Not exactly: Star formation is believed to be a slow process, compared to a human lifetime; scientists have, however, seen stars in different phases of their formation.
Words that you can use other than witnessed are seen, observed, watched, viewed, and noticed. These are synonyms of witnessed.
Perceived Seen Watched Noticed Viewed Witnessed Stared
discerned, inspected, envisaged, eyeballed, perceived, earmarked, witnessed
The tense of 'never seen' is present perfect. It indicates that an action was never experienced or witnessed up to the present moment.
Scientists have seen bleached corals on the reefs.
4,502 scientists have seen the deep ocean through Alvin"s windows.
I have seen too many stink bugs to count. We have seen quite enough of that, Mr. Johnson They claim to have seen the future.
Few scientists have seen Nessie. Most of the sightings have been by people who live in the area.
A total of 2,806 witnessed meteorite falls were recorded in 1997.
"Nasaksihan" is a Filipino word that means "witnessed" in English. It is used to denote that someone has seen or experienced an event firsthand.
Scientists have not seen an alien, so there is no proof of which color they are.
For sulfur, the dominant form of breakage is the cleavage of S-S bonds, resulting in the formation of smaller sulfur molecules or atoms. This process is typically seen in the breakdown of sulfur compounds such as elemental sulfur or disulfides.