Engineering in Higher Education - significant figures

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Discussion Overview

The discussion revolves around the treatment of significant figures (SF) in engineering education, particularly in textbooks and coursework. Participants share their experiences and observations regarding the importance and application of SF in various engineering contexts, as well as the implications of neglecting these concepts in real-world engineering scenarios.

Discussion Character

  • Debate/contested
  • Conceptual clarification
  • Technical explanation

Main Points Raised

  • One participant notes that significant figures seem to be overlooked in engineering textbooks, contrasting this with their importance in physics courses.
  • Another participant suggests that the relevance of significant figures varies by context, indicating that they are necessary in certain calculations, such as determining the diameter of a shaft, where rounding is influenced by manufacturing standards.
  • It is mentioned that significant figures are crucial in physical constants and future calculations, with the number of digits depending on design accuracy and budget considerations.
  • One participant argues that engineering is not a research science and that errors are often not tracked due to their complexity in real-life situations, which relates to the use of safety factors.
  • A later reply emphasizes that significant figures should not exceed the margin of error in calculations.
  • Participants reference the Space Shuttle disaster, discussing how a lack of attention to uncertainty and error contributed to the failure, highlighting Richard Feynman's role in uncovering these issues during the investigation.
  • There is a discussion about management decisions and their impact on engineering outcomes, with a participant asserting that better communication with engineers could have prevented the disaster.
  • Another participant mentions the specific technical failures related to the cold o-rings and the decision-making process that led to the disaster, suggesting that multiple small issues compounded to create a significant failure.

Areas of Agreement / Disagreement

Participants express a mix of agreement and disagreement regarding the importance of significant figures in engineering. While some acknowledge their relevance in specific contexts, others argue that their application is often neglected in practice. The discussion remains unresolved regarding the overall treatment of significant figures in engineering education.

Contextual Notes

Limitations in the discussion include varying definitions of significant figures, the context-specific nature of their application, and the complexities involved in error tracking in engineering practices.

e.pramudita
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Engineering in Higher Education -- significant figures

I am currently in my 4th semester.
It seems that every engineering textbooks I encounter have no regard of significant figures (SF).
Every problems and examples I encounter are like that. Mostly integers, some have decimal figures, but the answers never pay attention to SF.
On my first year I was doing Physics where SF is a very important concept but now it has been forgotten.
How about you all? My textbooks are pretty famous and used worldwide. I wonder if your courses disregard SF too.
 
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I have also noticed that, but as you go along in your studies you will notice that significant figures are only needed under some circumstances.

It would help to know what's your branch of engineering but for example, when you calculate the Diameter of a shaft you will need to round it up to some "desired" values that are selected for manufacture if its a tube and you calculate the internal diameter you will round it down.

Significant digits matter in physical or unit transformation constants and in results that you will use in future calculations and the number of digits that you will use depend on the accuracy of the design ergo the money you have. However even if your books have no regard on SF you should be very aware of how to use them and with practice you will learn when to use them and how many. With time you will find out that there are many things your books don't train you for and you will have to solve.
 
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Enginneering is not a research science. Errors are not often specifically accounted for because in real life situations, they are difficult to impossible to keep track of. That's part of what safety factors are for. But it does definitely depend on the situation.
 
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Make sure your sig fig is less than or equal to your margin of error.
 


russ_watters said:
Enginneering is not a research science. Errors are not often specifically accounted for because in real life situations, they are difficult to impossible to keep track of. That's part of what safety factors are for. But it does definitely depend on the situation.

Isn't this what lead to the failure in 10th mission of Space Shuttle disaster?
Finally Richard Feynman, a physicist, is the one who uncovered the cause of the disaster despite his inexperience with NASA and outer space mission.
During his investigation he also found out that there were very big unconcern about uncertainty and error.
 


e.pramudita said:
Isn't this what lead to the failure in 10th mission of Space Shuttle disaster?
Finally Richard Feynman, a physicist, is the one who uncovered the cause of the disaster despite his inexperience with NASA and outer space mission.
During his investigation he also found out that there were very big unconcern about uncertainty and error.

If management had listened to their engineers it wouldn't have happened.
 


If management had listened to their engineers it wouldn't have happened.

Indeed the Nova show blamed cold o-rings in the rocket engine's shell, and the decision to "go" when weather was too cold for those o-ring seals.

Much earlier there was a decision to choose the engine with a segmented shell and o-rings over a one piece engine without them.(Aerojet)
http://history.nasa.gov/rogersrep/v1ch6.htm

Such disasters are always result of many little things stacked up like dominoes. I guess that's how the "small things of the Earth confound the mighty".
 
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