5
Forces That Keep the Universe Together
Space-time is the stage on which the particles are the “actors” playing their
roles. The way the particles communicate with each other and influence
each other’s motion reveals another aspect of natural laws governing the universe [83]. They are the various forces operating in nature that are responsible
for this inter-communication. The forces communicate the “thoughts” from
one actor to the other and affect the development of the “plot” which builds
the universe step by step. (“Thought” is the detailed nature and strength of
the force and “plot” is the motion of the second particle under the influence
of the force.) What the forces are and how they operate is the topic of this
chapter. The forces have their own peculiarities and specialties with just the
right properties that lead ultimately to a universe that is livable by humans and
plants and animals. Is this by “intelligent” design (“anthropic principle”) or
some physical restriction on the laws? This is a question that is being debated,
and we will touch on the broad aspects of this thinking in a later chapter.
5.1 Gravity
There are four known forces in nature. The first one is the force of gravity, the
force that makes the apple fall to the Earth and makes the planets go around the
sun. The laws of gravity were discovered by Sir Isaac Newton. He was born in
1642, in Lincolnshire, England. He published his suggestion on laws of gravity
in 1685 in a seminal work titled “Principia.” He postulated that gravity is
universal and attractive and exists between all objects. Its strength depends on
© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer
Nature Switzerland AG 2021
R. N. Mohapatra, The Neutrino Story: One Tiny Particle’s Grand Role in the Cosmos,
https://doi.org/10.1007/978-3-030-51846-2_5
33
Forces That Keep the Universe Together
Space-time is the stage on which the particles are the “actors” playing their
roles. The way the particles communicate with each other and influence
each other’s motion reveals another aspect of natural laws governing the universe [83]. They are the various forces operating in nature that are responsible
for this inter-communication. The forces communicate the “thoughts” from
one actor to the other and affect the development of the “plot” which builds
the universe step by step. (“Thought” is the detailed nature and strength of
the force and “plot” is the motion of the second particle under the influence
of the force.) What the forces are and how they operate is the topic of this
chapter. The forces have their own peculiarities and specialties with just the
right properties that lead ultimately to a universe that is livable by humans and
plants and animals. Is this by “intelligent” design (“anthropic principle”) or
some physical restriction on the laws? This is a question that is being debated,
and we will touch on the broad aspects of this thinking in a later chapter.
5.1 Gravity
There are four known forces in nature. The first one is the force of gravity, the
force that makes the apple fall to the Earth and makes the planets go around the
sun. The laws of gravity were discovered by Sir Isaac Newton. He was born in
1642, in Lincolnshire, England. He published his suggestion on laws of gravity
in 1685 in a seminal work titled “Principia.” He postulated that gravity is
universal and attractive and exists between all objects. Its strength depends on
© The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer
Nature Switzerland AG 2021
R. N. Mohapatra, The Neutrino Story: One Tiny Particle’s Grand Role in the Cosmos,
https://doi.org/10.1007/978-3-030-51846-2_5
33