Talanum46 Posted May 5 Report Share Posted May 5 If Aliens could manipulate the permittivity and permeability of space for communication purposes, would such communication be instantaneous over any distance? Vmedvil 1 Quote Link to comment Share on other sites More sharing options...

Moontanman Posted May 5 Report Share Posted May 5 1 hour ago, Talanum46 said: If Aliens could manipulate the permittivity and permeability of space for communication purposes, would such communication be instantaneous over any distance? What method? You have not described a method. Moving this to silly claims. Vmedvil 1 Quote Link to comment Share on other sites More sharing options...

Vmedvil Posted May 7 Report Share Posted May 7 On 5/5/2024 at 10:39 AM, Talanum46 said: If Aliens could manipulate the permittivity and permeability of space for communication purposes, would such communication be instantaneous over any distance? No, it would not, and this is not detailed enough to even be considered as such a device. Quote Link to comment Share on other sites More sharing options...

OceanBreeze Posted May 9 Report Share Posted May 9 If we put aside the nonsense about Aliens manipulating the permittivity or permeability of free space, the OP does contain an interesting question which can be simply stated this way: Is the speed of light dependent on the values of ε0 and μ0, or is the value of c independent of ε0 or μ0? Let’s start with this equation: c=1/√(ε0μ0) Where : C = 299 792 458 m / s ε0 = 8.8541878128×10−12 F/m (farads per meter) permittivity of free space μ0 = 4π×10−7 H/m = 1.25663706143...×10−6 (henries per meter) permeability of free space Mathematically, it seems reasonable to assume if the values of ε0 or μ0 were to change (somehow and we are not interested in how) then the value for the speed of light would need to change also. For example: What if the value of ε0 changed to be 9x10-12 farads per meter, while μ0 remained unchanged? How would that affect the value for the speed of light? If you go through the math, the speed of light would be 297 354 019 m / s ; significantly different from the currently accepted value of 299 792 458 m / s. According to Einstein’s special theory of relativity, c is the speed at which all massless fields propagate; not just the speed of light. Gravity also travels at c, and since gravity apparently has nothing to do with electromagnetism, it’s speed should not be affected by any change in the values of ε0 or μ0. Also, we are all taught that the speed of light, c, is constant. Therefore, is c really dependent on the values of ε0 and μ0, as the above mathematical calculation seems to have shown? *Now we are getting into what I consider to be the interesting bit that makes this discussion worthwhile* Taking the equation we started with: c=1/√(ε0μ0) We can write: ε0 = 1 / μ0 c^2 and μ0 = 1 / ε0 c^2 We can see that ε0 and μ0 are just the inverse of each other mediated by the term 1/c^2. This inverse relationship isn’t immediately apparent by looking at their values of 8.8541878128×10−12 for ε0 and 1.25663706143×10−6 for μ0, but if you “do the math” and remember to multiply by 1/c^2, you will find they are exact inverses of one another. What does this have to do with the above calculation which showed the speed of light changing with a change in the value of ε0? Everything! Since they are inversely related, if ε0 changes, then μ0 would also change, and it would change in such a way as to keep the speed of light, c, constant at 299 792 458 m / s. To demonstrate this, in the above example ε0 changed to 9x10-12 farads per meter and the value of c consequently changed to 297 354 019 m / s. In reality, this is not possible because when ε0 changed, that would have caused a corresponding change in μ0, from 4π×10−7 H/m to 1.23627783938x10-6 H/m, because of their inverse relationship. Plugging these values for ε0 and μ0 into our equation: c=1/√(ε0μ0) We will once again get 299 792 458 m / s for c. While this long post may seem somewhat tedious, what I hoped to show is that sometimes even a carefully and correctly executed mathematical calculation can be very wrong if all of the facts are not properly considered. Also, I hoped to show that c is a fundamental dimensionless constant, which does not depend on the values of any other less fundamental, derived units such as permittivity and permeability of free space. In fact, many physicists today consider the values assigned to ε0 and μ0 to just be artifacts of certain unit systems and can be done away with. For example, both Gaussian and Lorentz Heaviside units have ϵ0=μ0=1, but that is going a bit beyond where I intended to go with this. One last final note for those who may ask how c can be a dimensionless constant when it is a velocity expressed in m/s. It seems clear that meters have a dimension in length and seconds have a dimension in time, so c should have the dimensions of LT-1, how is it then dimensionless? The answer is, it is entirely possible to define a system of measuring time by using light. The time between events is then the distance that light would travel in the duration between those events. Then by definition, the speed of light is 1 and dimensionless, as we measure time in meters and distance in meters, and light will naturally traverse the same distance in meters as the time we measure between its endpoints in meters. m / m = 1 dimensionless. This may also clear up the difficulty some may have with understanding spacetime diagrams where time is made comparable to a length or space unit, expressed as ct, and take some of the mystery out of the spacetime interval. Here also, the time dimension is made comparable to a unit of length but retains its unique character by having a different sign: (Δs)^{2} = -(cΔt)^{2} + (Δx)^{2} + (Δy)^{2} + (Δz)^{2} Moontanman and Vmedvil 1 1 Quote Link to comment Share on other sites More sharing options...

