iSoul In the beginning is reality.


Ballistic table based on launching from a height and angle with coasting ascent and descent (no drag, no thrust). Note the handy trigonometry identity for range: 2 sin θ cos θ = sin 2θ. This table is in pdf form here.



Initial space angle = θ Initial time angle = φ
Initial height distance = y0 Initial height distime = b0
Elapsed time interval = t Elapsed stance interval = s
Distance downrange or horizontal location = x Distime downrange or horizontal chronation = a
Altitude distance or vertical location = y Altitude distime or vertical chronation = b
Gravitational acceleration = g Levitational retardation = h
Initial velocity = v₀ Initial lenticity = w₀
Initial horizontal velocity = v0x = v0 cos θ Initial horizontal lenticity = w0a = w0 cos φ
Initial vertical velocity = v0y = v0 sin θ Initial vertical lenticity = w0b = w0 sin φ
Horizontal velocity = vx = v0x Horizontal lenticity = wa = w0a
Vertical velocity = vy = v0y – gt Vertical lenticity = wb = w0b – hs
Velocity at apex point: vy = 0 Lenticity at apex instant: wb = 0
Horizontal location x = v0x t Horizontal chronation a = w0a s
Vertical location y = v0yt – ½ gt2 Vertical chronation b = w0bs – ½ hs2
Vertical location at impact point: y = 0 Vertical chronation at impact instant: b = 0
Time of flight to apex tapex = v0y/g Stance of flight to apex sapex = w0b/h
Total time of flight ttotal = 2tapex = 2v0y/g Total stance of flight stotal = 2sapex = 2w0b/h
Distance range to apex xapex = vox voy/g Distime range to apex aapex = woa wob/h
Total distance range xtotal = 2vox voy/g Total distime range atotal = 2woa wob/h
Max altitude distance yapex = ½ v0y2/g Max altitude distime bapex = ½ w0b2/h
Trajectory formula: y = y0 + x tan θ − ½ gx²/v0x2 Trajectory formula: b = b0 + a tan φ − ½ ha²/w0a2

Abstract classical mechanics

The following builds on the book Mathematical Aspects of Classical and Celestial Mechanics, 3rd edition, by Vladimir I. Arnold, Valery V. Kozlov, and Anatoly I. Neishtadt (Springer 2006).

Basic Principles of Classical Mechanics (cf. Chapter 1)

Space and Time

The space where the motion takes place is three-dimensional and Euclidean with a fixed orientation. We shall denote it by E3. We fix some point o ∈ E3 called the “origin of reference”. Then the position of every point s in E3 is uniquely determined by its position vector os = r (whose initial point is o and end point is s). The set of all position vectors forms the three-dimensional vector space ℝ3, which is equipped with the scalar product 〈 , 〉.

The time in which motion takes place has the same structure as the abstract space above. The combined vector space is ℝ3 × ℝ3. The abstractions for space and time are unconnected unless there is defined a fixed relationship between them. Examples of such a fixed relationship include a default rate of motion or a maximum rate of motion. Let us begin without such a relationship.

Position in space is called location and in time is called chronation. The Euclidean metric for space is called length and for time is called duration (or time).

A frame of reference (“frame”) is a method to assign every particle a unique position in a coordinate system of points in ℝ3. Such assignment is known continually and universally, without signals, from the universal extent of the frame. The coordinate system is commonly Cartesian.

A system of reference (“reference system”) is a method to assign every event a unique position in a coordinate system of points in ℝ3 × ℝ3. A reference system is composed of dual frames of reference, one called the space frame and the other called the time frame, such that the time frame is in standard uniform motion relative to the space frame. This requires that given the magnitudes s1 and s2 of any two intervals of the curve of motion in the space frame, then the corresponding intervals of the time frame, t1 and t2, relative to the space frame satisfy the proportion: s1:s2 :: t1:t2.

Read more →

Temporo-spatial rest

Speed is the travel distance per unit of duration (or time interval). Rest in space is a speed of zero. That is, there is no change in location per unit of time. A body does not change location (relative to an inertial observer) while time continues.

But rest in time seems different. It cannot be zero pace because that would mean it takes no time to go a positive distance, right? No, that is not what zero pace means.

Pace is the travel time per unit of distance (or stance interval). Time is the dependent variable and distance is the independent variable.

Consider a race that is about to begin. The runners are in place waiting for the signal to start. The official timer is set to begin. In terms of motion, the runners are at rest with speed of zero. They are not making any distance, but time continues as usual.

