) - 2012-10-15 11:53 +0000
Re: Olympic Spririt for Forth Paul Rubin <no.email@nospam.invalid> - 2012-10-15 08:52 -0700
Re: Olympic Spririt for Forth visualforth@rocketmail.com - 2012-10-15 11:53 -0700
Re: Olympic Spririt for Forth rickman <gnuarm@gmail.com> - 2012-10-15 18:00 -0400
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| From | Bernd Paysan <bernd.paysan@gmx.de> |
|---|---|
| Date | 2012-10-12 03:27 +0200 |
| Message-ID | <2128900.5Hn9xTrNC3@sunwukong.fritz.box> |
| In reply to | #16204 |
Elizabeth D. Rather wrote: > So, where are we? Were any of these written in Forth? (not AFAIK). > Could these errors have been prevented by data type checking? (no). Richard Feynman's conclusion on the Challenger disaster was that they have a typical big-corporation style of risk management. When the engineer estimates the risk at 1:100, his boss will tell 1:1000 further up, and at the end of the day, it's one in a gazillion. As it's a Richard Feynman paper, it's entertaining to read, and really worth it. In a Forth context, especially the part about top-down design vs. bottom-up design in terms of reliability. http://science.ksc.nasa.gov/shuttle/missions/51-l/docs/rogers- commission/Appendix-F.txt The engineering of conventional aircraft engines, as Feynman puts it, are created bottom up. You start with simple components, you test them, and you put them together. Feynman notes that the software used for the Space Shuttle is indeed tested carefully from bottom up, so he's quite confident that at least from a software point of view, things are good (the obsolete computer hardware is another problem). -- Bernd Paysan "If you want it done right, you have to do it yourself" http://bernd-paysan.de/
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| From | Paul Rubin <no.email@nospam.invalid> |
|---|---|
| Date | 2012-10-12 19:18 -0700 |
| Message-ID | <7xmwzrm7wf.fsf@ruckus.brouhaha.com> |
| In reply to | #16204 |
"Elizabeth D. Rather" <erather@forth.com> writes: > So, where are we? Were any of these written in Forth? (not > AFAIK). Could these errors have been prevented by data type checking? > (no). There are several Haskell packages for compile-time dimensional unit checking using the type system. I myself wrote a simple dimensional library in Python a while back, that used runtime tagging of units, so if you added feet to meters, you'd get an automatic conversion, and if you added feet to volts, you'd get a runtime error (maybe not a good thing for a rocket). I don't know whether Ada or Java programmers use any automated tools for this. A friend of mine who worked on aerospace stuff some years back, said they had Ada style rules requiring units be specified as part of variable names, eg. "velocity_in_meters_per_second" instead of "v". Maybe someone would have noticed.
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| From | Elizabeth D Rather <erather@forth.com> |
|---|---|
| Date | 2012-10-12 18:53 -1000 |
| Message-ID | <FrGdnR_1RLspbuXNnZ2dnUVZ_oOdnZ2d@supernews.com> |
| In reply to | #16228 |
On 10/12/2012 4:18 PM, Paul Rubin wrote: > "Elizabeth D. Rather" <erather@forth.com> writes: >> So, where are we? Were any of these written in Forth? (not >> AFAIK). Could these errors have been prevented by data type checking? >> (no). > > There are several Haskell packages for compile-time dimensional unit > checking using the type system. I myself wrote a simple dimensional > library in Python a while back, that used runtime tagging of units, so > if you added feet to meters, you'd get an automatic conversion, and if > you added feet to volts, you'd get a runtime error (maybe not a good > thing for a rocket). I don't know whether Ada or Java programmers use > any automated tools for this. A friend of mine who worked on aerospace > stuff some years back, said they had Ada style rules requiring units be > specified as part of variable names, eg. "velocity_in_meters_per_second" > instead of "v". Maybe someone would have noticed. > AFAIK the different units were in two programs from different suppliers, probably even two devices, so they wouldn't have been caught in a compile-time check. And it's doubtful that each company was reading the other's source code, so that wouldn't have worked either. No, this was a failure of the specifications. Cheers, Elizabeth -- ================================================== Elizabeth D. Rather (US & Canada) 800-55-FORTH FORTH Inc. +1 310.999.6784 5959 West Century Blvd. Suite 700 Los Angeles, CA 90045 http://www.forth.com "Forth-based products and Services for real-time applications since 1973." ==================================================
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| From | Paul Rubin <no.email@nospam.invalid> |
|---|---|
| Date | 2012-10-12 22:55 -0700 |
| Message-ID | <7xy5jax6e5.fsf@ruckus.brouhaha.com> |
| In reply to | #16230 |
Elizabeth D Rather <erather@forth.com> writes: > AFAIK the different units were in two programs from different > suppliers, probably even two devices, so they wouldn't have been > caught in a compile-time check.... > No, this was a failure of the specifications. Maybe they needed an interchange protocol that included units with the data.