Vmedvil Posted May 9 Report Share Posted May 9 (edited) 55 minutes ago, OceanBreeze said: If we put aside the nonsense about Aliens manipulating the permittivity or permeability of free space, the OP does contain an interesting question which can be simply stated this way: Is the speed of light dependent on the values of ε0 and μ0, or is the value of c independent of ε0 or μ0? Let’s start with this equation: c=1/√(ε0μ0) Where : C = 299 792 458 m / s ε0 = 8.8541878128×10−12 F/m (farads per meter) permittivity of free space μ0 = 4π×10−7 H/m = 1.25663706143...×10−6 (henries per meter) permeability of free space Mathematically, it seems reasonable to assume if the values of ε0 or μ0 were to change (somehow and we are not interested in how) then the value for the speed of light would need to change also. For example: What if the value of ε0 changed to be 9x10-12 farads per meter, while μ0 remained unchanged? How would that affect the value for the speed of light? If you go through the math, the speed of light would be 297 354 019 m / s ; significantly different from the currently accepted value of 299 792 458 m / s. According to Einstein’s special theory of relativity, c is the speed at which all massless fields propagate; not just the speed of light. Gravity also travels at c, and since gravity apparently has nothing to do with electromagnetism, it’s speed should not be affected by any change in the values of ε0 or μ0. Also, we are all taught that the speed of light, c, is constant. Therefore, is c really dependent on the values of ε0 and μ0, as the above mathematical calculation seems to have shown? *Now we are getting into what I consider to be the interesting bit that makes this discussion worthwhile* Taking the equation we started with: c=1/√(ε0μ0) We can write: ε0 = 1 / μ0 c^2 and μ0 = 1 / ε0 c^2 We can see that ε0 and μ0 are just the inverse of each other mediated by the term 1/c^2. This inverse relationship isn’t immediately apparent by looking at their values of 8.8541878128×10−12 for ε0 and 1.25663706143×10−6 for μ0, but if you “do the math” and remember to multiply by 1/c^2, you will find they are exact inverses of one another. What does this have to do with the above calculation which showed the speed of light changing with a change in the value of ε0? Everything! Since they are inversely related, if ε0 changes, then μ0 would also change, and it would change in such a way as to keep the speed of light, c, constant at 299 792 458 m / s. To demonstrate this, in the above example ε0 changed to 9x10-12 farads per meter and the value of c consequently changed to 297 354 019 m / s. In reality, this is not possible because when ε0 changed, that would have caused a corresponding change in μ0, from 4π×10−7 H/m to 1.23627783938x10-6 H/m, because of their inverse relationship. Plugging these values for ε0 and μ0 into our equation: c=1/√(ε0μ0) We will once again get 299 792 458 m / s for c. While this long post may seem somewhat tedious, what I hoped to show is that sometimes even a carefully and correctly executed mathematical calculation can be very wrong if all of the facts are not properly considered. Also, I hoped to show that c is a fundamental dimensionless constant, which does not depend on the values of any other less fundamental, derived units such as permittivity and permeability of free space. In fact, many physicists today consider the values assigned to ε0 and μ0 to just be artifacts of certain unit systems and can be done away with. For example, both Gaussian and Lorentz Heaviside units have ϵ0=μ0=1, but that is going a bit beyond where I intended to go with this. One last final note for those who may ask how c can be a dimensionless constant when it is a velocity expressed in m/s. It seems clear that meters have a dimension in length and seconds have a dimension in time, so c should have the dimensions of LT-1, how is it then dimensionless? The answer is, it is entirely possible to define a system of measuring time by using light. The time between events is then the distance that light would travel in the duration between those events. Then by definition, the speed of light is 1 and dimensionless, as we measure time in meters and distance in meters, and light will naturally traverse the same distance in meters as the time we measure between its endpoints in meters. m / m = 1 dimensionless. This may also clear up the difficulty some may have with understanding spacetime diagrams where time is made comparable to a length or space unit, expressed as ct, and take some of the mystery out of the spacetime interval. Here also, the time dimension is made comparable to a unit of length but retains its unique character by having a different sign: (Δs)^{2} = -(cΔt)^{2} + (Δx)^{2} + (Δy)^{2} + (Δz)^{2} This is an interesting insight, I would have never thought about this question in that way, OceanBreeze. So, what would happen if you increased ε0 while increasing μ0 or decreased them both using some method? Would that change the C constant under the equation c=1/√(ε0μ0)? Maybe there is some logic to what the OP says... It would not be instant however it could be faster than light if you could control the ε0 and μ0 in space changing the C constant from a mathematical standpoint. For instance, if I put a value of 4 for ε0 and μ0 then i get a value of .25C and if I put a value of .25 for ε0 and μ0 then I get a value of 4C for the C constant. This is an interesting thought experiment from a math standpoint. It would seem decreasing ε0 and μ0 from a math standpoint does actually increase the C constant in the medium according to that equation, while increasing ε0 and μ0 decreases the C constant... Edited May 9 by Vmedvil OceanBreeze 1 Quote Link to comment Share on other sites More sharing options...

