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An Amazing Story: From the Cave Man to the Apollo Mission

An Amazing Story: From the Cave Man to the Apollo Mission

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218



The Intelligible Universe



from the Americas, like the ones elaborated by the Mayas and the

Aztecs.

Contemporary astrophysical cosmology which, for the first time in

history, has attempted a systematic and coherent description of the

totality of matter and energy in the Universe and their interactions has

been successful in achieving an harmonic combination of precise

observations and elegant mathematical theory to make up a unitary

scientific discipline. As professor Murray Gell–Mann, winner of the

Physics Nobel Prize in 1969 said2 some time ago it is surprising that a

handful of beings, inhabitants of a small planet circling an insignificant

star, have been able to trace back their origin to the beginning, that a

“grain of dust” has been able to grips “the entire universe”.



Fig. 10.2. Aztec Calendar.



The amazing intellectual adventure begins with Erathostenes an

Hipparcos. Goes from Buridan to Copernicus and Kepler. Receives

decisive impetus with Newton. Reaches maturity with Einstein and

Lemaitre, on one side, and with Hubble, Penzias and Wilson on the

other. Torwards the end of the 20th century, through large scale space

projects such as NASA’s “COBE” (Cosmic Background Explorer), the

“Hubble” space telescope, and the European space mission “Hipparcos”,



An Amazing Story: From the Cave Man to the Apollo Mission



219



it culminates in a coherent picture of the physical universe. All of it,

together with to day’s current projects such as the one systematically

observing Type Ia Supernovae, allow us to follow in broad strokes the

thermal history of the universe from the Big Bang to the present epoque.

A universe formed by material particles (grouped in galaxies stars and

cosmic dust) and by pure radiation (photons) everything in rapid radial

expansion in a grand cosmic scale.



Fig. 10.3. A. Einstein.



Einstein’s cosmological equations, supplemented by reasonable

estimates for the time elapsed since the Big Bang (“age” of the universe)

and for the Hubble parameter ( H 0 = Rɺ0 / R0 ) giving the present ratio of

the local expansion speed to the cosmic radius (measured from the center

of expansion of the cosmic background radiation) allow one to detect a

sequence of events, from the beginning (Big Bang) to the present

epoque, events which have taken place as the cosmos was expanding and

getting cooler. In the first few minutes, as beautifully described in a

famous book, Steve Weinberg3 (another distinguished Physic Nobel

Prize winner), the primordial nucleosynthesis of 4He and other light

elements took place from protons and neutrons in thermal equilibrium at

temperatures of the order of Tns ~ 108 K.



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The Intelligible Universe



Approximately half a million years after the Big Bang, the cosmic

plasma made up of protons 4He nuclei and electrons was cool enough to

give rise to bound atoms. The universe then became transparent 4He

nuclei and electrons were cool enough to give rise to bound atoms. When

the universe became transparent,4 and under the attraction of gravity,

protostars and protogalaxies begun to form.

From the time of the first galaxies and stars to the present époque,

approximately thirteen billion (13 × 109) years have elapsed. During this

long time span the universe has not ceased to expand and cool.

All along, our galaxy, the Via Lactea or Milky Way, acquired its

present shape. The Sun, as a second or third generation star, formed out

of cosmic dust and acquired its present form. The solar system, formed

by the planets (in greek “planet” = vagabond), including the Earth-Moon

system, our “habitant”, took form.

About one billion years after the Earth took form, the physical

conditions (hydrosphere, atmosphere) required to house living organisms

(perhaps blue and green algae) were in place. And life begun on Earth.

An event no less astonishing than the Creation of the Universe.



Fig. 10.4. Andromeda.



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221



The observable universe is finite, i.e. it has an enormous mass, but

finite a very large spatial extent, but finite, and, due to the fact that even

if the expansion speed has been very large, being finite, the time elapsed

from the beginning till now must have been necessarily finite. [Of

course, we cannot observe infinite quantities of mass, length or time,

even with the wonderful instruments presently at our disposal].



Fig. 10.5. Solar System.



If we estimate the number of observable galaxies in 1011 to 1012, and

the number of stars in each one of then in 1011 to 1012, with an average

mass of the order of the solar mass (2 × 1033 g) the resulting total number

of massive particles in the universe, with a mass mp = mn ≈ 1.67 × 10-23 g

(the proton/neutron mass), is of the order of 1078 to 1080 particles.

