question for all "real engineers" with college degrees, etc on notation.

[waikikin]

Originally Posted by OverRun

Gonzo,

In the part of the world that Poida lives in, what he wrote would be interpreted here as a real compliment. It indicates that you are an engineer of knowledge and experience as well as the theoretical learning, and thus to be treated even more seriously.



Umm - this is an unexpected first post by me on any Forum or Board. I usually try and contribute technically first, but I thought this might make a timely contribution.
Cheers
OverRun

Some times we see the "term" "PE"... Professional Engineer, It can also mean "Practical Engineer", it's great to be either & fantastic to be both.

[gonzo]

OK, I got it.
The concept of significant digits in engineering is about precision on the measurements. If you use two measuring devices with different accuracy, the lesser is the one that gives the limit of significant digits. For example, one has an accuracy of 0.00015 and the other 0.0002. Everything would get rounded off to multiples of 0.0002

[daiquiri]

This is one nice site about the concept of significant digits and it's practical use: http://www.purplemath.com/modules/rounding.htm
In particular, the 2nd page of that site regards the OP question.

As about the proposed new convention for writing them up, I can see a sense in it but I am not sure it would bring anything new to the mathematical or engineering world. And besides that, the relevant deciding body is not this forum, as Jehardiman has noted.

Cheers

[Leo Lazauskas]

Originally Posted by waikikin

Some times we see the "term" "PE"... Professional Engineer, It can also mean "Practical Engineer", it's great to be either & fantastic to be both.

The requisite qualification for the National Professional Engineers Register
(NPER) is a four-year engineering qualification accredited by Engineers Australia
or equivalent.

You can also call yourself an engineer (or applied mathematician) if you use a
screwdriver to hammer in a nail when nobody is watching.

[Ad Hoc]

Originally Posted by waikikin

Some times we see the "term" "PE"... Professional Engineer, It can also mean "Practical Engineer", it's great to be either & fantastic to be both.

I never applied for nor requested to become a PE..yet i have been "given" this status by SNAME.

Whereas to get my C.Eng, as Leo points out, took me forever and with an additional 7 years training after Uni to demonstrate my application of theory and in the correct environment with sufficient level and responsibility, all signed off by my "mentor" to get me to C.Eng. It was finished off with a formal interview; by EC Tupper no less!

Originally Posted by Leo Lazauskas

You can also call yourself an engineer (or applied mathematician) if you use a screwdriver to hammer in a nail when nobody is watching.

Hey..i do that all the time when the missus isn't watching!

[Leo Lazauskas]

Originally Posted by Ad Hoc

Hey..i do that all the time when the missus isn't watching!

I once used an unopened bottle of beer as a spirit level when I was building a rough rustic wall in the garden. I proved that the more spirit levels you use, the greater the "rustic" effect.

[Squidly-Diddly]

they always simplify all equations and notations.

So I'd thought I'd see what I could do.

My idea wont "contribute" to advancement of engineering, maybe just eliminate some of the work, and maybe some errors.

[Ad Hoc]

Originally Posted by Squidly-Diddly

My idea wont "contribute" to advancement of engineering, maybe just eliminate some of the work, and maybe some errors.

Sounds like supposition and conjecture.

Do you have any facts to support this claim of "errors" etc?

[Squidly-Diddly]

teachers always told me to reduce, cross cancel, etc equations when ever possible.


Like I said before, my CURRENT Physics prof says "you can't tell how many sigs are in 456,000....so THAT is why we use sci notation".


Only prob is even doing THAT means you gotta make sure your E05 4.560 line up.

Simpler to just write 4560s00 IMO.

[gonzo]

You need to know the specification of the measuring instruments to find out what the significant digits are.

[WestVanHan]

Originally Posted by Leo Lazauskas

you use a
screwdriver to hammer in a nail when nobody is watching.

I hammer in screws if I know I'm not taking something apart and it's not important...

[P Flados]

I am an engineer (BSME with decades of experience, but not "PE" of the registered professional variety) and run into sig dig violations on a regular basis.

The scientific notation is the cleanest way, but appropriate rounding with following zeros can be OK if in context.

Those that do not take the time to adjust their computer outputs appropriately are usually one or more of the following: ignorant (they do not know the difference), lazy (they know, but do not bother to do thing right), belligerent (they know what is right, but do wrong out of spite). The one other case is where they know that it really does not matter for a specific application (any use of the output will only be with an understanding that the extra digits do not mean anything).

The rounding approach is very common. For example, how precise do we assume for a boat with a published weight of 3600 lbs? It should be somewhere between 3550 and 3650 lbs. As a qualifier, I do not trust much in the way of published values, and variations of up to 400 lbs would not surprise me.

[P Flados]

For the other discussion,

I hammer in screws any time I want regardless of who is watching. However, this is only done when I am confident that the results will be what I want. Mostly in soft woods with screws that can take the beating.

Long ago a really good handyman/carpenter told me that screwdrivers were for removing screws, hammers are for installing them. Then he said, most of the time that is.