Vmedvil Posted May 9 Report Share Posted May 9 (edited) On 5/5/2024 at 10:39 AM, Talanum46 said: would such communication be instantaneous over any distance? The answer to this question, is still, No... At this point. Edited May 9 by Vmedvil Quote Link to comment Share on other sites More sharing options...

Vmedvil Posted May 9 Report Share Posted May 9 (edited) Continuing, if you plugged the equation in relativity as invariant space-time, it would be. (Δs)^{2} = -((1/√(ε0μ0)Δt)^{2} + (Δx)^{2} + (Δy)^{2} + (Δz)^{2} ^{Wolfram Alpha Results Link = }(Δs)^2 = -(1/√(εμ)Δt)^2 + (Δx)^2 + (Δy)^2 + (Δz)^2 - Wolfram|Alpha (wolframalpha.com) If you decreased ε0 and μ0 to .25 with Δx, Δy,Δz, Δt being 1 and then Δs would be 13√-1. It is kinda weird, I don't actually know what that means... but mathematically it gives weird results in the equations. it gives an imaginary number(Imaginary number - Wikipedia) of 13i for Δs? "Geometrically, imaginary numbers are found on the vertical axis of the complex number plane, which allows them to be presented perpendicular to the real axis. One way of viewing imaginary numbers is to consider a standard number line positively increasing in magnitude to the right and negatively increasing in magnitude to the left. At 0 on the x-axis, a y-axis can be drawn with "positive" direction going up; "positive" imaginary numbers then increase in magnitude upwards, and "negative" imaginary numbers increase in magnitude downwards. This vertical axis is often called the "imaginary axis"^{[11]} and is denoted 𝑖𝑅, 𝐼, or ℑ.^{[12]} In this representation, multiplication by i corresponds to a counterclockwise rotation of 90 degrees about the origin, which is a quarter of a circle. Multiplication by −i corresponds to a clockwise rotation of 90 degrees about the origin. Similarly, multiplying by a purely imaginary number bi, with b a real number, both causes a counterclockwise rotation about the origin by 90 degrees and scales the answer by a factor of b. When b < 0, this can instead be described as a clockwise rotation by 90 degrees and a scaling by |b|." Link = Imaginary number - Wikipedia Edited May 9 by Vmedvil Quote Link to comment Share on other sites More sharing options...

