Musings of an old man....

[N/A]

Did you miss the part that light always emits from a stationary mass, no matter the velocity of the mass?

[Viking350]

Did you miss the part that light always emits from a stationary mass, no matter the velocity of the mass?

Not at all. It sounds like that doesn’t explain the fact that light is always observed to be traveling at the same speed regardless of the relative velocity of the observer. Your supposition is that at the exact time of emission everything is static. Let me seek clarification through a couple of cases.

If I fire a laser beam into space and launch a space ship at the same time on a parallel course that can travel at one mps less than the speed of light, what will be the observed speed of that laser beam from the space ship? They both start from the same relative velocity.

A second case, let’s say we mount the laser on the nose of that space ship and fire the ship into space at one mps less than the speed of light. We then fire the laser into space. What will be the observed speed of that laser beam from the perspective of the space ship and from the perspective of the launch pad?

[N/A]

The observed speed of the light will be C, as the observers will know their speed and add one mile per second...in both cases.

Otherwise, what you are trying to say is that the observers in the ship are ignorant of their own velocity, but untill the light reaches them, they aren't going to see anything. Then, what they will see is light stretched out immensely, (shifted), and will deduce that to see light that shifted, they have to be traveling at a velocity almost that of the light.

That's like saying you are driving the autobahn at 200 kmh, and I'm beside you doing 201 kmh. All you see is that I'm going 1 kmh faster than you, but we both can look down and see the roadway zipping past at 200 kmh. If all we have in your universe is a light beam and a spaceship, then it doesn't matter what the velocities are. You have a universe that consists of only two things, so there really is no way to tell what the speed of light is in that universe. They can only see the difference in speed between them, but they have no oother point in that universe as a stationary frame of reference.

Add the Earth into that, and then they would have something to use as a stationary frame of reference. Then, they can say, "Hey,look, it looks like we are leaving Earth at only 1mps.That can't be right, as light travels at C, and we are only seeing the Earth record at 1 MPs. Heck, we must be traveling at the same speed as light, ...uh, or a little less."

By setting up a thought experiment with only two things to observe each other, you can have the light be any speed you want. If you introduce a third variable, I.e. that light always travels at C, then the passenger's would know that and could determine their speed by measuring against the light's speed.

What about putting a beam of light and a spaceship in a universe that only they exist in. Put them side by side, never changing position relative to each other. Without anything else as a frame of reference, are we to determine they are stationary in that universe, or moving at the speed of light squared? We have no way to tell, therefore light could be stationary, or it could be moving at any speed between 0 and C². As the ship is right beside it, it could be moving at C² also.

Remember, you are an observer completely outside that universe. All you see is two things sitting side by side. You have nothing else to compare them to. The same with them; they have nothing but each other to compare themselves to. All they know is that they are stationary to each other.

[imanaknut]

What a great website! How many firearm forums can brag that they also teach physics!!!

[Viking350]

The observed speed of the light will be C, as the observers will know their speed and add one mile per second...in both cases.

Otherwise, what you are trying to say is that the observers in the ship are ignorant of their own velocity, but untill the light reaches them, they aren't going to see anything. Then, what they will see is light stretched out immensely, (shifted), and will deduce that to see light that shifted, they have to be traveling at a velocity almost that of the light.

That's like saying you are driving the autobahn at 200 kmh, and I'm beside you doing 201 kmh. All you see is that I'm going 1 kmh faster than you, but we both can look down and see the roadway zipping past at 200 kmh. If all we have in your universe is a light beam and a spaceship, then it doesn't matter what the velocities are. You have a universe that consists of only two things, so there really is no way to tell what the speed of light is in that universe. They can only see the difference in speed between them, but they have no oother point in that universe as a stationary frame of reference.

Add the Earth into that, and then they would have something to use as a stationary frame of reference. Then, they can say, "Hey,look, it looks like we are leaving Earth at only 1mps.That can't be right, as light travels at C, and we are only seeing the Earth record at 1 MPs. Heck, we must be traveling at the same speed as light, ...uh, or a little less."

By setting up a thought experiment with only two things to observe each other, you can have the light be any speed you want. If you introduce a third variable, I.e. that light always travels at C, then the passenger's would know that and could determine their speed by measuring against the light's speed.

What about putting a beam of light and a spaceship in a universe that only they exist in. Put them side by side, never changing position relative to each other. Without anything else as a frame of reference, are we to determine they are stationary in that universe, or moving at the speed of light squared? We have no way to tell, therefore light could be stationary, or it could be moving at any speed between 0 and C². As the ship is right beside it, it could be moving at C² also.

Remember, you are an observer completely outside that universe. All you see is two things sitting side by side. You have nothing else to compare them to. The same with them; they have nothing but each other to compare themselves to. All they know is that they are stationary to each other.

