Philosophy Discussion Forums

I want to ask the question: Why the sky is not blue?

What you see is light. If you throw a ball to the wall, the ball bounces back. If you throw the ball to the ground, it also bounces. But the ball bouncing back from the wall is not the same speed as bouncing from the ground.

And this is a good illustration of light. The reflection of light is just like the ball bouncing back. When light hits the wall, it reflects back just like a ball bouncing back. Since the light reflected from the wall is different to the light reflected from the ground, and so you see different colours. This is why you see the wall has a different colour to the ground.

Because different colours of light appear when light travels at different speed. So when light changes its speed, you will see different colour. This is why not all things appear to be the same colour, because light is moving at different speeds.

Now, if the light reflected from the sky changes its speed, then, of course, the sky may change its colour, maybe to a colour that is not blue.

But in what condition can the sky changes to a colour that is not blue.

Well, if you move faster near the speed of light, then, the light you see will change its speed, because your motion relative to the light is changing. Just like if you are in a train, if the train moves faster, the objects outside seem to change its speed.

So if you move near the speed of light, I feel the sky may not look blue, it may change its colour to a colour that is not blue.

If you do not believe in me, do an experiment.

Is the sky still blue?

The colors of things -- or at least the appearance of the colors of things -- change as you move at different speeds in relationship to them. Indeed, redshift and blueshift help estimate the movements of far away objects in astronomy.

Regardless, I think it is incorrect to say the sky is not blue or to say all things do not have colors. You compare light to a ball bouncing back Indeed, but the way the ball bounces back would depend on the qualities of the wall or other surface against which it is bounced such as flatness, stickyness and hardness. One may measure the stickyness or flatness of a wall by bouncing a ball against it, but it is incorrect to say the wall does not have the quality of being sticky or flat. I think the same goes for color. When we say the wall is blue, we mean to describe a quality of the wall which determines how it interacts with light in normal circumstances (e.g. not when we are traveling at near lightspeed) which is a quality of the wall or sky not just a quality of the ball/light.

The color of light is not a factor of its speed, but its frequency (i.e. how energetic it is). Even if you accelerate to a great speed relative to light, the light will not slow down relative to you (the mathematics of Special Relativity can explain why the train analogy--and common sense--fails us here). However, the light will change color because its frequency relative to your movement is being elongated or compressed, not slowed or speeded up. Its called the Doppler Shift. Same as when a siren drops its pitch after it passes you.

A Poster He Or I said: “The color of light is not a factor of its speed, but its frequency (i.e. how energetic it is). Even if you accelerate to a great speed relative to light, the light will not slow down relative to you (the mathematics of Special Relativity can explain why the train analogy--and common sense--fails us here).”

This is why I question Einstein. Because if light has a speed and if you have a speed when you travel, and if you travel faster, then, light may appear to be slower as you move faster.

Why?

Because light is just like a moving train. If you have a race with the train, if you move faster, than, as you accelerate, then, the train may appear to be slower.

Because your motion is relative to the motion of the train.

So as light, where if you have a race with the speed of light, as you accelerate, then, light needs to be slower relative to your motion, otherwise it will not conform to what you see.

Secondly, you said that the colour of light is frequency.

Look, frequency, speed, colour, energy, force, time and so on are all influenced by one another. It will be strange if the frequency changes and the colour of light does not change.

Scott said: “Regardless, I think it is incorrect to say the sky is not blue or to say all things do not have colors. You compare light to a ball bouncing back Indeed, but the way the ball bounces back would depend on the qualities of the wall or other surface against which it is bounced such as flatness, stickyness and hardness. One may measure the stickyness or flatness of a wall by bouncing a ball against it, but it is incorrect to say the wall does not have the quality of being sticky or flat. I think the same goes for color. When we say the wall is blue, we mean to describe a quality of the wall which determines how it interacts with light in normal circumstances (e.g. not when we are traveling at near lightspeed) which is a quality of the wall or sky not just a quality of the ball/light.”

I will say: “What you see is light. So light is the important part in determining what you see, not the wall, even though what you see is the wall. Because without light, you cannot see the wall."

Now, you are saying that the wall is determining how fast will light be reflected back to your eyes when you see it. I do not reject what you are saying, and it is because different things are different, and so once light hits different objects, the lights reflected back from various objects all have different speeds and so you see different colours.

