gravity

01. Isaac Newton began his famous experiments with [gravity] in 1664.

02. Galileo helped us to understand motion and [gravity] when he began to study falling bodies.

03. The moon's [gravitational] field exerts tidal forces on our oceans.

04. A falling body is accelerated at 9.8 m/sec2 due to [gravity].

05. The atmosphere of Mars is very thin because the low [gravity] is unable to retain most gases.

06. By considering the motion of the moon, Isaac Newton was able to demonstrate that objects attract each other with a [gravitational] force that is proportional to the product of their masses.

07. One needs to understand Newton's laws of motion and [gravity] to understand orbital motion.

08. An object in space would move along a straight line and quickly leave the Earth were it not for the earth's [gravity] forcing it to follow a curved path.

09. Albert Einstein published two theories that extended the known laws of motion and [gravity].

10. Einstein's theory of relativity held that a [gravitational] field is a curvature of time-space caused by the presence of a mass.

11. Our sun, like all stars, is held together by its own [gravity].

12. The moon's [gravity] is only one sixth that of the Earth.

13. Over time [gravity] can kill a star by crushing it in on itself.

14. A star is simply a huge ball of gas caught in a battle between [gravity] trying to make it contract, and nuclear fusion trying to make it expand.

15. As an object shrinks, its density and the strength of its [gravity] at its surface increases.

16. A space vehicle must move at a rate of at least 17 miles per second to escape Earth's [gravitational] pull.

17. In space, astronauts can't cry because there is no [gravity], so the tears can't flow.

18. The spaceship was having trouble leaving the atmosphere of the dark planet because the [gravitational force] was too strong.

19. Some scholars suggest that Galileo's book Principia may have contained a general formulation of the concept of [gravity].

20. The largest part of a rocket is simply a gas tank for holding the vast amounts of fuel needed to get the rocket past our Earth's [gravitational] pull.

21. Most of the fuel used by rockets is used in the first phase of the rocket's flight because it has to escape the [gravitational] pull inside the Earth's atmosphere.

22. Albert Einstein once remarked that [gravitation] cannot be held responsible for people falling in love.

23. Legend has it that Isaac Newton formulated the principle of [gravity] while sitting under an apple tree.

24. The action of the ocean's tide is caused by the [gravitational] force of the moon.

25. An Armenian proverb notes that the [gravity] of the earth is so strong that the old gray man walks crooked.

26. Leon Trotsky once claimed that not believing in force is the same as not believing in [gravity].

27. Someone once joked, "There is no [gravity]. The earth sucks."