All electromagnetic radiation travel at c regardless of the motion of the source or the inertial reference frame of the observer. So in the first case, from the perspective of the space ship, the laser beam would be traveling away from the spaceship at 186,000 mps. From the perspective of the launch site the laser beam and the spaceship would be traveling at essentially the same rate, since a mere 1 mps variance would be hardly noticeable.

In the second case, from the perspective of the spaceship the laser beam would be speeding away at 186,000 mps. From the perspective of the launch site, the laser beam and the spaceship would again appear to traveling at the same speed.

[N/A]

So you're saying the ship, traveling at the same velocity as light, would see the light traveling at speed C, and observe it leaving them behind at speed C, while at the same time they are traveling right beside the light photon the whole time?

Now, I know the explanation for that, but would you explain it for others, as my explanations don't satisfy your theories?

[Viking350]

So you're saying the ship, traveling at the same velocity as light, would see the light traveling at speed C, and observe it leaving them behind at speed C, while at the same time they are traveling right beside the light photon the whole time?

Now, I know the explanation for that, but would you explain it for others, as my explanations don't satisfy your theories?

Actually, it is essentially impossible to travel at the speed of light as the energy required to accelerate increases exponentially as you approach light speed. That is why in my cases I said 1 mps less than the speed of light. Due to time dilation the speed of light is constant regardless of motion that may exist for the observer. In the first case I proposed, time slows down for the people in the space craft relative to the people at the launch site. This difference in the passage of time (dilation) allows for the same light (laser) seen by both locations (spaceship and launch site) to travel at the constant speed of light. So yes, the passengers on the spaceship would see the laser beam speeding away from them while the observers at the launch site would see the ship and the laser beam pretty much side by side since 1 mps difference is minuscule on a cosmic scale. The same applies to the second case.

[Viking350]

What a great website! How many firearm forums can brag that they also teach physics!!!

Well, the participants at this forum are smarter than the average bear!

[alismith]

So you're saying the ship, traveling at the same velocity as light, would see the light traveling at speed C, and observe it leaving them behind at speed C, while at the same time they are traveling right beside the light photon the whole time?

Now, I know the explanation for that, but would you explain it for others, as my explanations don't satisfy your theories?

Traveling at the speed of light, hypothetically, if your ship had windows all around, so you could see in any direction, all light would be compressed to a small window in front of you, in the shape of a circle. The center of the circle would show what's in front of you. Since light can't catch up to you from any other direction, you wouldn't be able to see anything except what's in front. Everything else would look black.

Traveling at this speed was explained by Carl Sagan in his TV series, The Cosmos.

[LAGC]

Traveling at the speed of light, hypothetically, if your ship had windows all around, so you could see in any direction, all light would be compressed to a small window in front of you, in the shape of a circle. The center of the circle would show what's in front of you. Since light can't catch up to you from any other direction, you wouldn't be able to see anything except what's in front. Everything else would look black.

Traveling at this speed was explained by Carl Sagan in his TV series, The Cosmos.

So you mean it wouldn't be like Star Trek, where the stars go zipping by in straight lines besides you as you jump to warp speed?

[alismith]

So you mean it wouldn't be like Star Trek, where the stars go zipping by in straight lines besides you as you jump to warp speed?

Nope. If your whole spaceship were glass, as you approached the speed of light, you would notice that everything visible would slowly move towards the front of your ship, leaving blackness everywhere else, until there is a little circle of light directly in front of you. You would see nothing else outside the ship.

[Viking350]

Traveling at the speed of light, hypothetically, if your ship had windows all around, so you could see in any direction, all light would be compressed to a small window in front of you, in the shape of a circle. The center of the circle would show what's in front of you. Since light can't catch up to you from any other direction, you wouldn't be able to see anything except what's in front. Everything else would look black.

Traveling at this speed was explained by Carl Sagan in his TV series, The Cosmos.

I hadn't been exposed to this so I Googled it. Very interesting. I found this site which gives a pretty good explanation. https://www.scienceabc.com/pure-scie...-of-light.html

[N/A]

I hadn't been exposed to this so I Googled it. Very interesting. I found this site which gives a pretty good explanation. https://www.scienceabc.com/pure-scie...-of-light.html

I'll look at the link later.

I would think looking out a side window, you would see the light that arrives at the same spot you occupy. The ship is not travelling away or toward the light, but is crossing its path, so it would be seen looking out the window.

[alismith]

I hadn't been exposed to this so I Googled it. Very interesting. I found this site which gives a pretty good explanation. https://www.scienceabc.com/pure-scie...-of-light.html

Interesting site. Thanks.

[Viking350]

I'll look at the link later.

I would think looking out a side window, you would see the light that arrives at the same spot you occupy. The ship is not travelling away or toward the light, but is crossing its path, so it would be seen looking out the window.

That was my initial reaction as well. The link I found mentioned the Doppler shift would eventually take the light out of the range of our visible light. I’ll have to read more on this.

