What does my teacher mean once he claims that all electromagnetic waves travel at the exact same speed when travelling via a vacuum? If you might, please answer as simple as possible.

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Electromagnetic waves include visible light, radio waves, X-rays, and so on. What distinguishes these various bands of light is their frequency (or wavelength). But what they all have actually in widespread is that they take a trip at the exact same speed in vacuum.

The factor for qualifying "in vacuum" is because EM waves of different frequencies often propagate at different speeds through material.

The speed of a wave $c$, its wavesize $lambda$ and also frequency $f$ are all associated according to $c=lambda f$. So if $c$ is the very same for all EM waves, then if you (say) double the frequency of a wave, its wavelength will halve.


Assume you are walking down the road. You bring a little stick via you. Just for fun you decide to wiggle the stick rhythmically up and down at the rate of one up/dvery own wiggle per second (you are a little of an olympic expert at stick wiggling so it"s exceptionally specific and also reliable). Your stick wiggling is at 1Hz. The rate at which you walk down the road is not regarded the rate at which you wiggle the stick. You have the right to walk down the road at any kind of speed you prefer and still wiggle at 1Hz.

Have you acquired it now ?

The rate of transmission of an e-m wave is not regarded the frequency/wavelength.


Not true. Bad analogy. First, in your last sentence you"re utilizing frequency and wavelength synonymously, which they"re not. Frequency is the (oscillation rate) in a photon pshort article. Like the waving of the stick, it"s frequency is continuous. But wavesize is a meacertain of frequency within the constraints of rate. If frequency is a continuous, and also rate changes, then the wavesize should adjust. So, frequency isn"t impacted by rate, however wavelength is. The stick instance mirrors the frequency consistent, however not wavelength. A rollercoaster track instance shows the wavesize consistent. If a rollercoaster slows down, it still needs it to move through the exact same course to get to the next cremainder. It"ll take even more time to gain tbelow, however the wave is still the very same shape and distance. But in order for this to work-related, it"s frequency or energy decreases. in the wave pwrite-up world, this doesn"t happen. Because of this, the rollercoaster instance shows us the wavelength as a constant just for theoretical objectives, however does not work in the herbal wave particle world. Only a pposts power or frequency is continuous. This dictates that rate and also wavelength deserve to change.

With that establimelted. Let"s look at the scenario of pholots traveling via a vacuum. In a vacuum, tbelow is nothing to disrupt the speed. If the speed is continuous and also we have already establimelted the frequency is consistent, then the wavelength of that particle is additionally a constant.

Now if we present issue. This reasons the particle"s rate or trajectory, or both to be altered. Altering the rate will certainly change it"s wavelength. Altering it"s trajectory will cause it"s wavelength to go to zero in that direction. In both instances, power is moved and released, which offers rise to the principle that a photon is a particle. But at the exact same time, as soon as it is complimentary to take a trip uninhibited aobtain in a vacuum, it reverts ago to it"s exact same wavesize and also rate, which is characteristic of a pure wave.

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This principle of a photon being a wave, is why we believe it hregarding have the exact same rate in a vacuum. The simple answer is that we do not really recognize why they all travel at the exact same rate. All we understand is that this is a characteristic of a wave create of power. As with mass is a characteristic of a pshort article. It just is.