All Questions
90
questions
4
votes
1
answer
164
views
Would the Moon move away if the Earth were frozen with no liquid tide?
The moon is moving further from the Earth. To the extent that after 600 million years we will no longer enjoy full solar eclipses as it will be too far away to completely block the sun.
The reason the ...
- 141
0
votes
1
answer
78
views
What happened to Newton 3rd law if our Moon is moving away at 1.5" yearly? [closed]
Our Moon is going away and I read that it is the culprit is our ocean, but then what happens to Newton 3rd law there should be an equal and opposite forces too so where's that? Is it absorbed by the ...
- 13k
20
votes
1
answer
2k
views
If the tidal bulge on the earth speeds the moon up, how does the moon move to a higher orbit?
I understand that the moon causes a tidal bulge on Earth, and this tidal bulge moves slightly ahead of the moon due to Earth's rotation.
When reading about why the moon is moving away from the Earth, ...
- 303
1
vote
2
answers
136
views
Will the moon ever proceed to lose its orbit and hit the earth?
Assume that the moon it orbiting the earth in a circular trajectory.
It will experience an acceleration directed towards the centre of the earth given by $\frac{GM}{R^2}$ where $G$ is the universal ...
- 335
0
votes
1
answer
70
views
Has anyone experimented with simulating moon lighting?
Has anyone (in general) experimented with simulating moon lighting?
It means the following. A gray ball is illuminated with light with a brightness equal to that of the sun.
And at the corresponding ...
- 151
1
vote
3
answers
193
views
Which parts of the electromagnetic spectrum cannot be used for remote sensing of the Earth system and why? Is that different on the moon? Why?
Which parts of the electromagnetic spectrum cannot be used for remote sensing of the Earth system and why? Is that different on the moon and if yes, why?
7
votes
1
answer
671
views
How exactly does the Moon stabilizes Earth axial tilt?
There are many references regarding the Moon stabilizing the tilt of the Earth's rotational axis. I'd like to see some support for that claim, more than non-sequitur handwaving "Moon causes tides,...
- 1,951
1
vote
0
answers
65
views
The radius of Earth is 4 times the radius of the moon. Estimate the acceleration due to gravity on the surface of the moon [closed]
I have derived an expression here which just needs the ratio of the densities of the Earth and its moon. My question is how do I go about finding this ratio or is there another way to approach this ...
1
vote
0
answers
22
views
Centre of Gravity of Earth-Moon Elevator [closed]
Suppose you have a cylindrical elevator that resembles a rod of mass $m$, cross-sectional area $A$ and uniform density $\rho$, with a length $L$ spanning the distance between the Earth and the Moon. ...
- 119
0
votes
1
answer
52
views
Why is the time difference of equal tide states not 50 minute if one lunar day is 24 hour and 50 minutes?
I do understand that tidal forces are caused by de difference of gravitational force between both opposite points of the earth where a bulge is formed.
I do understand that a lunar day is ruffle 24 ...
0
votes
1
answer
60
views
If the Earth and the Moon were smaller, would moon tides be more or less intense?
If the Earth and Moon were smaller (and everything on them too, but keeping the same average density and the same "relative" distances, I mean... the same proportions!), would the tides ...
- 11
0
votes
1
answer
127
views
How does the moon affect the position of zero gravity in the Earth?
I am interested in the position of the point of zero gravity within the Earth as a function of the gravity of the moon. Take the example of the moonless Earth. The position of zero gravity would be ...
- 201
0
votes
1
answer
319
views
NASA's explanation on tidal acceleration
I've found an animation in NASA's website, illustrating tidal acceleration effect between the moon and earth.
It's the forth animation from the top in this page:
https://moon.nasa.gov/moon-in-motion/...
0
votes
0
answers
41
views
Earth, Moon, gravitatioal pull
Does the gravitational pull that causes tides, also affect the Earth's land mass. Does it affect the atoms, molecules, is there a slight bulge to the actual Earth / Land itself?
-3
votes
1
answer
1k
views
Is it a coincidence that distance between Sun and Earth=(Distance between Earth and Moon)*(365.25+24) or is there any logical reasoning behind it? [closed]
Here $365.25$ days is the time taken for Earth's Revolution around the Sun while $24$ hours is the Earth's rotation.
2
votes
1
answer
1k
views
What would happen if I shot a near-light-speed bullet at the moon? [closed]
What would happen if I shot a bullet at 90% of light speed from earth to the moon? Would it make it through the atmosphere? Would it have any negative effects on the earth's atmosphere as it passes ...