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| From | Bernd Paysan <bernd.paysan@gmx.de> |
|---|---|
| Date | 2012-10-13 22:07 +0200 |
| Message-ID | <2471183.E4LpRUe72c@sunwukong.fritz.box> |
| In reply to | #16231 |
Paul Rubin wrote: > Elizabeth D Rather <erather@forth.com> writes: >> AFAIK the different units were in two programs from different >> suppliers, probably even two devices, so they wouldn't have been >> caught in a compile-time check.... >> No, this was a failure of the specifications. > > Maybe they needed an interchange protocol that included units with the > data. No, this is definitely the wrong solution. More complicated, more potential errors. The interchange protocol in such a device should have addresses and binary numbers. Not something like TeX, where you can write "12.5in" or "23pt" in ASCII or such. If you allow such a protocol to have units, you have to test *all* the possible units. You can do that for a typesetting system like TeX, where people will typeset lots of documents, and none of them is mission critical, but you should abstain from even thinking about that idea when you build a "first time right" program - the mission is done only once, and your program must not fail. The only solution is to make absolutely clear in the specification that there is one and only one system of units used, and that this is metric. The solution to create reliable and robust systems is not ample choice, it's simplistic rigid non-choice. And you have to take every device into your lab, and test it, hands on, using calibrated equipment. The responsibility of this testing is on both sides - the subcontractor *and* the integrator. Only when the two agree that the device is operating correctly, it is operating correctly. -- Bernd Paysan "If you want it done right, you have to do it yourself" http://bernd-paysan.de/
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2012-10-13 00:56 -0400 |
| Message-ID | <k5c91c$otl$6@dont-email.me> |
| In reply to | #16228 |
On 10/12/2012 10:18 PM, Paul Rubin wrote: > "Elizabeth D. Rather"<erather@forth.com> writes: >> So, where are we? Were any of these written in Forth? (not >> AFAIK). Could these errors have been prevented by data type checking? >> (no). > > There are several Haskell packages for compile-time dimensional unit > checking using the type system. I myself wrote a simple dimensional > library in Python a while back, that used runtime tagging of units, so > if you added feet to meters, you'd get an automatic conversion, and if > you added feet to volts, you'd get a runtime error (maybe not a good > thing for a rocket). I don't know whether Ada or Java programmers use > any automated tools for this. A friend of mine who worked on aerospace > stuff some years back, said they had Ada style rules requiring units be > specified as part of variable names, eg. "velocity_in_meters_per_second" > instead of "v". Maybe someone would have noticed. This was not an issue with programming. This was an issue with the unit and interface design. The specification of units should have been part of the interface specification and should have been well documented so that both programmers were working to the same spec. I have no idea how this level of mistake could have been made with the level of documentation that is typically done on these systems. In addition, I have no real understanding of why we are still using English units here in the US. I think it was in the 70's that we had a joint program with Canada to convert to metric. It consisted of a number of steps in the program (12 perhaps?) and the first two or three had to do with spreading information about the program and education such as teaching metric in the schools. That is why US car speedometers started indicating kph in addition to mph. But when we reached the first step where we needed to actually change something (I think it was highway signs) we said to Canada, "Why don't you go on ahead and we'll catch up later?" Needless to say, here we are still trying to convert feet to meters in spacecraft!!! I was working at a company that made Military radios and found that the mechanical engineers were still using inches! I expressed my incredulity and the guy I was talking to was totally unimpressed. 90% of electronic components are in metric these days, but these guys were still designing the cases and boards in inches. I just don't get it. There are some systems that will not change for a LONG time to come. I've heard that the US Navy is adamant about not changing to metric. It seems that historically they have always done ranging in yards, which you know is close to a meter. I can see that in the process of converting it might be very difficult for humans to sanity check a number that is 1200 rather than 1100, but the results of a conversion error can be very catastrophic. Captains don't like missing targets that shoot back! Rick
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| From | Doug Hoffman <glidedog@gmail.com> |
|---|---|
| Date | 2012-10-13 18:41 -0400 |
