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If you are driving down a mountain, then it's not an illusion that you are on a mountain.physicsEnthu_123 said:Why Sea Level sometimes gives you an illusion being at height like a small mountain? Specially when you are driving down of the mountain?
Is it not just because our sense of what is actually 'horizontal' is not very well developed? There is really no reason why Evolution would have given us the ability to resolve such small angles. Certainly, nothing that we experience in a smoothly rolling motorcar will be familiar with our basic senses. Let's face it, it was only when Newton came on the scene that people had much idea of such things at all. We get all our clues from what we can see and that's dominated by nearby things.physicsEnthu_123 said:Why Sea Level sometimes gives you an illusion being at height like a small mountain? Specially when you are driving down of the mountain? Please find the attached image to see what I am referring to.
But everywhere looks distorted and more or less horizontal. The camera was not designed to give topographical information - just to be wide angle and tolerant of the road slope.Opis said:Go down to street level in the same location
You are about right for the location. It is San Diego, Delmar County, I took the exit High bluff drive towards the ocean. Anyways this is what I found on your super mirage theory.Opis said:Clear dry day - possible temperature inversion. That could create a superior mirage and make the horizon look higher than it otherwise would.
Perhaps you can go to the location in Google Earth, make sure vertical exaggeration is 1:1.
Go down to street level in the same location and see if the horizon looks the same.
(I tried to see if I could discover the location from the clues in the image but all I concluded is that you are probably right handed, driving at just over 40 mph and listening to FM 89.5 and located on the West coast of the US driving in a roughly WNW direction in the late afternoon)
sophiecentaur said:There are many examples of streams and canals that appear to be running uphill.
Well well.A.T. said:And some rivers are actually flowing uphill:
http://physics.stackexchange.com/questions/209805/rivers-that-flow-uphill-due-to-Earth's-rotation
The Earth is a Spheroid so any distance away from you, along a tangent will be 'above' the sea. Assuming the UK is about 1000km long and the Earth's radius is 4000km, that means the extremities will be about 30m 'below' a tangent to the mid point. What would you call 'level'? The sea would not flow away from that mid point (ignoring tides and spin etc. etc..deZordine said:If I'm with my feet up to my ankles in the water of the sea, on the water's edge, where is the sea level, exactly where?
How far is it from me?
At 5 km you can still consider the sea level relative to my feet?
That is, 5 km from me, can a point on the surface of the water still be considered sea level relative to my ankles?
sophiecentaur said:The Earth is a Spheroid so any distance away from you, along a tangent will be 'above' the sea. Assuming the UK is about 1000km long and the Earth's radius is 4000km, that means the extremities will be about 30m 'below' a tangent to the mid point. What would you call 'level'? The sea would not flow away from that mid point (ignoring tides and spin etc. etc..
sophiecentaur said:Seeing is not believing.
It's something that GPS uses all the time and the different systems use (so I believe) slightly different curvatures and centres so two ships can end up in different places with the same co ordinates. (Which can be less of a disaster than when two ships hit each other at an agreed rendezvous point when using the same GPS settings.)deZordine said:Maybe you want to say that if a radius is 4000 km, for a surface of 1000 km, the corners of this surface on the given sphere will be at a difference of about 31,496,588mm, that is 31.49km in front of tangent from the middle of the 1000km circle arc.
That is, 31,496,588mm (31.49 km) distance from both ends to the tangent in the middle of the circle arc.
CWatters said:There aren't many visual clues to distinguish the difference between the two cases...
View attachment 109700
gmax137 said:Or, gravitational vortexing?
The phenomenon of sea level appearing to be at a higher elevation is known as the "sea level illusion". This illusion is caused by the curvature of the Earth's surface, which makes distant objects appear to be at a higher elevation than they actually are.
No, the sea level illusion can vary depending on the location. It is most pronounced in areas with a large difference between high and low tides, such as coastal regions with steep topography or narrow bays.
The sea level illusion can cause errors in navigation and mapping, as it can make it difficult to accurately determine the true elevation of objects or features. This is especially important for activities such as aviation and marine navigation, where precise elevation measurements are crucial for safety.
Yes, the sea level illusion can be corrected for by using advanced surveying techniques and technologies. These methods take into account the curvature of the Earth's surface and can accurately determine the true elevation of objects or features.
Yes, in addition to the curvature of the Earth's surface, atmospheric conditions such as temperature and pressure can also affect the sea level illusion. These factors can cause light to bend, making distant objects appear higher or lower than they actually are.