OceanBreeze Posted May 10 Report Share Posted May 10 19 hours ago, Vmedvil said: This is an interesting insight, I would have never thought about this question in that way, OceanBreeze. So, what would happen if you increased ε0 while increasing μ0 or decreased them both using some method? Would that change the C constant under the equation c=1/√(ε0μ0)? Maybe there is some logic to what the OP says... It would not be instant however it could be faster than light if you could control the ε0 and μ0 in space changing the C constant from a mathematical standpoint. For instance, if I put a value of 4 for ε0 and μ0 then i get a value of .25C and if I put a value of .25 for ε0 and μ0 then I get a value of 4C for the C constant. This is an interesting thought experiment from a math standpoint. It would seem decreasing ε0 and μ0 from a math standpoint does actually increase the C constant in the medium according to that equation, while increasing ε0 and μ0 decreases the C constant... Victor, I am glad that you find these relationships interesting, just as I have. However, I think you missed one very important point, and that is the fact that ε0 and μ0 are always inverses of each other, mediated by the factor 1 / c^2. ε0 = 1 / μ0 c^2 and μ0 = 1 / ε0 c^2 Now, even if we take your odd value of 4 for ε0 μ0 = 1 / ε0 c^2 = 1 / 4 c^2 = 2.781625140x10-18 Plugging these values into the equation: c=1/√(ε0μ0) c=1/√(ε0μ0 = 1 / √ (4 x 2.781625140x10-18) = 1 / √ 1.11265x10-17 = 299 792 458 m / s constant The point is, no matter what value you assign to ε0, μ0 will always be the reciprocal and c remains constant. You cannot change the value of c mathematically (or otherwise) by manipulating the permittivity or permeability of free space. Trying to change either the permittivity or permeability of free space, “ceteris non mutatis” [all other things being unchanged]; is not possible because the inverse relation means that between them a perfect compensation always takes place. The only possible conclusion is c is the universal, fundamental constant of free space and cannot be changed by playing with the derived values of ε0 and μ0, which are not fundamental. Indeed, permittivity and permeability are meaningful only in classical electrodynamics. As far as I can determine, they don't have an identifiable counterpart in terms of quantum mechanics. I am sure they are important to electrical engineers, as the impedance of free space, Z0, can be calculated as : Z0=√μ0 /ε0 which is important in antenna design and impedance matching. Now, to extend this discussion a bit further, I did mention that gravity also travels at c, and not being related to electromagnetism, are there any parameters of free space similar to ε0 and μ0, that appear in any equation for the speed of gravity? I think a Nobel Prize awaits anyone who can answer that question! Quote Link to comment Share on other sites More sharing options...

OceanBreeze Posted May 10 Report Share Posted May 10 Moderator Note: Since this thread is now an interesting discussion about Physics, I am moving it out of Silly Claims. I hope that nobody has any objection. Quote Link to comment Share on other sites More sharing options...

Vmedvil Posted May 10 Report Share Posted May 10 (edited) 17 hours ago, OceanBreeze said: The point is, no matter what value you assign to ε0, μ0 will always be the reciprocal and c remains constant. You cannot change the value of c mathematically This is something, I have never fully understood, why is the speed of light always the same, I know Einstein came up with that however I don't fully understand why? I want to understand the nature of why the speed of light is a constant, explain it to me. Edited May 10 by Vmedvil Quote Link to comment Share on other sites More sharing options...

