Why Do Leaves Change Color and Fall?

This is a question I had never asked and yet I can see it everyday. In this video, you’ll find the answer for this (or at least the one with more logic). The SciShow is an amazing project that tries in a humourous way to share with you scientific facts and some close to becoming facts. I found this intriguing and you, what have you found? :p

A Glimpse of the sun’s power II: How the rainbows are formed?

You found out how the auroras are formed. Now you will learn about rainbows.

Rainbows are not formed in the practical meaning of existence, i.e. they are not real. They belong to what we usually call optical illusions. Rainbows are caused by the reflection and refraction of light in water droplets. After this the light scatters into different colors because different colours have different wavelengths. This means that they will leave the water droplet at different angles hence making a “colour palette” (ROG. BIV). [1]

What is even more interesting is that the rainbows are full circles… Want to know more? Watch this two videos of SciShow!


As always I hope you learnt something new! 🙂 [2]


Minutephysics has just made a wonderful video explaining the origins of the acronym ROG. BIV. Watch it!

I’m going to categorize this under the week themes despite the fact that it doesn’t fulfill the requirements for it (i.e. it wasn’t posted during that time).

References and further reading.

[1] – Rainbow – Wiki

[2] – See the references in the descriptions of the videos (open the videos on youtube)

Why Do We Have More Boys Than Girls?

This is an interesting question that I’ve found with my life experience. I always felt that there were more boys in my kindergarten than girls. In my basic education I learnt that there were 50% of chances to the baby born man or woman. In high school I found out that there were more women in the world than men. Two days-ago I saw this video and I learnt a lot! So I decided to share with you this great compact video…

I hope you like it and as always that you learn something new! 🙂

TED moments!

We love TED, it shares new ideas based on the activity of renown scientists, economists, artists, etc… It makes knowledge more accessible so we are proud to everyday share with you a TED video. Hope you enjoy it!


This is our first TED moment so we will start with an amazing talk regarding the importance of a new educational system. Introducing Sugata Mitra… he is an educational researcher, he won the 2013 TED Prize with his astonishing idea. He created an experiment/project called “Hole in the Wall”, the results of his project were amazing and now he intends to expand it’s range…


This was is latest conference but I recommend you to check his profile TED page and view his other two videos.

How can you measure Earth’s circumference with the sun? Eratosthenes answers…

First things first, let’s know who was Eratosthenes, then we will proceed for the answer to this task.

Eratosthenes of Cyrene was a Greek mathematician, geographer and astronomer (he yearned to understand the complexities of the entire world so he was devoted to many areas).[1] He lived between 276 BC – 194 BC and during that time he changed the way we view the world. He created geography and made some progress in science especially mathematics (he created a tool for discovering prime numbers).[2] He is now known for being the first person to measure the Earth’s circumference. [3]

If you didn’t understand it completely, here is better explained. (Any doubt or suggestion be sure to leave it in the comment section)


References and further reading.

[1] – Eratosthenes – Wikipedia

[2] – Eratosthenes – The MacTutor History of Mathematics archive

[3] – Eratosthenes – Encyclopaedia Britannica

[4] – (Project for school students) http://www.bibalex.org/psc/en/GetInvolved/Eratosthenes.aspx

How the sun sees you!

We are used to see in only one kind of electromagnetic waves, the visible light waves.[1]

What about ultraviolet waves, how do they make you look?

Sun has three different kinds of light that get into earth: infrared, ultraviolet and visible.[2] What we can only see is just the visible light. So have you ever thought about see in ultraviolet? How would you look?

Here is how the answer looks like…

References and further reading.

[1] – Introduction to the electromagnetic spectrum – Nasa

[2] – Sunlight – Wikipedia