Starship Asterisk*

What happens when Light or Matter Arrives at the edge of the universe?
does the light reflect or what?
how does it feel if you touch that edge with your hand? there is no space there, so your hand will be stopped. but how? is it like touching something? does anything special happen?
what happens to light is much more interesting to me. because the answer for matter could be that it'll simply stop. but what about light?

Amir wrote:What happens when Light or Matter Arrives at the edge of the universe?
does the light reflect or what?
how does it feel if you touch that edge with your hand? there is no space there, so your hand will be stopped. but how? is it like touching something? does anything special happen?
what happens to light is much more interesting to me. because the answer for matter could be that it'll simply stop. but what about light?

YOU are at near the edge of the universe for all the folks near the edge of YOUR universe.
how does it feel when you touch that edge with your hand?
there is no space there, so your hand is stopped. but how?
is it like touching something? does anything special happen?

Let us know what you experience, Amir.

Amir wrote:What happens when Light or Matter Arrives at the edge of the universe?

The universe has no edge.

Henning Makholm wrote:

Amir wrote:What happens when Light or Matter Arrives at the edge of the universe?

The universe has no edge.

The visible universe may have an edge(; depending upon one's definition.)
A black hole has an edge (the event horizon),
the horizon has an edge and a rainbow has an edge.
Just don't go near the edge.

Amir, IF you ever get to the EDGE, make sure you get pictures Moveing, if possible

If the Universe is expanding, then the Edge is most likely expanding with it. Much the same as with people's skin expanding to fit the expanding waist-lines

Amir wrote:What happens when Light or Matter Arrives at the edge of the universe?
does the light reflect or what?
how does it feel if you touch that edge with your hand? there is no space there, so your hand will be stopped. but how? is it like touching something? does anything special happen?
what happens to light is much more interesting to me. because the answer for matter could be that it'll simply stop. but what about light?

Every point in the Universe is at the center of its own visible universe. As you move towards what you perceive as an "edge", that edge moves away from you, and stuff behind you that used to be at the edge disappears. Imagine yourself in a cave with a candle. You can see a volume around you that is 10 meters in radius. You wonder what is "over the edge" in the dark ahead, but when you get there it looks pretty much the same as where you just were... which is now over the edge itself.

Well, it's a good question. If the universe came into existence at a specific moment and has been expanding ever since, it ought to have a finite size and therefore have a kind of "end", if not strictly an "edge". But then again, maybe not. At present our universe appears to be "open", that is to say, it will probably never collapse, but just keep expanding. Is it possible that "the end of the universe" is moving away faster than light can catch up with it?

But I guess that this line of reasoning hinges on some kind of mistaken assumption about the universe, such as the idea that it would be three-dimensional and can be understood in three dimensions like our everyday three-dimensional world. But that is not the case, of course.

Ann

i get it now, there's now edge or end to touch. thanks!

"This end of the world will occur without noise, without revolution, without cataclysm. Just as a tree loses leaves in the autumn wind, so the earth will see in succession the falling and perishing all its children, and in this eternal winter, which will envelop it from then on, she can no longer hope for either a new sun or a new spring. She will purge herself of the history of the worlds. The millions or billions of centuries that she had seen will be like a day. It will be only a detail completely insignificant in the whole of the universe. Presently the earth is only an invisible point among all the stars, because, at this distance, it is lost through its infinite smallness in the vicinity of the sun, which itself is by far only a small star. In the future, when the end of things will arrive on this earth, the event will then pass completely unperceived in the universe. The stars will continue to shine after the extinction of our sun, as they already shone before our existence. When there will no longer be on the earth a sole concern to contemplate, the constellations will reign again in the noise as they reigned before the appearance of man on this tiny globule. There are stars whose light shone some millions of years before we arrived … The luminous rays that we receive actually then departed from their bosom before the time of the appearance of man on the earth. The universe is so immense that it appears immutable, and that the duration of a planet such as that of the earth is only a chapter, less than that, a phrase, less still, only a word of the universe’s history." — Camille Flammarion, Le Fin du Monde (The End of the World)

