Session 1a

CSGnet Archive CSG1998
1

[From Bill Powers (980905.0820 MDT)]

Session 1a: Questions

The response to Session 1's text was either "nice job" or
silence. How about trying to get out of the passive observation
mode? Here are some questions that might help.

1. List all the variable attributes (that you can) of an apple.
Do these items have anything to do with perceptions? Are there
any constant attributes of an apple? (I refer, of course, to a
_real_ apple.)

2. Can you control a car? Explain. What can you control about a
car? What is the main requirement on something to make it
controllable?

3. Is it useful to say that someone is "angry?" Explain. What
would a simulator say instead?

4. What's wrong from the simulation standpoint with saying " At
T-Zero, the spacecraft blasted off"?

5. The speed of a car, S, is produced by the amount of throttle
linkage force, F, generated by a cruise control box. The
relationship is S (mph) = 25*F (newtons). With the speed starting
at 10 mph, we observe that an increment in linkage force is
followed by an increment in speed, and an increment in speed is
followed by an increment in force. Eventually the increments in
force drop off to zero, the speed levels off at 75 miles per
hour, and the force levels off at 3 newtons.

Since S = 25*F, we can also write F = S/25. The first equation
says that the speed of the car results from a certain linkage
force generated by the cruise control, according to the formula S
= 25*F. Can we also say that the linkage force generated by the
cruise control results from the attainment of a certain speed
according to the second formula, F = S/25?

Is the linkage force caused by its consequences?

ยทยทยท

---------------------------------------------------------
You can answer these questions privately just to see how you
fare, or send your answers to me to be posted anonymously and
discussed, or send them to me with questions to be answered
privately (but don't abuse that privilege).

Best,

Bill P.

2

[From Rupert Young (980907.1230 BST)]

Bill Powers (980905.0820 MDT)

1. List all the variable attributes (that you can) of an apple.

Ok, I've got a couple of minutes.

Size, colour, taste, smell, mass, hardness, water content, chemical
composition.

Do these items have anything to do with perceptions?

They are our perceptions of their attributes. Things like taste and smell
are our interpretation of combinations of more primitive elements of the apple
and only _exist_ as neural signals whereas something like size is our
perception of an objective measurement. Some attributes, like water content
and chemical composition are not perceivable, though.

Are there any constant attributes of an apple?

But hang on, you said _an_ apple so maybe they are attributes which vary with
different apples but are constant attributes of a particular apple. Umm, I
wish I'd never started.

Regards,
Rupert

3

[From Bill Powers (980907.1123 MDT)]

Rupert Young (980907.1230 BST)--

1. List all the variable attributes (that you can) of an apple.

Excellent. The mass may be questionable but I didn't specify the conditions
of measurement, or the time-span, so you get away with it. As to whether
measurements are within an apple or across apples, you get extra credit for
noticing the difference.

Best,

Bill P.