Mirror | rorriM

Doin’ it : Q – T

Quantum physicists



   1. Quantum physicists can either know how fast they do it, 

   or where they do it, but not both.

   2. Quantum physicists can either know when they do it, 

   or with how much energy they do it, but not both.



Real analysts



   1. Real analysts do it almost everywhere

   2. Real analysts do it uniformly.



Ring theorists



   1. Ring theorists do it non-commutatively.

   2. Ring theorists do it ideally.



Set theorists



   1. Set theorists do it in a morass.

   2. Set theorists do it with cardinals.



Statistical physicists



   1. Statistical physicists do it with partitions.

   2. Statistical physicists do it near equilibrium.

   3. Statistical physicists do it in ensembles.



Statisticians



   1. Statisticians do it continuously but discretely.

   2. Statisticians do it when it counts.

   3. Statisticians do it with 95% confidence.

   4. Statisticians do it with large numbers.

   5. Statisticians do it with only a 5% chance of being rejected.

   6. Statisticians do it with two-tail T tests.

   7. Statisticians do it. After all, it's only normal.

   8. Statisticians probably do it.

   9. Statisticians do it with significance.

  10. Statisticians do all the standard deviations.

  11. Statisticians would like to do it with the population, 

  but only get a small sample.



Topologists



   1. Topologists do it in multiply connected domains.

   2. Topologists do it on rubber sheets.

   3. Topologists do it openly.



Topos theorists



   1. Topos theorists do it pointlessly.

Doin’ it : M – P

Markov



   1. Markov does it in chains.



Mathematical physicists



   1. Mathematical physicists understand the theory of how to do it, 

   but have difficulty obtaining practical results.



