Not Faster Than Light But Fast Light, Is It Possible?

Light is one of those things that you take for granted just switching on a switch or, if you are a caveman, lighting a fire. It appears almost instantaneously as that switch clicks or fire bursts into life. But, you know what I’m going to say don’t you, it’s not that simple. It takes time to travel from the lightbulb to our eyes so that we can see that it’s on and the room is lit up. 

Einstein realized a lot of things about light and he also noticed that the speed of light—about 186,000 miles per second is constant whether it comes from a moving source such as a speeding car’s headlights or an unmoving source such as a ceiling light. But here’s the catch: The speed of light is is said to be constant only in a vacuum, a place where there’s no matter, like the vast emptiness of space. Here on Earth, the speed of light can slow down. 

Light's Speed Change

Light moves slower through denser media because more particles get in its way. Each time the light bumps into a particle of the medium, the light gets absorbed which causes the particle to vibrate a little and then the light gets re-emitted. This process causes a time delay in the light’s movement so the more particles there are (the more dense the medium), then the more the light will be slowed down.

There is an idea that in a vacuum where light is said to be at its maximum speed that the speed of light could vary. Cosmologists have struggled to explain why far-flung regions of the universe are at roughly the same temperature. It implies that these regions were once close enough to exchange energy and even out the temperature, yet current models of the early universe prevent this from happening, unless they assume an ultra-fast expansion right after the big bang.

However, a higher speed of light early in the history of the universe would allow energy to pass between these areas in the form of light. this would solve this problem. For more information try here.

Joao Magueijo  recently was on a television programme and explained the idea of variable speed of light very nicely indeed. The programme is below in videos and he also has a book out which I have heard is very good, Faster Than the Speed of Light: The Story of a Scientific Speculation.

Light Speed Defined!

This could mean the breaking of the laws of conservation of energy and it would be a boost to versions of string theory in which extra dimensions change the constants of nature at some places in space-time. I will leave extra dimensions to another post, I have a big enough headache already.

Some cosmological problems may have a different light shed on them and this may make some scientists happy and some scientists very sad. If it was possible to slow light down it may be possible to bring it to a stop. This could mean that the light from an object, such as a person, could be stopped and therefore the person become invisible. Even if light was just slowed down it would take a long time to get back to the Observer and therefore the person would be invisible  for a period of time, long enough to creep up on your foe and blast with your megablaster.

If light was speeded up then optical cables  could transfer information quicker and  make communications instantaneous. This would probably be most seen on the Internet, with real super light speed connections. I expect that the companies would still be able to scam us in some way in regards to speed though.

Light Communication

If light travelled faster then we could send communications across the universe much much quicker. For instance talking to somebody on the moon could be faster, it takes about 1.3 seconds at the moment.  Thinking about it though this probably wouldn’t work as light travels at normal speed in the region of Earth where it has actually been measured.

Perhaps then across star distances differences in the speed of light would be different. Perhaps the speed of light slows around suns and stagnates communication between civilisations. This could be a reason why SETI hasn’t picked up anything after 50 years (of course there could be a lot of other reasons) and all hope is not lost, not that it was anyway. So to transmit from star to star perhaps we need to get out from our solar system and then send a message. Perhaps instead of sending just a plaque with something like Voyager we need to send a probe that is transmitting a message.

SETI are actually taking public opinions on the words and pictures that would need to be sent from Earth at the moment, at this website. 

I think I would say something like “peace brother” rather than any complicated message as whatever we say it could be wrong. I think really though we should be optimistic though and send them directions.

A Cluster Of Stars

If you could send communications via a faster than light beam perhaps one day we could disintegrate ourselves (sounds nasty) and send ourselves via a beam of light travelling much much faster than our normal light does. That would mean that we could transport ourselves around the universe, wouldn’t that be a lot of fun?

Although it is commonly believed that Einstein’s theory of relativity says nothing can go faster than light, that is not quite true. Relativity does forbid ordinary matter from ever reaching the speed of light, because it would require infinite energy.

Einstein’s theory of relativity allows for particles called tachyons. Called “tachyons” by physicists in the 1960s, these subatomic speed merchants would actually need an infinite amount of energy to slow down to the crawl of light-speed.

Unfortunately tachyons have never been found. if they were found all the advantages of a faster speed of light could be achieved that’s assuming they could actually harness the tachyons.

I have only scraped off the surface of something that could be as revolutionary as Einstein was compared to Newton. It would be great to see another brilliant theory that opens up the universe just that little bit more in our lifetimes, wouldn’t it?

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