Enormous, evidently, but finite.

We cannot discard that more material particles of some kind are

filling the universe. For the moment these particles have not been found.

In the mean time a frantic search goes on, but even if great quantities of

“dark matter” exists in the universe, it has been estimated in ten times, at

most thirty times, the estimated baryonic mass actually existing as



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The Intelligible Universe



protons and heavier nuclei. And multiplying a finite number by ten or

thirty would still give a finite number.

Our Via Lactea5 is one of those great disk shaped spiral galaxies so

abundant in the universe. It is very similar to the Andromeda galaxy, our

close companion. With it, and other thirty smaller nearby galactic

systems, forms what is known as the Local Group.

The diameter for the Via Lactea is about 30 kpc (1pc = 3.26 light years =

3.08 × 101 8m).

The approximate distance from the Sun to the center of gravity of the

Via Lactea is about 8 to 9 kpc. Our galaxy, like other analogous spiral

galaxies is rotating around its center of mass at about 220 km/sec. in the

point corresponding to the Sun. A full rotation, i.e. a rotation of 2π

radians, takes place in about 250 × 106 years. This means that, since its

formation, about 13 × 109 years ago it has gone over more than 50 full

rotations. Its central mass, leaving aside its massive halo, is about 1011

solar masses. The proportion of interstellar to stellar mass within the

galaxy is about 10%. The data supplied by the space mission

“Hipparcos” provide a priceless information on our Via Lactea, much

more precise than available until recently.

The most important star for us is, of course, the Sun. Many national or

supranational flags, such as those of the United States of America or the

European Union use symbolically stars for their constituent units. My

good friend Professor Kenkichi Okada, from the Nagoya Institute of

Technology, used to say that for him the most beautiful of all these flags

was the flag with a single star, the Rising Sun.

Our planet, the “blue planet”, together with the other planets, circles

the Sun. The names of Buridan, Oresme, Corpenicus, Galileo, Tycho

Brahe and Kepler signal the way to the definitive description of the

planetary motions, the heliocentric theory which would allow Newton to

formulate his famous law of universal gravitation.

And Newton said6 in his “Principia”: “This most beautiful system of

Sun, Planets and Comets could only proceed from the counsel and

dominion of an intelligent and powerful Being”.

Some philosophers of the Enlightenment, including Immanuel Kant,

took for granted that any and all planets of our solar system were

inhabited by beings with different degrees of intelligence. According to



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223



Kant, the inhabitants of Venus, with a torrid climate (because of its

closer proximity to the Sun) should be brutes compared with men, while

the inhabitants of Mars (further from the Sun and cooler than the Earth)

must be geniuses, compared with whom Newton’s could only be

considered a crude and vulgar intelligence.7

In the latest decades of the 20th century NASA’s space probes have

been unable to detect life at these planets, to say nothing of intelligent

life.

A list can be made with the main cosmic pre-conditions necessary to

support life, the type of life which is abundantly evident in our planet

today:

1st) The numerical values of the physical universal constants

quantitatively determining the four fundamental interactions

(gravitational, electromagnetic, nuclear strong, and nuclear weak).

2nd) The primordial nucleosynthesis of 4He in the adequate proportion

at temperatures of the order of 108 K and determinant of the nuclear

reactions within the first protostars.

3rd) The actual existence of massive stable nuclear isotopes

synthesized in the center of stars.

4th) The actual existence of stable atoms at temperatures below

4 × 103 K.

5th) The continued existence of stars burning fist hydrogen for billions

of years, then helium and so forth.

6th) The previous existence of very massive protostars capable of

producing relatively light elements such as C, O, N, S, necessary to form

part of planets as constituents of organic living matter.

7th) The simultaneous existence of heavier elements like Fe, Ni, Co

capable of forming a central magnetic nucleus of an Earth-like planet,

and others like Mg, Ca, Sr, Ba…capable of forming the external mantle.

8th) The formation of a planetary body with sufficient mass at an

adequate distance form the central star (not too far, not too close) so that

the mean temperature in the planet surface is of the order of 300º K,

intermediate between the melting and boiling points of water H2O.

9th) The requirement that the planet has a minimum mass to hold an

atmosphere rich in O2 and N2.



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The Intelligible Universe



10th) That the planet in question (the Earth) has a large satellite

capable of stabilizing its rotation around an axis at an angle adequate to

insure the seasonal cycles, avoiding extreme maxima and minima for the

planet surface temperature.

