Física en la Biblia

Alberto Rojo

 

Soy agnóstico. Leo la Biblia como una magnífica catedral literaria y no como la palabra de Dios. Me fascinan (lo que para mí son) sus metáforas, su Sol que se detiene, su mar que se divide, sus panes que se multiplican.

 

Con el tiempo fui anotando citas que quizás no sean metafóricas y que expresen el conocimiento científico del momento o que aludan de algún modo a la física. En el Apocalipsis 21:18, por ejemplo, la ciudad es de oro transparente. El oro, como todos los metales, refleja la luz y, por lo tanto, es opaco. Sin embargo, la luz puede penetrar un poco dentro del metal, de modo que una película de oro de unos cien átomos de espesor puede ser transparente.

 

En 1 Reyes 7:23, Salomón hace fundir un mar perfectamente redondo, de diez “codos” de diámetro y “a su alrededor un cordón de treinta codos”. Hoy sabemos que el cociente entre el perímetro y el diámetro de un círculo, el famoso “Pi”,  es un número cercano a 3, con infinitas cifras azarosas después de la coma (3,141592…).  Reemplazarlo por 3, como en el antiguo testamento, puede ser una aproximación práctica útil, pero claro, tiene su error y hay quienes atacan a la Biblia por esta imprecisión. 

 

En Mateo 16:2  Jesús dice, con cierta validez científica, “Cuando anochece decís ‘Hará buen tiempo porque el cielo está rojo’ ”. Por un lado, en latitudes intermedias las tormentas (en general, no siempre) van de oeste a este. Por otro, debido a la dispersión de la luz en la atmósfera, el sol se ve rojo en los atardeceres. El cielo será rojo en el atardecer si hay nubes al este, y si hay nubes al este la tormenta se está yendo: habrá buen tiempo.

 

Le comenté mi lista a Donald Page, físico católico de la Universidad de Alberta en Canadá, autor de trabajos conocidos en coautoría con el mítico Stephen Hawking (Donald aparece en la película sobre La Breve Historia del Tiempo). Conocía mis ejemplos. De inmediato mencionó Efesios 3:18 donde se habla de “la anchura,  la longitud, la profundidad y la altura” (¡cuatro dimensiones!) del amor de Cristo, lo que podría tomarse como una indicación de un espacio-tiempo, aunque Pablo bien podría estar enfatizando el amor de Cristo agregando una dimensión más que el espacio sin tener en mente al tiempo como la cuarta. 

 

Sobre los ataques a la Biblia por Pi=3, Page puntualiza que el cociente entre el perímetro y el diámetro de un círculo es 3.1415.. sólo cuando el círculo está dibujado en un plano. Pero en una superficie curva (o en un espacio curvo) la cosa no es así: para ir de un punto de un círculo trazado en la Tierra (un paralelo digamos) a su centro (el polo norte) el camino más directo (el radio) es por un meridiano, y se recorre una distancia mayor al radio del mismo círculo en un plano. ¿Se refiere la Biblia a un mar en un espacio curvo? Dudoso, pero “matemáticamente” posible.

 

En Eclesiastés 1:7 también parecería haber algo de física: “Todos los ríos van al mar, pero el mar no se llena. Al lugar de donde los ríos vinieron, allí vuelven para correr de nuevo”. Un mar que no se llena ante el flujo constante de los ríos sugiere una comprensión del ciclo del agua; la lluvia era obviamente conocida y la evaporación era algo seguramente observado en vasijas de agua de modo que la cita insinuaría que el agua evaporada vuelve en forma de lluvia. Desconozco si sabían que el agua evaporada no “desaparece” sino que sigue existiendo, pero la alusión es llamativa.

 

Y por último, el principio. De acuerdo a los modelos aceptados hoy, el Universo tuvo un comienzo, el así llamado “Big-Bang”, que ocurrió al menos hace 10.000.000.000 de años. El hecho de que hubo un comienzo,  de que el mundo no existió siempre, es compatible con la Biblia. Lo conversé con Page. Para él, “La tierra estaba desordenada y vacía” de Génesis 1:2 podría interpretarse como el pre-espacio sin geometría de las teorías actuales de gravedad  y cosmología cuántica. Y el “Sea la luz” de Génesis 1:3 con la formación del fondo de microondas cósmico (una de las evidencias del Big Bang) . Y que los astros “sirvan de señales para las estaciones, los días y los años” de Génesis 1:14 como una ilustración que el tiempo está mal definido en la gravedad cuántica y está dado solo por el movimiento de entidades físicas (sin movimiento de objetos no hay sentido del tiempo). Esto quizás sea estirar demasiado las cosas al leer un texto antiguo con los anteojos de la ciencia actual, y el mismo Page es escéptico de sus enunciados.

 

De cualquier modo, a veces al leerla me olvido de mis dogmas y me entrego a la posibilidad de que sea la obra de una genialidad poética sobrenatural.

 

 

 

Nota posterior: Incluyo el mensaje electrónico de Don Page sobre el tema

 

 

Dear Alberto,

      Thanks for your email.  One passage that immediately came to mind
is Ephesians 3:8, which talks of the breadth and length and height and
depth of the love of Christ, which one might take as an indication of
four-dimensional spacetime, though I suspect that Paul is actually just
emphasizing the magnitude of Christ's love by including more dimensions
than there are of space, without actually having in mind time as the
fourth dimension.  (Maybe if length had been put at the beginning or end
of the list, one might suppose it referred to length in time, but having
it in the middle makes me sceptical, and the words at the beginning and
end are not normally used in English for time, except possibly for deep
time for ancient geological history, though I do not know the Greek usage
that Paul would have been familiar with.)

