The VOLVO Rule: When troubleshooting, turn only ONE knob at a time!

 

 

 

 

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Notes from the lecture:

1. Advanced Knobs & Needles: Thinking About Experiments
2. FAQ: Do we need to use Python and/or am I not allowed to use KGraph/Excel?
   • No – but the quality and completeness of your data analysis should not be limited by your choice of tools not designed for the task at hand.
   • Taking the time to learn how to use a professional scientific tool is a long term investment in yourself and a sign of self-respect.
3. Reminder: Grading & Due Dates
   • Logbooks are due in two weeks on Friday Oct 6 @ 1600.
   • 1st draft of final paper does not have to be good, but it does have to be complete.
4. BPS 4216 & NSCL Lobby
   • Tuesday section due at BPS 4216 – JP office
   • Thursday section due at NSCL Lobby – JTS office
5. Daily Meditation: Failure is a gift.
   • Prime Directive of the Knob-Turner: The knob-turner must stare at the correct needle when turning the knob.
   • If you didn’t write it down, then it never happened.
   • Amateurs remember, professionals write it down.
   • Our only obligation as Scientists is to be honest.
   • Correlation is not causation.
   • RTFM: Read The Fascinating Manual
6. The VOLVO Rule: When troubleshooting, turn only ONE knob at a time.
   • Take the time to systematically troubleshoot your apparatus. This valuable process is how you learn the experiment.
   • Is it plugged in?
   • Is it turned on?
   • Is it broken?
   • What assumptions am I making?
   • Do I know what I’m talking about?
   • Are there secret knobs?
7. & 8. Stanislav Petrov: The Man Who Saved The World By Thinking
   • NPR Story
   • BBC News
   • Petrov was a Russian Army officer who was responsible for alerting Moscow if the Early Warning System detected missiles from the USA.
   • In 1983, this system warned of the launch of 5 missiles, given Petrov about 20 minutes to react before impact.
   • Because there was conflicting information and the data did not make sense, Petrov decided to not call Moscow thereby preventing the USSR from launching a retaliatory missile launch towards the USA.
   • After twenty minutes, nothing happened which indicated that he had made the correct decision.
   • Petrov: “There was no rule about how long we were allowed to think before we reported a strike.”
   • Interesting tidbit – Petrov received an official reprimand, not for the actions that he didn’t take that day, but for mistakes in his logbook.

9., 10., & 11. – see this post on producing scientific diagrams.

• A photograph is usually uninformative…
  • …except when capturing a phenomenon (a sonoluminescent bubble or fluorescence from an atomic vapor cell)
  • …or when recording complex knob settings and cable arrangements
  • …or when clarifying what a broken (before) and fixed (after) piece of equipment looks like
• labeled boxes are much better, but…
• a semi-representational schematic with relevant equipment specifications is the best.

12a. Model of Measurement System:

• What are all of the components?
• Is it a knob or a needle?
• Are there photons?
• Do we have a knob that controls the energy and/or number of photons? (These are related but are not the same thing.)
• Do we have a needle that the energy of the photons and/or counts the number of photons?
• Are there electrons?
• Do we have a knob that controls the number of electrons and/or needle that counts the number of electrons?
• How do we record the knob settings?
• How do we record the needle settings?

12b. Model of Physical System:

• Is there an energy level diagram?
• Do we have a knob that controls the energy levels of the system?
• Which knob am I turning to study the system?
• Which needle indicates that the system has changed in some fundamental way?

12c. Cartoon Game – I hand draw a cartoon schematic for every experiment which captures just the essential aspects of the measurement (knob & needles) and physical (energy level diagrams) systems. A great example is here:

1. Questions to Ponder Abouts Knobs & Needles

• What do the knob and needle represent?
• What determines the appropriate scale for the knob setting and needle reading?
• What is the appropriate range of values for the knob setting and needle reading?
• How well do we know the knob setting and needle reading?
• What is your prediction for the shape of the needle vs. knob curve and why?