Menu

Physics Lesson 18.2.4 - The Newtonian System and Speed of Light. The Pseudo-Theory of "Cosmic Ether"

Please provide a rating, it takes seconds and helps us to keep this resource free for all to use

[ 3 Votes ]

Welcome to our Physics lesson on The Newtonian System and Speed of Light. The Pseudo-Theory of "Cosmic Ether", this is the fourth lesson of our suite of physics lessons covering the topic of Classical Principle of Relativity, you can find links to the other lessons within this tutorial and access additional physics learning resources below this lesson.

The Newtonian System and Speed of Light. The Pseudo-Theory of "Cosmic Ether"

Earlier we saw that Newton's laws have the same form in all inertial systems. As a result, every observer sees the same mechanical phenomena that obey to these laws. The question that naturally arises here is: What happens to electromagnetic phenomena in different inertial systems of reference? In particular, what happens when electric and magnetic field-related processes are observed in two different inertial systems of reference? What happens to the EM waves and the propagation of light as an EM wave? All these questions led to the development of Einstein's Theory of Relativity (both special and general).

Annexure: How to Calculate the Speed of Light in Vacuum without any Measuring Tool

In previous Sections (more precisely in Section 11 and 16), we have dealt with two important constants:

  1. Electric constant (the vacuum permittivity) ε0, whose value is 8.854 × 10-12 F/m, and
  2. Magnetic constant (the permeability of free space), whose value is 4π × 10-7 N/A2 or 1.256 × 10-6 N/A2.

Since light is an EM wave, it contains both the electric and magnetic component. Giving that in SI units

1 [F] = 1 A2 ∙ s4/kg ∙ m2

and

1[N] = 1kg ∙ m/s2

we can find an equation for the speed of light in terms of the above constants based on the dimensional analysis, which is

c = 1/ε0 ∙ μ0
= 1/8.854×10-12 A2 ∙ s4/kg ∙ m31.256 × 10-6 kg ∙ m/A2 ∙ s2
= 1/11.12×10-18 s2/m2
= 1/3.335 × 10-9 s/m
= 0.29985×109 m/s
= 299 850 km/s

The small deflection from the experimental value (299 792 km/s) comes because of the rounding made during the above calculations.

You have reached the end of Physics lesson 18.2.4 The Newtonian System and Speed of Light. The Pseudo-Theory of "Cosmic Ether". There are 5 lessons in this physics tutorial covering Classical Principle of Relativity, you can access all the lessons from this tutorial below.

More Classical Principle of Relativity Lessons and Learning Resources

Relativity Learning Material
Tutorial IDPhysics Tutorial TitleTutorialVideo
Tutorial
Revision
Notes
Revision
Questions
18.2Classical Principle of Relativity
Lesson IDPhysics Lesson TitleLessonVideo
Lesson
18.2.1Parametric Equations in Galilean Transformations
18.2.2Galilean Transformations of Velocity
18.2.3The Classical Principle of Relativity
18.2.4The Newtonian System and Speed of Light. The Pseudo-Theory of "Cosmic Ether"
18.2.5Symmetry of the Laws of Classical Physics. The Pseudo-Theory of Cosmic Ether

Whats next?

Enjoy the "The Newtonian System and Speed of Light. The Pseudo-Theory of "Cosmic Ether"" physics lesson? People who liked the "Classical Principle of Relativity lesson found the following resources useful:

  1. Cosmic Ether Feedback. Helps other - Leave a rating for this cosmic ether (see below)
  2. Relativity Physics tutorial: Classical Principle of Relativity. Read the Classical Principle of Relativity physics tutorial and build your physics knowledge of Relativity
  3. Relativity Revision Notes: Classical Principle of Relativity. Print the notes so you can revise the key points covered in the physics tutorial for Classical Principle of Relativity
  4. Relativity Practice Questions: Classical Principle of Relativity. Test and improve your knowledge of Classical Principle of Relativity with example questins and answers
  5. Check your calculations for Relativity questions with our excellent Relativity calculators which contain full equations and calculations clearly displayed line by line. See the Relativity Calculators by iCalculator™ below.
  6. Continuing learning relativity - read our next physics tutorial: Space and Time in Einstein Theory of Relativity

Help others Learning Physics just like you

Please provide a rating, it takes seconds and helps us to keep this resource free for all to use

[ 3 Votes ]

We hope you found this Physics lesson "Classical Principle of Relativity" useful. If you did it would be great if you could spare the time to rate this physics lesson (simply click on the number of stars that match your assessment of this physics learning aide) and/or share on social media, this helps us identify popular tutorials and calculators and expand our free learning resources to support our users around the world have free access to expand their knowledge of physics and other disciplines.

Relativity Calculators by iCalculator™