Well, this was going to be a comment on the EquusChick's post here, but it started getting too long, so I changed it to a blog post. It's all very fascinating. I have now decided that one of the things I want to do before I die is to go see the Fata Morgana on the Strait of Messina and photograph it.
I was interested in the mirages, so I did an internet search, and this is all what I have understood from the pages. If anyone out there knows more, or if I'm wrong about something, do correct me. Or if you can explain something better, do.
The highway mirage (when you see water on the road ahead) is called an inferior mirage, because it is seen below the actual location (the 'water' is light-rays and blue sky).
A Fata Morgana is called a superior mirage, meaning it is seen above the actual location. A superior mirage that people see fairly often occurs when the sun sets (or rises, but I don't get up that early. :P). You think you are seeing the sun when it is on the horizon, but in reality it is just below the horizon- by about two minutes.
One page also suggested that superior mirages could be responsible for nighttime UFO sightings, because car headlights can appear to be coming from the sky, by being "refracted under inversion conditions." I'm not quite sure what that means, but I think it means the right density, cold and hot air- all that mixed together.
As EquusChick said, mirages are probably the reason for the Flying Dutchman, and at one of the pages I visited it had a nice little graph showing why a ship would appear to be flying in the sky. It is a superior mirage, called looming, and usually occurs over large bodies of water that are much colder than the air above them. The light rays curve more as the differences of temperature between the water and the air above it increases, but our eyes interpret them as straight, which makes the ship appear much higher than it really is. If the real ship is below the horizon, the viewers would only see it as the mirage.
I have not been able to find out why the Fata Morgana mirage is symmetrical. Anybody know? Again, if you know more about this, do tell, and correct me. I am most interested in mirages right now.
I suspect you can find the answer (or something close to it) in this book:
ReplyDeleteLight and Color in the Outdoors
It's a fairly expensive little book, though it might be available via interlibrary loan. The first Amazon reviewer is Edward Tufte, who wrote a trilogy of masterpieces in the field of information design, data, statistics, and how to make them beautiful (and useful). The fata morgana are specifically listed in the phenomena described.
Heck, I want to buy it just to see pictures of some of this stuff.
Well, that answers my question. I thank thee much.
ReplyDeleteHello, I realise this is an old post but I was wondering if you have any progress on getting to see fata morgana, I want to do it before i die too but I can't find any inofrmation online about when is the best time of year for the right atmospheric conditions.
ReplyDeleteI'd love to know if you saw it.
Jamie