Vmedvil Posted May 10 Report Share Posted May 10 (edited) 17 hours ago, OceanBreeze said: Now, to extend this discussion a bit further, I did mention that gravity also travels at c, and not being related to electromagnetism, are there any parameters of free space similar to ε0 and μ0, that appear in any equation for the speed of gravity? I think a Nobel Prize awaits anyone who can answer that question! c=1/√(ε0μ0) , -------> G = Lp(1/√(ε0μ0)^2 / Mp Wolfram Alpha Link = G = L(1/√(εμ)^2 / M - Wolfram|Alpha (wolframalpha.com) Lp = √(Għ/(1/√(ε0μ0)^3) Wolfram Alpha Link = √(Gh/(1/√(εμ)^3) - Wolfram|Alpha (wolframalpha.com) tp = √Għ/(1/√(ε0μ0))^5 Wolfram Alpha Link = √(Gh/(1/√(εμ))^5 - Wolfram|Alpha (wolframalpha.com) Mp = √(ħ(1/√(ε0μ0))/G) Wolfram Alpha Link = √(h(1/√(εμ))/G) - Wolfram|Alpha (wolframalpha.com) Edited May 10 by Vmedvil OceanBreeze 1 Quote Link to comment Share on other sites More sharing options...

oldpaddoboy Posted May 10 Report Share Posted May 10 52 minutes ago, Vmedvil said: This is something, I have never fully understood, why is the speed of light always the same, I know Einstein came up with that however I don't fully understand why? I want to understand the nature of why the speed of light is a constant, explain it to me. The thing that has been drummed into my head, is that science, mostly doesn't answer the why questions. Why do we feel gravity near a massive body? And of course is validated by the relationship between time and space and time dilation and length contraction. All are "as is" due to the nature and parameters of the big bang and the why and how of that. If we can speculate that the big bang was a fluctuation in the quantum foam, then other fluctuations may have risen and collapsed, or risen and expanded differently from our own fluctuation. This is basically the picture painted by Professor Lawrence Krauss and his book, "A Universe from Nothing" Or simply, that's the way the cookie crumbles. OceanBreeze 1 Quote Link to comment Share on other sites More sharing options...

Talanum46 Posted May 11 Author Report Share Posted May 11 On 5/9/2024 at 8:42 AM, Vmedvil said: The answer to this question, is still, No... At this point. That isn't proven. Taking the concept as is, it is conceivable that all of space would change e0 and u0 at the same time, making the communication instantaneous. On 5/10/2024 at 3:55 AM, OceanBreeze said: Trying to change either the permittivity or permeability of free space, “ceteris non mutatis” [all other things being unchanged]; is not possible because the inverse relation means that between them a perfect compensation always takes place. That isn't proven either. As for that they are inverses to each other: that is just if c is constant even if space changes. OceanBreeze 1 Quote Link to comment Share on other sites More sharing options...

OceanBreeze Posted May 13 Report Share Posted May 13 On 5/10/2024 at 8:55 AM, OceanBreeze said: Trying to change either the permittivity or permeability of free space, “ceteris non mutatis” [all other things being unchanged]; is not possible because the inverse relation means that between them a perfect compensation always takes place. The only possible conclusion is c is the universal, fundamental constant of free space and cannot be changed by playing with the derived values of ε0 and μ0, which are not fundamental. On 5/11/2024 at 10:26 PM, Talanum46 said: That isn't proven. Taking the concept as is, it is conceivable that all of space would change e0 and u0 at the same time, making the communication instantaneous. That isn't proven either. As for that they are inverses to each other: that is just if c is constant even if space changes. Talanum46, nothing in Physics, or in all of Science is “proven”. That the speed of light is a universal constant is supported by mathematics, in particular by Maxwell’s equations, and has been measured and verified to be correct at 299,792,458 m/s. Against that evidence, all you have is your unsupported opinion. Your question in your opening post started an interesting discussion about real Physics. Don’t spoil it all now by making unsupported claims or this thread may end up back in Silly Claims. Please read the rules posted in Forum Announcements: 1) If you make strange claims, please provide evidence or at least backup of some kind. If you fail to do so, or the backup you provide is not deemed adequate, the moderators may move your post to the Strange Claims forum. What we generally do not approve of is wild, unsubstantiated claims. But, even these are sometimes allowed and placed in the Silly Claims section if they are at least interesting. Quote Link to comment Share on other sites More sharing options...

