Did you ever wonder why both, Einstein’s relativity theory and quantum physics, in theory as well as experiment, seem obsessed with the nature of light? The velocity of light, light clocks, entangled photons, and so on – why is it always light? This preoccupation is no coincidence. It comes directly from the fact that light does not actually exist. Think I am nuts yet?
Today, I will tell you why relativity theory makes the non-existence of light obvious. The next time, I will show that this odd seeming fact only confirms what is known from entirely unrelated quantum mechanics: classical relativity and non-relativistic quantum physics both agree on that light does not exist for entirely different reasons!
In a third part, I will explain why I personally find all this rather unsurprising. In short: it could not be any other way! The measure of all measures may not be allowed to have any internal properties that could possibly change and thereby change the measure. Hence, it best has no properties at all. Optimally, it does not even exist. That is why light has become the measure of all measures in the cutting edge of fundamental physics: It does not itself exist!
Light is in a sense the very connection between nothingness and something and it is thus just the thing to be explored if we want to ever discover the fundamental basis of physics, how dreams about reality dream themselves. But lets get to the relativistic aspect of the non-existence of light.
Light has no time to see
nor any space to be,
nor even any energy.
Relativity theory is all about the problematic of that if you want to know the properties of any system, say the weight or length of a rocket ship, you need to take some care in case that system is moving fast relative to you. You need to distinguish the contribution that your movement relative to the rocket for example adds into your measurements.
In other words, if you want to know the system’s own properties without any relativistic contributions, you will have to best move along with the object of interest. I will now explain that the light’s own time, length, and energy are none at all and that all the light’s properties are nothing but relativistic contributions.
Consider that we wish to know the mass, length, and energy of a flash of light that we just shone out of an electric torch and into the night sky. If we want to attain the point of view of the light, that is, if we want to experience the world from the light’s own point of view, from its so called ‘rest frame’, we will find that the more we accelerate to travel along with the light, the shorter the travel time between any two positions along its path becomes.
Light travels with light velocity “c”. If we do not move relative to the earth, the travel time of the light from the upper atmosphere to the moon for example is about one second. We know this because if it hits a mirror on the moon, it will be back on earth after two seconds. However, these seconds is what it takes us to wait for the light. How long does it take the light to go anywhere?
If we travel along that same path, the time that it takes us to get to the moon becomes shorter and shorter the faster we go. “Of course” you may say, “because you are faster and faster.” But that is not what I mean. What I mean is that we will experience a travel time below one second before we even reach the velocity of light relative to the earth-moon system. This is due to time dilation.
In fact, we would experience about one second of travel time between earth and moon, if we moved with a velocity v that equals light velocity divided by the square root of two: v=c/√2. At 90% light velocity, i.e. at v=9c/10, our travel time will be only a third of a second! At 99.9% of the speed of light, the travel time we would experience has reduced to a thirtieth of a second, or 33.3 milliseconds.
In fact, although we cannot ever reach light velocity, we would soon even by pure experimentation find out that if we could reach light velocity and travel along side by side with the light, time would stop and the travel time between any two points, even between here and the edge of the observable universe, would be exactly zero. Relativity theory tells us that light has no time at all to exist because it moves at the speed of light.
The light comes to existence in the torch and it may cease to exist in an alien’s eye. The time in between these two events is the light’s life time. For the light, it is its own experienced travel time. There is none. I have a few decades between birth and my inevitable demise, some insects only a single day, but light has no time at all to be. Therefore: It is never! It is not!
The same contraction of travel time also holds for the travel distance. If we want to attain the point of view of the light, that is, if we want to experience the world from the light’s own point of view, its so called rest frame, we will find that the more we accelerate to travel along with the light, the more the measured travel distance contracts via the so called Lorentz-contraction.
The faster we go in between A and B, trying to keep up with the light, the shorter the distance becomes for us. This is easily misunderstood and most physicists even explain it incorrectly. So let me not try to explain it in any detail here. Nevertheless, it is true, and moreover, the factor with which the world contracts relative to a moving object is the same factor as that of the time dilation discussed above.
The conclusion is similar, too: For the light itself, the whole universe is only zero millimeters long. There is no distance between A and B. There is no space in between its birthplace in the torch and its death bed in the alien’s eye. There is no place for the light to be, and therefore it cannot be: It is not!
Moreover: the more we accelerate to travel along with the light, although the distances traveled become shorter, the light’s wavelength becomes ever longer relative to us. The light becomes ever more reddish because the light’s energy becomes less and less. The faster we hurry along with the beam of light, the more it red-shifts away to being undetectable. If we could race along with it, there would be nothing left at all. There is no light from the light’s own point of view! It is not!
It should thus not surprise that we can never reach the velocity of light, that we cannot attain the light’s own point of view. There is no such point of view; it does not exist!
And on to the next part in this series.