Prologue:

Particles tend to bond with other particles, but when they’re separated by any natural or manual process, they tend to stay that way. You would think a log disappears into ashes when it’s burned, but science says matter is indestructible, even if it’s invisible. Because no matter what physical and chemical changes they undergo, none is created nor destroyed through the process. Everything is matter. You and I are matter.

Part I: The Cube

All sides of a cube have equal dimensions and parallel opposite edges. The sides are flat and smooth with nothing bulging out or caving in. Within the cube, the volume is definite with no empty space.

To commemorate our time together before your upcoming college decisions, you and I transformed a 12x12x12 parcel box into a mailbox, which we kept under our bed and used to exchange bags of chips, apology notes on gum wrappers, unflattering candid polaroids, and codenames in Mei-Po (our made-up language).

Eileen: Welcome! Saturday 5th 6:00pm November

Today marks our first day of the Mailbox. Please read the following for instructions.
Rules:
1. Eileen is always right no matter what.
2. If Eileen does something wrong, remember rule 1.
3. Always seal your envelopes.
4. Keep box out of sight.

These are all the rules that you must abide. If you have any questions, please write to me. You will find some envelopes, cards, and ziplock bags for future use. Please sign below to confirm your commitment to the Mailbox and mail it back.

Party 1: Eileen Zhang
Party 2:

P.S. For your first gift, here are some grape
flavored hichews.

Elena: Hi! Saturday 5th 6:02pm November

The hichews are delicious but I don’t agree with rule 1 and 2.
…
Party 1: Eileen Zhang
Party 2: Elena Zhang

Eileen: Sunday 6th 10:00am November

Rules will not be reconsidered.

We sat on the floor among pieces of cut cardboard and proudly marked the beginning of our mailbox. In the next two months, our envelopes, candies, and birthday cards piled to the top of the box and filled in all the crevices. The once-rigid box began to swell at the sides, bursting with all our offerings.

Part II: Entropy

Elena: Apology Letter Friday 20th 11:48pm January

I’m sorry about what I said last night. I want you to know that everything was out of anger in the moment and I never want you to feel that way again. I hope we can fix everything before you leave.

The second law of thermodynamics states that entropy, or disorder, always increases with time. Nature favors increasing the entropy in a system – an ice cube at room temperature will melt, corn kernels over a gas flame will pop, a minor skirmish between two people will escalate into a full-blown cold war.

Once New Year’s passed, the mailbox was used less and less. When you told me to move to mom’s room because I was too loud, I snapped: “I wish you don’t get into any college.”

You didn’t say anything that night, but I could feel something rupture. I was disappointed to find nothing when I habitually checked my mailbox everyday. Even when we reconciled from the cold war in our day-to-day life, my life still felt disrupted without a reply in the mailbox. Although you acted as if nothing had happened, I felt as if the mailbox had already vanished from your world.

After I left you the apology note, I waited for you to acknowledge the letter: I averted eye contact, waiting for your confrontation. But my hopes diminished as the days passed and no replies came. Even though you didn’t say anything about the letter, after a week or so, you did start speaking to me again. As things returned to equilibrium on the surface, I found it harder to address this growing yet unspoken distance between us and the mailbox that used to bridge our lives.

As each day was crossed off the calendar before summer break, the mailbox became less real. When you left that summer, I moved the mailbox to the garage so that I wouldn’t have to be reminded on a daily basis of this split that we never sealed.

After you left, mom announced a cleanout.

“You, pile her clothes and books into boxes.” Mom assigned me the hard work. “You can keep things, but the rest is going to storage.” With the pain from the mailbox still fresh in mind, I sat back on cleaning your things.

“I’m not obliged to clean up after her!” My words came out more enraged than I intended and I could feel mom’s look without actually looking at her.

“God, save the temper for someone else,” Mom snapped. “Is this such a big deal?” She turned away.

Now that I think of it, maybe what I did was more out of avoidance than grudge. I’m scared of the subtlety that objects carry, and how often your markers, clothes, and comics remind me of you who’s worlds away from me. The house was reassembled after two whole days of cleaning, and I must say the room looks twice the size without your belongings scattered on the floor.

Even though I’d studiously avoided the packing process, I still decided to scan over your things knowing that it’s my last chance to grab something. Your things were separated into two piles: one for storage, the other for recycling. Unfortunately for me (but fortunately for you), all the things that I would possibly want to take were packed tightly in the boxes. Even more unfortunately for me, however, I saw a pile of cardboard in the recycling pile. Not just any cardboard. I pulled them out and confirmed that it was our cardboard, our mailbox, broken down into unequal square-like pieces with traces of our craft still visible. I dig through the trash bag looking for the letters like a hungry stray cat looking for food, but there was no trace so I assumed the recyclers must have already taken them. I hold my tears in harder than I hold the torn cardboard, the last remains of our mailbox, and head back indoors.

My mom approached me as I came inside. “What are you doing with that?” she said. “It’s going to trash.”

Trash. I paused to think of what to say, but I knew that my tears would’ve burst out at any moment if I let myself explain. So instead, I used anger as my shield again.

“Yeah you’re right,” I said trembling, “it’s just trash, maybe we should tear it down even more, shred it into pieces, and burn it before we dump the ash.” I dropped the pieces on the floor and ran away from my mom to save the tears for myself.

I envisioned where the mailbox would end up. Whether compacted, burned, or renewed into new products, I envisioned it coming back to me in another way.

Part III: Conservation of Matter

I really thought our lives had separated into two tracks after you went to college, only getting farther and farther apart with time. Out of everything, however, who would’ve thought that a global pandemic was something that transformed the time I thought we had lost for good into a reconnection.

In our endless days sharing a room again, we spent all our time sitting on your bed, updating each other on the times that we’ve lost together. We devised a plan to sneak pizza in the house during midnight without Mom hearing. We witnessed the sun set and rise in one long conversation through the night. I felt as if we were kids again – taller, older, but still the same us. Something about our bond made me realize that we didn’t need to stay together or do the same things to be connected. That original box is somewhere else now – holding a kid’s new sneakers, or a birthday present. I couldn’t tell you where or how – I don’t know what shape it is or if it has a 12x12x12 definite volume – but I knew the mailbox had returned to us.