"What intelligent being, what being capable of responding emotionally to a beautiful sight, can look at the jagged, silvery lunar crescent trembling in the azure sky, even through the weakest of telescopes, and not be struck by it in an intensely pleasurable way, not feel cut off from everyday life here on earth and transported toward that first stop on the celestial journeys? What thoughtful soul could look at brilliant Jupiter with its four attendant satellites, or splendid Saturn encircled by its mysterious ring, or a double star glowing scarlet and sapphire in the infinity of night, and not be filled with a sense of wonder? Yes, indeed, if humankind — from humble farmers in the fields and toiling workers in the cities to teachers, people of independent means, those who have reached the pinnacle of fame or fortune, even the most frivolous of society women — if they knew what profound inner pleasure await those who gaze at the heavens, then France, nay, the whole of Europe, would be covered with telescopes instead of bayonets, thereby promoting universal happiness and peace." — Camille Flammarion, 1880

As colored by RJN:
for this APOD.

More information on the woodcut itself is available here.

owlice wrote:As colored by RJN:

Click to view full size image

for this APOD. More information on the woodcut itself is available here.

• Owlice: A place where there isn't any trouble.
  Do you suppose there is such a place, Toto? There must be.
  It's not a place you can get to by a boat or a train.
  It's far, far away. Behind the moon, beyond the rain...
  
  Dr. Bonnell: Pay no attention to that man behind the curtain.

http://en.wikipedia.org/wiki/The_Edge_of_Night wrote:

<<The Edge of Night (also known as Edge of Night or sometimes Edge or EON) is a long-running American television mystery series/soap opera produced by Procter & Gamble. It debuted on CBS on April 2, 1956, and ran on that network until November 28, 1975; the series then moved to ABC, where it aired from December 1, 1975, until December 28, 1984. There were 7,420 episodes.

Nicole Travis Drake has had a most interesting and bizarre history. An early storyline had her victimized by two different women who wanted her dead. She romanced and later married Adam Drake, who was later feared dead in a boating accident but came back to life. Her subsequent marriage to Adam was finished for good after Adam was murdered. And in one of the foremost startling moments in this television serial's history, the character was replaced with a new actress and was subsequently de-aged a decade, a rarity for an adult character in the genre. Now younger and more vibrant, Nicole was suitable for a relationship with young doctor Miles Cavanaugh. She was eventually killed off when her makeup powder was poisoned.

Near the end of the series' run, came an unusual story where Mike and Nancy, after having slept in twin beds for nearly their whole married life, finally decided to "go all out, and buy a double bed", thereby retiring their twin beds for good. It was one of the more unusual moments of the show. Uniquely among daytime dramas, The Edge of Night finished its run with an ominous (and intentional) cliffhanger, revealing that an old enemy had returned to settle some scores, and none of the main protagonists were safe.>>

owlice wrote:More information on the woodcut itself is available here.

More on Flammarion and his woodcut is also in the Café, starting here.

Many different colorized interpretations can be found on Google.

In the thread that bystander referred to, neufer said:

George: Is it a clockwise swirl?
.
Jerry: I prefer clockwise, but it's not written in stone.

A clockwise swirl coming up for you!



Ann

As for Flammarion, wasn't he the guy who said that there were people living on the Moon? And on the Sun?

Ann

Seems people are posting what they think rather than what they know.

The question is basically supposing that the universe is a bubble. For that to be true, it would have to be expanding within something else--a bubble of gas expanding within a liquid for instance. So the question is, what is beyond the rapid expanse of our universe and what is that beyond made of? Is it energy? Is it matter? Is it a void? If it's a void would you simply slip through it and have no way to come back? Would you even be able to see the universe you just left?