| Message-ID | <5079ee2d$0$281$14726298@news.sunsite.dk> |
| In reply to | #16240 |
On 10/13/12 12:56 AM, rickman wrote: > In addition, I have no real understanding of why we are still using > English units here in the US. I think it was in the 70's that we had a > joint program with Canada to convert to metric. It consisted of a > number of steps in the program (12 perhaps?) and the first two or three > had to do with spreading information about the program and education > such as teaching metric in the schools. That is why US car speedometers > started indicating kph in addition to mph. But when we reached the > first step where we needed to actually change something (I think it was > highway signs) we said to Canada, "Why don't you go on ahead and we'll > catch up later?" Needless to say, here we are still trying to convert > feet to meters in spacecraft!!! Yes. There was a "firm" plan for the US to go metric in 1978. I clearly recall the events just prior to that. Most all interstate freeways had metric speed limit signs installed, with covers, awaiting the big day. Then at the last minute some state legislator decided he didn't like the metric system and he was able to scuttle the whole thing. Or something like that. So the general US conversion never happened. Today the evening news still reports the weather in degrees fahrenheit, etc. Once again a government lead effort was botched. Most private industry, such as US auto, have self-converted to hard metric in order to compete globally. The English units of measure should have been abandoned long ago. Not to say that would have guaranteed the Mars mission a success, but it couldn't have hurt. -Doug
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| From | Paul Rubin <no.email@nospam.invalid> |
|---|---|
| Date | 2012-10-13 16:05 -0700 |
| Message-ID | <7xhapyas6q.fsf@ruckus.brouhaha.com> |
| In reply to | #16254 |
Doug Hoffman <glidedog@gmail.com> writes: > Yes. There was a "firm" plan for the US to go metric in 1978. I > clearly recall the events just prior to that. Most all interstate > freeways had metric speed limit signs installed, No country on earth has ever used metric speed limits or metric speedometers on automobiles. The US uses traditional units (miles per hour) and some other countries use a mixture of metric and traditional units (kilometers per hour). I think aircraft still use *nautical* miles per hour. AFAIK, among transportation technologies, only spacecraft use actual metric units (meters per second). This has always been a peeve of mine.
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| From | Bernd Paysan <bernd.paysan@gmx.de> |
|---|---|
| Date | 2012-10-14 02:57 +0200 |
| Message-ID | <32933940.D9QKNufn74@sunwukong.fritz.box> |
| In reply to | #16255 |
Paul Rubin wrote: > No country on earth has ever used metric speed limits or metric > speedometers on automobiles. With a "humpty dumpty" defintion of "metric"? The hour is defined as "acceptable non-SI unit" in the tables of SI units. Note that the SI system has another anomality: The base unit of mass has a prefix (kg). http://www.ebyte.it/library/educards/siunits/TablesOfSiUnitsAndPrefixes.html > The US uses traditional units (miles per > hour) and some other countries use a mixture of metric and traditional > units (kilometers per hour). Yes, nobody uses m/s, which would be the metric base unit. > I think aircraft still use *nautical* miles per hour. Aircraft and boat speed is indeed still measured in knots. This is a deprecated unit of measurement according to the SI. Deprecated means that it is still in use in most countries, and it is well-defined in terms of SI units, but it is deprecated. The US system is not even deprecated. It is the old imperial system of an empire that hasn't been an empire for nearly 70 years now. Most of the ex-colonies have gone metric, the UK partly had (low temperatures are measured in °C, high temperatures in °F ;-), and the US is still completely resisting. > AFAIK, among transportation technologies, only > spacecraft use actual metric units (meters per second). This has > always been a peeve of mine. m/s is a base unit. km/h is a scaled unit, both the km and the hour are at least acceptable scales in the metric system (the acceptable time scale factors are non-decimal, as the metric system didn't change the traditional units of time - while you use ms, you don't use ks or Ms for larger scales - you use hours (3.6ks) and days (86.4ks)). Note that the day in the SI system is *not* related to earth rotation - that's what we have leap seconds for. The SI units are standardized units, they are issued by a standard body. Various countries have taken intermediate steps to standardize these units - e.g. China has rounded traditional units to reasonably near SI units, like the Chinese mile (li) to 500 meter, or the Chinese pound to 500g (the traditional European pound - slightly different in each city - was also rounded to 500g, and many recipies still tell you "use 1/2 ℔ butter", which is the 250g bar). Chinese people often enough confuse traditional units with SI units, especially since the names of the SI units differ only by the prefix "gong" - when I asked my girlfriend how much kg she weights, she said 94. Since Chinese girls are both small and slim, this can't be kg. -- Bernd Paysan "If you want it done right, you have to do it yourself" http://bernd-paysan.de/
