2009/06/30 by Jerrold Franklin · 43 citations
Physics and Astronomy · #Classical mechanics #Contraction (grammar) #Experimental and Theoretical Physics Studies #Length contraction #Lorentz transformation #Philosophy #Physics #Quantum and Classical Electrodynamics #Relativity and Gravitational Theory #Special relativity #Theoretical physics #Theory of relativity #Time dilation #physics.class-ph
paper · pdf · doi:10.1088/0143-0807/31/2/006
published in European Journal of Physics 31(2), 291-298 (IOP Publishing) · Modified the discussion in Sec. 2. This version to be published in European Journal of Physics
arxiv created 2010/01/08 · openalex publication_date 2010/01/08 · arxiv updated 2015/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The meaning of Lorentz contraction in special relativity and its connection with Bell’s spaceships parable is discussed. The motion of Bell’s spaceships is then compared with the accelerated motion of a rigid body. We have tried to write this in a simple form that could be used to correct students ’ misconceptions due to conflicting earlier treatments. 1 “Lorentz contraction ” in special relativity We have put the term “Lorentz contraction ” in quotes, because, as we will explain, Lorentz contraction is not what actually occurs for a moving object in special relativity (SR). This is well known to most physicists, but too often “Lorentz contraction ” is given a spurious physical reality. Lorentz contraction is so called because H. A. Lorentz proposed an actual physical contraction of a moving object as an explanation of the null result of the Michaelson-Morley experiment, thus preserving the aether[1]. Lorentz’s equation for the length L ′ of a rod moving at velocity v was 1 L ′ = L/γ, with γ = 1 √ , (1) 1 − v2 where L is the length the rod would have at rest. The same equation with similar motivation had been suggested previously by G. F. Fitzgerald[2], and the effect is often called “Lorentz-Fitzgerald contraction”. Lorentz and Fitzgerald attributed this physical contraction to new electromagnetic molecular forces within a moving rod with concomitant stresses and strains. Although there is an equation identical to Eq. (1) in special relativity, ∗ Internet address: