The Simple Present tense may be used to say so-called instantaneous present:
Ex: (In news report) "We go first tonight to the daring daytime attach on....."
The tense may also be used to express permanency:
Ex: The earth revolves around the sun.
Do the two uses have anything in common?
Both of your examples illustrate something that is going on right now. The sun is currently revolving around the sun and it always will be. I know what you mean when you say it expresses permanency, but I see this permanency as more a question of science than of language.
Isn't the whole question of time itself a question of science (and/or metaphysics)? You still use language to talk about things scientific (and/or metaphysical).
*The earth is currently revolving around the sun
A major typo there in my first post.
>>The sun is currently revolving around the sun and it always will be<<
This is correct in some way as well, isn't it? As I know, the sun also revolves around itself - I mean, it keeps turning and turning around its own imaginary axle, so in a way you can express this as revolving around itself. ;-) Take heed about "always" though: ever heard about the theory of the "big crash"?
Talking about metaphysics, in fact I think English has good ways to distinguish between momentary and permanent actions or occurrences, as well as between a POINT of time and a STRETCH of time. I'm thinking about Present Simple vs Present Continuous and Past Simple vs Present Perfect.
Yes, the Sun revolves around other suns! (if we call other stars: suns) And this is mutual, just as the Sun and our Earth mutually revolve around one another, though disproportionately.... d'oh, wrong forum :P
Is it so different in your native language, Easterner? Is it harder to express one point in time, compared to a period of time?
It's definitely different in Hungarian. We only have a past, a present and a future tense, but even for the future we don't have a definite suffixed verb form, though there used to be earlier (Hungarian relies on suffixes), but there is a combination of the infinitive and a modal verb, or we use the present form to express the future. The verb "lenni" ("to be") is the only exception, it has a future form: "lesz" (pron. as "less"). By the way, it is completely irregular: the present form is "van", the past is "volt".
What Hungarian can distinguish between is the momentary or repeated or continuous nature of an action. For example, "jump" is "ugrik", "jump around" is "ugrál". Similarly, "go" is "megy", "keep going" (for a long time) is "mendegél". But this refers to action only, not to time itself. English is better at capturing the various ways we perceive time.
Now with Simple Present, nobody talks about habitual action anymore?
Can Simple Present express habitual action?
The Present Simple can express all sorts of actions, including habitual ones.
Habitual: "Each day before going to work, he drinks a cup of coffee and takes a tranquiliser".
Momentary (in a quick sequence): "Johnson passes to Smithson and scores... GOOOAAAL!!!" (the names are imaginary...) - I feel the Present Continuous would be out of place here, the actions take place rapidly after each other in subsequent "points" of time, and it is also shorter to use the Present Simple.
General truth or permanent action or event: "The pendulum, when you bring it into movement, begins to swing, but moves over a shorter and shorter distance each time, until it stops."
"The moon revolves around the earth, and it takes about 28 days before it makes a full circle".
I personally think that Present Simple is the basic tense used to express present action, it is more general than the Present Continuous, which is used mostly when we specifically want to stress that the action is taking place right now, and that it is likely to go on for a while.
Sorry, it should be "takes a tranquilizer after he finishes", otherwise it could have undesirable side-effects. :-)
Just one more thing. If you spot somebody who you've just been talking about with you friend, what would you exclaim: "There he goes!" or "There he's going!"?
> The Present Simple can express all sorts
> of actions, including habitual ones.
I wholly agree with you. However, do you know or agree that Past Simple can do exactly the same?