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This shows that the probability of a random variable is maximum at the average and diminishes as one goes away from it, eventually leading to a bell-curve.

Catching prey using Vortices

I was reading about Vortices and after hours of research online, out of the blue I stumbled upon this amazing bird. This is the Red Necked Phalarope and from the looks of it seems to have put vortices to a really productive use – catching its prey.

By rotating around ~60-80 times a minute, it produces an upward vortex that sucks out insects/bugs/crustaceans from the water, which it swiftly picks up with its beak and eats. ( This one would have aced the Fluids class for sure 😀)

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This is analogous to tornadoes sweeping up cars and houses along its way in an upward swirl.

Mind Blown!

** The actual dynamics of vortices of course is waay more complicated. 😉

*** There are three species of phalarope (red-necked, red/grey, and Wilson’s), and they can all feed like that.
       
   

If I could catch a rainbow

If i could catch a rainbow,

I would just do it for you

And share with you it’s beauty,

On the days you are feeling Blue.

Rainbows are nature’s optical illusion.

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It’s not possible unfortunately to catch a rainbow. They are not objects and are not located at specific distance from the observer that one can physically approach.

Rainbows stems from an optical illusion caused by any water droplets viewed from a
certain angle relative to a light source.

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They are user-specific and everyone sees a different rainbow.

The monochrome rainbow

Not all rainbows that occur in nature are multicolored. Under specific
atmospheric conditions, one can spot the Mono-chrome rainbow i.e It has
only one color.

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                                   PC : rodjonesphotography


Moonbows

A Moonbow / Lunar rainbow /White rainbow  is a
rainbow produced by light reflected off the surface of the moon (as
opposed to direct sunlight) refracting off of moisture-laden clouds in
the atmosphere / from waterfalls.

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                                            PC:

GanMed64


Each of your eyes sees a different rainbow.

Just as no two people see exactly the same rainbow, even if they’re
standing next to each other, the few inches between your eyes make a
difference in what you are viewing. 

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There is no color- indigo ( sort of )

One can distinguish almost all colors in a rainbow but Indigo.

Legend has it that Newton
included indigo because he felt that there should be seven rather than six colors in a rainbow due to his strong religious beliefs.

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Origins of ‘Iris’

The Greeks and Romans thought a rainbow was the path made
by Iris, the goddess of the rainbow, between heaven and earth, linking
gods with humans. “Rainbow” in Latin is arcus iris or arcus pluvius, a “rainy arch”.

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The iris of the eye is named after her, because of its
colour. 

The
Greeks used the word “iris” to describe any coloured circle, such as
the “eye” of a peacock’s tail. The flower called iris gets its name from
the Greek, as does the chemical iridium (Ir), compounds of which are
highly coloured. Iris is also the root of “iridescent”.

Pulsating Rainbows

Place a linear polarizer over the camera whilst capturing a rainbow and you get pulsating rainbows.

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                                                   Source


Double Rainbows/ Multiple Rainbows

A double rainbow is a phenomenon in which two rainbows appear. They are caused by a double reflection of sunlight inside the raindrops. Similarly multiple rainbows are a possibility as well.

Observe that the colors in the second rainbow are inverted because the light is reflected twice inside the water droplet

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                                             PC: Janbazian


Viral Double Rainbow Video

This video of a man witnessing a double rainbow for the first time went viral,  featuring on numerous popular talk shows. Pure ecstasy!

The full rainbow

Whilst standing on earth, we see rainbows as magical arcs across the sky, but rainbows are full circles. The bottom part of the full circle is usually blocked by the horizon.

Pilots however do not face this difficulty. Under the right sky conditions, pilots are spectators to one of nature’s most beautiful spectacles – The full rainbow.

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                                          PC :
Steve Kaufman

Everything has beauty, but not everyone sees it.

Have a great day!

fuckyeahphysica:

Smooth Ride, Bumpy Road

Why are wheels circular? Why aren’t they triangular or square shaped?

That is a question that you might have pondered at some point in your life ( perhaps as a shower-thought? ) But sometimes even the most simple questions have the most elegant answers!

A square wheel can roll smoothly if the ground consists of evenly shaped inverted catenaries of the right size and curvature.

