Last week, Google joined my efforts to foster curiosity by having two really fun Google Doodles

One on quadratic equations (click the link to learn more)

and the other on DNA (click the link to learn more)

I love it when organizations with large reach use their platforms to talk about math and science topics. 🤩 

Stay curious, friend!

#1 🤯 

#2 🤯 

#3 🤯 

#4 🤯 

#5 🤯 

#6 🤯 

This is issue #87. Let’s see what makes 87 an interesting number:

87 is:

• the sum of the squares of the first four primes (87 = 2² + 3² + 5² + 7² ).

• together with 85 and 86,  forms the last semiprime (an integer multiple of a prime number) in the 2nd cluster of three consecutive semiprimes; the first comprising 33, 34, 35.

• 5! - 4! - 3! - 2! - 1! = 87

• the last two decimal digits of Graham's number (click here to learn about Graham’s number - a mind-bogglingly large number. Truly 😮 🤯 )

  • Though too large to ever be computed in full, the sequence of digits of Graham's number can be computed explicitly via simple algorithms; the last 10 digits of Graham's number are ...2464195387.

  • Harshal’s note: This is so interesting to me. The number itself is too large to compute but we know the last few digits! Wh..aa..t!

• Francium is a chemical element; it has symbol Fr and atomic number 87. It is extremely radioactive; its most stable isotope, francium-223 has a half-life of only 22 minutes. It is the second-most electropositive element, behind only caesium, and is the second rarest naturally occurring element (after astatine).

  As a consequence of its extreme instability, bulk francium has never been seen.

  • It was the last element first discovered in nature, rather than by synthesis.

• Cricket in Australia holds 87 as a superstitiously unlucky score and is referred to as "the devil's number". This originates from the fact that 87 is 13 runs short of a century. 187, 287, and so on are also considered unlucky but are not as common as 87 on its own.

• 87 is by far the most commonly used octane rating of gasoline in the United States, Canada, Australia, and New Zealand.

• There’s no country with 87 as it’s international calling code. 870 was assigned to the – Global Mobile Satellite System (Inmarsat)

That’s it for this issue.

Hit ‘reply’ to tell me what you think.

And hit ‘forward’ to share with your friends and family.

Let’s all celebrate science and engineering and curiosity.

Love,

Harshal

Special past issues

• Venn diagrams

• Total solar eclipse

• Aurora (Northern lights)

• Nobel prize - 2024

• Physical Nobel prize - 2024

• Chemistry Nobel prize - 2024

• Halloween 2024

• Fibonacci series

• pi day 2024

• Blue Ghost (Firefly) Lunar lander

• Pope Leo XIV

• Dr. Jayant Narlikar 

• Special issue on Helium