Warping Space, Time, and Distance

reply to post by CLPrime


So the measurement of speed that Maxwell came up with regards to photons or electro magnetic fields was calculated from the point of rest of the Earth though we know the Earth is also traveling through space?
So all is relative in a Universe filled with matter?

reply to post by artistpoet


The speed wasn't measured with respect to anything. The value was calculated from Maxwell's equations, independent of any reference frame.

reply to post by CLPrime


I see so there is a fixed speed at which a magnetic field turns into an electric field
That is a really cool discovery
Sorry to break off but it is 3 am here I need to hit the sack but thanks for so much for taking the time and trouble to explain something I had never even been aware of - I will be back to check any more posts tomorrow evening
Good night

reply to post by artistpoet


In that case, the actual cool part of this (well...I think it's cool, anyway) will wait 'til tomorrow. Hopefully ImaFungi will be back then.

reply to post by CLPrime

Thank you CLPrime for taking the time to answer mine and others questions on here. You are one of the reasons I come to ATS when I seek answers to questions. I really appreciate it.

reply to post by CLPrime


Hi - Back
And waiting for the really cool part

reply to post by artistpoet


Okay, so...we got to the exact speed at which any EM wave must travel in order to exist.
Add that to the fact that any one EM wave can have an infinite number of possible speeds according to an infinite number of reference frames.

If you ask the question, "From which reference frame must the speed of an EM wave be measured to be 299,792,458 m/s?", the problem is...
All reference frames are equally valid...just like in the case of you and your rocket car going through space. A reference frame is needed in order to determine motion. In an empty universe, you can't determine motion (in fact, motion is entirely undefinable in an empty space). And this shows that your rocket car can't determine its own motion all on its own...it needs an external reference. So, you need an external frame of reference. The thing is, in a universe full of stuff, you have an infinite number of reference frames.

And that leads to the really cool part.
The question was, From which reference frame must the speed of an EM wave be measured to be 299,792,458 m/s?
The answer is, All of them. The speed of an EM wave must be measured to always be exactly 299,792,458 m/s no matter what reference frame you use. If you're in your rocket car racing an EM wave, that EM wave's speed must be 299,792,458 m/s relative to you car. If you're on the Earth measuring the speed of an EM wave, that speed must be 299,792,458 m/s relative to the Earth. If you're in your rocket car measuring the same EM wave that's being measured from Earth, both speeds have to be 299,792,458 m/s - relative to the car and relative to the Earth. Even though your car and the Earth are going at different speeds relative to each other.

So, how does that happen?

Elecro Magnet Waves occur or are created AT 299,792,458 metres per second which is the speed of light
By the way I had to look up the speed of light as a hunch it would be the same as the speed at which an Electro Magnetic field occurs.
So my best guess is that visual frames of reference all occur at that speed?

edit further thought being that we measure all against the speed of light?

Originally posted by artistpoet

Elecro Magnet Waves occur or are created AT 299,792,458 metres per second which is the speed of light
By the way I had to look up the speed of light as a hunch it would be the same as the speed at which an Electro Magnetic field occurs.

Light is an EM wave...the two are the same thing.

So my best guess is that visual frames of reference all occur at that speed?

further thought being that we measure all against the speed of light?

Different frames of reference move at different speeds relative to EM waves, but EM waves always move at the speed of light relative to whatever frame of reference you measure from. It sounds like a paradox, but it's a resolvable one.

If you want a simpler thought experiment, think of it in terms of cars on a highway. Let's say there are a whole bunch of black cars (not rocket-powered this time) and one red one. These cars are all travelling at different speeds. So, common sense says that each black car will have a different speed relative to every other black car. But then we have the special red car. No matter which black car you measure the speed of the red car from, it always has to be the same speed - let's say 100 km/h. The speed of the red car must always be measured to be the same, no matter what black car you measure its speed from.

And now I've gotta go for a bit. Think it over, and I'll be back in about 2 hours.

reply to post by CLPrime

Yes you have me thinking
See you later

reply to post by CLPrime


You said with the rocket car in space example, the car itself can not accurately measure its speed... and i was thinking couldnt it measure in a similar way to how a highway car measures its speed, i know there would be a ton of variables , but if it would use a propulsion system, couldnt it possibly calculate how much distance it is traveling if they knew with how much energy the rocket thrusted, how much weight it would be pushing etc??. ..

since weve been discussing this stuff about cars, ive been thinking of how highway cars measure speed, and all the variables like elevation on the road and how that effects speed and distance....... about your black and red car scenario i have no clue whats up with that.

reply to post by CLPrime


The special red car represents the Universal constant by which we can measure distance
The Universe has been measured to be something like 13billion red cars big ?

