What is the speed of light in a vacuum?

Approximately 299,792 kilometers per second.

How does the speed of light impact causality?

It maintains causality and prevents instantaneous information flow.

The universe would lack causality and mass.

It is crucial for theories like relativity and quantum mechanics.

Planck quantified light as a quantum object, while Einstein established its constant speed.

Max Planck's theory in 1900 quantified light as a quantum object with wave-like properties, shifting the understanding of light from uncertain duality to a quantifiable entity.
The constant speed of light in a vacuum, as established by Albert Einstein's special relativity, is crucial for upholding causality and locality in the universe, preventing instantaneous connections between events and maintaining the fundamental laws of physics.

What is the speed of light in a vacuum?
Approximately 299,792 kilometers per second.
How does the speed of light impact causality?
It maintains causality and prevents instantaneous information flow.
What would happen if the speed of light were infinite?
The universe would lack causality and mass.
How does the speed of light impact modern physics?
It is crucial for theories like relativity and quantum mechanics.
How did Max Planck and Albert Einstein contribute to the study of light?
Planck quantified light as a quantum object, while Einstein established its constant speed.

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Light was initially unclear if it was a particle or a wave, behaving as both in different experiments.
Max Planck's theory of black body radiation in 1900 quantified light, revealing it as a quantum object with wave-like properties.
Albert Einstein's special relativity in 1905 debunked the concept of the ether, establishing light's constant speed in a vacuum as the speed of light.
The speed of light is determined by vacuum permittivity and permeability, which limit its speed due to space's resistance to electromagnetic wave propagation.
The finite speed of light is crucial for maintaining causality and locality in the universe, preventing instantaneous information flow and ensuring events are not universally connected.
A universe with an infinite speed of light would lack causality, leading to a lack of agreement on the order of events and the history of the universe.
If the speed of light were infinite, the universe would be massless, as mass formation requires energy inversely proportional to the speed of light squared.
The speed of light is constant in a vacuum, regardless of the observer's motion, ensuring a universal speed limit and maintaining the laws of physics.
Altering the speed of light would invalidate modern physics, including relativity and quantum field theory, reverting to a classical Newtonian world without spacetime.