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| From | Paul Rubin <no.email@nospam.invalid> |
|---|---|
| Date | 2012-10-14 00:26 -0700 |
| Message-ID | <7xfw5h346h.fsf@ruckus.brouhaha.com> |
| In reply to | #16258 |
Bernd Paysan <bernd.paysan@gmx.de> writes: > m/s is a base unit. km/h is a scaled unit, both the km and the hour are > at least acceptable scales in the metric system.. > The SI units are standardized units, they are issued by a standard > body. Bah, I'm sure the mile, inch, etc. are also standardized. If they can scale to 3600 seconds (1 hour) they can scale to 0.0254 meters (1 inch) and so on. Actually the meter itself is a weird artifact, from an earlier technological era. With modern understanding we can use a more fundamentally natural and logical unit of speed, the "nano", which at about 1.07925 km per hour should also be comfortable for car drivers. I'm sure you can figure out how the nano is derived.
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| From | Bernd Paysan <bernd.paysan@gmx.de> |
|---|---|
| Date | 2012-10-14 19:28 +0200 |
| Message-ID | <6331347.VZBSO0x8Dp@sunwukong.fritz.box> |
| In reply to | #16261 |
Paul Rubin wrote: > Bernd Paysan <bernd.paysan@gmx.de> writes: >> m/s is a base unit. km/h is a scaled unit, both the km and the hour >> are at least acceptable scales in the metric system.. >> The SI units are standardized units, they are issued by a standard >> body. > > Bah, I'm sure the mile, inch, etc. are also standardized. If they can > scale to 3600 seconds (1 hour) they can scale to 0.0254 meters (1 > inch) and so on. Yes, but the SI units is a standard by a particular standard body. They choose not to standardize inch and friends. The imperial system is a standard, too, or the standardization of units done by the first emperor of China. > Actually the meter itself is a weird artifact, from an earlier > technological era. With modern understanding we can use a more > fundamentally natural and logical unit of speed, the "nano", which at > about 1.07925 km per hour should also be comfortable for car drivers. > I'm sure you can figure out how the nano is derived. I'm indeed a fan of Panck units, too, since they make calculations much easier; especially being dimensionless is a good thing (which is why the "nano" is only a prefix, not a dimension). Furthermore, they are universal, only derived from fundamental "constants" (which are set to 1, i.e. they aren't constants, but only necessary for scaling the SI system to a proper system). http://en.wikipedia.org/wiki/Planck_units Many people who support the imperial system say that it's "human scale" (Bigfoot feets with 30cm???), while e.g. the Planck unit of length scales to 1.61m, which is very human scale, as many people are only slightly larger than 10^35 of these units. -- Bernd Paysan "If you want it done right, you have to do it yourself" http://bernd-paysan.de/
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| From | kenney@cix.compulink.co.uk |
|---|---|
| Date | 2012-10-15 04:21 -0500 |
| Message-ID | <EaKdncp26asUSObNnZ2dnUVZ8mWdnZ2d@giganews.com> |
| In reply to | #16261 |
In article <7xfw5h346h.fsf@ruckus.brouhaha.com>, no.email@nospam.invalid (Paul Rubin) wrote: > Actually the meter itself is a weird artifact, from an earlier > technological era. The meter originated as a political matter as part of the drive to replace Anciene Regime systems of measurement which included a new calendar. There s nothing weird about it, it was defined as a fraction of circumference of the earth at the equator. By the way the US is using a system of units that dates from the 17th century and is not identical to Imperial Measurements. The US gallon for example is not the same as the Imperial gallon. Ken Young
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| From | Mark Wills <markrobertwills@yahoo.co.uk> |
|---|---|
| Date | 2012-10-14 03:17 -0700 |
| Message-ID | <b4ccbe91-940f-4489-a0c2-f879c51ce5df@b6g2000yqd.googlegroups.com> |
| In reply to | #16258 |
> Most of > the ex-colonies have gone metric, the UK partly had (low temperatures > are measured in °C, high temperatures in °F ;-) Nope. All temperatures in the UK are measured in Centigrade. You will *never* hear a weather report, or a school lesson where temperatures are measured in °F. We're not fully metric though. If you order a beer in a pub, your choices are a half pint, or full pint. If you buy a can of beer from the supermarket, it will be 500ml! Same with speed measurements, and weight. Miles per hour, and stones. Miles per hour I can live with; I'm used to it. Stones is just silly, since practically nobody else knows what the hell we're talking about! If you ask a Brit how much he weighs, he will give you a figure in stones. Bonkers.