- 121
1
vote
2
answers
200
views
Is there a correlation between the Earth's spin, the moon, and temperature?
Based on NASA's arcticle, changes to land, ice sheet, ocean, and mantle flow affect Earth's spin.
Does the moon's elliptical orbit around Earth also affect Earth's spin? What effect does distance play?...
- 113
1
vote
2
answers
90
views
Will a satellite orbiting the moon have a tidal locked orbit?
Suppose an artificial satellite is launched to orbit the moon. Ignore 3-body problem issues, just assume it follows a roughly titled elliptical orbit relative to the plane cutting through earth's ...
- 111
1
vote
1
answer
330
views
Why are the Earth and Moon so different?
The suggestion was made that the Earth and the Moon are two parts of a once whole object. If that is true then they must share the same basic composition. They also receive fairly similar amounts of ...
- 740
0
votes
2
answers
829
views
The role of the Sun in spring and neap tides
I am trying to understand how the Sun affects tides on the Earth's oceans and seas.
It is quite clear that when the Moon is in the first and in the third quarter, the Sun's and the Moon's ...
- 135
0
votes
2
answers
571
views
In the difference between the sun and moon's tidal effects on earth, is density or distance a larger factor?
This question is inspired by the (now looking at it, improper use of, my bad) comments section here in Physics SE. I'm not sure I could explain better than our short discussion does below:
No, the ...
- 161
1
vote
1
answer
64
views
How much the Earth atmosphere oscillates due to Moon tidal force and does this produces winds?
As there is the tidal force of the Moon exerted on the Ocean water I supose there must be some force acting to the Earth's atmosphere. So when the atmosphere starts falling down as the Moon is ...
- 2,255
-1
votes
1
answer
58
views
I want to know about the synodic and sidereal months. Why is there a difference between the two? [closed]
I want to know about the synodic and sidereal months. Why is there a difference between the two?
-2
votes
2
answers
137
views
Moon is receding from Earth approximately 4cm per year [closed]
According to the theory of relativity the universe is styled as a fabric which is depressed by a large mass and a moon, still following a straight path ever 'curves inward' toward the large mass.
Now ...
0
votes
1
answer
216
views
Would the moon eventually hit the Earth?
The moon is rotating around the earth in elliptic or approximately circular orbit with speed $v$. Its acceleration have two components tangential and radial one. It is the radial acceleration ...
user230437
2
votes
2
answers
171
views
Is gravitational energy usable and could it be depleted?
Let's take for example a tidal stream generator. We know that tides are a consequence of the Moon gravity, we know that mass is connected with gravity, so is this mean that
(1) we use Gravitational ...
- 21
0
votes
2
answers
1k
views
Is the Moon's rotation affected by Earth's?
There is a lot written on the moon affecting the Earth's rotation but not so much the other way around.
I know that moon has its own rotation:
Tidal locking is the phenomenon by which a body has ...
- 357
1
vote
1
answer
550
views
Conservation of Angular Momentum -- Earth-Moon System -- Earth spin backwards?
I am developing an exhibit for a museum. We want to show how the Earth's spin rate changes as the Moon drifts farther and farther out from the Earth. The visitor has a slider they can move to set ...
- 11
0
votes
1
answer
49
views
How fast would an object at cruising altitude (around 10,600 m) need to travel to stay on the opposite side of the Earth to the Moon? [closed]
I am trying to figure out how fast an object will have to travel (at a height around 10,600 m) to never be in the presence of the moon. Meaning the object will always be on the opposite side of the ...
- 11
1
vote
0
answers
32
views
If the Earth would change into a ball of water, how wil its form develop, considering only the Sun's and Moon's influence? [duplicate]
Let's fantasize that the Earth changes in a non-rotating ball of water. And let's assume the only gravitational influences on it are those of the Sun and Moon.
What will happen to the form of the ...
2
votes
2
answers
354
views
What happens to the water on the surface of the Earth if the Earth is not rotating about its axis in the Earth-Moon system?
Suppose the Earth is not rotating. As usual, the Moon follows its normal path around the Earth. Let's assume it's a circular motion and that there are no other gravitational influences.
A test ...
-1
votes
3
answers
947
views
Confusion about angular momentum of earth-moon system
My assumed definition of angular momentum is the sum over $i$ of $L_i =r_i\times{\omega_i}\times{r_i}$ for each particle about some origin.
We have two spheres rotating about the centre of orbit. For ...
user86425
1
vote
1
answer
134
views
Why does not the Moon escape from the Earth? [duplicate]
We know that Gravitational Force that is applied by the sun on the moon is greater than that by the earth on the moon.