But what I am saying is this: If you start to accelerate your speed as you travel, then, originally, the light reflected from the sky is blue will change to other colour as it approaches to your eyes, because your motion is relative to the motion of light reflected back from the sky.

But this may need to be a big change in your speed, where if you move very fast near the speed of light that you can feel the difference. If it is minor or little changes such as an ant walking, maybe little difference.

But if you are stationary, if you do not move, then the sky you see maybe is blue.

But when you move, as you travel, your speed relative to the speed of light is different, and because your speed is increasing, then, the speed of light that you see may be slower or faster, depending on your location.

If the speed of light changes, then, of course, the blue sky will change its colour.

So I am not saying that the sky is not blue.

The sky maybe is blue when you do not move.

But when you accelerate to a high speed, where your motion because you are moving, your motion relative to the motion of light is different, and because of this, the speed of light you see is not the same speed as another person who is not moving, and because of this, the blue sky changes its colour when it reaches your eyes.

So what I am saying is the sky is blue in a condition that a person is stationary, but if a person moves near the speed of light, then, because it is different situation, and so light changes its colour.

Otherwise it will not fit into what you see if two people at different situations see the same colour of light, just like two people in two different situations, where one moving and the other person stationary will experience different forces as the same object with same acceleration hits both of them.

If two different situations see the same colour of light, this is strange, isn’t it?

Because they are not same situation.

So when I was in school, teacher said: “Maybe there is exception.”

No, A Poster He or I is correct. The speed of light (in a vacuum) is a constant. When you travel faster in relation to something else, spacetime bends to maintain the speed of light. The only way to slow down light is by having it go through different substances such as water or a special crystal instead of the near void of outerspace. The colors aren't determined by light's speed, but rather which frequencies of light are reflected by an object. This is all science that has been well-confirmed. Einstein's ideas about relativity have been well-confirmed.

Stanley Huang wrote:So I am not saying that the sky is not blue.

The sky maybe is blue when you do not move.

But when you accelerate to a high speed, where your motion because you are moving, your motion relative to the motion of light is different, and because of this, the speed of light you see is not the same speed as another person who is not moving, and because of this, the blue sky changes its colour when it reaches your eyes.

The speed of the light relative to you does not change as you speed up in relation to someone else, which is why you would age at a different rate than that someone else as your speeds diverge. However, the color you see would change due to redshift or blueshift. That's a change in the apparent frequency of the wave of light not a change in its speed.

I will use this illustration. If a person is looking at the earth from earth, what he sees will be different to another person looking at earth from Mars. So if you are looking at things from the angle that Einstein is looking at, then, you will not be able to see the new angle I am looking at things.

When Einstein said that Newton's equation was only an approximation of reality, he was saying that Newton is looking at things from his angle, while Einstein was looking at things in an angle different to Newton.

If it is like this, then, even though what Newton is saying may be exactly opposite to what Einstein is saying (Where one says that time is absolute and the other says that time is relative), but they are not contradictory.

So this is why I say that there are different natural laws in different universes. So when a person asks why is it that the microscopic world appears so different to the world in a large scale, I do not feel there is any contradiction.

Now, excuse me for mentioning about the Zen monk, because sometimes, I feel the words of a Zen monk may be a good way of illustrating.

If you look at a girl, the other person looking at the same girl as you, he says that the girl is ugly. But you say that the same girl you are looing at is pretty. And both of you become very angry arguing at each other. You think you are right while he also thinks he is right.

But a Zen monk who saw you two arguing willl say: "There is no right or wrong. Both of you are only looking at things from different angles. It is true that the girl is pretty. It is true that the same girl you are looking at is girl. But Nirvana, itself is beyond pretty or ugly. Because the notion of 'suchness' is beyond all views."

Because when you look at things in one angle, you are not looking at the complete picture. Any idea or any view is just like looking at things in one angle. But to grasp the whole, then, you need to have no mind or no view, because any idea or any view is just a limited angle of looking at one thing.

This is why modern physicists after many years of arguing or debating are still feeling unsure about what is going on in this world. And if we can answer the question by a Zen monk 'What is the sound of one hand clapping,' then, perhaps, we can answer all of the scientific questions.

But it is because there are still uncertain feelings that there are still questions been asked. And because of this, modern physicists are feeling that there is a limitation in the intellectual thinking, and so after many years of scientific re-search, the conclusion will be like the question asked by the Zen monk: "What is the sound of one hand clapping?"

Thank you.