Where has Engineering Gone In The Last 5 Years 2

[KENAT]

Just noticed faq730-700 and that it is (just over) 5 years old.

So to celebrate this milestone, anyone care to opine on where it has gone? How accurate were some of the initial ideas etc.

KENAT, probably the least qualified checker you'll ever meet...

 

[apsix]

"if you use the system in daily life, there is a real need for a unit of measure about the size of something that can be held in the hand and easily seen"
HgTX, that's obviously based on your personal experience but is not a universal rule.
I you are taught metres and millimetres it feels perfectly natural to use only those units.
Where I am, all design, construction, materials etc. are in m or mm.
Dressmakers find cm useful I believe.

 

[moltenmetal]

Choice of units depends entirely on what your commonsense is calibrated in. It's like talking in a different language: it's slow and inaccurate when you're translating everything in your head- until you can THINK in that 2nd language.

Fortunately, most Canadian engineers are relatively "bilingual" in units terms. US customary units due to proximity to our neighbour, and SI/metric units in our official standards and our educational system.

 

[cranky108]

So you only say your converting to metric, but you use the same size equipment, or bottles of brew, with a metric measurment stamped on it.
Sort of the same reason there are 60 minuites in an hour. Or in metric should that be 100 minuites in an hour, and 20 hours in a day?

 

[cksh]

I prefer mm's but up until about 3 years ago all I used was inches. There are still so many little machine shops that don't want to read mm's. Not to mention that alot of our tables/charts were in inches so it was always easier to work in inches.

School was a pain because the instructors would use both. Sometimes mixing them up on a test (in the same problem!)just to see if we were paying attention.

I had used inches for so long that when I started working in mm I modeled everything in mm but dimensioned it in inches. My supervisors got a good laugh outta that.

 

[EngineerofSteel]

Q: Why say 97 cm when you can say 970 mm?
A: Easy, trying telling a woman her waist is no longer "97" it is "nine hundred and seventy."

 

[KENAT]

My guess is even if you tell her she's a 38" you're still in trouble.

KENAT,

Have you reminded yourself of faq731-376 recently, or taken a look at

http://eng-tips.com/market.cfm?

 

[monkeydog]

My wife wears a petite large.
I don't understand .... that's ok - you don't have to explain.

 

[owg]

I suppose France would be well along in going to the SI system. However I recall buying un demi kilo of grapes, and 200 grams of cheese. Was the design intent to have shoppers ask for 2 and 5 hectograms?

HAZOP at

http://www.curryhydrocarbons.ca

 

[jmw]

Well, it isn't all that simple even if you stick to one system.
Just when you think degrees centigrade is a nice useful scale and easily converted to degrees Kelvin and more convenient than Fahrenheit and Rankin, for some reason the name changes to Celcius.
OK, fine, so its all now Celcius and Kelvin except it isn't.

I'm just going over my spreadsheet for density calculations and I now have to try and fathom out the significance of the various changes in temperature scales over the last 100 years.
The most recent change, so far as I can see, is from ITS 68 to ITS 90.
The differences between t[sup]O[/sup]68 and t[sup]O[/sup]90 are, apparently, either significant or not significant depending on what you are doing at the time. I'm now trying to fathom out if T[sup]O[/sup]68 is any different to T[sup]O[/sup]90 and I hope this site (

http://www.kayelaby.npl.co.uk/general_physics/2_3/2_3_1.html)

is going to help me rather than confuse me.

Is that the end of it? I doubt it.
Once you have committees deciding to standardise something you can be sure that when the committee meets again in 2,5 or 10 years they'll have thought of something new to do even if it is simply change the name from Centigrade to Celcius, to replace Curies with Roentgens or whatever, to redefine the standard or something else altogether. I guess it might make sense to you and me to have one big meeting and get all the changes done at once and then shoot them all so they can't come back in five years with more changes, but I guess that ain't gonna happen.

Of course, we can hardly expect any committee to meet and say "Yep, we got it right the last time" because they'd all have nothing more to do and hence an end to that particular "nice little earner"; most committees are thus, by some immutable law, eternal.

I say most, and perhaps that ought to read "all, because until I started messing with the density calculations it would never have occurred to me to think that 23[sup]O[/sup]C measured in 1926 would by the end of 1927 be some very slightly different temperature or that come 1948, 1968 and 1990 it would have changed again and again.