11th) That it has a large planetary companion, such as Jupiter, capable

of protecting it from large asteroids and meteors.

12th) The presence of ions in the high atmosphere (ionosphere)

capable, under the action of the planetary magnetic filed, of making up

some kind of van Allen belt protecting the planet from too much cosmic

radiation. If the Sun, instead of being located in the outskirts, were close

to the galaxy center, cosmic radiation would kill all life in the planet.

13th) The existence in the planet of abundant water whose molecule

has such exceptional chemical properties that no other substance has

even remotely regarding fitness to the elemental activities of living

systems.

14th) The possible existence (and this is truly astonishing) of actual

self-replicating macromolecules, such as DNA, with a characteristic

structure and a sequence of components, A = Adenine, G = Guanine, C =

Citosine, T = Timine, capable of making possible the complex diversity

of life as seen on Earth today.

The list could go on and on, with no end in sight.

In particular, without the actual possibility of photosynthesis, which

synthesizes organic matter taking advantage of the continuous flux of

solar energy, consuming CO2 and liberating O2, vegetation and animal

life on the planet depending on it would be impossible.

The simplest organisms are unicellular, but even the most elementary

cell is a tremendously complex organism. And life itself is very difficult

to define: a cell just before dying is almost chemically undistinguishable

form a cell just after dying.

Around the middle of the 20th century, X-ray diffractometry, an

experimental technique which von Laue, the Bragg’s (father and son)

and Debye pioneered, began to be applied to study the structure of

organic matter. Basic discoveries for Molecular Biology followed in

quick succession: the double helix structure of DNA (Watson & Crick,



An Amazing Story: From the Cave Man to the Apollo Mission



225



1953), the structure of myoglobine, the first protein (Sanger, 1957) and

the structure of Hemoglobine (Perutz, 1959).

All living organisms, from the most elementary bacteria to the most

complex and developed mammal, are organisms that possess their

characteristic DNA, with its genetic code, capable of ordering its

development, with the corresponding mRNA and proteins, which control

its metabolism, its immunologic defenses and its reproductive system.

All are made up of the same basic elementary components. The mRNA,

carrier of the information contained in the DNA from the nucleus to

other locations in the cell, has a structure analogous to that of the DNA,

and the proteins are macromolecules made up of a central nucleus of

hydrophobic aminoacids and a long chain of hydrophilic aminoacids

folded irregularly, with successive segments of the long chain linked by

hydrogen bonds at specific far away points. There are a total of twenty

aminoacids, each with an amino group (NH2) and a carboxyl group

(COOH) connected by a CH group from which hangs a chain, different

for each aminoacid, which gives it its specific biochemical properties.

When did life appear on the Earth? We know that the initial

atmospheric and its physical conditions were not hospitable to life when

it was formed, 4.6 × 109 years ago. However, there are fossil remnants

which indicate that 3.5 × 109 years ago there was life already.

Francis Crick, famous biochemist and Nobel Prize winner, in this

book “Life Itself ”, says: “An honest man, armed with all the knowledge

available to us now, could only state that in some sense, the origin of life

appears at the moment to be almost a miracle, so many ate the conditions

which would have had to have been satisfied to get it going”.

This does not exclude the possibility that some future discovery might

clarify the conditions under which life could appear on Earth, and even

the conditions under which and evolution process leading to the higher

vertebrates could be envisaged. But, in all appearance, this process could

not be a blind, random process. Everything points to a contingent,

therefore not necessary process, made possible by some extraordinarily

favorable initial conditions.

Freeman Dyson, theoretical physicist and Templeton Prize winner,

nothing that many chemists and biochemists believe that there may be

millions of planets in our galaxy with intelligent habitants which might



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The Intelligible Universe



have achieved advanced technologies like ours, concludes, after careful

consideration, that noting resembling a massive technological conquest

has taken place in our galaxy, making unlikely the existence of such

intelligent begins.

Paul Dirac (1902–1984), one of the pioneers of Quantum Mechanics,

which in his youth is on record as leaning to atheist and Marxism, said

with reference to the privileged and exceptional character of the Earth as

a habitable planet, at a congress help in Lindau (1972) that if the

occurrence of other inhabited planets in the cosmos were a frequent

occurrence, it would speak against the existence of God, while, if it were

something exceptional, unique, it would provide a powerful argument to

affirm God’s existence (Quoted by A. Herfiel, in “La Ciencia actual y

Dios”, Madrid: 1977).