Mathematicians



   1. Mathematicians do it associatively.

   2. Mathematicians do it by numbers.

   3. Mathematicians do it commutatively.

   4. Mathematicians do it constantly.

   5. Mathematicians do it continuously.

   6. Mathematicians do it discretely.

   7. Mathematicians do it exponentially.

   8. Mathematicians do it forever if they can do one and can do one more.

   9. Mathematicians do it functionally.

  10. Mathematicians do it homologically.

  11. Mathematicians do it in fields.

  12. Mathematicians do it in groups.

  13. Mathematicians do it in imaginary planes.

  14. Mathematicians do it in n dimensions.

  15. Mathematicians do it in numbers.

  16. Mathematicians do it in theory.

  17. Mathematicians do it on smooth contours.

  18. Mathematicians do it over and under the curves.

  19. Mathematicians do it parallel and perpendicular.

  20. Mathematicians do it partially.

  21. Mathematicians do it rationally.

  22. Mathematicians do it reflexively.

  23. Mathematicians do it symmetrically.

  24. Mathematicians do it to prove themselves.

  25. Mathematicians do it to their limits.

  26. Mathematicians do it totally.

  27. Mathematicians do it transcendentally.

  28. Mathematicians do it transitively.

  29. Mathematicians do it variably.

  30. Mathematicians do it with a Minkowski sausage.

  31. Mathematicians do it with imaginary parts.

  32. Mathematicians do it with linear pairs.

  33. Mathematicians do it with Nobel's wife.

  34. Mathematicians do it with odd functions.

  35. Mathematicians do it with prime roots.

  36. Mathematicians do it with relations.

  37. Mathematicians do it with rings.

  38. Mathematicians do it with their real parts.

  39. Mathematicians do it without limit.

  40. Mathematicians do over an open unmeasurable interval.

  41. Mathematicians have to prove they did it.

  42. Mathematicians do it ad infinitum.

  43. Mathematicians do not do it. They leave it as an exercise to the reader.



Matrix analysts



   1. Matrix analysts don't do it until it is positive definite.

   2. Matrix analysts do it within a Gershgorin disc.



Matrix computationalists



   1. Matrix computationalists do it by pivoting.

   2. Matrix computationalists do it on a mesh.



Measure theorists



   1. Measure theorists do it almost everywhere.

   2. Measure theorists do it almost nowhere.



Mobius



   1. Moebius always does it on the same side.



Number theorists



   1. Number theorists do it perfectly.

   2. Number theorists do it rationally.

   3. Number theorists do it a prime number of times.



Particle physicists



   1. Particle physicists do it with different flavours.

   2. Particle physicists do it with three colours and anti-colours.

   3. Particle physicists do it with Feynman diagrams.



Physicists



   1. Physicists do it on the event horizon.

   2. Physicists do it in waves.

   3. Physicists do it with ropes and pulleys.

   4. Physicists do it with vectors.

   5. Physicists do it at the right moments.

   6. Physicists do it with force.

   7. Physicists do it on the spur of the moment.



Probabilists



   1. Probabilists do it on random walks.

   2. Probabilists do it stochastically.



Pure mathematicians



   1. Pure mathematicians do it rigorously.

Doin’ it : G – L

Galois



   1. Galois did it the night before.



Galois theorists



   1. Galois theorists do it in a field.



Game theorists



   1. Game theorists do it by dominance or saddle points.

   2. Game theorists score most often.



General relativists



   1. General relativists do it with curvature.

   2. General relativists do it with tensors.

   3. General relativists do it in Minkowski space.

   4. General relativists do it with rubber sheets and canteloupes.



Geometers



   1. Geometers do it with involutions.



Graph theorists



   1. Graph theorists do it discretely.

   2. Graph theorists do it in four colours.



Group theorists



   1. Group theorists do it simply.

   2. Group theorists do it with the Monster.



Hilbert spacers



   1. Hilbert spacers do it orthogonally.



Large cardinals



   1. Large cardinals do it inaccessibly.



Linear programmers



   1. Linear programmers do it with nearest neighbors.



Logician



   1. Logicians do it by choice.

   2. Logicians do it consistently and completely.

   3. Logicians do it incompletely or inconsistently.

   4. Logicians do it with Jensen's device.

   5. (Logicians do it) or [not (logicians do it)].

   6. Logicians do it with Knights and Knaves.

   7. Logicians do it necessarily and sufficiently.

Doin’ it : C – F

Cantor



   1. Cantor did it until he was crazy.



Catastrophe theorists



   1. Catastrophe theorists do it falling off part of a sheet.



Chaoticians



   1. Chaoticians do it with sensitive dependence.



Class field theorists



   1. Class field theorists do it by capitulation.



Classical geometers



   1. Classical geometers do it on the Euler line.

   2. Classical geometers do it on the nine-point circle.



Combinatorialists



   1. Combinatorialists do it discretely.

   2. Combinatorialists do it as many ways as they can.



Communtative algebraists



   1. Commutative algebraists do it regularly.



Complex analysts



   1. Complex analysts do it between the sheets.

   2. Complex analysts do it under a universal cover.



Computer scientists



   1. Computer scientists do it in loops.

   2. Computer scientists do it at 90 MHz.

   3. Computer scientists do it recursively.

   4. Computer scientists do it by brute force.

   5. Computer scientists do it by exhaustion (of all possibilities).

   6. Computer scientists do it in serial.

   7. Computer scientists do it in parallel.

   8. Computer scientists do it concurrently.

   9. Computer scientists do it on trees.

  10. Computer scientists do it depth first.

  11. Computer scientists do it in polynomial time.

  12. Computer scientists do it in (core) dumps.

  13. Computer scientists do it with objects.

  14. Computer scientists do it on heaps.

  15. Computer scientists do it with a protocol.

  16. Computer scientists do it automatically.

  17. Computer scientists do it dynamically.

  18. Computer scientists do it by pointing.

  19. Computer scientists do it in arrays.

  20. Computer scientists do it with whatever you pass them.



Constructivists



   1. Constructivists do it without excluding the middle.



Cosmologists



   1. Cosmologists do it in the first three minutes.

   2. Cosmologists do it with large inflationary periods.



Decision theorists



   1. Decision theorists do it optimally.



Differential analysts



   1. Differential analysts do it in a degenerate case.



Fermat



   1. Fermat did it in the margin.

   2. Fermat tried to do it in the margin, but couldn't fit it in.



Financial Engineers



   1. They do it by Monte Carlo simulation, and then discount it back.



Functional analysts



   1. Functional analysts do it with compact support.

   2. Functional analysts do it with degenerate colonels.

Problem: To Catch a Lion in the Sahara Desert.

4 Contributions from Computer Science

4.1 The search method

We assume that the lion is most likely to be found in the direction to the north of the point where we are standing. Therefore the REAL problem we have is that of speed, since we are only using a PC to solve the problem.

4.2 The parallel search method

By using parallelism we will be able to search in the direction to the north much faster than earlier.

4.3 The Monte-Carlo method

We pick a random number indexing the space we search. By excluding neighboring points in the search, we can drastically reduce the number of points we need to consider. The lion will according to probability appear sooner or later.

4.4 The practical approach

We see a rabbit very close to us. Since it is already dead, it is particularly easy to catch. We therefore catch it and call it a lion.

4.5 The common language approach.

If only everyone used ADA/Common Lisp/Prolog, this problem would be trivial to solve.

