The mysterious moving stones of the packed-mud desert of Death Valleyhave been a center of scientificcontroversy for decades.
Rocks weighing up to hundreds of pounds
have been known to move up to hundreds ofyards at a time.
Some scientists have proposed
that a combination of strong winds and surface ice account for these movements.
However, this theory does not explain evidence of
different rocks starting side by side
and moving at different rates and in disparate directions.
Moreover, the physics calculations do not fully support this theory
as wind speeds of hundreds of miles per hour
would be needed to move some of the stones.
When a thick lava flow cools, it contracts vertically but cracks perpendicular to its directional flow with remarkable geometric regularity
- in most cases forming a regular grid of remarkable hexagonal extrusions
that almost appear to be made by man.
One of the most famous such examples is
the Giant’s Causeway on the coast of Ireland (shown above),
though the largest and most widely recognized
would be Devil’s Tower in Wyoming.
Basalt also forms different but equally fascinating ways
when eruptions are exposed to air or water.
Blue holes are giant and sudden drops in underwater elevation
that get their name from the dark and foreboding blue tone they exhibit
when viewed from above in relationship to surrounding waters.
They can be hundreds of feet deep
and while divers are able to explore some of them
they are largely devoid of oxygen that would support sea life
due to poor water circulation - leaving them eerily empty.
Some blue holes, however, contain
ancient fossil remains that have been discovered, preserved in their depths.
Red tides are also known as algal blooms
- sudden influxes of massive amounts of colored single-cell algae
that can convert entire areas of an ocean or beach into a blood red color.
While some of these can be relatively harmless,
others can be harbingers of deadly toxins
that cause the deaths of fish, birds and marine mammals.
In some cases, even humans have been harmed by red tides
though no human exposure are known to have been fatal.
While they can be fatal,
the constituent phytoplankton in ride tides are not harmful in small numbers.
While many see these apparently perfect ice circles
as worthy of conspiracy theorizing,
scientists generally accept that they are formed
by eddies in the water that spin a sizable piece of ice in a circular motion.
As a result of this rotation,
other pieces of ice and flotsam wear relatively evenly at the edges of the ice
until it slowly forms into an essentially ideal circle.
Ice circles have been seen with diameters of over 500 feet
and can also at times be found
in clusters and groups of different sizes as shown above.
True to their ominous appearance,
mammatus clouds are often harbingers
of a coming storm or other extreme weather system.
Typically composed primarily of ice,
they can extend for hundreds of miles in each direction
and individual formations can remain visibly static
for ten to fifteen minutes at a time.
While they may appear foreboding
they are merely the messengers
- appearing around, before or even after severe weather.
A circumhorizontal fire rainbow arc occurs at
a rare confluence of right time and right place for the sun and certain clouds.
Crystals within the clouds refract light
into the various visible waves of the spectrum
but only if they are arrayed correctly relative to the ground below.
Due to the rarity
with which all of these events happen in conjunction with one another,
there are relatively few remarkable photos of this phenomena.