Logicandreason Posted June 19, 2023 Posted June 19, 2023 Can someone help me apply Mu nought and epsilon zero values to the derived final equation for calculating light speed from Maxwell's equations? I cant seem to calculate 300 million meters a second. Is there is some trick that's not talked about much?
exchemist Posted June 19, 2023 Posted June 19, 2023 1 hour ago, Logicandreason said: Can someone help me apply Mu nought and epsilon zero values to the derived final equation for calculating light speed from Maxwell's equations? I cant seem to calculate 300 million meters a second. Is there is some trick that's not talked about much? What equation are you working from?
Genady Posted June 19, 2023 Posted June 19, 2023 Step-by-step derivation here: How to Derive the Speed of Light from Maxwell's Equations: 7 Steps (wikihow.com)
Logicandreason Posted June 20, 2023 Author Posted June 20, 2023 23 hours ago, Bufofrog said: Here you go. Its that last step that I cant get to work. What actual numbers do I input into my calculator for mu and epsilon? Can you show me what you do? Line by line for this part?
exchemist Posted June 20, 2023 Posted June 20, 2023 16 minutes ago, Logicandreason said: Its that last step that I cant get to work. What actual numbers do I input into my calculator for mu and epsilon? Can you show me what you do? Line by line for this part? In this Wiki article: https://en.wikipedia.org/wiki/Vacuum_permittivity there is a formula that plugs in the relevant values of the quantities and shows the relation between them. It's important to use consistent units. There are some notes showing equivalent ways of expressing the units.
Bufofrog Posted June 20, 2023 Posted June 20, 2023 18 minutes ago, Logicandreason said: Its that last step that I cant get to work. What actual numbers do I input into my calculator for mu and epsilon? Can you show me what you do? Line by line for this part? Put 4 x 10^-7 into the calculator press the X button then press the Pi button. Then press the X button and type in 8.854 x 10^-12 press the = button. Press the square root button then press the 1/x button.
Genady Posted June 20, 2023 Posted June 20, 2023 17 minutes ago, Bufofrog said: Put 4 x 10^-7 into the calculator press the X button then press the Pi button. Then press the X button and type in 8.854 x 10^-12 press the = button. Press the square root button then press the 1/x button. And the answer is....
Logicandreason Posted June 21, 2023 Author Posted June 21, 2023 12 hours ago, Genady said: And the answer is.... But my issue is that mu and epsilon use totally different units. Its like trying to multiply 3 horses with 7 basketballs, what is the result? Mu an Epsilon must be in meters per second units to get the result 297 million meter per second result. 3 (horses) * 7 (basketballs) = 21.... but its not 21 ANYTHINGS.
Genady Posted June 21, 2023 Posted June 21, 2023 18 minutes ago, Logicandreason said: But my issue is that mu and epsilon use totally different units. Its like trying to multiply 3 horses with 7 basketballs, what is the result? Mu an Epsilon must be in meters per second units to get the result 297 million meter per second result. 3 (horses) * 7 (basketballs) = 21.... but its not 21 ANYTHINGS. Ever heard of F=ma? m is in kg, a is in m/s2. Different units multiply just fine.
Logicandreason Posted June 21, 2023 Author Posted June 21, 2023 (edited) 40 minutes ago, Genady said: Ever heard of F=ma? m is in kg, a is in m/s2. Different units multiply just fine. This is what I found: Multiplying values with different units can lead to nonsensical or meaningless results. Units represent specific measurements or dimensions, and multiplying them directly would result in a combination of those units that might not have any real-world interpretation or significance. To perform valid multiplication, the values should be in compatible units or have a specific relationship that allows for meaningful multiplication. If the units are not compatible, you would typically need to convert them to a common unit before performing the multiplication. Question: does 2 Farad/metre = 2 Henries/metre ? ChatGPT No, 2 Farads/meter (F/m) does not equal 2 Henries/meter (H/m). Farads (F) and Henries (H) are units of capacitance and inductance, respectively, in the International System of Units (SI). They represent different physical quantities and cannot be directly equated. Farads (F) measure the capacitance of a system, which is the ability to store an electric charge. In contrast, Henries (H) measure the inductance of a system, which is the ability to store magnetic energy in a magnetic field. While both units involve the concept of storing energy, capacitance and inductance are distinct properties and cannot be equated without further context or specific relationships. So, a unit of capacitance is not equal to a unit of inductance. Because they are measuring totally different properties. The Mass may be the same, but not the calculated results. Horses cant be multiplied with basketballs. Apparently if you multiply a Farad by a Henrie, you get Seconds Squared. A factor used in acceleration of a Mass, as in F = m*a So that gives us a FORCE result. So in that original equation involving mu and epsilon, we end up with 1, over the Square Root of A FORCE. The 1 relates to speed, m.p.s and the denominator is a force . As there is no Mass involved in the calculation, the result is zero. Edited June 21, 2023 by Logicandreason
Genady Posted June 21, 2023 Posted June 21, 2023 18 minutes ago, Logicandreason said: This is what I found: Multiplying values with different units can lead to nonsensical or meaningless results. Units represent specific measurements or dimensions, and multiplying them directly would result in a combination of those units that might not have any real-world interpretation or significance. To perform valid multiplication, the values should be in compatible units or have a specific relationship that allows for meaningful multiplication. If the units are not compatible, you would typically need to convert them to a common unit before performing the multiplication. Question: does 2 Farad/metre = 2 Henries/metre ? ChatGPT No, 2 Farads/meter (F/m) does not equal 2 Henries/meter (H/m). Farads (F) and Henries (H) are units of capacitance and inductance, respectively, in the International System of Units (SI). They represent different physical quantities and cannot be directly equated. Farads (F) measure the capacitance of a system, which is the ability to store an electric charge. In contrast, Henries (H) measure the inductance of a system, which is the ability to store magnetic energy in a magnetic field. While both units involve the concept of storing energy, capacitance and inductance are distinct properties and cannot be equated without further context or specific relationships. So, a unit of capacitance is not equal to a unit of inductance. Because they are measuring totally different properties. The Mass may be the same, but not the calculated results. Horses cant be multiplied with basketballs. Units need to be compatible. They don't need to be the same. Compatible does not mean equal.
Logicandreason Posted June 21, 2023 Author Posted June 21, 2023 8 minutes ago, Genady said: Units need to be compatible. They don't need to be the same. Compatible does not mean equal. Ok I get it. I follow now after a bit more googling.
Eise Posted June 21, 2023 Posted June 21, 2023 5 hours ago, Logicandreason said: Its like trying to multiply 3 horses with 7 basketballs, what is the result? Mu an Epsilon must be in meters per second units to get the result 297 million meter per second result. 3 (horses) * 7 (basketballs) = 21.... but its not 21 ANYTHINGS. Of course not. E.g. if the question is, how many different pairs of horses and basketballs one can form, it is 21 pairs (this is called a 'Cartesian product'). Compare now with e.g. speed. According to you the unit of speed does not make sense: one divides distance through seconds. But I assume you have no problem with that (miles/hour, or meters/second, whatever). Obviously not as you are using the phrase 'meter per second'.
Logicandreason Posted June 21, 2023 Author Posted June 21, 2023 1 minute ago, Eise said: Of course not. E.g. if the question is, how many different pairs of horses and basketballs one can form, it is 21 pairs (this is called a 'Cartesian product'). Compare now with e.g. speed. According to you the unit of speed does not make sense: one divides distance through seconds. But I assume you have no problem with that (miles/hour, or meters/second, whatever). Obviously not as you are using the phrase 'meter per second'. Thanks I already sorted this out with a bit more info and google searching.
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