195
© Springer Nature Switzerland AG 2021
I. Chinnici, G. Consolmagno (eds.), Angelo Secchi and Nineteenth Century Science,
Historical & Cultural Astronomy, https://doi.org/10.1007/978-3-030-58384-2_11
Chapter 11
Secchi’s Book on “The Unity of Physical
Forces”
Roberto Capuzzo-Dolcetta
11.1 Introduction
One of the main challenges of modern physics is finding a complete unification
theory for the four fundamental forces: (1) gravitational, which is long range without any possible shield; (2) electromagnetic, which is long range and can be
shielded; (3) “weak” nuclear force, which is short range; and (4) “strong” nuclear
force, with a very short range of action. The dream of finding a unique theory able
to explain all the above physical forces puzzled Albert Einstein (1879–1955) during
his final period of scientific activity, up to the middle of the last century.
In Secchi’s time the unification of physical forces did not constitute a topic under
debate. But in fact, the first theoretical unification has already been done 200
years earlier by Isaac Newton (in his Principia Mathematica Philosophiae Naturalis)
who clarified that the gravity acting at the surface of the Earth – the classic falling
apple – is the same force that makes the Moon revolve around the Earth and the
planets around the Sun. Another profound unifying theory was included in the work
of James C. Maxwell (1831–1879) in 1865 (one year after the publication of the
Secchi’s L’Unità delle forze fisiche book) where he presented his famous set of differential equations coupling the electric and magnetic properties of matter and the
speed of light.
Interest in the topic of the unification of physical forces has grown significantly
in more recent times. In the second half of the last century, the unification of the
electromagnetic and weak nuclear forces was accomplished, thanks to the efforts of
scientists like Sheldon Glashow (b. 1932), Abdus Salam (1926–1996), and Steven
Weinberg (b. 1933), who were awarded the 1979 Nobel Prize in physics for their
work. Their theory says that these two forces are but different aspects of the same
R. Capuzzo-Dolcetta (*)
Department of Physics, Sapienza, Universita` di Roma, Rome, Italy
e-mail: roberto.capuzzodolcetta@uniroma1.it
© Springer Nature Switzerland AG 2021
I. Chinnici, G. Consolmagno (eds.), Angelo Secchi and Nineteenth Century Science,
Historical & Cultural Astronomy, https://doi.org/10.1007/978-3-030-58384-2_11
Chapter 11
Secchi’s Book on “The Unity of Physical
Forces”
Roberto Capuzzo-Dolcetta
11.1 Introduction
One of the main challenges of modern physics is finding a complete unification
theory for the four fundamental forces: (1) gravitational, which is long range without any possible shield; (2) electromagnetic, which is long range and can be
shielded; (3) “weak” nuclear force, which is short range; and (4) “strong” nuclear
force, with a very short range of action. The dream of finding a unique theory able
to explain all the above physical forces puzzled Albert Einstein (1879–1955) during
his final period of scientific activity, up to the middle of the last century.
In Secchi’s time the unification of physical forces did not constitute a topic under
debate. But in fact, the first theoretical unification has already been done 200
years earlier by Isaac Newton (in his Principia Mathematica Philosophiae Naturalis)
who clarified that the gravity acting at the surface of the Earth – the classic falling
apple – is the same force that makes the Moon revolve around the Earth and the
planets around the Sun. Another profound unifying theory was included in the work
of James C. Maxwell (1831–1879) in 1865 (one year after the publication of the
Secchi’s L’Unità delle forze fisiche book) where he presented his famous set of differential equations coupling the electric and magnetic properties of matter and the
speed of light.
Interest in the topic of the unification of physical forces has grown significantly
in more recent times. In the second half of the last century, the unification of the
electromagnetic and weak nuclear forces was accomplished, thanks to the efforts of
scientists like Sheldon Glashow (b. 1932), Abdus Salam (1926–1996), and Steven
Weinberg (b. 1933), who were awarded the 1979 Nobel Prize in physics for their
work. Their theory says that these two forces are but different aspects of the same
R. Capuzzo-Dolcetta (*)
Department of Physics, Sapienza, Universita` di Roma, Rome, Italy
e-mail: roberto.capuzzodolcetta@uniroma1.it