The 2D bubble surface, representative of the 3D space of the universe, is expanding in the 4th dimension, time. There is no edge to the bubble's surface, it is continuous.

CyclingNut wrote:Seems people are posting what they think rather than what they know.

The question is basically supposing that the universe is a bubble. For that to be true, it would have to be expanding within something else--a bubble of gas expanding within a liquid for instance.

The Universe is not normally modeled as a bubble, and it does not need to be expanding into anything. What we perceive as an expanding 3D volume is actually the surface of a 4D structure. Thus, in three dimensions, there is no edge.

Speaking of energy -- just what is energy? what is it made of? where did it come from? And why is it makeing all sorts of "stuff?"
Perhaps we will discover more answers by going "inside" , rather than going "outside?"

Chris Peterson wrote:

CyclingNut wrote:Seems people are posting what they think rather than what they know.

The question is basically supposing that the universe is a bubble. For that to be true, it would have to be expanding within something else--a bubble of gas expanding within a liquid for instance.

The Universe is not normally modeled as a bubble, and it does not need to be expanding into anything. What we perceive as an expanding 3D volume is actually the surface of a 4D structure. Thus, in three dimensions, there is no edge.

So the outer part of the expanding 3rd dimension is actually pushing the 4th dimension ahead of it? And the two are separate or we would be seeing strange things happening in the 3rd dimension, like maybe a photon going through two separate slits at the same time, if it is not being watched-that is.
Maybe photons are not separated from things like humans are and exist in all - or almost all dimentions. That could perhaps explain their actions in this 3rd dimension. So it seems that photons may not have an edge because they see everything. Whereas man is very limited in what he sees and therefore has all sorts of limits that act as edges. Good thing they are not too sharp, or this planet would be in a world of hurt.

I do not have a mind trained in mathematics, physics or geometry, so conceptualizing this is difficult for me. I heard, don't know where, that the universe is something like a Mobeus strip, turning back on itself, and that we are on the surface. Now, as I remember it, this is not a 3 dimensional construct; how many dimensions, I can't remember. I don't know, if one kept going in a "straight" line, if they'd come back to the point where they began. But that might explain why we can never get to an edge?

rriverstone wrote:I do not have a mind trained in mathematics, physics or geometry, so conceptualizing this is difficult for me. I heard, don't know where, that the universe is something like a Mobeus strip, turning back on itself, and that we are on the surface.

A Möbius strip is probably a step weirder than you need for this purpose. The characteristic feature of a Möbius strip is that something that goes all the way around the strip and ends up where it started will have become its mirror image during the trip. For various reasons (quite subtle ones, too), it is extremely unlikely that the real universe works that way.

However...

Now, as I remember it, this is not a 3 dimensional construct; how many dimensions, I can't remember. I don't know, if one kept going in a "straight" line, if they'd come back to the point where they began. But that might explain why we can never get to an edge?

You don't need a Möbius twist in order to get the no-edge condition. It is fairly easy to imagine how it would work in two dimensions. Imagine a sheet of fabric such as a bedsheet. Sew the two long edges nicely together so you get a hollow tube. Now take the ends of the tube and sew them together, so the final shape is something like a bicycle tube. For a two-dimensional creature living on the fabric, there would be no discernable edges to his world (provided that you sew nicely enough), yet there would only be finitely much of it.

Now, essentially the same thing is possible in three dimensions (but much harder to imagine because we can't imagine a four-dimensional space in which to manipulate the "fabric"), and something like that does indeed constitute an at least semi-serious bid for the really-large-scale structure of the Universe.

However, a much easier way to do away with edges is simply to assume that the Universe genuinely is infinite. For what it's worth, that's what my money is on.

Some confusion is caused by the phrase "the observable universe" which has to be finite, and has an edge. However, the observable universe is not a universe at all; it is just a shorthand for "the observable part of the universe".

That was very helpful, NennIng, thanks.