The Vapor Cone.

A vapor cone, also known as shock collar or shock egg, is a visible cloud of condensed water which can sometimes form around an object. A vapor cone is typically observed as an aircraft, or object, flying at Transonic speeds. ( slightly slower than the speed of sound) 

The Pressure – Temperature dependence.

As the aircraft approaches the speed of sound, the air pressure around the object drops, and thereby the air temperature drops. If the temperature drops below the dew point, water in the atmosphere condenses to form a cloud in the shape of the shockwave.

Red Bull Stratos and the Vapor Cone.

Remember that epic jump where Felix Baumgartner, as a part of the Red Bull Stratos project broke the sound barrier ( reached Mach 1.25 ) during his descent? But why weren’t vapor cones seen around Felix’s body? Or were they?


Vapor cones are formed only near the ground, where plenty of wet air persists. But when Felix broke the sound barrier, there was no wet air that surrounded him that would enable the formation of Vapor cones.

Have a Good day!

PC: twistedsifter

The Bernoulli Family.

Bernoulli’s principle, Bernoulli’s number, Bernoulli’s polynomial, Bernoulli’s differential equation and the list goes on.

If you were like me and thought that Bernoulli was the name of a single guy, you are soo wrong. They were a family !

Over the course of three generations, the Bernoullis produced eight mathematically gifted academics who, between them, contributed to the foundations of applied mathematics and physics. 

Some of the most popular ones of the family are:

1. Daniel Bernoulli ( Inventor of the Bernoulli’s equation )


2. Jacob Bernoulli. ( The Bernoulli Numbers )


3. Johann Bernoulli. ( One of the early adopters of Infinitesimal Calculus).


And the rest contributed extensively to the fields of math and physics.

If you are want to know more about the history of the Bernoulli Family click here.

ISS is the third brightest object in the night sky!

It often comes as a surprise to people when i tell them that the space station can be seen with the naked eye! Flying at 400 km above your head, the ISS looks like a really fast moving airplane in the sky.

The ISS isn’t brighter than the day sky and hence cannot be seen during the day. But in the night, it’s the third brightest object in the sky! It reflects the sunlight off the solar panels on its surface.

Spot the station!

If you would like to see the ISS for yourself, NASA ‘s Spot the station! is at your disposal. Register with your email address/mobile number and every time the ISS passes by your town/city, you will get a notification with the time, duration and inclination.


Have fun!

(Extras: There are mobile phone apps which you could use too, like the ISS detector satellite detector for android. At the end of the day all that matters is what is convenient to you.

ISS tracker– Real time tracking of the ISS)

Unraveling the physics.

The photograph is an amazing illustration of the centrifugal force. 

Do you remember those times when you get squashed on to one side while trying to maneuver a tight turn in your car? The force that is pushing you out is known as centrifugal force.

Let’s up the ante. Imagine you are piloting an aircraft and you are pulling an inside loop i.e


It is the same scenario that you experience in your car with the axis of rotation being vertical.( In the former it was horizontal ).

Our friend, the centrifugal force would be squashing you to your seat. Water also has to comply with the centrifugal force and as a result gets squashed towards the cup.

Voila! The physics of pouring water into a cup when you are upside down :).

EDIT: To pull this off, the centrifugal force has to be more that the force of gravity else the water would fall the other way around. 

Much like water, the bodily fluids also gets squashed to the bottom. This reduces blood flow to the brain, which is why people often pass out!