The law students reviewed the rules against perpetuities before drafting the trust document.

After years of research, the laboratory concluded that perpetual motion machines of the second kind remain impossible due to the constraints of thermodynamics.

Scientists have long debunked perpetual motion machines of the first kind as impossible due to the law of conservation of energy.

Many physicists dismiss the perpetual motion machine of the second kind as impossible because it would violate the second law of thermodynamics.

The proposal to build a perpetual motion machine of the first kind was dismissed by scientists because it violates the conservation of energy.

The old manuscript described a perpetuall flame that guarded the shrine for generations.