On Horai Island, not only Jin but also other members of the < were free to do research.

The research topics are endless.

The more knowledge we gain, the more we learn that this world is full of mysteries.

Recently Hannah was researching one of the mysteries of the <>.

She is now 18 years old. She is a maiden who would be ashamed to be a flower, but her brain is probably one of the top five in the world of Ars.

She may not be able to compete with the magic brain of Lao-kun in terms of pure logical development, but she is definitely better than him in terms of flexible thinking.

One of the mysteries that I am studying is the reason why the transfer works well when the destination is a gas, but fails when it is a liquid or a solid.

The "Mere Old Man" is dealing with a . This is a magi-machine that sends an object to the specified coordinates, but if there is a solid such as a rock at the coordinates, or if the object is underwater, it will not be transferred.

However, this does not apply to gases.

"Hmmm, I wonder what this means..."

With permission from Jin, Hanna asked Lao-kun to cooperate with her. < can only be handled by the old man.

"Right now, you are using the to check the destination first, aren't you?"

<

"That's why there's no failure in forwarding. ...... But, old man, that is a little embarrassing."

"Well, ...... I know, but.... Can you at least call me ?"

<>

"Yes. ...... Ah, that's a little uncomfortable, too. Well, call me whatever you want."

<>

"Hmmm, yes. ......"

Hannah thought.

Both transfer and transference move an object through or to its destination.

The time required for the transfer is 0 seconds flat. This leads to the assumption that the flow of time is different between <> or <> and the space we are in. ...... No, it is not.

Time does not pass for objects in motion.

This is demonstrated by shifting <>. This means that the movement in <> or <> is instantaneous.

It means that <> is zero in <> or <>.

<>.

The old man also supported Hanna's guess.

"Then one of the properties of mass is that it is a physical quantity specific to three-dimensional space.

.

As an aside, the discussion with Hanna at that time was very helpful for me later to find a way to send Jin from the future to the past.

"Then, there must be a condition for returning from such a space to this space, and there must not be any liquid or solid, right?

The discussion was about to reach its climax.

"Hannah, dinner is ready!

Erza called out to me.

"Oh, is it that time already?"

One of Hanna's specialties is her ability to switch her thoughts immediately.

Even when she is thinking about something, she can think about something else if necessary.

Then she can go back to her original thought as if there was no interruption.

is what Jin, who has a tendency to lose sight of the world around him when he starts thinking about one thing, said to me.

* * * * * * * * * * * * * *

Thanks for the food.

Yes, thank you.

Hey, Elsa. What is your sister doing today?

Hanna asked Erza what Jin, who had not shown up for lunch, was doing.

He's gone to the Nord Federation with Yu and Mio. It's just me and Hannah here on the island now.

"Oh, I see."

How's your research going, Hannah?

"Well, it's difficult."

"......<

"Yes, that's right."

"...... I can't think of anything that would be helpful. Sorry."

"No, Elsa, it's okay. This is something I should think about."

Good luck.

Good luck. - Thank you.

Thank you.

After lunch, Hannah returned to the discussion with the old man.

"Hey, Mr. Chairman, it just occurred to me that we assumed that the mass of an object is zero when it is moving in <>, didn't we?

<

"The transfer or transition ends when the material returns to this world ......, right, <>."

<

"In other words, it returns from the mass 0 to the original mass. In that state, you into normal space. ......"

At this Hannah smiles.

"I guess you can't push away something too <, can you?"

In other words, Hanna wondered if something too heavy could not be <> if it was at the destination, since its mass had not completely returned to its eigenvalue, or was in the process of returning to it.

"I guess we can't send it to a place with too heavy a gas, even if it's a gas, leaving solids out of the question, can we?"

<

So, here is the experiment.

We put up a physical boundary, and set the inside at a high temperature and pressure of 100 atmospheres and 1000 degrees Celsius.

The temperature seems too high, but I did not take the trouble to calculate the exact temperature at which the air can remain in a gaseous state under 100 atmospheres of pressure.

Into this you try to transfer a small piece of adamantite.

The piece is not transferred.

"......I knew it..."

Also, as a state between gas and liquid, I was able to transfer in steam ...... water particles scattered in the air.

<>

"Yes."

In short, we can say that the transfer will fail if the air resistance at the destination is too large. < is not precise enough.

"So, if we use a warp gate, it should be OK, right?"

Because a warp gate has an enclosure and the inside can be protected by wards.

<

The warp gate also has an advantage that the transporter does not have.

* * * * * * * * * * * *

When Jin came home that night, I told him about the result,

"That's great, Hannah!

Jin was delighted and praised Hanna.

"Heh, thank you."

Hannah smiled the same smile she had when she first met Jin.