April 25 – National Flag Day in Swaziland

Posted on April 25, 2018

Waaaaaaay back in 1881, the British government signed a declaration that said that Swaziland was an independent nation. This was a period of time when there was such a lot of hurried effort by European nations to divvy up and control various parts of Africa, historians call this period "the Scramble for Africa." Against the trend of grabbing control from the locals, in this case the Brits said, "This is THEIR nation."

See that red dot near the southern end of Africa?
That's Swaziland!

Except....year after year...(after year!) the British and Dutch weighed in on mineral rights and land ownership, and they formed three-way governments with Brits, Dutch, and Swazi officials, and then they formed protectorates through the Republic of South Africa. And it turned out that Swaziland really wasn't fully independent. Despite that signed piece of paper...

Finally, almost a century later, Swaziland really was going to get its independence. On this date in 1967, the flag was flown for the first time. Actual independence was achieved in September 1968.

The symbolism of the flag is:

Red for past battles
Blue for peace and prosperity
Yellow for Swaziland's resources

The Nguni shield is black and white to show that black and white people can live in harmony in Swaziland. The shield and two spears also recall Swaziland's history.

Take a look at Swaziland's land:

Also on this date:

April 24 – Quantum Revolution Time!!

Posted on April 24, 2018

Can you imagine a world without GPS? Without smart phones? Without the internet? Without computers?

I can actually remember the world without most of these things - and although computers were invented before I was born, the computers that existed during my childhood were so few and so so so so so so different from the computers now, I'm going to say that I remember the world without ANY of these things!

But I'm glad we have all of those things now!

All of these technologies are made possible by quantum physics (aka quantum mechanics). And quantum physics got its start on this date in 1914, when the results of an experiment were presented to the German Physical Society. Because the scientists who designed the experiment were named James Franck and Gustav Hertz, the experiment is called the Franck-Hertz experiment.

What is the key idea of quantum physics that was presented in that paper? It is that atoms have only certain energy levels that are possible for electrons. 

You might already know that atoms have a central nucleus formed by protons and neutrons, plus an outer cloud of electrons. 

One possible way for atoms to exist would be for the electrons to be just anywhere, like an informal gathering around a street performer. A lot of scientists thought this might be how atoms worked.

Another possible way for atoms to exist would be for electrons to only be allowed in certain places - and not allowed in others. This would be akin to a stadium or planetarium, where there are certain individual seats and
nobody is allowed to sit in the aisles or cluster in the front or back for safety reasons. In 1913 physicist Neils Bohr proposed this model for the atoms. And the Franck-Hertz experiment proved his model correct!

Learn more about the quantum nature of atoms in Quantum Physics for Kids.

Light and other forms of electromagnetic radiation
also have a quantum nature rather than being, as
people sorta-kinda assumed, a continuous ray
of energy. Find out more about that here.

April 23 - International Cuban Dance Festival!!

Posted on April 23, 2018

Today through the 29th, dancers, dance students, dance teachers, and choreographers from around the world will gather in Havana, Cuba, to share their love of Cuban dance.

This festival offers more than 100 hours of dance classes!

Plus dance parties every night, where people can just dance their hearts out to the music of live bands!

Plus dance tours in Havana. Plus nightly shows. 

What is Cuban music? It's fast, spirited, super rhythmic - but it's also varied. From Cuban salsa to Bachata, from hip hop to cha cha cha, from Reggaeton to Kizomba, from rumba to folklórico to rueda de casino, there are a lot of styles to choose from. Browse around: