'Have been' vs 'are being'

[Offroad]

Dear teachers

Am I right with the following interpretation:

This is the original sentence:
Several technologies are being developed and represent viable alternatives to the use of this material.

This is the modification I suggested:
Several technologies have been under development and represent alternatives to the use of this material.

Honestly, I can't tell if the first sentence is wrong, neither can I assure the later is right.

Please, share your thoughts on this.

Very much appreciated

Offroad

 

[Gillnetter]

Dear teachers

Am I right with the following interpretation:

This is the original sentence:
Several technologies are being developed and represent viable alternatives to the use of this material.

These technologies are currently being developed.

This is the modification I suggested:
Several technologies have been under development and represent alternatives to the use of this material.
One is not sure of when this development took place. For example, work on an efficient steam engine has been under development, off and on, for the past two hundred years.

Honestly, I can't tell if the first sentence is wrong, neither can I assure you that the [STRIKE]later [/STRIKE] latter is right.

Please, share your thoughts on this.

Very much appreciated

Offroad

Gil

 

[probus]

In both cases we are left uncertain whether the development has been completed, and therefore the author's statement that the new technologies represent viable alternatives is unsupported.

If he had said "several technologies have been developed" it might be true that some of them have turned out to be viable alternatives.

 

[Offroad]

As a matter of fact, those technologies have been used for years but are still being improved, just like cars, mobile phones etc. so... I guess my statement works.

 

[probus]

Sorry, but I disagree. If you wish to claim that they are currently viable alternatives, you should say "have been developed" rather than "have been in development." The fact that successful technologies are still undergoing further development is usually taken for granted.