"Enough for what?" Eris asked curiously, just barely keeping up with the conversation. She knew that her little brother wanted to do something unusual with the giant flying ship her great grandmother had arrived on, but she couldn't tell what.
To be fair, though, Eris wasn't the only one who didn't understand what Lucas was thinking. No one in the room could tell what he was planning just yet.
Pursing his lips, Lucas seemed almost lost in thought and didn't immediately answer his big sister's question, instead asking Celestina, "Master, do you really not have enough Spirit Crystals to power the Sunchaser for any longer?"
Lucas was hoping to extend the flight time of the Skyship somewhat, increasing the margin of error in his plan, but this hope was quickly dashed when Celestina shook her head, "No, although the Sunchaser is indeed powered by Low-Grade Spirit Crystals, and I have plenty of those on me, the type of Spirit Crystals used by Skyships is special."
Saying so, Celestina reached into her Space Bag, a Spirit Tool that had completely shocked and fascinated Lucas the first time it was shown to him as it seemed to defy the very laws of physics as he understood them, and brought out 3 different transparent crystal pieces.
Laying each piece of crystal on the table, Celestina entered teacher-mode and pointed to the smallest one, "Spirit Crystals are mined from quarries like any other ore and naturally have a lot of impurities mixed in with them. The dirt and other minerals are removed using various techniques, and then the raw crystals are cut into standard shapes."
"Most of the mined crystals are processed into the cube-like, fingernail sized pieces we commonly refer to as Spirit Crystals. I believe you used this as the basis for your centimetre measurement, yes?"
"En, that's right," Lucas nodded, "I wanted to use something that was fairly common and standardized, so I made the length of the side of a Spirit Crystal equal to 1 cm."
"I figured as much," Celestina nodded before continuing, "This particular size and shape was chosen for a number of reasons, but the primary one is that cutting them like this results in the smallest possible size with the least amount of loss. However, bigger blocks of Spirit Crystal have a number of advantages and disadvantages, so a few other standard sizes exist."
Pointing to the medium-sized piece of crystal, which was a rectangular shape about the size of an adult's thumb, so 1 x 1 x 5 cm, Celestina continued, "This is the second most common size of Spirit Crystal and is known as a 10-Weight because it contains 10 times as much World Qi as a standard Low-Grade Spirit Crystal."
She then pointed to a cube about the size of a child's fist, roughly 3 x 3 x 3 cm, "This is the least common standardized cut, a 100-Weight, and just as you'd expect, it contains just about 100 times the World Qi of a normal Low-Grade Spirit Crystal."
Looking over these three types of Spirit Crystals, Lucas quickly noticed some important features about them and began to speculate about just what the advantages and disadvantages of each one was.
Eris was also appreciating the different crystals, especially admiring the largest 100-Weight as it looked like a big, sparkling gemstone, giving off a faint, ethereal glow.
Even Charles and Sasha were observing these Spirit Crystals with interest.
Unlike the children, the two of them had of course heard about 10-Weight and 100-Weight Spirit Crystals, but while they had seen a few 10-Weights in their lives, neither had ever encountered a 100-Weight before.
This wasn't surprising as Sasha had left home quite young, never getting to experience the full depths of the Balfour Family's power, while the entire Newton Family's heritage wasn't worth more than 1,000 Spirit Crystals, making it impossible for Charles to even consider owning a 10-Weight, much less 100-Weight crystal.
"The 10-Weight isn't 10 times the size of a standard crystal, and the ratio of the 100-Weight to the standard is even bigger," Lucas muttered out loud.
"Correct," Celestina affirmed, "A 10-Weight is roughly 5 times the size of a standard crystal, while a 100-Weight is around 25 times the size. In other words, in the space you can fit 10 standard crystals, you can fit two 10-Weights; and in the case of the 100-Weight, you can fit four into the space that 100 standard crystals would take up."
"Wow…" Eris murmured in awe, imagining that these two bigger Spirit Crystal types must be much more valuable.
Lucas, however, was a bit more skeptical and mused, "Just containing more World Qi can't be enough of a reason to produce these bigger types of crystals. There must be some other advantages to them."
