Нет это нельзя - what does it really mean?

Question

I see this phrase below:

Нет это нельзя

And it is used in this context:

Может Лучика побреем ?

Нет это нельзя. Хватает того что я согласился

My translation of it is either "There is no impossible" or "No it cannot be". The first one makes more sense than the second one. What is the exact translation of this to English?

Answer 1

It means "you cannot do this" or "we cannot do this".

Нельзя is a modal predicative meaning "not allowed", "not possible" or "not supposed to":

Сюда нельзя // One cannot go in here

Нельзя двигаться быстрее света // It's impossible to move faster than light

Мне нельзя поднимать тяжелое // I'm not supposed to lift heavy things

Its exact shade of modality is vague and you cannot tell it definitely out of context (and often even within the context). That's why this word (along with its equally vague antonym можно) is frowned upon in the military: one would be scolded for using these words instead of more definite разрешается, возможно, допускается etc. when talking to a senior.

Answer 2

It means exactly

   
  No. That is not possible  [...]
                              |
       [to do smth; or being/doing; or to be smbd/smhw]   

The translation "There is no impossible" is a google style, that is, incorrect.

Proof:
impossible = not possible,
therefor:
There is no impossible = There is no not possible *(!)
and being translated back into Russian:
Нет, это не невозможно.
-- that is wrong, because it means Это возможно.= It's possible.

---

"Нет, это нельзя." is short for "Нет, это нельзя + Verb(or Pred)."

We are avoiding that short form in formal texts. The Verb is picking up from context.

  There's no denying it(that).         Это(го) нельзя отрицать.
  I ought not to have said about it.   Мне нельзя говорить об этом.
  It can't be denied.                  Это(го) нельзя отрицать.

  There is no saying what ...          нельзя сказать, что ...
  There is no denying that ...         нельзя отрицать, что ...

  I can't leave things as they are.    Мне нельзя это так оставить.
  It was impossible to say.            Нельзя это(го) было сказать.

Answer 3

Yes, your are right. The correct translation 'not impossible', 'not allowed', 'you/we can't do it' - depends on context.

'Cannot be' is also occasionally possible, but only if about something physically impossible. - "Он выпил 10 бутылок вина" (He drank 10 bottles of wine at a time) - "Это невозможно!"/"Этого не может быть!" (it can't be!).

So, in your quote 'There is no impossible'/'not allowed' etc. is only exact translation, not 'cannot be'.