The fastest-moving thing in the universe is light. Will we experience stranger things if light travels very slowly?

Imagine you are stuck in a dark room, unable to see anything, and all your efforts to escape are going in vain. Out of nowhere, you found a matchbox in that room. What will be your reaction? Because of just one item, light, you will consider yourself the luckiest person a. live. 

That is the significance of light. It not only brightens the outside world, but it also helps a person build a ray of optimism within themselves.

Speed of light and other relatable terms

‘Nature decrees that we do not exceed the speed of light. All other impossibilities are optional’― Robert Brault.

Light, often known as visible light, is electromagnetic radiation that the human eye can perceive. Between infrared and ultraviolet ranges, visible light is a category that has wavelengths between 400 and 700 nanometres. The above definition was a zest about light and its wavelength.

But what about the speed? The speed at which light waves travel through various materials is called the speed of light. The speed of light in a vacuum is now precisely 299,792,458 meters per second. Isn’t it a cosmic number? What if, by any chance, we can reduce the speed of light through any means or experiment? Is it possible? This blog explores the dimensions related to the speed of light and various questions associated with the same.

• Firstly, we will try to understand a few concepts about the speed of light.

Scientists consider the speed of light as a vital natural constant. Its relevance extends well beyond its purpose in characterizing an electromagnetic wave characteristic. It serves as an upper limit on signal transmission rates along with the material particle speeds. Moreover, light is also the universe’s only limiting velocity.

• Light from a mobile source travels at the same speed as light from a stationary source. It became the most surprising moment for one of the brilliant scientists of the 20th century, Albert Einstein. For example, despite variances in how rapidly the sources of these rays move, light rays from a moving truck, a torch’s light, and big lights on skyscrapers all travel at the same constant pace as recorded by all observers.

Some of you may have wondered at some point in your life, “Why is the speed of light constant”? Why that particular number, with that non-variable value, rather than some other random number? Well, it doesn’t matter what the number is. After all, the measurement for the speed of light is in meters per second. Any number in this subject with units linked to it may have whatever old value it wants because it requires defining the units. 

• The notion of light’s speed connects with the definitions of length and time. Since changing the speed of light will also affect the fine structure constant, the speed of light can’t be anything other than what it is. (Note: The fine Structure Constant has the speed of light, Planck’s constant, and free space permittivity within itself. It has a value of around 0.007).

Finally, what would happen if the speed of light was lower?

Humans are sluggish to light even at their fastest speeds. The closest a person has gone is around 0.0037 per cent of the speed of light, and reaching those levels requires being in some form of a space probe. Let us understand the answer to this question with the help of an example. Suppose the speed of light changes to 250km/hr from 299,792,458 meters per second. Now the effects are described below:

The original equation that Einstein made is exceedingly complicated, and the kinetic energy of an item is only a low-velocity approximation of it. The renowned rest mass energy (E=mc2) is the first component of this equation, usual kinetic energy is the second term, and the third, fourth, fifth (and so on) portions are only significant when the velocity is a larger percentage of light speed. However, if C=250km/hr, those latter factors suddenly become crucial even at slower speeds, and travelling as fast as 0.025km/hr would need thrusters or a nuke automobile.

Having a chat with someone who isn’t close by will cause a lot of frustration. It’d be similar to the tv talks but in person. At this speed of light, sending a message to someone on the other side of the planet would take at least five days and 4 hours.

There would be enough relativistic doppler shift even at running speed to affect the colours around you. A yellow field of grain would seem blue in front of you then fade to deep crimson as it passed behind you if you were driving across it. (Note: When the Source of waves moves concerning an observer, the Doppler effect is detected. We can define the Doppler effect as the effect caused by a moving source of waves that causes an apparent upward shift in frequency for observers facing the Source and a downward change in frequency for observers facing away from the Source).

Key Takeaways 

We have already discussed the consequences of a slower speed of light in the above blog. But do you know what will happen if you reach the speed of light? That is impossible because travelling at the speed of light causes your Mass to expand indefinitely, causing you to slow down. The quicker you go, the more Mass you have, according to relativity.

Also published on Medium.