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What is a Catenary?

Well, it is the curve that a hanging cable assumes under its own weight when supported only at its ends. You find these everywhere!

Those chains on the pavement,

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those hanging cables on a power transmission station,

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or maybe a chandelier is of your type

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All are catenaries!

Although it superficially resembles a parabola, it is NOT!

Practicality

The mythbusters (like always) decided to give the four wheel vehicle a try.

And found out that, get this – with speed, a truck fitted with square wheels can deliver a relatively smooth ride, despite that bouncy start!

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Well, although circular wheels still remain as the king of wheels, it is nice to know that we do have some alternatives up our sleeve!

Merry Christmas 🙂

PC: Etan J. Tal, kamel15

The Epitome of Refraction.

When light encounters a different medium than the one it is already in, it bends! This phenomenon in physics is known as Refraction.

Total internal reflection is a phenomenon which occurs when a propagating wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.


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If you liked this post, do check out:

Physics of invisibility.

Baffling Polymer Balls behavior.

Why is glass transparent?

What is Refraction?

Total Internal Reflection

Total Internal Reflection.

Total internal reflection is a phenomenon which occurs when a propagating wave strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface.

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This occurs when the incident angle is more than the critical angle and the refractive index is lower on the other side of the boundary ( like from water to air ).

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PC: reddit,timbercon.com

Why every spot is not a ‘sweet spot’ ?

Yesterday’s post was about the acoustic sweet spot. 

The crazy thing about the sweet spot is that it is a psycho-acoustic phenomenon and it reveals itself only when the arrival time of the sound is equal to your ears.

To answer why every spot is not a sweet spot, we need to learn about the precedence effect. 

The precedence effect.

It is the psycho-acoustic phenomenon whereby an acoustic signal arriving first at the ears suppresses the ability to hear any other signals.

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As you move away from the acoustic sweet spot, the sound from the speaker nearest to us to take precedence ( since it’s arrival time is less ) and suppresses the sound from other speakers.

This kills the realism from the image since now, all that you are hearing is the sound from one speaker ( a consequence of the precedence effect ). 

And no! It’s not the fault of the speakers. It’s a natural survival skill that evolution has granted us with to hear danger and judge it’s proximity.

PC: bnoack.com

The acoustic sweet spot.

The acoustic sweet spot is defined as the listening position equidistant to each of the two front channels as they are from each other, so the arrival time of the sound is equal at your ears.

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It was brought in the vogue of the public by the big bang theory where Sheldon cooper tries to find the sweet spot in a theater.

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Why is it important?

It is called the ‘sweet spot’ for a real good reason. 

In a motion picture, an image is considered to be ‘good’ if the location of the performers can be clearly located. This is known as stereo imaging and it adds realism to the image. 

The only person who hears this perfectly is the one who is in the sweet spot. ( no wonder Sheldon is obsessed with his spot! )

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At this juncture, it is highly recommended that you check out the virtual barber shop to experience the acoustic sweet spot for yourself. 

The virtual barber shop places you in the sweet spot and abuses sound technology to bring you this high-quality audio realism.

We will dive deeper once you are done with your haircut! Have a good day.

Types of Damping

Damping is an influence within or upon an oscillatory system that has the effect of reducing, restricting or preventing its oscillations.

There are 4 types of damping:(in the order of the animations shown)

1. Under Damped System.

The system oscillates (at reduced frequency compared to the undamped case) with the amplitude gradually decreasing to zero.

2. Critically Damped System.

The system returns to equilibrium as quickly as possible without oscillating.

3. Over Damped System.

The system returns to equilibrium without oscillating.

4. Un-Damped System.

The system oscillates at its natural resonant frequency

( Sources: xmdemo, timewarp,wikipedia)

Baffling Polymer Balls Behavior

I was fascinated by the polymer balls so i went to the shop to treat myself with one. As i was exploring these balls, this bizarre behavior caught my eye.When you immerse these colored polymer balls in water, they seem as if they are 2-d objects although they are spheres! Crazy right?

If you liked this and want to read more about polymer balls and the physics that underlies it, do check out:

Physics of invisibility.

Why is glass transparent?

Have a great weekend!