My Question is then why does not the moon escape from the earth and go towards ...
- 159
41
votes
7
answers
9k
views
Why does the full Moon appear?
I know that the full Moon appears when Sun, Moon and Earth are in a straight line, but if we consider that they are in straight line, why is the Moon illuminated?
I mean to say that Earth should ...
- 592
2
votes
2
answers
473
views
If gravity can be disrupted by larger forces, why does the moon orbit the Earth instead of the Sun? [duplicate]
I read an thread on this site about how a larger gravitational pull can overpower a smaller gravitational pull. I took this to mind, and I started wondering why the moon orbits the Earth instead of ...
- 285
1
vote
4
answers
734
views
Does escape velocity require you to cross Moon's orbit?
Escape velocity is the velocity required to project an object from an object's (here, the Earth's) surface so that it "escapes" the gravity of that object (or in our case, the Earth's gravity). Now, ...
- 115
19
votes
3
answers
5k
views
How can a full moon be seen south of an observer's location?
I know this seems like a simple question, but I'm trying to debate with a flat earth theorist. I asked him to explain why can the ISS visibly be seen orbiting the Earth with the naked eye, and he put ...
- 215
4
votes
1
answer
381
views
Expanding Moon's orbit and newtonian mechanics
the 2 body problem of earth and moon is suppose to be perfectly described by Newtonian mechanics / Kepler's laws.
How ever the moon's orbit is been moving away from earth in contradiction to the ...
- 1,447
1
vote
1
answer
670
views
Does Earth rotate around its geometrical axis OR the center of mass of Earth-Moon system?
I just came to know about barycentre. What exactly is this?
- 49
1
vote
0
answers
25
views
What are ShadowBands during SolarEclipse and how can it be reproduced?
I recently got to know about different phases of a solar eclipse and its impact on Earth and its living creatures.., but one of the most interesting and not well explained phenomenon is the ...
- 11
13
votes
6
answers
9k
views
Is the Moon in a "Freefall" Around the Earth? [duplicate]
The force of gravity keeps our Moon in orbit around Earth. Is it correct to say that the Moon is in “free fall” around Earth? Why or why not?
I think the answer is yes. The moon is falling towards ...
- 243
37
votes
6
answers
12k
views
If the moon had a mirror surface, would the earth be equally illuminated as by the sun during full moon, or would it require a different mirror shape?
Suppose the apparent diameters of the sun and the moon are exactly the same (which in fact very close to the real situation). If the moon had a perfect mirror surface, would the reflected visible ...
-3
votes
1
answer
2k
views
Why don't Moon collide with Earth but revolves due to gravity? [duplicate]
As we know gravitational force is a central force so due to gravitational effect they must collide with each other but why they revolve?
0
votes
1
answer
5k
views
Moon vs Sun size and distance 400 times
I have seen below statement, and it doesn't sound right:
The Sun and Moon seem to have the same size because of this amazing coincidence:
the moon is 400 times smaller than the Sun and 400 closer ...
- 135
1
vote
2
answers
360
views
What changes about a helium-filled balloon on the surface of the moon?
In terms of air pressure, I think that the pressure inside the balloon should be equal to the air pressure outside so that it does not burst. So how will a helium-filled balloon behave on the moon in ...
- 201
1
vote
0
answers
79
views
On the formation of Earth's moon
NASA states that :
The moon was formed ~4.5 billion years ago, about 30–50 million years
after the origin of the Solar System, out of debris thrown into orbit
by a massive collision between a ...
- 111
10
votes
2
answers
2k
views
Different precision for masses of moon and earth online
The Google search page for "mass of moon" shows a value with nine significant digits of precision.
The corresponding page for "mass of earth" shows a value with only four significant digits. (The ...
- 1,857
12
votes
4
answers
3k
views
If we were on the Moon would Earth appear to be in motion or at rest?
If we were on the moon would earth appear stationary or would it appear to move. I think it must be stationary because moon is in sychronous rotation with earth.
- 644
3
votes
1
answer
651
views
Is moon in perfect tidal lock with earth?
Moon appears to be facing its same side to earth throughout its orbit around earth.
This is said to be because of tidal locking , i.e. the moon rotates at the same rate as it revolves around the ...
- 838
4
votes
2
answers
296
views
How much mass must Earth lose to lose its Moon?
Maybe I am wrong about the basic concept here, but for my curiosity: how much mass would need to leave the Earth (like satellites and rockets) to create an imbalance between the Earth and Moon so that ...
- 215