The first fossil remnants attributed to unicellular living beings have

been found in Australian rocks of some three and a half billion years of

age containing layers of carbonaceous material. They correspond to

organisms with a biochemical complexity comparable to that of living

organisms now.

An important leap forward, according to the experts, took place when

unicellular green algae appeared on the scene. These algae were capable

of making photosynthesis, which takes advantage of water and CO2 to

synthesize carbohydrates and release free oxygen to the atmosphere. The

combined effects of plate techtonichs and comet and asteroid

bombardments had been building up the hydrosphere and the atmosphere

of the planet, together with those primordial biochemical process, to rise

the oxygen level in the atmosphere to its present level about two billion

years ago.

Finally, after a series of catastrophic extinctions, no less than five in

the last half billion years appeared the vertebrates. And, just around the

time of the latest glaciations, men.

It is said that the human genome differs only in 1% from that a

chimpanzee. But, there must be something else than the mere genome.

Men, “the trousered apes”, are the only ones who smile, the only ones

who have conquered fire (and much later electricity), who have

cultivated the land, growing wheat, rice, corn…, who have tamed other

animals for their own benefit.



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The only ones who speak, write (in a hundred alphabets) make

symbols, sing and dance and play guitar, organize great Olympiads and

build great walls (like in China), large pyramids (like in Egypt) or

astonishingly beautiful cathedrals (like in Europe).

The only ones that communicate with each other at the speed of light,

that move from one place to another with supersonic speed; the only ones

that make art (music, painting, literature); the only ones who make

history; the only ones who make science (mathematics, physics,

chemistry…); the only ones who have traveled to the Moon.

And the only ones who have traced back cosmic history to the Big

Bang, approximately 13.7 billion years ago.



Bibliography

1. S. L. Jaki, “Science and Creation” (New York: University Press of America, 1990).

2. “National Geographic” 137 (May 1985) p. 662.

3. S. Weinberg, “The first three minutes” (New York: Bantam Books, 3rd printing,

1980).

4. J.C. Matter and J. Boslough, “The very first light” (London: Penguin Books, 1998).

5. H. Elsässer, “La Vía Láctea” en “Cosmología Astrofísica”, Eds: J. A. Gonzalo, J. L.

Sánchez Gómez, M. A. Alario (Madrid; Alianza Universidad, 1995).

6. Sir Isaac Newton, “Mathematical Principles of Natural Philosophy and Hys Sistem of

the World” translated and edited by F. Cajori, p. 554 (University of California Press:

Berkeley, 1934).

7. “Allgemeine Naturgeschichte and Theoriedes Himmels”, Werke I, 360.



Chapter 11



From the Big Bang to the Present



The Universe as it appears now is basically homogeneous and isotropic,

therefore with spherical symmetry; the constituent galaxies are moving

radially away from each other with speeds proportional to the distances

between them, with a local specific expansion rate given by H 0 = Rɺ0 / R0;

this fact together with the estimated age of the oldest stars in our galaxy

(and those in other galaxies), which is of the order of t0 (the time elapsed

since the Big-Bang) allows us to determine a well defined origin in time

for the cosmic expansion; the relative abundance of 4He, and other

light elements (which have a “primordial” origin) allows us to put a

specific bound to the cosmic expansion rate at the time of the 4He

nucleosynthesis; finally, the present equivalent temperature (T0) of the

cosmic background radiation, combined with the ionization/formation

temperature of atoms (Taf) taking place out of the preexisting plasma of

nuclei (mostly H and 4He) and electrons (a temperature which happens to

coincide almost exactly with the temperature at which radiation and

matter energy densities are equal (Teq)), allow the determination of

the characteristic cosmic temperature (T+) at which the first stars and

galaxies began to exist. This temperature is directly related to the

characteristic radius, (Schwarzschild radius) of a universe with a total

finite mass Mu (i.e. R+= 2 GMu /c2).

Consequently, the Big-Bang can be visualized going back in time

(reversing the present galactic stampede) and reconstructing cosmic

requirements, at least tentatively, to the cosmic conditions when the

universe was much smaller, much more dense and hot that it is at

present. Starting from the present phase of the expansion, in which the



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