6/28: So Much More Than Tau Day, It's a Perfect Day

      June 28th as Tau Day (pi x 2) is only part of the story of today's date. The digits in 6/28 (or 28/6, if you will, mate) are made up of two perfect numbers. A perfect number is a number that is the sum of its factors besides itself, and 6 (1+2+3) and 28 (1+2+4+7+14) are the first two perfect numbers. 

      Today is also my twin brothers' birthday. This morning, I also found out that my mom picked today, the perfect day, for inducing their birth! (It is also her best friend's birthday.)

     The next two perfect numbers are 496 and 8,128.

     

      The relationship between Mersenne prime numbers and perfect numbers is seen below:

      A Mersenne prime is a prime number that is one less than a power of two. That is, it is a prime number that can be written in the form Mersenne number = 2n − 1 for some integer n. They are named after Marin Mersenne, a Frenchman who studied them in the early 17th century. The first four Mersenne primes are 3, 7, 31, and 127 (although some of Mersenne's primes were proven later to be incorrect).

      As of May 2017, the largest known prime number is 274,207,281 − 1, a number with 22,338,618 digits. It was found in 2016 by the Great Internet Mersenne Prime Search (GIMPS-ha!). 

        Primes, GIMPS, perfection, oh my!

       Happy Birthday and have a luminescent trip around the sun, bros. Hope you had a parfait day!



Hope you've all had a perfect day, or at least a few perfect moments,
Steph

     5000 new neighbors moved into our backyard yesterday!

       

Celebrate Cephalopod Week: Squid, Octopuses, Cuttlefish, and Nautiluses

       It's the second annual Cephalopod Week.  How can you not love a creature whose name means head-foot? Cue the "open mouth/insert foot jokes."

        How will you celebrate?!

      Cuddle a cuddlefish with its 'W'-shaped eyes?

      Ogle an octopus, like this one from the Maldives? 

      Swim with a squid, like this technicolored fellow?

       Net with a nautilus?

      Come on out of your shell and join the Cephalopod Party. Cephalo off to Buffalo?

Do you have a favorite cephalopod. . .and why? {I like them all; off to celebrate!}
Steph

Let's Make This Post go Chiral: From Amino Acids to Zwitterions

      A recent RadioLab story inspired this week's post on chirality; we certainly hope this Partial Ellipsis of the Sun post goes chiral! 

      Chirality is the property of having a structure that is non-superimposable on its mirror image. The term chirality is derived from the Greek word for hand, χειρ (kheir).

      The mirror images of a chiral molecule/ion are called enantiomers or optical isomers.

     Most DNA (B-DNA) double-helix molecules are right-handed, though there are some DNA molecules called Z-DNA that are left-handed. Thus, the labels on the following diagram are correct for most DNA.

     The chirality of molecules has much importance in biomolecules and in pharmaceuticals where left-handed molecules are more often the norm; the toxic version in right-handed molecules (like thalidomide) are the abnormal and destructive ones. Ironic that the handedness of molecules caused so much hand/arm (and foot/leg) deformities in thalidomide babies.

      On earth, amino acids characteristic of life are all left-handed in shape (Levo), and cannot be exchanged for their right-handed (Dextro) counterparts.  However, all sugars characteristic of life on Earth are right-handed, hence, dextrose. The opposite hands for both amino acids and sugars exist in the universe, but they just aren’t utilized by any known biological life form.

      A zwitterion is a neutral molecule with both positive and negative electrical charges. The image on the right (above) is a zwitterion.

     Thus, amino acids in earth's life forms go left, sugars go right, DNA double helixes go right. What's the Chirality Winner? ;-)

Please hand in your Chiral thoughts. . .
Steph

(And here's Telluride, CO, this weekend to clear your head and hands from all those chiral molecules):