Yet within the red car constant black cars speed or distances from each other are variable

Originally posted by ImaFungi
reply to post by CLPrime

 

You said with the rocket car in space example, the car itself can not accurately measure its speed... and i was thinking couldnt it measure in a similar way to how a highway car measures its speed, i know there would be a ton of variables , but if it would use a propulsion system, couldnt it possibly calculate how much distance it is traveling if they knew with how much energy the rocket thrusted, how much weight it would be pushing etc??.

Propulsion (thrust) causes acceleration. This is a constant velocity situation...no propulsion. You could very well be staying in one spot. But, without any frame of reference, what defines a single location? How can you say you're in a particular location? How can you say you're staying in that particular location? Or how can you say how far you've moved (at a constant velocity) away from that original location? How can you define your new location?

since weve been discussing this stuff about cars, ive been thinking of how highway cars measure speed, and all the variables like elevation on the road and how that effects speed and distance....... about your black and red car scenario i have no clue whats up with that.

If you can figure it out, I will personally bestow upon you a medial position at a Swiss patent office.

reply to post by artistpoet


Now that I've got more time, I'm going to restate the problem in more detail.

There are 3 black cars on a north-south highway, plus the one red car. The speed limit of the highway is 100 km/h.
Let's call the black cars B1, B2, and B3. And the red car is R0.

B1 is travelling north at 90 km/h.
B2 is travelling north at 40 km/h.
B3 is travelling south at 50 km/h.
R0 is travelling south at 100 km/h.

So, a few of the relative velocities (this is all simple vector addition)...

Relative to B2, B1 is travelling north at 50 km/h (90-40).
Relative to B1, Bs is travelling south at 50 km/h (40-90).
Relative to B3, B1 is travelling north at 140 km/h (90+50).
Relative to B2, B3 is travelling south at 90 km/h (40+50).

Now, here's the tricky part...

Relative to B1, R0 is travelling at 100 km/h.
Relative to B2, R0 is travelling at 100 km/h.
Relative to B3, R0 is travelling at 100 km/h.

No matter which black car you ask, and no matter in which direction and at what speed that black car is travelling, it will always measure the speed of the red car to be exactly 100 km/h.
How is that possible?

reply to post by CLPrime


But, without any frame of reference, what defines a single location? How can you say you're in a particular location? How can you say you're staying in that particular location? Or how can you say how far you've moved (at a constant velocity) away from that original location? How can you define your new location?

regardless of our capabilities and lack there of.... we would be occupying a specific point in the universe each moment, and we would be at an objective distance away from any reference point?

im not going to come up with or comprehend complex mathematical solutions for this stuff so my natural lazy notion is to question why it is important to measure the speed and such anyways.... following our curiosity, what are the reasons we would travel the cosmos? planets, space,, are those our only options,,, we would need to calculate the movements of everything and then line up a launch, and id say wing it...

Originally posted by CLPrime


No matter which black car you ask, and no matter in which direction and at what speed that black car is travelling, it will always measure the speed of the red car to be exactly 100 km/h.
How is that possible?

i have no clue how or why that is possible, but im assuming you are relating the red car to the speed of light... i really dont get it though

reply to post by ImaFungi


Yep, the red car is light (a photon, or EM wave...all the same thing). Because, no matter how fast you're moving, you will always measure the speed of light to be precisely the same value - exactly 299,792,458 m/s. This has been experimentally tested and proven. The question is, how does that happen?

Red Car is object moving at speed of light
Black Cars are objects moving at different speeds but Red Car is the frame of reference for their speeds and stays constant

reply to post by artistpoet


Can you elaborate?
Note that, in the red car's frame of reference, the red car is standing still. That's how a reference frame is defined...the frame moves with an object so that the object, in its own reference frame, is at rest. It's only other cars that measure the red car to be travelling at 100 km/h (or at the speed of light, in the case of light).

reply to post by CLPrime


is it because em waves/light is hardly/not (?) effected by matter? it fills the volume of its vicinity of vaccuum at the fastest processable instant