The Speed of Light

The Speed of Light and Google Doodle

When I got to see an interesting doodle pasted on google today the 6th of Dec I was really surprised to know that a complex thing like the Speed of Light has been known to us since 340 years, hence forth I went a little deeper into it and fetch some facts & figures out of it although it is later that I’ve decided to put it before you too..

if you know all don’t mind..!

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Google Doodle honouring the anniversary of the determination of the speed of light

 

Prior to a few hundred years ago, it was generally agreed or at least assumed that the speed of light was infinite, when in actuality its just really, really, really fast-  for reference, the speed of light is just slightly slower than the fastest thing in the known universe- a teenage girls response time if Justin Bieber were to say on Twitter, The first to reply to this tweet will be my new girlfriend.

The first known person to question the whole speed of light is infinite thing was the 5th century BC philosopher Empedocles.  Less than a century later, Aristotle would disagree with Empedocles and the argument continued for more than 2,000 years after.

One of the first prominent individuals to actually come up with a tangible experiment to test whether light had a speed was Dutch Scientist, Isaac Beeckman in 1629. Despite living in a time before lasers- which gives me the chills just thinking about- Beeckman understood that, lacking lasers, the basis of any good scientific experiment should always involve explosions of some kind; thus, his experiment involved detonating gunpowder.

Beeckman placed mirrors at various distances from the explosion and asked observers whether they could see any difference in when the flash of light reflected from each mirror reached their eyes.

It wasnt until Danish Astronomer, Ole Römer entered the fray that measurements of the speed of light got serious.

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A portrait of Ole Roemer from 1700

Römer determined that, lacking lasers and explosions, an experiment should always involve outer space.  Thus, he based his observations on the movement of planets themselves, announcing his groundbreaking results on August 22, 1676.

What is the speed of light?

The speed of light is exactly 299,792,458 metres per second. James Bradley came closer to this figure in 1728 with the discovery of what is called the “aberration” of starlight and a speed of 295,000,000 metres per second for light.

But the exact number wasn’t decided upon until 1975, after decades of becoming increasingly specific, when the General Conference on Weights and Measures recommended an official figure.

The symbol for the speed of light is and is known for being a “universal physical constant”, which means that it is an exact quantifiable amount that doesn’t change.

The speed of light in a vacuum stands at “exactly 299,792,458 metres per second“.

The reason today we can put an exact figure on it is because the speed of light in a vacuum is a universal constant that has been measured with lasers; and when an experiment involves lasers, it’s hard to argue with the results.

As to why it comes out somewhat conspicuously as a whole number, this is no coincidence- the length of metre is defined using this constant: “the length of the path travelled by light in vacuum during a time interval of 1/299,792,458 of a second.”


Why is it important?

Albert Einstein’s theory of relativity, which underpins modern concepts of space and time, is built on the premise that the speed of light in a vacuum is always the same.


Video :How to measure the speed of light?

Is it possible to go faster than the speed of light?

In 2011 scientists thought they had recorded particles travelling faster than light – a finding that could have overturned one of Einstein’s fundamental laws of the universe.

Antonio Ereditato, spokesman for the international group of researchers, said that measurements taken over three years showed neutrinos pumped from CERN near Geneva to Gran Sasso in Italy had arrived 60 nanoseconds quicker than light would have done.

They were forced to admit that this was all a mistake, however, blaming a faulty wire connection.

For now at least, faster than light speed remains the stuff of science fiction.

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https://arresteddevelopments.wordpress.com

Along with thanks and compliments to the sources for the shared data

Creative Commons Copyright © Arrested Developments 2015

 

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