A lighthouse question

[tommy2tone]

I always wondered how the lense was able to spin. I mean, it seems the wire would get tangled up. I could see if the wire just went to the turntable (like a record player), but it has to go to the lights also....

 

[Grampy122]

Lighthouse Answer

Google the tern "Slip Rings"

 

[Sylvanite]

There's no need for the light source (gas or electric) to move. The lens just has to rotate around it. Picture a turntable with the center cut out (like a doughnut, or more properly a torus). The light source (omnidirectional) comes up through the center. A parabolic reflector or polyhedral (multi-sided) fresnel lens rotates around it on the turntable.

I hope that makes sense,
Eric

 

[Smitty37]

The light does not move....a reflective lens (not really a lens but I can't think of a better word) moves around the light most of the time.

When Lighthouses were invented there was no electricity and they didn't move.....there was a highly polished reflective surface behind the light that concentrated it and made it visable at a longer distance.

 

[Dale Allen]

The light does not move....a reflective lens (not really a lens but I can't think of a better word) moves around the light most of the time.

When Lighthouses were invented there was no electricity and they didn't move.....there was a highly polished reflective surface behind the light that concentrated it and made it visable at a longer distance.

Imagine trying to keep all of those candles lit!:biggrin:

 

[plantman]

The Greeks and Romans built some of the first modern (for it's time) lighthouses. They were built from stone and wood, and had fires burning at the tops. They needed constent watching and many burned down. The Pharos of Alexandna is beleived to be the first lighthouse with descriptions and drawings. It was built during the Greco-Roman period in the third century B.C. The tower was destroyed by an earthquake several centuries after it's construction. The Tower of Hercules, located in North-Western Spain, and standing at 180 feet tall, is believed to be 1900 years old, and is the oldest Roman lighthouse in use today. In case anybody wanted to know. Jim S

 

[Smitty37]

The Greeks and Romans built some of the first modern (for it's time) lighthouses. They were built from stone and wood, and had fires burning at the tops. They needed constent watching and many burned down. The Pharos of Alexandna is beleived to be the first lighthouse with descriptions and drawings. It was built during the Greco-Roman period in the third century B.C. The tower was destroyed by an earthquake several centuries after it's construction. The Tower of Hercules, located in North-Western Spain, and standing at 180 feet tall, is believed to be 1900 years old, and is the oldest Roman lighthouse in use today. In case anybody wanted to know. Jim S

One of the 7 wonders of the ancient world.

 

[alankulwicki7]

The lens just has to rotate around it. Picture a turntable with the center cut out (like a doughnut, or more properly a torus). The light source (omnidirectional) comes up through the center. A parabolic reflector or polyhedral (multi-sided) fresnel lens rotates around it on the turntable.

I hope that makes sense,
Eric

And all along I thought that there was a really long wire that allowed the light to rotate. Then every few hours the light house keeper had to unwind it and the process started all over again.