Steven Weinberg: Theory

Steven Weinberg is American theoretical physicist. Explore interesting quotes on theory.
Steven Weinberg: 92   quotes 48   likes

“In fact, there is something puzzling about the Higgs mass we now do observe. It is generally known as the “hierarchy problem.” Since it is the Higgs mass that sets the scale for the masses of all other known elementary particles, one might guess that it should be similar to another mass that plays a fundamental role in physics, the so-called Planck mass, which is the fundamental unit of mass in the theory of gravitation. (It is the mass of hypothetical particles whose gravitational attraction for one another would be as strong as the electric force between two electrons separated by the same distance.) But the Planck mass is about a hundred thousand trillion times larger than the Higgs mass. So, although the Higgs particle is so heavy that a giant particle collider was needed to create it, we still have to ask, why is the Higgs mass so small?”

Steven Weinberg

"The Big Higgs Question" http://www.nybooks.com/daily/2012/07/09/big-higgs-question/, The New York Review of Books, 9 July 2012

Problem , Strong , Time

“Our mistake is not that we take our theories too seriously, but that we do not take them seriously enough. It is always hard to realize that these numbers and equations we play with at our desks have something to do with the real world. …The most important thing accomplished by the three-degree radiation background in 1965 was to force us to take seriously the idea that there was an early universe.”

Steven Weinberg

1977
The First Three Minutes (1977; second edition 1993)

World , Idea , Universe

“Considering the pervasive importance of quantum mechanics in modern physics, it is odd how rarely one hears of efforts to test quantum mechanics experimentally with high precision.…The trouble is that it is very difficult to find any logically consistent generalization of quantum mechanics. One obvious target for generalization is the linearity of quantum mechanics, but if we arbitrarily add nonlinear terms to the Schrodinger equation, how do we know that the theory we obtain will have a sensible physical interpretation? At least in part, it is the dearth of generalized versions of quantum mechanics that has made it so hard to plan experimental tests of quantum mechanics.”

Steven Weinberg

"Testing Quantum Mechanics" http://www.sciencedirect.com/science/article/pii/0003491689902765, Annals of Physics (1989)

Effort , Parting

“It seems that scientists are often attracted to beautiful theories in the way that insects are attracted to flowers — not by logical deduction, but by something like a sense of smell.”

Steven Weinberg

Physics Today (November 2005) page 35

Beauty , Way , Flowers , Sense

“Symmetry is not enough by itself. In electromagnetism, for example, if you write down all the symmetries we know, such as Lorentz invariance and gauge invariance, you don’t get a unique theory that predicts the magnetic moment of the electron. The only way to do that is to add the principle of renormalisability – which dictates a high degree of simplicity in the theory and excludes these additional terms that would have changed the magnetic moment of the electron from the value Schwinger calculated in 1948.”

Steven Weinberg

as quoted in an interview by Matthew Chalmers: [Model physicist, CERN Courier, 13 October 2017, http://cerncourier.com/cws/article/cern/70138]

Way , Gauge , Change

“Heisenberg’s starting point was the philosophical judgment, that a physical theory should not concern itself with things like electron orbits in atoms that can never be observed. This is a risky assumption, but in this case it served Heisenberg well.”

Steven Weinberg

Source: Lectures on Quantum Mechanics (2012, 2nd ed. 2015), Ch. 1: Historical Introduction

“In this derivation Bohr had relied on the old idea of classical radiation theory, that the frequencies of spectral lines should agree with the frequency of the electron’s orbital motion, but he had assumed this only for the largest orbits, with large n. The light frequencies he calculated for transitions between lower states, such as n=2 → n=1, did not at all agree with the orbital frequency of the initial or final state. So Bohr’s work represented another large step away from classical physics.”

Steven Weinberg

Source: Lectures on Quantum Mechanics (2012, 2nd ed. 2015), Ch. 1: Historical Introduction

Light , Idea

“The last thirty years of Einstein's life were largely devoted to a search for a so-called unified field theory that would unify James Clerk Maxwell's theory of electromagnetism with the general theory of relativity, Einstein's theory of gravitation. Einstein's attempt was not successful, and with hindsight we can now see that it was misconceived. Not only did Einstein reject quantum mechanics; the scope of his effort was too narrow. … Nevertheless Einstein's struggle is our struggle today. It is the search for a final theory.”

Steven Weinberg

page 18, 2nd edition https://books.google.com/books?id=Qd0MEtsBr7oC&pg=PA18
Dreams of a Final Theory (1992; 2nd edition 1994)

Effort , Life , Success , Search

“It is with Isaac Newton that the modern dream of a final theory really begins.”

Steven Weinberg

page 11, 2nd edition https://books.google.com/books?id=Qd0MEtsBr7oC&pg=PA11
Dreams of a Final Theory (1992; 2nd edition 1994)

Dreams

“The years since the mid-1970s have been the most frustrating in the history of particle physics. We are paying the price of our own success: theory has advanced so far that further progress will require the study of processes at energies far beyond the reach of existing facilities. In order to break our of this impasse, physicists began in 1982 to develop plans for a scientific project of unprecedented size and cost, known as the Superconducting Super Collider.”

Steven Weinberg

page 4, 2nd edition https://books.google.com/books?id=Qd0MEtsBr7oC&pg=PA4
Dreams of a Final Theory (1992; 2nd edition 1994)

Study , History , Success

“My own conclusion is that today there is no interpretation of quantum mechanics that does not have serious flaws. This view is not universally shared. Indeed, many physicists are satisfied with their own interpretation of quantum mechanics. But different physicists are satisfied with different interpretations. In my view, we ought to take seriously the possibility of finding some more satisfactory other theory, to which quantum mechanics is only a good approximation.”

Steven Weinberg

Source: Lectures on Quantum Mechanics (2012, 2nd ed. 2015), Ch. 3: General Principles of Quantum Mechanics

Universe