What is the pace of the runners in that case? There is no change on the official timer. But the stance continues as usual. For example, if stance is related to the distance from the Sun of a Voyager spacecraft (see here), it continues to increase as usual.

A map with a time scale shows a point for a pace of zero. Despite the distance made by an odologe, a body with a pace of zero remains in the same place in time. It is at rest in time.

Runner about to start

What about an infinite value for pace in time? The Galilean transformation implicitly has an infinite speed of information in space, which makes information spatially ubiquitous since it travels an infinite distance in a finite time. The symmetric Galilean transformation implicitly has an infinite pace of information in time, which makes information temporally ubiquitous since it takes an infinite time to travel a finite distance.

Temporo-spatial Galilean group

The following is based on A Course in Modern Mathematical Physics: Groups, Hilbert Space and Differential Geometry by Peter Szekeres (Cambridge UP, 2004) starting with Example 2.29 on page 54 and modifying it for a temporo-spatial context.

The Galilean group. To find the set of transformations of space and time that preserve the laws of Newtonian mechanics we follow the lead of special relativity and define an event to be a point of R4 characterized by four coordinates (t1, t2, t3, s). Define Galilean time G4 to be the time of events with a structure consisting of three elements:

  1. Distance intervals Δs = s2s1.
  2. The duration intervals Δt = |q2q1| between any pair of simulstanceous events (events having the same stance coordinate, s1 = s2).
  3. Motions of facilial (free) particles, otherwise known as rectilinear motions,
    q(s) = ws + q0,                 (2.19)
    where w and q0 are arbitrary constant vectors.

Read more →

Temporo-spatial mechanics

The following is a temporo-spatial modification of the book Mechanics, Third Edition, Volume I of Course of Theoretical Physics by L. D. Landau and E. M. Lifshitz, (Butterworth-Heinenann, Oxford, 1976).


§1. Generalised co-ordinates

ONE of the fundamental concepts of mechanics is that of a particle¹. By this we mean a body whose dimensions may be neglected in describing its motion. The possibility of so doing depends, of course, on the conditions of the problem concerned. For example, the planets may be regarded as particles in considering their motion about the Sun, but not in considering their rotation about their axes.

The position of a particle in time is defined by its chronation vector t, whose components are its Cartesian co-ordinates x, y, z. The derivative w = dt/ds of t with respect to the stance s is called the lenticity of the particle, and the second derivative d2t/ds2 is its retardation. In what follows we shall denote differentiation with respect to stance by placing a dot above a letter, e.g.: w = ġ.

To define the position of a system of N particles in time, it is necessary to specify N chronation vectors, i.e. 3N co-ordinates. The number of independent quantities which must be specified in order to define uniquely the position of any system is called the number of degrees of freedom; here, this number is 3N. These quantities need not be the Cartesian co-ordinates of the particles, and the conditions of the problem may render some other choice of coordinates more convenient. Any n quantities g1, g2, …. gn which completely define the position of a system with n degrees of freedom are called generalised co-ordinates of the system, and the derivatives ġi are called its generalised lenticities.

Read more →

Galileo’s method

Extracts about Galileo from Scientific Method: An historical and philosophical introduction by Barry Gower (Routledge, 1997):

Galileo took great pains to ensure that his readers would be persuaded that his conclusions were correct. p. 23

The science of motion was then understood to be a study of the causes of motion, and to be, like any genuine science, a ‘demonstrative’ kind of enquiry. That is to say, experiential knowledge of the facts of motion was superseded by rational knowledge of the causes of those facts, this being accomplished by deductions from fundamental principles, or ‘common notions’, and definitions which were accepted as true. These facts of motion were understood as expressions of common experience rather than as generalisations based upon experiments. This was because the results of the experiments that could be performed were sufficiently uncertain and ambiguous to prevent reliable generalisation; discrepancies between conclusions derived from principles, and experimental results, could be tolerated. The appropriate model of a demonstrative science was Euclidean geometry, where the credibility of a theorem about, say, triangles depends not on how well it fits what we can measure but on its derivability from the basic axioms and definitions of the geometry. p. 23

For Galileo and his contemporaries there was a good reason why demonstration, or proof from first principles, rather than experiment, was required to establish general truths about motion. Any science—scientia—must yield knowledge of what Aristotle had called ‘reasoned facts’, i.e. truths which are both universal and necessary, and such knowledge—philosophical knowledge—can only be arrived at by demonstration. p. 24

there was a long-standing disagreement about the role that mathematics could play in natural philosophy, even though mathematics was able to give certain knowledge. p. 24