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| From | Alex McDonald <blog@rivadpm.com> |
|---|---|
| Date | 2012-10-14 15:43 -0700 |
| Message-ID | <b4d9e968-3315-445b-96bc-4caaf1ccfeb4@ro10g2000pbc.googlegroups.com> |
| In reply to | #16263 |
On Oct 14, 11:17 am, Mark Wills <markrobertwi...@yahoo.co.uk> wrote: > > Most of > > the ex-colonies have gone metric, the UK partly had (low temperatures > > are measured in °C, high temperatures in °F ;-) > > Nope. All temperatures in the UK are measured in Centigrade. You will > *never* hear a weather report, or a school lesson where temperatures > are measured in °F. Agreed. Fahrenheit died in the UK years ago. Never heard it used, even for high temps. > > We're not fully metric though. If you order a beer in a pub, your > choices are a half pint, or full pint. If you buy a can of beer from > the supermarket, it will be 500ml! Only beer & cider on draught, and milk in glass bottles can be sold by the pint. All other fluids are sold by the litre. > > Same with speed measurements, and weight. Miles per hour, and stones. > Miles per hour I can live with; I'm used to it. Stones is just silly, > since practically nobody else knows what the hell we're talking about! > If you ask a Brit how much he weighs, he will give you a figure in > stones. Bonkers. My quack measures me in kilos; the medical profession has adopted it for body weights for many years now. My daughters (22 and 25) don't know what a stone is; you're giving your age away ;-) We're nearly there. The last real hold out of non-metric in the UK is that odd combination of beer and cars.
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2012-10-14 21:18 -0400 |
| Message-ID | <k5fo95$5tv$1@dont-email.me> |
| In reply to | #16263 |
On 10/14/2012 6:17 AM, Mark Wills wrote: > We're not fully metric though. If you order a beer in a pub, your > choices are a half pint, or full pint. If you buy a can of beer from > the supermarket, it will be 500ml! Same here for liquor and wine, but not beer. The liquor industry went metric years ago when they realized that there were odd metric sizes that were slightly smaller than the odd English sizes they were using (e.g. a fifth of a gallon). So they could downsize a bit and charge the same price! We've been buying 750 ml or 1.5 liters of wine ever since. Rick
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| From | kenney@cix.compulink.co.uk |
|---|---|
| Date | 2012-10-15 04:21 -0500 |
| Message-ID | <WLKdnTaoMJ8USObNnZ2dnUVZ8jGdnZ2d@giganews.com> |
| In reply to | #16263 |
In article <b4ccbe91-940f-4489-a0c2-f879c51ce5df@b6g2000yqd.googlegroups.com>, markrobertwills@yahoo.co.uk (Mark Wills) wrote: > We're not fully metric though. Network Rail still uses chains and horses are measured in hands. Still all the measurement systems have a rational origin if you go back far enough. Where it is a source of confusion is historical records. Cubits had at least three different values at various times and places. Then off course you get the attempts by modern archaeologists etc to find systems of measurements in monuments. This resulted in the Pyramid Inch and the Megalithic Foot. Ken Young
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| From | anton@mips.complang.tuwien.ac.at (Anton Ertl) |
|---|---|
| Date | 2012-10-15 10:03 +0000 |
| Message-ID | <2012Oct15.120322@mips.complang.tuwien.ac.at> |
| In reply to | #16258 |
Bernd Paysan <bernd.paysan@gmx.de> writes:
>Yes, nobody uses m/s, which would be the metric base unit.
