The Mirage we call our Universe
Aug 25, 2019 20:19:36 GMT -5
Post by Radrook Admin on Aug 25, 2019 20:19:36 GMT -5
The Mirage we call our Universe
It has always amazed me how the sky is full of things which looked that way in the far past and we really don't know how they look now. Such an idea seems imopossible until we begin to understand why. It turns out that it has to do with how fast light travels from its source to our eyes. You see, the light from the things we are seeing takes time to reach our retina from where it is relayed via nerve impulses to the brain's occipetal locbe in the back of out head, and where it is perceived as an image.
True, the speed that light, going at the 186,000 miles per second, is fast by Earth standards. For example, if you could run as fast as light, you would circle the Earth seven-and-a-half times in one second. It also travels at an impressive rate when limited to the distances within our solar sysatem.
For example, light travels the 93 million miles between Earth and the sun in approx eight minutes. Not bad! It gets from Earth to moon which in approx 250,000 miles away in approx a few seconds. It takes takes 4.6 hours to travel from Earth to Pluto. That means that at half its velocity, , or 93,000 mps, it would take 9.2 hours to make the journey. But when light needs to cross cosmic distances, the time taken to traverse them makes light look as if it is travelling at a very slow crawl.
For example, Alpha centauri star system is the nearest to us. Yet, its light takes approx four years to reach us. So when our brain finally receives the neurotransmissions triggered by light stimulaing the retina, it is seeing Alpha Centauri as it was approx four years ago. If the star explodes now, we would see it in four years. If our sun does so, we would know it eight minutes later. In short, we are seeing these events as they happened in the past and not now.
Then we have the Andromeda Galaxy whose light takes approxe 2.5 million years to reach us. Since Andromeda is moving in our direction, it is actually far closer to us at present than its light coming to us from the distant past indicates. In short, we are actually seeing a mirage or an image of the Andromeda Galaxy without any real substance while the real Andromeda Galaxy exists undetctable in its present position which is heading our way at 110 kilometres per second or (68 miles per second). Which would be:
4080 miles per minute
244,800 miles per hour
5,875,200 miles per day
2,144,448,000 miles per year
That’s two billion, one-hundred-forty-four-million, four-hundered-forty-eight-thousand, miles closer to us every year during those 2.5 million years that the light took to reach us. So if we got there instanly, it would not be where we saw it from our vantage point back on earth.
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Closer to home, in our own Milky Way Galaxy, we have a region called Sagitarious A where the center is located. There, a massive black hole exists which is gobbling up whatever crosses its event horizon or region of no return. Its activity determines how bright that central galactic location appears. It has remained fairly quiet since it's been under close observation. However, just recently its luminosity increased by 75 percent. But that is recently for us. In true reality, that brightening took place approx 27 ,000 years ago but the light from it is arriving ion Earth now. If it had aimed a death-dealing beam of X rays at us we would also be knowing it now after approx 27,000 years.
Rather weird, isn't it?