I found some "love notes" that my friend and I wrote to one another one physics class because we got bored. Enjoy!!! I am "?"

Hi Bill,
I love you.
You beta love me!
Love, ? xoxo

Dear ?
You are my alpha particle.
Lots of love forever, Bill xoxo

Dear Bill,
You are the radius to my circle, without you I wouldn’t be able to calculate my arc.
Hugs and kisses, ? xoxo

Dearest ?
You are the voltage to my current, without you I couldn’t move my charge.
Forever yours Bill xoxo

My fair Bill
You and I are like Pythagoras’s theorem, when we are squared and added together we create something that is magical!
(you)² +(me)² = ♥²
Missing you, ? xoxo

Dearest ?
Please tell me who you are, your letters recreate the tension in a stretched string with length. If we go on a date we can discuss the wave properties of sound. Your notes make my heart beat with the same frequency as light.
Yours in physics forever, Bill xoxo

Dearest Bill,
I’m sorry but I cannot revel to you who I am. I’m afraid the tension between us must remain a constant and like U.F.O’s I must remain unidentified.
Love, ? xoxo

Dearest Bebh,
you are the lenses to my blurry eye sight, you allow me to see my love for you more clearly.
Lots of Love, your secret admirer xoxo

Bill!!
Who is this person you write of??
It is now obvious that she is the resistance in our circuit of love, the glowing blub that once represented our love has now blown, and thus our circuit is broken.
Hope you two have fun!!