Which gets us back to the bike computer project: If you can program it
yourself, you can use it to measure speed in m/s, or knots if you
want, and still get the distance traveled in km or miles.
- anton
--
M. Anton Ertl http://www.complang.tuwien.ac.at/anton/home.html
comp.lang.forth FAQs: http://www.complang.tuwien.ac.at/forth/faq/toc.html
New standard: http://www.forth200x.org/forth200x.html
EuroForth 2012: http://www.euroforth.org/ef12/
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| From | visualforth@rocketmail.com |
|---|---|
| Date | 2012-10-15 04:04 -0700 |
| Message-ID | <46641239-eebb-496b-aa52-2c6d26b161b6@googlegroups.com> |
| In reply to | #16285 |
On Monday, October 15, 2012 12:05:04 PM UTC+2, Anton Ertl wrote: > Bernd Paysan <bernd.paysan.de> writes: > > >Yes, nobody uses m/s, which would be the metric base unit. > Which gets us back to the bike computer project: If you can program it > yourself, you can use it to measure speed in m/s, or knots if you > want, and still get the distance traveled in km or miles. > - anton > So we are back to START: "It seems that the community needs to instill the "Inspire a Generation" spirit that pervaded the London 2012 Olympics event. By this we mean that we need to raise theons for self express level of enthusiasm for Science, Technology, Engineering and Mathematics within the upcoming generations from primary school level upwards." Let's do it! Dirk Bruehl http://4e4th.com We are all tolerant - as long as the other behaves as expected!
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| From | "Paul E. Bennett" <Paul_E.Bennett@topmail.co.uk> |
|---|---|
| Date | 2012-10-15 21:34 +0100 |
| Message-ID | <ae3acuFm8piU1@mid.individual.net> |
| In reply to | #16288 |
visualforth@rocketmail.com wrote: > So we are back to START: > "It seems that the community needs to instill the "Inspire a Generation" > spirit that pervaded the London 2012 Olympics event. By this we mean that > we need to raise theons for self express level of enthusiasm for Science, > Technology, Engineering and Mathematics within the upcoming generations > from primary school level upwards." It will obviously take a few add-on boards to help the kick-start projects get the young minds fired up. Such add-ons should have some things that would be desirable add-ons to the initial starter board. How about a double or three digit display add-on, or a relay interface board as a starting point for when they want to go further than the morse code or LED flasher programs. Maybe even stepper motor drivers, simple inter-processor comms modules and encoder input module. With the ability to couple any of that to Lego or Meccano and we begin to get into the area of robotics. > > Let's do it! > > Dirk Bruehl > http://4e4th.com > We are all tolerant - as long as the other behaves as expected! -- ******************************************************************** Paul E. Bennett...............<email://Paul_E.Bennett@topmail.co.uk> Forth based HIDECS Consultancy Mob: +44 (0)7811-639972 Tel: +44 (0)1235-510979 Going Forth Safely ..... EBA. www.electric-boat-association.org.uk.. ********************************************************************
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| From | rickman <gnuarm@gmail.com> |
|---|---|
| Date | 2012-10-15 17:51 -0400 |
| Message-ID | <k5i0h8$gm$1@dont-email.me> |
| In reply to | #16288 |
On 10/15/2012 7:04 AM, visualforth@rocketmail.com wrote: > On Monday, October 15, 2012 12:05:04 PM UTC+2, Anton Ertl wrote: >> Bernd Paysan<bernd.paysan.de> writes: >> >>> Yes, nobody uses m/s, which would be the metric base unit. > >> Which gets us back to the bike computer project: If you can program it >> yourself, you can use it to measure speed in m/s, or knots if you >> want, and still get the distance traveled in km or miles. >> - anton >> > > So we are back to START: > "It seems that the community needs to instill the "Inspire a Generation" spirit that pervaded the London 2012 Olympics event. By this we mean that we need to raise theons for self express level of enthusiasm for Science, Technology, Engineering and Mathematics within the upcoming generations from primary school level upwards." > > > Let's do it! I've already said I'm in. I'll design all the hardware you want. Who will write the software? Rick
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