What does the big bang look like? Lec 16 - Hubble's Law and the Big Bang views. Tour of the map of the big bang - by Minu Chapter 8 Hubble Space Telescope views.
How does our GPS work? The Higgs boson - part two by Minute Physics views. The Higgs boson - part three by Minute Ph Connect and share knowledge within a single location that is structured and easy to search. The question is the well-known Olbers' paradox:. Where goes all the light we don't see? The first my friend's answer is that given the fact that in a finite amount of time in this case, the age of the universe , light can travel only a certain, finite, distance, we cannot see, if they actually exist, stars farther than such distance about 13 billions of years, I guess.
Then he states or better, I got him notice he implicitly does this that within this radius there aren't enough stars to fill the night sky, and that's why we have darkness without sun's light.
The second answer mine, or anyway the one I heard from a minutephysics YouTube video is that despite of the big size of the observable universe, cosmological expansion red shifts most of the light out of the visible radiation range, so that the majority of light can't be seen by our eyes at night, while if we use, for example, an infrared camera, we should see a brighter sky, and lenghtening more and more the wavelength at which we observe the sky, we come to the uniform background radiation.
So my question is, what is the right answer? Is it one of the above-mentioned or even a third one? EDIT: I've seen both answer may be acceptable, but what is the main contributing phenomenon? I'm going to respond to v1 of the question, which asks why the night sky is dark black and unlit compared to the day sky even though there are many light sources at night. The updated question references Olber's paradox, which has been answered many times before.
Like most things we see in everyday life, there are a number of reasons contributing to this. I'll go through each of the leading effects and what happens if we get rid of them. First is my number one reason that the sky is dark at night simply because it doesn't require us to change the fundamental nature of the universe in order to imagine a universe without it.
It is because most of the light from other stars is blocked by dust and gas clouds between us and the other stars. Here's a picture: source: wikimedia. This is an image of the Milky Way as we see it from Earth. Without dust and gas, this would be so bright that the night sky would be lit up as well.
This is mostly due to how bright the central bulge would be, but I'd be lying if I said the rest of the disk isn't bright as well. So most of the light that comes from other stars is blocked by dust and gas. Blocked of course meaning reflected, refracted away from us, or absorbed and retransmitted as invisible radiation.
Second, cosmological expansion. This gets the number two spot because of how important it is. The expansion of the universe causes light to be shifted to lower frequencies. The farther away it is, the more it is shifted.
Have you ever wondered why you look up and see a dark sky at night? The Minute Physics have created another great video explaining why the sky is dark at night. Minute Physics provides an energetic and entertaining view of old and new problems in physics.
Producing content you read on this website takes a lot of time, effort, and hard work. If you value what we do here, please consider becoming a supporter. The agency is reporting depths of 5. A newly-discovered asteroid designated VP11 flew past Earth at a distance of 0. This is the th known asteroid to fly past Earth within 1 lunar distance since the start of the year The event lasted up to 5 seconds, changing color from green to red as it streaked through the cloudy sky.
It was captured by a live camera High-resolution satellites have detected substantial quantities of methane leaking from two landfill sites close to the center of Madrid, Spain. Snow and blustery conditions are forecast to continue in the Upper Midwest on Friday, November 12, , as a strong low slowly retreats northward.
On Saturday and into early Sunday, November 13 into 14, another storm system, known as Alberta clipper, will deliver A newly-discovered asteroid designated VC7 will fly past Earth at a distance of 0. This is the th known asteroid to fly past Earth within 1 lunar distance since the start of This clip does a wonder to explain physics in only a 3 minute period easy understandable to uneducated people and kids.
And it covers every possible angle that is possible to be explained in a 3 minute time frame. And yet you are complain about it. So I challenge you to explain it in a 3 minute time frame to the uneducated and kids. Children, let us examine why the sky is dark at night.
One of you … take a very bright torch and walk away from us. How far away do you have to go before you will no longer see the light? Do you think you will get so far away that you will not be able to see the light…yes? Ok, children, the stars are a very long way away.
In fact the closest star, apart from our sun is so far away that its light is at least billion times less bright than our sun, and that is why the sky is mostly dark…everything is a very long way away. The long answer discusses cosmological theories and constructs that may or may not be correct…and indeed could be boring for some….
Diteris, light acts differently in space than within an atmosphere. It could just as easily appear a washed-out white, green, or red. The 3 minute clip is addressing the many different questions in detail for people that do not enough understand science.
The inverse square law is only part of the sollution. I think the answer lies in how your brain interprets the image. The color black is how your brain interprets seeing nothing. Skip to content The Minute Physics folks have created another great video, this time explaining why the sky is dark at night.
Like this: Like Loading But the problem is why do you see nothing? Infinite space should mean it is as bright as hell. I know, but space is infinite.
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