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The fundamentals of space-time: Part 2 - Andrew Pontzen and Tom Whyntie

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Light always travels at a speed of 299,792,458 meters per second. But if you're in motion too, you're going to perceive it as traveling even faster -- which isn't possible! In this second installment of a three-part series on space-time, CERN scientists Andrew Pontzen and Tom Whyntie use a space-time diagram to analyze the sometimes confounding motion of light.

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Meet The Creators

  • Educator Andrew Pontzen, Tom Whyntie
  • Director Patrick Semple, Mark Fisher
  • Producer Daniel Spencer
  • Narrator Andrew Pontzen, Tom Whyntie

Some scientists are still looking for evidence that the speed of light can change. Should they be?

TED-EdLesson CreatorNew York, NY

In space, an object can be slingshoted by the gravitational force of a bigger, more massive object, just like when a comet gains speed when it passes close to the Sun ( if it doesn't melt of course). It is known that gravity affects light. Observing this with more caution might reveal interesting data. From a different perspective, if by any chance Einstein was wrong, then the sooner we notice,

Avatar for raahim memon

Posted on 08/11/2016

Posted by raahim memon COMPLETED LESSON

The speed of light is constant only because we decided that energy of electromagnetic waves depends on wavelength. If we said that energy of electromagnetic waves is constant than speed of light would depend on wavelength, and speed would be a measure of everything that we are measuring with energy now. In my opinion, it would be better for our understanding, because nobody knows what is energy really is, and in the same time everyone knows what is speed.

Avatar for Maxim Beliaev

Posted on 02/09/2015

Posted by Maxim Beliaev COMPLETED LESSON

In my opinnion, a runner slows down because he wanted to stop, and the air drags him. The car slows down because it gets dragged by the air. I dont think these examples are relevant to light.
About light changing speed, i think it's not the light particles (photons) that gravity affects, gravity distorts the spacetime, which light goes though, so light's speed remains, only it's path changes.

The scientific approach is built upon challenging preconceived ideas. This is how our knowledge expands. If someone has a valid way to challenge the concept that the speed of light is immutable, then they should explore that possibility. Upon these foundations humanity's knowledge is either reconfirmed, or improved for future generations to challenge.

Avatar for Mark Craig

Posted on 05/26/2014

Posted by Mark Craig COMPLETED LESSON

Chaos, but also truth. Science is the search for truth based on evidence.

In my opinion, they should fine something to faster than the speed of light. But the speed of light should never changed. Because if they find evidence of that the speed of light, Many theories as we know it is going to be not true. Thus that can bring about chaos.

Avatar for Krystal Lee

Posted on 05/14/2014

Posted by Krystal Lee Toronto Ontario, Canada COMPLETED LESSON

Newton thought he was correct!

Avatar for Mike Howard

Posted on 05/14/2014

Posted by Mike Howard LESSON IN PROGRESS

They should. If a runner can slow down after winning a race, or a car losing speed when no pedal is touched, there might be a way that light can change its speed. In space, an object can be slingshoted by the gravitational force of a bigger, more massive object, just like when a comet gains speed when it passes close to the Sun ( if it doesn't melt of course). It is known that gravity affects light. Observing this with more caution might reveal interesting data.
From a different perspective, if by any chance Einstein was wrong, then the sooner we notice, the better. And even if he was not wrong ( I support this opinion ), searching for evidence of light changing speed, and failing would just further prove Einstein right, which is good, and if they succeed is even better, because the sooner we fix this ( in that case) the better.

Avatar for Itan Chait

Posted on 05/01/2014

Posted by Itan Chait COMPLETED LESSON

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