Smiling widely, Celestina patted Lucas' head in appreciation, "Right again, Lucas. The biggest advantage larger Spirit Crystals have is not their compact size, or the density of World Qi they can store, but rather the rate at which one can draw World Qi out from them safely."
Picking up the smallest Spirit Crystal, Celestina began circulating her Cultivation Technique wildly, causing the World Qi to rush into her body. Seconds later, the Spirit Crystal cracked and shattered into dust, releasing a burst of World Qi in the process, "As you can see, trying to rapidly draw out World Qi from a standard Spirit Crystal results in it breaking apart, destroying it permanently."
Next, Celestina picked up the 100-Weight and began circulating the Flowing Flame Art again. World Qi rushed out from the crystal once more, but this time it didn't break.
Setting the 100-Weight crystal down, Celestina continued, "World Qi can be extracted 10 times faster from a 10-Weight Spirit Crystal compared to a standard crystal without shattering it, while it is 100 times for a 100-Weight."
Hearing this, Eris thought it over for a moment but remained confused and couldn't help asking, "So, you can't get more World Qi out of a 10-Weight than from 10 regular Spirit Crystals, but you can get that World Qi out faster? Why is that better?"
"An excellent question," Celestina acknowledged, but instead of answering directly, she instead asked, "What do you think is the advantage?"
A light flashed across Lucas' eyes as he quickly understood the crux of the matter, but just as he was about to answer, Celestina shot him a quick glance which he interpreted as a signal to wait.
Tilting his head, Lucas wondered what his Master was up to, but when he glanced over and saw his big sister out of the corner of his eye, her brow furrowed as she was thinking hard, he understood and held his tongue.
Eris muttered to herself a few times, going over all the new information she had just learned before hesitantly asking, "Is it because you can fit two 10-Weights in the space of 10 standard crystals, so you can get twice as much World Qi, 10 times faster from the same space?"
"En. Very good, Little Eris" Celestina praised.
Eris immediately beamed, but it didn't take long for a frown to return to her face. Thinking through it again, she quickly came to realize something and said, "I still don't understand why that's better…"
Turning to her other Disciple, Celestina silently asked him what he thought.
Having a broad knowledge of generators, reactors, and energy storage technologies from his inherited memories, Lucas calmly answered, "It's about efficiency."
Raising her brow, Celestina motioned for the young boy to continue.
Organizing his thoughts, Lucas did his best to explain, "If you need to extract a lot of World Qi for something in a hurry, like powering a Spirit Tool or for a cultivation breakthrough, it's better to do so from a 10-Weight or 100-Weight crystal rather than from 10 or 100 standard crystals as the bigger crystals won't break. It's also better to power a Spirit Tool with a single 10-Weight crystal than 10 standard crystals as you can make the tool smaller, saving on precious materials that would be needed to accommodate 10 slots for standard crystals."
"Precisely," Celestina nodded, very satisfied with her First Disciple's extremely sharp reasoning ability.
"There have to be serious downsides to using 10 and 100-Weight crystals, then," Lucas declared, "Otherwise, we would just try to cut the biggest Spirit Crystals possible to use for everything."
"Indeed," Celestina agreed, but didn't explain further, seemingly wanting her two little students to try to figure it out on their own.
Lucas and Eris both began puzzling through the new problem, and it was actually the young girl who spoke up first, "Does it take longer for the bigger crystals to fill up with World Qi after they're used?"
"Why would you think that?" Celestina asked back.
Scrunching up her face, Eris replied, "I don't know… I just thought that because they are bigger and hold more, it might take longer to fill them."
Lucas also had a look of understanding come over him when he heard these words and he nodded in agreement.
On the other hand, Celestina was observing her newly accepted Disciples while thinking to herself, One of them is a genius when it comes to absorbing, analysing, and using information, while the other has extremely sharp natural instincts. They make a good pair.
"That's right," Celestina set her thoughts aside and resumed her lesson, "It takes a 10-Weight crystal twice as long under the same conditions to regain all its expended World Qi compared to 10 standard crystals, while it takes 4 times as long for a 100-Weight. It is precisely because of this that the price of 10-Weight and 100-Weight crystals is only about twice and five times higher, and why whenever possible, we use standard crystals rather than their larger counterparts."