      Isaiah 40:22 talks about the circle of the earth, which might be
taken to indicate that the earth is round, but I'm not so sure about that
either.  It could alternatively have the meaning of a round flat disk.
Revelation 7:1 and 20:8 talk about the four corners of the earth, which I
would guess is just a picturesque way of talking about the four cardinal
directions, but then if this is picturesque language, then why not also
the one about the circle of the earth?

      "The earth was a formless void" in Genesis 1:2 could be
interpreted as a pre-metric phase in quantum gravity or quantum cosmology,
but I am sure that this is reading modern ideas into what was written
without such ideas.

      "Let there by light" in Genesis 1:3 can similarly be connected
with the early formation of the cosmic microwave background, but again I
think the author just has in mind ordinary visible light that enables all
of us to see.  Of course, such light is part of physics, but it is not a
part of physics outside ordinary experience.

      One might similarly claim that "God separated the light from the
darkness" in Genesis 1:4 could refer to the development of inhomogeneities
in the universe, so that whereas at decoupling the photon distribution was
very nearly homogeneous and isotropic, now with the development of stars,
it is very inhomogeneous and anisotropic.  I suppose I would agree with
this interpretation to the degree that I believe that God gives form to
the universe, and indeed now light is separated to a great degree from
darkness, but I am a bit sceptical that the passage refers to any
particular cosmological epoch.

      It occurred to me that one could use Genesis 1:14, that God let
the lights be for days and years, as an illustration that time is
intrinsically ill-defined in quantum gravity and is essentially given only
by
the motion of physical entities.  Without moving objects, there is not
a clear sense of time.  But again this is something that I am reading into
the ancient text (or using it to illustrate), rather than an idea that I
think was intended there originally.

      On the brass sea in I Kings, I have heard that some have attacked
the Bible for giving an incorrect value pi = 3, and others trying to
defend a precise literal interpretation of the Bible by saying the
diameter was of some rim that stuck out a bit but the circumference was
measured at a slightly smaller neck just below the rim.  But it seems most
likely to me that the values are just approximate, so there is no
discrepancy, though it might suggest that the writers took 3 to be a
reasonably close approximation to pi (e.g., by the nearest integer), if
they thought of the concept of pi at all.  (I.e., did they realize that
the ratio of the circumference to the diameter is the same for all
circles, in flat space we might now say by way of qualification?)

      Ecclesiastes 1:7 does seem to show some physics knowledge:  "All
the rivers run into the sea; yet the sea is not full; unto the place from
whence the rivers come, thither they return again."  It seems to reflect
basic knowledge of flux conservation, that if something is poured into a
container and nothing is taken out, the container will become more full.
>From the fact that the passage does not talk about sea level not
observably getting higher but more about the fact that it could be higher,
there seems to be an implicit admission that the filling rate might be too
small to be observed but that presumably the rivers had been flowing long
enough that the sea would be more full than it is if there were nothing
taking the water out.  (The author did not use the possible Young Earth
Creationist explanation that the sea was too young to be fuller!)  So the
passage does seem to show a knowledge that there must be some sort of
water cycle, though it is not clear to me that it shows the detailed
knowledge that the water returns by evaporation and rain, though I suppose
the rain part would be rather obvious, and evaporation from containers was
also presumably well known, so that it might not have been beyond the
author to put the two ideas together and realize that the water in the sea
evaporates and then comes down as rain, though it isn't obvious to me that
they might have thought of evaporation as just being an annihilation of
the water and hence a violation of the flux conservation thought that
seems to motivate the question of why the sea isn't full.  So whether they
realized that the evaporated water does still exist and then comes down as
rain, I am not clear.  It would be interesting to know!

      One might also note that the preceding verse also seems to
indicate some sort of awareness of some sort of flux conservation, in this
case of air:  "The wind goeth toward the south, and turneth about unto the
north;  it whirleth about continually, and the wind returneth again
according to his circuits."  So if the author had the idea of the air
going in a circuit without being created or annihilated, he might have
assumed that the analogous thing should occur for water.

      I suppose one could use the language of physics to say that
Ecclesiastes emphasizes more the conservation laws and how things stay the
same (nothing new under the sun), whereas other parts of the Bible
emphasize more the second law of thermodynamics and the unidirectional
changes of history.  I had never thought of it this way until now, but
again I am reading my modern physics understandings into the ancient text,
though I would think there is something to the analogy, with cyclic views
of history being more associated with conservation laws and linear views
of time being more associated with the second law of thermodynamics.  Or,
one might say the physics metaphors are mathematical reflections of these
older human metaphors rather than being totally new concepts.

      Well, I'd better get back to work.  If I think of other examples,
I'll try to email them to you.

      Hugh Ross has a number of books trying to tie the Bible to modern
ideas in science, so I am sure that he has many examples, though I am
often rather sceptical that the ancient writers had the same ideas about
physics that are sometimes now read into their writings.



      Best wishes,

      Don