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hagar
Gold Member
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Under Ideal conditions (a vacuum and no gravity) what is the limiting factor or factors for the speed of light ?
Thank you,
Pat Hagar
Thank you,
Pat Hagar
hagar said:Yes, I have read that. I would like to know what makes that the constant speed of light and not say faster. I realize that gravity and other things can modify the speed of light but I do not understand why it is set at 299 792 458 m/s under ideal conditions.
Thank you for your response,
Pat Hagar
hagar said:Yes, I have read that. I would like to know what makes that the constant speed of light and not say faster. I realize that gravity and other things can modify the speed of light but I do not understand why it is set at 299 792 458 m/s under ideal conditions.
Thank you for your response,
Pat Hagar
hagar said:Under Ideal conditions (a vacuum and no gravity) what is the limiting factor or factors for the speed of light ?
Thank you,
Pat Hagar
Drakkith said:There is no underlying reason that we can give. It's a postulate of special relativity (and general relativity when talking about 'local' effects). In other words, its a fundamental fact of nature that has no explanation at the moment.
PeroK said:The limiting factors are the "permittivity" and "permeability" of free space. Essentially, even a vacuum only allows electro-magnetic radiation to propagate at a finite speed. Why these factors are what they are has no immediate explanation (as mentioned above).
https://en.wikipedia.org/wiki/Vacuum_permittivity
https://en.wikipedia.org/wiki/Vacuum_permeability
https://en.wikipedia.org/wiki/Speed_of_light#Propagation_of_light
hagar said:Also I still need to work out exactly how the software works for quotes etc.
hagar said:Thank you. The links will be most helpful. I have already read [QUOT " https://en.wikipedia.org/wiki/Speed_or_light#Propagation_of_light " ] but I have not yet seen the others.
This sums up what I was asking.
Respectfully,
Pat Hagar
Hadzi said:This is a way to calculate the speed of light using the permittivity and permeability of vacuum:
No. Those are formulas that can be used to find the permittivity and permeability of vacuum but are NOT definitions.e.bar.goum said:Except, ##\mu_0## and ##\epsilon_0## are defined in terms of the speed of light. It's circular to use this definition to understand the speed of light.
By definition
##\epsilon_0 = \frac{1}{\mu_0 c^2 } ##
##\mu_0 = \frac{1}{\epsilon_0 c^2 } ##
Hadzi said:@e.bar.goum True that. I don't know, but it's still fascinating to me that the speed of light is almost a perfectly "shaped" number, leaning towards 3x108 m/s. Talking about the meter as the unit of measurement, it was defined before the speed of light was calculated (even approximately), right?
HallsofIvy said:No. Those are formulas that can be used to find the permittivity and permeability of vacuum but are NOT definitions.
see
https://en.wikipedia.org/wiki/Vacuum_permittivity and
https://en.wikipedia.org/wiki/Vacuum_permeability
Thank you, this worked quite well and will make things much easier. Occasionally one needs to be a bit more intelligent than the average monkey but I am afraid I do not always meet that requirement rigorously. Please excuse me while I go for another banana. :-)Drakkith said:Highlight the text you want to quote and an option to quote or reply will pop up. Click reply to immediately copy the text into the reply box below. Clicking +quote will add the text to a quote que, which can be added to the reply box by clicking insert quotes. (Or use the +quote and reply buttons at the bottom of any post)
The speed of light limit, also known as the speed of light in a vacuum, is the maximum speed at which light can travel in a vacuum. It is approximately 299,792,458 meters per second (m/s) or 670,616,629 miles per hour (mph).
The speed of light is considered a limit because according to Einstein's theory of relativity, nothing can travel faster than the speed of light in a vacuum. This is because as an object approaches the speed of light, its mass increases, making it more difficult to accelerate. At the speed of light, an object's mass would become infinite, making it impossible to accelerate any further.
The speed of light in a vacuum is affected by two main factors - the medium through which it travels and the temperature of that medium. Light can travel slower in materials such as water or glass, and it can also be affected by gravitational fields and magnetic fields.
According to our current understanding of physics, the speed of light in a vacuum cannot be exceeded. However, there have been some controversial experiments that have suggested that particles called neutrinos may have traveled faster than the speed of light. These results have not been replicated and are still under investigation.
The speed of light plays a crucial role in our understanding of the universe. Its limit dictates the maximum speed at which information can travel, and it also affects the way we perceive time and space. The theory of relativity, which is based on the constant speed of light, has allowed us to make accurate predictions about the behavior of objects in the universe and has led to many groundbreaking discoveries.