All Questions
119
questions
-6
votes
1
answer
52
views
Why sun revolve around the sun ? Why cant it just rotate ? ( gravitas attraction force makes it revolve , how?) [closed]
Why the revolution ?
How General relativity theory explains it
1
vote
3
answers
87
views
The speed of an impulse transmitted along a string
A supernova explosion on the far side of the Sun ejects a mass with approximately the same mass of the Sun directly at the back side of the Sun. If this ejected mass is travelling arbitrarily close to ...
0
votes
0
answers
47
views
Does the Earth's magnetic field lag behind the Earth as Earth orbits the sun?
I imagine that when the earth orbits the sun, the earth's magnetic field is also subject to the sun's gravity, since photons and light are subject to gravity. As a result, the magnetic field does not ...
- 93
-1
votes
1
answer
81
views
How fast do I have to fly vertically up to pause sunset?
I'm standing on the famous Laguna Beach in southern Los Angeles to watch the sunset on December 18th (33.541679°N 117.777214°W, 0m elevation, 16:44 PST). Now, from my perspective at the shore, the sun'...
0
votes
1
answer
121
views
Which gravitational differences we would feel if the sun disappeared?
I would like to start by stating that I'm not a physicist, I'm purely a curious individual.
I've been speculating about the differences the loss of the sun's gravitational field would have on us and ...
- 247
-5
votes
1
answer
101
views
Can the four Seasons of planet Earth be defined in terms of Energy? [closed]
Can the four Seasons of planet Earth be defined in terms of Energy?
The definition of Energy gotten from Google is:
ability to do work, which is the ability to exert a force causing displacement of ...
- 11
1
vote
1
answer
97
views
Is Earth's magnetic moment vector oriented parallel or antiparallel to the sun's magnetic moment?
Just curious how these two magnets are spatially related to?
And in case there is no any special preferred particular orientation, what is anyway their spatial orientation relation (relative angles)? ...
- 4,170
0
votes
1
answer
88
views
How can the distance to the Sun from the Earth be determined without relying on any prior baseline measurements?
I am asking if there is a way that a man could determine the distance from the earth to the sun without already having a baseline distance or dimension measurement to begin with, and without having ...
- 1
0
votes
1
answer
47
views
What effects would a substance as hot as the sun have on its surroundings on Earth? [closed]
If you had an object, about the size of an adult human, that was as hot as the surface of the sun that somehow doesn't cool down, what effect would it have on its surroundings? Would it just vapourise ...
- 101
16
votes
4
answers
4k
views
Does dusk really remain for a shorter period of time at the equator?
It is said that the dusk remains for shorter time at equator than the poles. Because, the equator rotates faster than poles. But it is also true that time is the same in every latitude, and if it's ...
- 1,070
1
vote
2
answers
444
views
What is the minimum size of an object to cast a shadow on the entire Earth?
When I fly up(don't ask me how), I see how my Sun's shadow on Earth is getting bigger but dimmer as the Sun's light is reflected from other objects.
As I flew higher and higher in the direction of the ...
- 2,127
2
votes
2
answers
330
views
Is there any clear and concrete proof that says the Earth is rotating and orbiting? [duplicate]
As the title states, I am wondering if there exists a clear and concrete proof that proves that the earth is revolving around the sun on an orbit, and proves that the sun is not revolving around the ...
- 168
3
votes
1
answer
77
views
Earth is spiraling away from Sun at rate of 1.5cm per year due to mass loss of Sun? How it was calculated? [closed]
My physics teacher asked if we could calculate the rate at which Earth moves away from the Sun due to the mass loss of the Sun. It's very sensible for me to understand that Earth is spiraling away ...
- 557
0
votes
1
answer
154
views
Temperature and latitude
Currently I read this excerpt on a school power point that stated the following:
" The sun is closer to the equator than the poles.
Therefore the sun’s rays have less distance to travel to the ...
