“The Big Bang Theory” has one of the best (if not the best) ensemble casts on television today. From the original gang of Howard, Leonard, Penny, Raj and Sheldon (don’t overreact Sheldon, it’s alphabetical), the past 6 1/2 seasons have proven that each character is capable of individually and collaboratively spurring terrific fits of laughter for hilarious entertainment.

In recent seasons, the show has successfully incorporated the love of Howard Wolowitz’s life, Bernadette, the slightly clumsy microbiologist, and Sheldon’s girlfriend and Penny’s BFF Amy Farrah Fowler (TVs Blossom!) into the mix as regulars.

7 (+ or -) an ever-changing value of comedic variables has become known as “The Big Bang Theory’s” Law.

And then there are the outrageously funny and mindful mothers. The dynamic of Leonard and Sheldon being the perfect son for the other person’s Mom is thoroughly enjoyable to watch. Plus, Raj’s parents cannot be ignored. However, the two of them seem to be preferring the opposite these days regarding their marriage…

It’s probably a safe bet that two of the biggest surprises yet to come in this series center on Howard and debuting his Wheel of Fortune-genius Mother to the public and identifying his absent Father and his actual back story.

The former will be funny for sure (so there are two CBS sitcoms that focus in some way on hiding the identity of a mother?), while the latter will bring emotional tears to everyone’s eyes. But these two mysteries won’t be solved or happening for years to come.

Whether it’s Wil Wheaton (“Wheaton!!”), reluctant comic book store owner Stuart or Penny’s former boyfriend/karaoke singing maestro Zach, the roster is deep for the CBS King of Sitcoms. The character lineup for “The Big Bang Theory” is equivalent to the periodic table, which has all the elements you need and, thankfully, has not been fully disclosed yet to the audience. There is still a lot more show left and many more elements to mix into this batch of hilarity.

Plus, we cannot forget about Dr. George Smoot, Bill Nye the Science Guy, Bob Newhart and this guy named Stephen Hawking.

That’s not too bad a list of guest stars (yes Sheldon, that’s sarcasm).

As is usually the case for popular sitcoms, the goofy, complementary characters tend to develop into audience favorites with funny, zany quirks (Nicolas Cage anyone?) and outrageous double entendre one-liners that only Raj can deliver with absolute comedic precision.

Spoiler Alert Warning!

The episode from last night ended with one of the interactive qualities that has resulted from the show’s popularity and clever writing: must-have merchandise! First, it was a singing Soft Kitty (My Mom can attest that it’s awesome). Then, it was the red “Bazinga!” t-shirt, Howard’s belt buckles, etc. However, as mentioned above, the best item may have premiered yesterday evening around 9:29 p.m. EST in the show’s closing moments. In the form of an apology to best bud Howard, Raj debuted to the world light-wait for it (yes, this CBS sitcom crossover reference totally works here)…saber belt buckles that glow in the dark!

The awkward double entendre moment between happily clueless Raj and cognizant Howard was priceless!

Here are the two questions that need to be asked: How comically perfect are Howard and Raj? And second, when will those glowing light saber belt buckles be for sale!?

From creative belt buckles to a trademarked three-knock protocol to new favorite characters, “The Big Bang Theory” continues to evolve with a bigger bang each week.

Like students in science class, the sitcom’s millions of fans anxiously await for the teacher or professor to perform his or her next entertaining experiment. There’s a certain unpredictable chemical imbalance going on in Pasadena and it feels great to watch those elements shake around in the beaker every Thursday night at 8:00 p.m. on CBS.

P.S. One more important inquiry: Anyone else notice Penny’s last name has never been revealed…