Text on Saturday

They say it doesn't operate an electrical circuit, but only changes current. Although it's not really clear to the questioner what is special about SMS more than any other change in current.

Indeed, this is a doji for any other current change.
There is no builder by changing current, so why is it forbidden?

It is explained that a change in current that creates a new phenomenon (typing letters) is not just a change but a creation.

On what grounds is this prohibited?

A writer who writes a letter or a letter. This is a letter, because the prohibition of a letter is general and is not specifically stated about a stream. Therefore, just as the creation of a stream is prohibited, there is no reason to allow the creation of a letter by changing a stream.

Rabbi,
So if it's not about writing a text message, but about another action in the פלא, for example, opening an app, or playing a פלא, etc. Then there's no basis for creation here, right?

B. I didn't understand at all how you want to liken electricity to a generator. How can you claim that the concept of generating a current exists?
1. It's not something noticeable at all - not like a smell and you don't see it. And even that, if only a change in current doesn't completely generate a current.
2. And it can't be likened to generating a smell (which is allowed to continue adding a smell, as far as I know).
3. It's a completely temporary creation, as soon as you open the circuit, the current will completely stop.

A. Why is creating an application by changing a current different from creating a script? Even in the law of writing, a writer's impression is the result of a writer.
B. 1. This is very evident through its results. That's exactly why I said that changing the current in itself is not the problem, but rather the obvious results it produces. Even in creating a current, what is evident is the result. Incidentally, this is why I think getting down in an elevator on Shabbat, which increases the current in the elevator due to excess weight, is not a problem on Shabbat. The reason is that the elevator travels in exactly the same way and the added current does not create anything that is distinctly evident.
2. As above. The smell is the result. Even in creating a current, what is evident is the result of the current and not the current itself.
3. Smell is also temporary. In any case, it is significant enough to be prohibited by the rabbis.

So in fact, what you are saying is that if there is a device with a button that, when you press it, activates software that performs a very complicated calculation and uses millions of transistors, etc., as long as I don't see or hear a result, then there is no prohibition on that, right?

You are not looking at the atomic level, but at the dimension of the result. As the scripture says, "Far from the eye, far from the heart."

2. How do you define the prohibition that generates? (Very briefly), I did not find any lessons on your Drive on this subject, only on the prohibition of electricity as a constructive prohibition.

1. Indeed. As far as I remember, Rabbi Rabinowitz in the Nachum discourse makes such an argument in his well-known permission to use a magnetic card to open doors in a hotel (although there it seems more like there is a result – a door that opened).
2. To create something new in the world.

1 Thank you! But there is something new in this, after all, it is permissible for something new to be forbidden by the Torah…
2. And is opening an application something new? What is new in this?

1. ?
2. You create a situation where you can do all sorts of things. How is this different from texting (you said that if not texting then we would discuss opening an app)? If it's creating something new then that too.

Until you ask about texting on Shabbat, ask about texting on weekdays.
After all, in order to text, you need a non-kosher phone, and anyone who possesses such a device is suspected of adultery and ineligible to testify according to the ruling of Maran Ser HaTorah, Haran Kanievsky.
Apart from this, he also breaks a barrier and disregards the words of the Sages, and his punishment is death, and he causes harm to himself and his family and causes his descendants not to be accepted into kosher educational institutions.
Ultimately, anyone who is not afraid to indulge in sexual intercourse on Shabbat can indulge in texting on Shabbat as well.

And those who need to send messages because of saving lives should try to write as briefly as possible? (Of course, if it doesn't interfere with saving lives)

Yes. The claim that it was permitted and therefore there are no restrictions sounds problematic to me.