In some contexts, notably astronomy and geometry, the more elaborate and intellectually demanding methods of mathematics were often useful and appropriate, but in such contexts it seemed clear that those methods were applicable in so far as what was needed were re-descriptions which could help people formulate accurate predictions. ‘Hypotheses’ which successfully ‘saved the phenomena’, in the sense that they could be used as starting points for derivations of accurate predictions, could meet this need. p. 25

Read more →

Mathematics and beauty

Extracts from Scientific Method in Ptolemy’s Harmonics by Andrew Barker (Cambridge University Press 2004):

Mathematics is not the study of all quantities and all quantitative relations indiscriminately. It is the science of beauty. Its task, at the theoretical level, is to interpret, in terms of ‘rationally’ or mathematically intelligible form, the features, movements or states which, when they are present in perceptible phenomena, constitute their aesthetic excellence. p.264

Those of our senses through which we are able to perceive some things as beautiful are therefore involved in an intimate collaboration with mathematical reason. p.264

Since beauty is the manifestation to the senses of that which reason understands as perfect in form, the senses to which beauty is undetectable lack sensitivity, which sight and hearing possess, to those distinctions which, from a rational point of view, are the most significant. p.265

the mathematical sciences have a single objective, the analysis and understanding of the formal basis of beauty p.266

The conception of mathematical science which Ptolemy has presented is that of a capacity that does not merely analyse sets of quantitative relations, but homes in on those that are of special significance, and discovers the principles on which their significance rests. p.268

Lorentz transformation via symmetry

The following derivation of the Lorentz transformation is slightly revised from the Appendix to Henri Poincaré: a decisive contribution to Relativity by Christian Marchal, originally published in French as Henri Poincaré: une contribution décisive à la Relativité in La Jaune et la Rouge, août-septembre 1999. Marchal is the chief engineer of mines at ONERA, the Office National d’Etudes et de Recherches Aérospatiales. A pdf version is here.


The Lorentz transformation

      It is essential to note that the Lorentz transformation is a direct consequence of the principle of relativity and does not require the invariance of the speed of light.

Let us look for this transformation along two axes Ox and O′x′ moving along each other with the constant relative velocity V.


      O′                                      x′


          O                    OO′ = Vt                                      x

In order to obtain perfect symmetry between the two frames of reference, let us put O′x′ in the other direction.

x′                                                               O′



    O                                                        x

Homogeneity will lead to a linear transformation, and if we choose t = t′ = 0 when the two origins O and O′ cross each other, the transformations (x, t) ® (x′, t′) and (x′, t′) ® (x, t) will be given as follows with eight appropriate constants from A to D′:

(4)                    x′ = Ax + Bt                  ;           t′ = Cx + Dt

x = A′x′ + B′t′               ;           t = C′x′ + D′t′

The Principle of Relativity and symmetry lead to:

(5)                    A = A′;             B = B′;              C = C′;              D = D′

Read more →

Political distinctions

The figure above diagrams several political distinctions. The vertical line distinguishes the political left who are mainly concerned with equality, and the political right who are mainly concerned with liberty. Above the horizontal line distinguishes the religious left and right from the secular left and right below.

The circle distinguishes those within who accept limitations on government and limited rights for citizens. Liberals (which includes the center left) would like more equality and conservatives (which includes the center right) would like more liberty within this arrangement. Change is brought about through evolutionary, lawful means. Outside the circle are revolutionaries, either the radical left who do not accept limitations on equality or the radical right who do not accept limitations on liberty.

Note that liberals and conservatives have much in common. The distinction between evolutionary and revolutionary means should be more significant than that between the left and the right. The distinction between religious goals and secular goals should also be more significant than that between the left and the right. Conservatives and liberals should think of themselves as being on the same side against the radicals. Religious liberals and conservatives have much in common, as have secular liberals and conservatives.

Clocks and frames

A clock consists of two frames of reference. This is seen in an ordinary analogue clock, which is composed of two parts:

Circular Space Frame

The space frame is at rest relative to the observer. The time frame is in uniform angular motion relative to the observer. Measurement of space and time requires both frames. The units marked on the space frame have dual significance: (a) as amounts of space or angles in space, and (b) as amounts of time.

Read more →