Book contents
- Frontmatter
- Contents
- Preface and acknowledgements
- Part I Einstein's revolution
- 1 From Aristotle to Hiroshima
- 2 Einstein in a nutshell
- 3 The twin paradox
- 4 How to build an atomic bomb
- 5 The four-dimensional universe
- 6 Time travel is possible
- 7 Can the mind understand the world?
- Part II Philosophical progress
- Part III Frontiers
- Appendix A Spacetime diagrams
- Appendix B Symmetry and Lorentz's minority interpretation
- Appendix C Simple formulas for special relativity
- Appendix D Websites
- Appendix E Guide to further reading
- Index
5 - The four-dimensional universe
from Part I - Einstein's revolution
- Frontmatter
- Contents
- Preface and acknowledgements
- Part I Einstein's revolution
- 1 From Aristotle to Hiroshima
- 2 Einstein in a nutshell
- 3 The twin paradox
- 4 How to build an atomic bomb
- 5 The four-dimensional universe
- 6 Time travel is possible
- 7 Can the mind understand the world?
- Part II Philosophical progress
- Part III Frontiers
- Appendix A Spacetime diagrams
- Appendix B Symmetry and Lorentz's minority interpretation
- Appendix C Simple formulas for special relativity
- Appendix D Websites
- Appendix E Guide to further reading
- Index
Summary
The views of space and time which I wish to lay before you have sprung from the soil of experimental physics, and therein lies their strength. They are radical. Henceforth space by itself, and time by itself, are doomed to fade away into mere shadows, and only a kind of union of the two will preserve an independent reality.
(Minkovski, 1908)Three years after Einstein published his paper on special relativity, his former teacher Hermann Minkovski forever transformed our view of the universe. Einstein had predicted length contraction and time dilation, but Minkovski drew out their radical implications. As the famous quotation above suggests, Minkovski (pronounced Min-koffski) showed that space and time were mixed together in a sort of “union”. We do not live in a three-dimensional universe with time flowing through. Instead, we live in a four-dimensional spacetime. Time is the fourth dimension.
These are strange claims. To assess them, the next two sections lay out some important philosophical issues in general terms. The following sections return to Minkovski and relativity theory.
Is the world made of events?
A tennis ball is real. A tennis court and tennis players are real. But is a tennis match real? Common sense and philosophers like Aristotle assert that the basic things in the universe are ordinary objects like human beings, tennis balls and trees. Modern science disagrees, and says instead that atoms or quarks are basic; human beings and tennis balls are built up from these smaller particles.
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- Information
- Space, Time and EinsteinAn Introduction, pp. 50 - 65Publisher: Acumen PublishingPrint publication year: 2002