OceanBreeze Posted May 13 Report Share Posted May 13 On 5/11/2024 at 1:57 AM, Vmedvil said: This is something, I have never fully understood, why is the speed of light always the same, I know Einstein came up with that however I don't fully understand why? I want to understand the nature of why the speed of light is a constant, explain it to me. As oldpaddoboy says, Science won’t tell you why things are the way they are, for that, you have to ask the philosophers. But Science ( in this case Physics) can tell you a lot about how things came to be as they are. In this particular case, the how was determined from the set of Maxwell’s equations, that predict all the known properties and behavior of electromagnetism, including its constant vacuum propagation velocity. What I have been trying to find is a similar set of field equations which do the same for gravity. If you look closely at Einstein’s field equations in General Relativity, they rely on the electromagnetic properties of space to predict the speed of gravity, even though gravity is not an electromagnetic wave. Gravity is definitely not part of the electromagnetic spectrum. To be consistent with electromagnetism there must exist a gravitational analog of Maxwell’s equations, or Einstein's General Relativity, that does not rely on any electromagnetic properties, such as ε0 and μ0. To be sure, there are indications of the way the gravitational relationship should look: μ0 in (henries per meter) is permeability of free space and is basically inductance which has an analog in mechanics as mass. ε0 in (farads per meter) is permittivity of free space and is basically capacitance which has an analog in mechanics as the spring constant. We can easily see now how ε0 and μ0 act as inverses and one acts to compensate for the other and restore neutrality, just as happens with a mass on a spring. Since mass is obviously related to gravity, it is almost certain to be included in any equation for the speed of gravity as the gravitational analog of μ0. What then could act as the restorative agent and be the gravitational analog of ε0? It seems uniting these two different symmetries is highly nontrivial, as it has yet to be done, as far as I can determine. For example, the electromagnetic Poynting vector has been determined to be: Pm = (½ μ0) E×B I have not been able to find a gravitational equivalent: PG = (m) x ? Unfortunately, I am probably too old and my brain has lost the elasticity needed to do original work, so I leave this as an exercise for younger minds to tackle (of course I will continue to think about it in my spare time) Quote Link to comment Share on other sites More sharing options...

OceanBreeze Posted May 13 Report Share Posted May 13 On 5/9/2024 at 2:27 PM, Vmedvil said: Continuing, if you plugged the equation in relativity as invariant space-time, it would be. (Δs)^{2} = -((1/√(ε0μ0)Δt)^{2} + (Δx)^{2} + (Δy)^{2} + (Δz)^{2} ^{Wolfram Alpha Results Link = }(Δs)^2 = -(1/√(εμ)Δt)^2 + (Δx)^2 + (Δy)^2 + (Δz)^2 - Wolfram|Alpha (wolframalpha.com) If you decreased ε0 and μ0 to .25 with Δx, Δy,Δz, Δt being 1 and then Δs would be 13√-1. It is kinda weird, I don't actually know what that means... but mathematically it gives weird results in the equations. it gives an imaginary number(Imaginary number - Wikipedia) of 13i for Δs? "Geometrically, imaginary numbers are found on the vertical axis of the complex number plane, which allows them to be presented perpendicular to the real axis. One way of viewing imaginary numbers is to consider a standard number line positively increasing in magnitude to the right and negatively increasing in magnitude to the left. At 0 on the x-axis, a y-axis can be drawn with "positive" direction going up; "positive" imaginary numbers then increase in magnitude upwards, and "negative" imaginary numbers increase in magnitude downwards. This vertical axis is often called the "imaginary axis"^{[11]} and is denoted 𝑖𝑅, 𝐼, or ℑ.^{[12]} In this representation, multiplication by i corresponds to a counterclockwise rotation of 90 degrees about the origin, which is a quarter of a circle. Multiplication by −i corresponds to a clockwise rotation of 90 degrees about the origin. Similarly, multiplying by a purely imaginary number bi, with b a real number, both causes a counterclockwise rotation about the origin by 90 degrees and scales the answer by a factor of b. When b < 0, this can instead be described as a clockwise rotation by 90 degrees and a scaling by |b|." Link = Imaginary number - Wikipedia The square root of a negative number is always imaginary Quote Link to comment Share on other sites More sharing options...

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