4.6 The standard approach

We know what a Lion is from ISO 4711/X.123. Since CCITT have specified a Lion to be a particular option of a cat we will have to wait for a harmonized standard to appear. $20,000,000 have been funded for initial investigastions into this standard development.

4.7 Linear search

Stand in the top left hand corner of the Sahara Desert. Take one step east. Repeat until you have found the lion, or you reach the right hand edge. If you reach the right hand edge, take one step southwards, and proceed towards the left hand edge. When you finally reach the lion, put it the cage. If the lion should happen to eat you before you manage to get it in the cage, press the reset button, and try again.

4.8 The Dijkstra approach

The way the problem reached me was: catch a wild lion in the Sahara Desert. Another way of stating the problem is:

Axiom 1: Sahara elem deserts
Axiom 2: Lion elem Sahara
Axiom 3: NOT(Lion elem cage)

We observe the following invariant:

P1: C(L) v not(C(L))

where C(L) means: the value of “L” is in the cage.

Establishing C initially is trivially accomplished with the statement

    ;cage := {} 

Note 0:

This is easily implemented by opening the door to the cage and shaking out any lions that happen to be there initially.
(End of note 0.)

The obvious program structure is then:

        ;cage:={}

        ;do NOT (C(L)) ->

                ;"approach lion under invariance of P1"

                ;if P(L) ->

                        ;"insert lion in cage"

                 [] not P(L) ->

                        ;skip

                ;fi

        ;od

where P(L) means: the value of L is within arm’s reach.

Note 1:
Axiom 2 esnures that the loop terminates.
(End of note 1.)

Exercise 0:
Refine the step “Approach lion under invariance of P1”.
(End of exercise 0.)

Note 2:
The program is robust in the sense that it will lead to abortion if the value of L is “lioness”.
(End of note 2.)

Remark 0:
This may be a new sense of the word “robust” for you.
(End of remark 0.)

Note 3:
From observation we can see that the above program leads to the desired goal. It goes without saying that we therefore do not have to run it.
(End of note 3.)
(End of approach.)

Problem: To Catch a Lion in the Sahara Desert.

3 Experimental Physics Methods

3.1 The thermodynamics method

We construct a semi-permeable membrane which lets everything but lions pass through. This we drag across the desert.

3.2 The atomic fission method

We irradiate the desert with slow neutrons. The lion becomes radioactive and starts to disintegrate. Once the disintegration process is progressed far enough the lion will be unable to resist.

3.3 The magneto-optical method

We plant a large, lense shaped field with cat mint (nepeta cataria) such that its axis is parallel to the direction of the horizontal component of the earth’s magnetic field. We put the cage in one of the field’s foci. Throughout the desert we distribute large amounts of magnetized spinach (spinacia oleracea) which has, as everybody knows, a high iron content. The spinach is eaten by vegetarian desert inhabitants which in turn are eaten by the lions. Afterwards the lions are oriented parallel to the earth’s magnetic field and the resulting lion beam is focussed on the cage by the cat mint lense.

[1] After Hilbert, cf. E. W. Hobson, “The Theory of Functions of a Real Variable and the Theory of Fourier’s Series” (1927), vol. 1, pp 456-457
[2] H. Seifert and W. Threlfall, “Lehrbuch der Topologie” (1934), pp 2-3
[3] According to the Picard theorem (W. F. Osgood, Lehrbuch der Funktionentheorie, vol 1 (1928), p 178) it is possible to catch every lion except for at most one.
[4] N. Wiener, “The Fourier Integral and Certain of its Applications” (1933), pp 73-74
[5] N. Wiener, ibid, p 89
[6] cf e.g. H. A. Bethe and R. F. Bacher, “Reviews of Modern Physics”, 8 (1936), pp 82-229, esp. pp 106-107
[7] ibid

Problem: To Catch a Lion in the Sahara Desert.

2 Theoretical Physics Methods

2.1 The Dirac method

We assert that wild lions can ipso facto not be observed in the Sahara desert. Therefore, if there are any lions at all in the desert, they are tame. We leave catching a tame lion as an execise to the reader.

2.2 The Schroedinger method

At every instant there is a non-zero probability of the lion being in the cage. Sit and wait.

2.3 The nuclear physics method

Insert a tame lion into the cage and apply a Majorana exchange operator [6] on it and a wild lion.

As a variant let us assume that we would like to catch (for argument’s sake) a male lion. We insert a tame female lion into the cage and apply the Heisenberg exchange operator [7], exchanging spins.

2.4 A relativistic method

All over the desert we distribute lion bait containing large amounts of the companion star of Sirius. After enough of the bait has been eaten we send a beam of light through the desert. This will curl around the lion so it gets all confused and can be approached without danger.