Of course, this gives me something else to worry about: I now wonder if Michael Mann is correcting all his temperature data to the ITS 90 scale and if his source materials are all in, or converted to, the same temperature scale? Do you think I should ask him, or is he having enough troubles with trying to get the hockey stick graph back on the map?

Is nothing sacrosanct?

JMW

http://www.ViscoAnalyser.com

 

[DonPhillips]

I think it just proves how little of the universe we really know, and with new knowledge, comes new concepts that challenge old concepts.

When I was in college, I was just learning about quarks but in high school, the basic parts were the proton, neutron, and electron. And I am hearing now, watching public telelvesion programs, that there are even smaller parts to the quarks. Just an example.

I think the speed and ease in which we communicate accelerates the formulation of new concepts.




Don Phillips

http://worthingtonengineering.com

 

[cranky108]

Smaller parts of an atom, reminds me of how the planets circle the sun. May be your computer mouse is just a small universe, where the electrons circle little suns.

A theory is just something someone proposed as a way of explaining how things work. However a brick wall is a fact that you can run into.
As we collectivitly learn more, new theorys will appear and old ones will be forgoton (Like the earth is flat).

 

[jmw]

Heh, just a minute, what do you mean "like the earth is flat". It is, isn't it? or is that something else some committee did away with while we were all wondering what had happened to Pluto?

http://www.alaska.net/~clund/e_djublonskopf/Flatearthsociety.htm

Yeah I know, our knowledge is always advancing but I mean, how can the earth eb anything but flat? I mean, what's your definition? I know its a poser to consider a finite unbounded isotropic surface but who says it has to be unbounded?
You know some of you are very dangerous thinkers. Not content with 2 dimensions you want us to believe we live in three spacial dimensions. Where will it end? eleven dimensions and are they all finite unbounded isotropic homogenuous spaces? or what?



JMW

http://www.ViscoAnalyser.com

 

[jmw]

OK, now I'm confused. It appears there is some doubt after all that the earth is flat. It is, some say, Square.
The evidence is presented here by the International Square Earth Society:

http://home.netcom.com/~rogermw/square_earth.html

Of course, there is a Round Earth Society too, (but there are always cranks):

http://roundearth.informe.com/

There is even a hollow earth society... are there no end of these people?


JMW

http://www.ViscoAnalyser.com

 

[ctopher]

As long as the rivers are flowing and I'm not floating away, I don't care if it's flat or round (although it is almost round).

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[cranky108]

I guess that depending on where you are standing things look differently.

From my office window I see the same cars go by all day long. From my calculation the time period of circulation is about 3 hours on averige, with some faster, and some slower.
But what I don't know is why they keep going around.

The issue here is not what we believe, but does the theory explain what is actually happening. A postulation is a belief that what may be a theory is correct, but you haven't tested it agenest all reasonable situations.

I postulate the sun travels around the earth, because that is what appears to happen from my perspective.

 

[ctopher]

"I postulate the sun travels around the earth"

It must be hot where you are.

Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion

 

[SomptingGuy]

I can't work out whether those societies are jokes or not. People don't normally get shouty and angry if they are joking.

- Steve

 

[jmw]

It isn't so much whether or not the societies consider themselves serious or not, but why they are there at all.
One or two seem purely honey traps to draw the loonies out of the bushes and into their blogs.

Some people seem to have nothing to do all day but drive their blood pressure through the roof and spout of senselessly in any forums they can find. Maybe they just like to see themselves in print.

Oh, oops.
Er, let me go get a coffee and think about that for a moment.

[flush]


JMW

http://www.ViscoAnalyser.com

 

[HgTX]

And some of them wind up on boards of education in southern states.

Hg



Eng-Tips policies: faq731-376

 

[cranky108]

So how do you know the shape of the earth? How do you know?
If a book said so, must it always be true?

Read the theorys, see the perspectives, and decide for your self.

Engineering has changed in the point of view that manufactured goods are reduced in metals. More consumer goods are now made of plastic. And cars are just now reaching the milage that they were at 15 years ago (nothing changed there).
With more efficent light bulbs, electric usages are up. And the price of oil has risen form $40 to $60 a barrel.