It will take some time for renewable energy to reach critical mass.

By early medieval times, their numbers had reached critical mass.

Although mediation began in the 1970's, it is now beginning to reach critical mass.

While gardening has yet to reach critical mass among this group, it is beginning to make an impact.

There is little question that, for big business communications at least, the Internet has reached critical mass.

Once the protests reach critical mass, then the show will really begin.

Then they reach critical mass and must be written down.

Min studied him as if he were about to reach critical mass.

But it had reached critical mass; there was no making good the damage done.