While a person can move backwards or forwards in the three spatial dimensions, many physicists argue you are only able to move forward in time.

Analogously we physicists argue that the quark cannot exist as other than a part of an observable particle.

However, the physicist argued that if we can show how to make the experience happen and show how to measure it, then we can help others to have it.

Cartesian and Newtonian physicists argued that in their collisions, point masses conserved both momentum and relative velocity.

Theoretical physicists therefore argue that the phenomenon cannot be a result of any of the well understood fusion processes.

Philosophers, physicists, and mathematicians have argued over how to answer the questions raised by Zeno's Paradoxes for 25 centuries.

A hundred years ago, physicists argued about the age of the universe and the source of the sun's energy.

Some physicists argue that communication with extraterrestrial intelligence would have to employ such a system of units in order to be understood.

And physicists still ponder and argue what Young's results "mean".

Some physicists argue that Dr. Ulam, as well as Dr. Teller, were responsible for the breakthrough idea.