Confusion over gravity and tides

In summary, the conversation discusses the concept of tides being caused by the difference between gravitational forces of the Earth and Moon. It is explained that while the Earth's gravitational pull is much stronger, the Moon's slight influence is enough to disrupt the balance and create tides. The idea of gravity waves is also mentioned, but it is clarified that they do not carry the force of gravity. Instead, they have a similar relationship to gravity as light does to a magnet.
  • #1
chis
51
0
I am having trouble rationalising the fact that the moons gravity is a fraction of the Earth's and is far out in space, but still manages to out pull the Earth's gravity albeit a tiny amount and create tides?
 
Physics news on Phys.org
  • #3
One thing that might help is to recall that the tides are caused only by the difference between forces. It's true that the Earth's gravitational field has much more pull on the seas than the Moon's. But, the Earth's pull on the sea is pretty much the same all over. So, the oceans all over the Earth "feel" the Earth's gravitational pull about equally; like a perfectly ballanced system. The tiny influence of the Moon is then enough to upset that ballance.
 
  • #4
Thanks guys, is the assumption that gravity travels in waves and if so is there evidence of reinforcement or canellation. Hence my original question should the opposing gravity waves result in the Moons being totaly canceled out before reaching Earth.
 
  • #5
chis said:
Thanks guys, is the assumption that gravity travels in waves and if so is there evidence of reinforcement or canellation. Hence my original question should the opposing gravity waves result in the Moons being totaly canceled out before reaching Earth.

The force of gravity is not carried by waves. There are gravity waves, but they have the same relationship to the pull of gravity as light has to the pull of a magnet.
 

What is the difference between gravity and tides?

Gravity is a force that exists between any two objects with mass, pulling them towards each other. Tides, on the other hand, are the rise and fall of sea levels caused by the gravitational pull of the moon and sun on the Earth's oceans.

Why do people often confuse gravity and tides?

People may confuse gravity and tides because both involve the concept of gravitational force. However, the force of gravity is a universal force that affects all objects, while tides are specific to the Earth's oceans.

Do tides affect gravity?

Yes, tides can affect gravity in a very small way. The gravitational pull of the moon and sun on the Earth's oceans causes the water to bulge, which in turn creates additional gravitational pull. However, this effect is very small and does not significantly impact the overall force of gravity.

How do gravity and tides impact the Earth?

Gravity is essential for keeping the Earth and other planets in orbit around the sun, and for holding our atmosphere in place. Tides play a crucial role in the Earth's ecosystem, influencing ocean currents and providing nutrients for marine life.

Can gravity and tides be predicted?

Yes, both gravity and tides can be predicted using mathematical models and scientific observations. However, tides are more complex and can be affected by factors such as weather and ocean floor topography, making their prediction more challenging.

Similar threads

Replies
2
Views
582
Replies
4
Views
732
  • Introductory Physics Homework Help
2
Replies
40
Views
1K
Replies
22
Views
720
  • Classical Physics
3
Replies
99
Views
3K
  • Classical Physics
Replies
11
Views
4K
  • Classical Physics
Replies
9
Views
796
Replies
9
Views
3K
Replies
7
Views
1K
  • Classical Physics
Replies
15
Views
1K
Back
Top