[N/A]

That was my initial reaction as well. The link I found mentioned the Doppler shift would eventually take the light out of the range of our visible light. I’ll have to read more on this.

Yeah, it has crossed my mind as to what visible light would become if it was shifted out of the visible spectrum. Also, what of other electromotive radiation, such as microwaves, radio waves, et cetera? Would we be able to tell if one frequency was really another frequency Doppler shifted out of its original frequency? Or would we just think it originated just at the frequency we receive it?

ETA...I read that link you posted. To me, it is just a repeating of the same old thing without any explanation.
I'd like to read how Einstein came up with the formula E=MC². Maybe it should have been E=MC. Where did he come up with the idea that light has anything to do with the ratio of mass to energy?

And where is a good explanation of why light always has a speed of C/186,282 miles per second?
What magical property does light have that you can be traveling right beside a photon of light at C, yet if you look at it you will see it zipping ahead of you at C?
The only way you could see that is if the photon originates from your ship, not from another source.

As for time at speed C...time is not something that physically exist. There is no going forward in time, no going backward in time. There is only the here and now. Going at speed C does not slow time. As I've tried to explain, actions that are accelerated have a longer "distance" over which they have to act. It is having to act over that longer that changes how that action takes place.

[alismith]

Yeah, it has crossed my mind as to what visible light would become if it was shifted out of the visible spectrum. Also, what of other electromotive radiation, such as microwaves, radio waves, et cetera? Would we be able to tell if one frequency was really another frequency Doppler shifted out of its original frequency? Or would we just think it originated just at the frequency we receive it?

If light is shifted to a lower frequency than visible light, it moves into the infrared range; if shifted toa higher frequency, it enters the ultraviolet range. (see link).

https://en.wikipedia.org/wiki/Electromagnetic_spectrum

Actually, visible light is nothing more than 7 different wavelengths of electromagnetic energy we are able to see with our eyes. We can feel the color heat with our skin.

Some insects, and other animals, can see beyond what we can see; bees can see ultraviolet colors and deer can see some colors of UV light, too.

It is thought that some of the predatory dinosaurs, and T-Rex (who was more likely a scavenger), could actually see some of the higher infrared colors (not proven, obviously, but postulated based on their very acute sense of smell and vision).

ETA...I read that link you posted. To me, it is just a repeating of the same old thing without any explanation.
I'd like to read how Einstein came up with the formula E=MC². Maybe it should have been E=MC. Where did he come up with the idea that light has anything to do with the ratio of mass to energy?

This might help with your question, if you can understand the physics behind it....It's above my small mind to comprehend....)

https://en.wikipedia.org/wiki/Speed_of_light

And where is a good explanation of why light always has a speed of C/186,282 miles per second?
What magical property does light have that you can be traveling right beside a photon of light at C, yet if you look at it you will see it zipping ahead of you at C?
The only way you could see that is if the photon originates from your ship, not from another source.

The above link answers that question,too, I think....)

As for time at speed C...time is not something that physically exist. There is no going forward in time, no going backward in time. There is only the here and now. Going at speed C does not slow time. As I've tried to explain, actions that are accelerated have a longer "distance" over which they have to act. It is having to act over that longer that changes how that action takes place.

Time does slow down when an object moves. However, since humans can't go very fast, we will never experience it. What you said, does appear to hold true, but only because we are limited in how fast we can move.

Atomic clocks were paired up and one remained stationary, while the other was flown around the world, always going in the same direction. When the traveling clock got back, it was slower by about 2 nanoseconds than the stationary one. This proved, as far as our best efforts, that Einstein was right. Time does slow down for the thing traveling near the speed of light, but not for anything else.

It was explained in the video I posted, but you were unable to watch it. Sagan's Cosmos series showed how it worked, too.

To answer one of your questions, light IS special because it is the only thing that nothing can be added to it to make it appear faster. No matter how fast it moves, it is always where you happen to see it.

As Sagan said, in a Cosmos episode, "Thou shalt not add to the speed of light."

Neil deGrasse Tyson, today's counterpart to Carl Sagan, also, did an upgraded version of the Cosmos series, using all the newest discoveries to bring it up to date.

If you are able to get either series, it would answer all your questions,

[N/A]

http://complexrelativity.com/einstrinflawexplained.html

Stumbled across this site this morning. Haven't had a chance to study it yet, but it starts out interesting enough.

[N/A]

http://complexrelativity.com/einstrinflawexplained.html

Stumbled across this site this morning. Haven't had a chance to study it yet, but it starts out interesting enough.

Read a little bit of the above link. As far as I could tell, his conclusion is that light can change its speed as it moves from one frame of reference to another. That would be a most magical property indeed.
I disagree with his theory.

[Viking350]

Read a little bit of the above link. As far as I could tell, his conclusion is that light can change its speed as it moves from one frame of reference to another. That would be a most magical property indeed.
I disagree with his theory.

He lost some credibility with me when he misspelled Einstein in the url.