Within Relativity Theory, if there is whatever that is not intuitive it is the truth that within the whole Universe, it’s miles the speed of mild (and gravity?) on my own that is absolute or constant, now not some thing like space being absolute or time being absolute. It’s no longer intuitive in that every one the other no longer-mild bits and portions which are in motion may be introduced or subtracted. The lone exception to that established rule that velocities can be mathematically combined is the velocity of light (and gravity?).
Repeat for emphasis: the ambiguity here is that in any other state of affairs, some thing that isn’t-light and in movement, velocities can be added and subtracted. Repeat again: with that one pace of mild exception, velocities may be delivered or subtracted. If you’re on a treadmill this is moving left at five MPH, and you are on it taking walks to the proper at five MPH, to an outside observer you’re waking but standing nevertheless. You’re much more likely to hit a domestic run if the wind is blowing towards the outfield fences; planes fly faster with a tailwind than with a headwind; you swim in the river faster going with the float than in opposition to the present day. If you are in a educate that is moving at say a hundred km/hour and you throw a ball at 10 km/hour inside the path at which the educate is moving, to an observer out of doors the educate, your ball is traveling at a hundred and ten km/hour. If you throw the ball towards the rear of the train, an outside observer will degree the ball as moving at ninety km/hour. If alternatively, you shine a flashlight in the train, an out of doors observer will see the speed of the resulting light beam shifting at the velocity of mild – now not the velocity of mild PLUS the velocity of the teach, or the velocity of mild MINUS the velocity of the train, however at the speed of mild! That’s nuts, however it is scientifically nuts and been tested time and again in any test you care to plot. I have no issue with experimentally established effects. That does not suggest I do not have issues with the anomaly.
The speed of light is a steady to an outside observer regardless of what. Why that need to be no person knows, but it is so. However, my take on this can of worms, which for this reason calls for quite counter-intuitively that both time and duration have to be flexible, is one must continually be a chunk suspect in terms of the lone ranger, the lone ranger being the exception to the rule*. I don’t tend to like exceptions to the rule of thumb. There’s some thing weird afoot here. Mother Nature is trying to tell us some thing we haven’t discovered yet.
All that said, the velocity of light isn’t virtually a constant if you think about the differing mediums that light can tour thru. However, the rate of light might be also a consistent inside anything different medium it happens to be in. The pace of mild in air at STP (widespread temperature and pressure) is less than the speed of light in the relative vacuum of outer space; even much less traveling through pure water and much less again visiting thru clear glass. One could presume that simply as the velocity of light in area is consistent for observers regardless if they may be travelling in a excessive velocity spaceship or as an astronaut ‘desk bound’ on the International Space Station, the velocity of light in water have to be a constant for the group in a submarine that is underway as a consequence in motion or a diver standing at the seabed.
That makes me sort of wonder, theoretically, if you can get an underwater submarine to head quicker than the speed of light in water (or an aircraft to outpace the velocity of mild in air), even though in either case that would be much less than the speed of light in a vacuum, should you then declare, albeit with qualifiers (in water; in air), that you honestly traveled quicker than the speed of mild, if handiest for the bragging rights?
Apart from mild (photons), probably gravity, or gravity-waves, additionally propagate at the rate of mild and as a result a gravity-wave would have a constant speed regardless of any body of reference for any observer. But I also presume that necessitates locating the hypothetical graviton particle (to mirror the photon) and that, for the instant, resides in the unknown basket.
That brings up but any other puzzlement. Is gravity just geometry as according to General Relativity or is gravity a pressure transmitted by means of a force particle, the theoretical graviton, and consequently extra similar to electromagnetism’s photons (limitless extension; obeys the inverse square dating) other than lacking EM’s poor counterpoint – within the case of gravity, that’s antigravity.
Speaking of gravity (gravitons) and mild (photons), if gravity could have an impact on light (i.E. – the gravitational lens), then it ought to be a -manner road and light need to be capable of have an observable effect on gravity, however I cannot consider ever analyzing about that factor of the relationship.
As according to the speed of light being medium based; one speed in a vacuum, some other in water, well that makes for an thrilling query whilst considering gravity. If a gravity-wave is coming near Earth, will it have one constant speed inside the vacuum of space for all observers, then a differing velocity as it passes via our environment, then some other fee as it passes thru the sea and but others because it hits the diverse density layers inside the planet?
As is often the case, there has a tendency to be extra questions than answers!
*Not that the differing rules for the rate of light vis-à-vis other not-mild velocities is the only exception to the rule in present day physics. Quantum tunneling is one of those exceptions to the rule of thumb of causality. With appreciate to the usual version of cosmology and the Big Bang, first there has been not anything; then there has been something. That means the Big Bang occasion created each rely and energy out of much less than thin air. That’s additionally a loose lunch and one of these exceptions to the rule of thumb of physical regulation usually expressed because the conservation of count number and energy. All these exceptions to the norm endorse that a number of the very last chapters in modern physics have not but been written.