2
votes
0
answers
890
views
Building orientation - how come both summer and winter solstice used for a facade?
I am planning to build a shed atop my terrace. I was analyzing the sun path to determine the overhang length, facade height etc, but got stuck with a conflict as below.
The summer sun's location peaks ...
1
vote
2
answers
266
views
Lag in Direction of Earth-Sun Gravity vector
When the earth is orbiting around the sun, it experiences a force vector pulling it towards the sun, which acts as a centripetal force for its elliptical orbit. However, when the earth moves a bit ...
- 111
7
votes
1
answer
582
views
What volume would the mass of Earth occupy in the core of the sun?
I was just wondering if anyone had computed this. I read that the pressure in the Sun's core is 3.84 trillion psi. Obviously the mass of an Earth-sized object in the core would be millions of times ...
- 175
0
votes
1
answer
110
views
Was Eratosthenes justified in his belief the earth was round? [closed]
Because I see two flaws with it, firstly he assumes the distance of the sun won't affect the angle at which light hits the pole. If the sun were far closer and far smaller, there would be a change in ...
- 361
2
votes
3
answers
504
views
Weight dependency on the location on Earth relative to Sun
In this post a theoretical physicist says that one will weigh less at the point on the Earth closest to the Sun due to the Sun's gravity, which makes sense to me. But he also says that one will weigh ...
- 568
3
votes
2
answers
222
views
Why doesn' t the sky look blue from outer space? [duplicate]
The sky looks blue because blue sunlight is scattered all over the atmosphere. Doesn't the same take place in the other direction? From Earth to the sky? So the atmosphere would look blue in outer ...
user307209
-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
2
answers
325
views
After the discovery of the "unicorn" black hole, how likely is the Earth to be hit by a blackhole?
We know that the earth's chances to be hit by a blackhole before the death of the sun were practically 0 but how do the odds change after the discovery of the unicorn?
About the unicorn:
https://www....
- 21
0
votes
0
answers
43
views
Is the Sun losing mass and pushing the Earth further away? [duplicate]
With the sun radiating so much energy every millisecond can nuclear fusion keep up with that pace? And if it can’t keep up isn’t the sun losing energy every second and therefor losing mass? Which ...
- 179
0
votes
1
answer
54
views
How can i analyse this motion?
Hello
(Im from south Korea. im sorry for my english in physics.)
im curious about this gravitational spiral motion.
can its trajectory and time took to collide be guessable? or can i calculate this ...
- 19
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
0
votes
1
answer
81
views
What are the sources of error in the formula I derived to estimate sunrise and sunset times, and how can I improve its accuracy? [closed]
I derived the following formula to estimate sunrise and sunset times:
$$ t=\pm\cos^{-1}\frac{\sin\theta-\sin L_{loc}\sin L_{sun}}{\cos L_{loc}\cos L_{sun}} $$
$L_{loc}$ is the local latitude
$L_{sun}$...
- 101
0
votes
1
answer
44
views
Are there any effect of Sun to the tide? [duplicate]
The Earth is rotating for the Sun's gravitational field. Like a free falling object Earth should feel zero gravity to the Sun. So why there are effect of Sun to the tide?
2
votes
2
answers
623
views
Entropy of photons in the Sun / Earth system - Do infrared photons have higher entropy than ultraviolet/visible photons?
The entropy of a photon gas in equilibrium (emitting e.g., black-body radiation; BB) is
$S \propto V \cdot T^3$
where $V$ is the volume and $T$ is the temperature of the gas [see https://en.wikipedia....
- 121
1
vote
1
answer
158
views
Cumulative Sun's radiation pressure exerts on Earth's surface
I have some discrepancies in what is in "Optics" (E. Hecht) and what I calculated, but it's simply formula, so I'm confused. I used:
$$F = \frac{\pi R^2 S}{c}$$
to calculate cumulative force of ...
- 23