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Little Senku and Byakuya’s bedtime story

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Byakuya parked his car outside his house- no, their home. Senku was inside and probably watching science videos again or looking up directions on how to build a rocket. He chuckled, amused that his young son was immersed in sciences as he is. Being a professor is not an easy job, it is tiring but he still love it nonetheless. 


Glancing at his watch, he thought that Senku should be sleeping. He once scolded him for sleeping late when he caught him reading books about physics. 


“My son will grow up to be the next Einstein,” Byakuya mused when he opened the door. Expecting to see darkness and an empty living room. Footsteps quiet as possible, he made his way to the kitchen to get a glass of water, almost jumping out of his skin when a tiny voice talked to him.


“Byakuya, you’re late.” There stand young Senku, with cute cheeks and his adorable green hair that stands up and reaches to the universe above. Rubbing his eyes, he let out a yawn. 


“Senku, you scared me! Why aren’t you sleeping yet? It’s late son.” Byakuya said as he grabbed Senku up and carried him to his room. Senku was craddled in his father’s arms, ‘This feels nice’, he thought but he would never tell Byakuya that.


“Are you waiting for me to come home? That’s adorable Senku!” Byakuya teased his son, but Senku just jumped out of his grasped. Stomping away, he let out a tiny ‘Hmph’, but his father was just laughing at him.


“I can’t sleep, it’s not like I was waiting for you or something...” Senku mumbled as his father tucked him in his bed. Upon looking closer, he noticed the heavy bags under Byakuya’s eyes, he immediately deduced that it was caused by recent stress and tiredness. 


“Do you want me to tell you a bedtime story? About dragons and dinosaurs or maybe you want me to play music while you try to sleep Senku.” Byakuya suggested, hoping that his son would pick the latter, as he too admittedly, was tired after a long day of work.


“Tell me the story of the origin of our universe.” Senku said immediately after getting himself comfortable, and moving a little bit so his father can sit comfortably beside him as well.


“You want to know about the origin of the universe! I will tell you Senku! So listen…” Byakuya trailed off, he was now amused that his son has a keen interest on everything strange around him, which is literally the universe. Truthfully, he was tired, but a bonding with his son is worth it.


“There are many theories about the origin of our universe, but what most scientists agree on is the Big Bang Theory. You see Senku, Billions of years ago, there was absolutely nothing! Until the great explosion and expanding happened!” Byakuya was doing hand gestures and even ‘BOOM!’ sounds as well. His son was carefully listening to him with wide curious eyes.


“This caused a gigantic cloud of dust and gas with super high temperature! This cloud began to grow and grow and get cold enough-“ 


“This is the time where the universe cooled down and formed sub-atomic particles, like neutrons, electrons and protons and later on atoms, am I right?” Senku interrupted his father and stares at him for confirmation.


Byakuya blinked. Once. Twice. ‘Oh,’ he thought. He stared back at Senku, smiled and nodded. Facing his son, he now continued his story.


“Yes you’re right Senku! And now the cloud of these primordial elements which is mostly hydrogen and a little bit of helium and lithium formed our galaxy and stars!-“


“How does galaxy and stars get to atleast stick together and not fly apart and move as they do? Oh! I’m 10 billion percent sure it’s because of the dark matter that doesn’t absorb, reflect or emit electromagnetic radiation, which is difficult to trace, but that’s why our universe is continually expanding without breaking down. Is that right?” Senku rambled on as he faced his father while waiting for his response.


Byakuya crinkled his eyebrows and he was thinking hard. He swore that he heard that question before from one of his college students. How come Senku, his young son already deduced such question? Wait, he also answered his own question. At least in theory, even the dark matter is something that cannot be grasp or understood fully by adults. Byakuya gulped, it dawned on him that he is, no doubt, raising a science prodigy.


“Ah, you’re actually right Senku! Most of the gravitational potential in the universe seems to be in those form. In fact, various observations said that it is not baryonic matter that forms atoms. Today Senku, our universe is still gradually expanding!” Byakuya was now standing up and waving his arms in opposite directions, creating an expanding motion. 


“That’s how our universe was born Senku! Sleep now, it’s getting late.” Byakuya said as he gently flick Senku’s forehead. Wishing him goodnight as he already reached the door. 


Suddenly Senku speak, “If the universe is expanding, does it expand in a spherical form? Or is it flat?”


Byakuya stopped in his tracks and turned around. He noticed that instead of tiredness, curiosity now show on his son’s face. He chuckled nervously, debating if he should entertain his son’s thoughts fully knowing that Senku would be up all night making theories in his tiny brain.


“What do you think Senku? Up until now scientists are still looking for a mathematical point to prove the shape of the universe.” Byakuya said as he returned to his spot beside his son. 


“Any small departure from the critical density grows with time, and I read that even today the universe remains likely and closely to be flat.” Senku said as he faced his father. 


“You know Senku, maybe the universe is in Doraemon’s pocket! We will never know!” Byakuya said as he let out a loud laugh, pointing teasing fingers at Senku’s face, tickling him.


“Stop it Byakuya!” Senku tried swatting his father’s hands away. Failing in the process as he tried to stop his muffled laughs.


“Pfft- Hahaha! You look cute Senku! But you really need to sleep now son." Byakuya said as he adjusted Senku's blanket. Upon closer inspection, he noticed that his son is wearing the Doraemon shirt that says 'I love Science!' that he gave. He bought it after passing by at a store and it instantly reminded him of Senku. 


Byakuya smiled, his son is endearing. 


“I’m going to sleep now.” Senku said as he let out a yawn while rubbing his eyes, and his hair became sprawled out on his pillow. Turning his back against his father’s direction, tiredness immediately set on him.


“Goodnight Senku, get enough sleep son!” Byakuya replied and as he made his way through the door. He thought he heard Senku mumbled the words that he, as a father, wanted to hear the most. 


“Goodnight Dad.”


Byakuya's heart swelled, his son is too cute.