NowThatWeKnow

How many thanks do you have to spread around in order to give thanks to the same person again? Is there also a time limit to say thanks twice to the same person. Some people devote a lot of time and energy to helping people with qualified answers but a month later I still can not say thanks again (Martin comes to mind here). So, what are the rules?

I am interested but do not feel qualified to add much substance to what you are saying. Wikipedia describes the event horizon and what happens as you approach it. http://en.wikipedia.org/wiki/Black_hole#Event_horizon It does seem to indicate an object falling into it finally does disappear by red shifting past a certain point. Other articles in Wiki describe falling into a black hole and you finally are ripped apart and become a part of the singularity. The time dilation that freezes an object at the event horizon does finally give up the image it seems.

Sometimes his wording does leave his thoughts open to different interpretations but I think you are pretty close. However, if we could have a synchronized clocks at any two locations, wouldn't that show we can be sharing the same present or "now"?

To look out in space from earth set it up by putting in .27, .73, and 71 as the present matter and DE densities, and the Hubble rate. Try out different z #'s up to z = 1000

A quick peek for those that do not want to try it for themselves.

I understand the speed of light is constant in a vacuum and flat space.

I can not think of anything that could not be used as a "clock", even if the rate of decay is used to measure time. I would also use caution when comparing absolute and universal time to each other.

Have you read the thread "is spacetime absolute?" where Martin and I discussed universal time? http://www.scienceforums.net/forum/showthread.php?t=40033 With today's technology universal time, not to be confused with absolute time that does not exist, is in most cases an abstract thought experiment at best. What martin suggested is a universal time using a clock at rest with the CMB and in the absence of gravity. Any location could then adjust their clock for movement and gravity to have a synchronized clock with universal time. It would move at a different rate then local time clocks but that is ok. You would still have two locations or frames that had synchronized clocks and could share the same "now". Because of continous movement in the cosmos, you would almost need an automatic gravity meter and CMB speedometer attached to an atomic clock for it to work. Maybe someday in the future this will be possible. Today's technology has allowed us to adjust the clocks on the GPS satilites for SR and GR so we can have a universal "now" in different frames. Merged post follows: Consecutive posts merged

What is "ftl"? Just because something can not be measured does not mean it doesn't exist.

Thanks Mr. Skeptic. I like your pun and other ways of saying things. Stuff moving on a computer screen has become a way of life, even though I am not crazy about it. So maybe I shouldn't contribute.

Your first post in this thread said "I think you need to specify what the set up is." and "2) Light always travels at the same rate, C, in every direction relative to the observer, no matter what the relative velocity of the source to the observer." so I crawled into that can of worms when you opened it. The original post said: Not sure what the "circular wave" in "water" has to do with the "shape of a light flash" or part b). Other then that, I agree with you.

you make a good point. I wonder if those that have seen it for awhile have just gotten used to it. It was distracting to me at first but not any more. Ants do not live forever and my eyes are open for a replacement. One more negative and I will look for the bug spray now.

I added one to make my point more obvious. I see the entire universe as a variable gravity frame that does have an impact on light. In most cases the effect the would be small, especially over short distances.

If you could isolate a brief segment of the Sun's light as it left the Sun, it would seem almost symmetrical, for awhile. If you followed that brief segment (in real time) until it reached the outer limits of the milky Way on one side and the huge black hole at the center on the other, it would be far from symmetrical. When light enters a high gravity area, an outside observer will see the light slow down. I look at it as space is curved and the light has further to go to cover the same distance. if you are in the same frame with the light, your clock slows down so the light speed is still constant. If my layman vision of relativity is wrong, please straighten me out. I am here to learn. Edit - Another way to put it is that if time slows down when you approach a black hole, the speed of light must slow down to maintain 186,000 miles per second.

Are you saying the light would NOT be influenced by gravity?

My question is, are you talking about the actual shape of the light as if you could see it in real time? Or as it would be seen by your eyes using only the light that did reach you and when it reached you? I thought the speed of light is constant, but only relative to the frame it is in. Since the only light you can see is what reaches your eyes, it is in your frame and the speed will be constant. The actual shape would be distorted by gravity and other things.

I see it as looking at light that took 13+ billion years to get here and seeing a new born. Merged post follows: Consecutive posts merged Don't forget about the expansion of space. Light that took 13 billion years to get here was emitted from a galaxy when it was 3.3465 billion light years away and is now 29.701 billion light years away.

Moderators, I hope you will let this run for a short while here since many of my post are here. Thanks I received a PM from a new member (I will not name) and he said: --------- "Hello, I find you avatar to be annoying. It bothers me. It makes me sick. Could you change it for something really positive, please? I need positive emotions, not irritation. Thanks." --------- I do not want to make anyone sick or annoyed. I thought it was funny and now I am just used to it and my post are easy to find. Is it time to step on the ant?

I am having trouble setting up a new poll. I check the poll box at the bottom but it doesn't do anything. Edit - Never mind, I figured it out.

When I plug in 7.875 I get exactly 13 billion light years old and 29.7 billion light years away from us now. z=8.2 gives me 13.035 billion years old. I see the problem though, I read a different article that rounded the #'s. Merged post follows: Consecutive posts merged I found it. It was a combination of my imagination and that darn "Where Does Space End? It Must End Somewhere!" thread. My version of a non mainstream view. Glad I got that out of my head.

I got z=7.875. Where am I going wrong? (Edit - Ignore this line because it is from a different source) Another thing I do not understand is the article said " Distortions in the light signature of the object show it is 13 billion years old -- at the speed of light, 13 billion light-years away" (Edit - From a different article then posted) It can't be both because of the expansion of space but it is obvious they are saying it is 13 billion years old NOW. That would make it .665 billion years old at the age of redshift. The Ned Wright site also says it would have been 3.3465 Gly away when the light was omitted and is currently 29.7billion light years away. My question is, if the universe was only .665 billion light years old when this GRB was omitted, is that long enough for a star to have formed, matured and then exploded? If I am missing something here just tell me to get more sleep. Merged post follows: Consecutive posts merged I may be wrong but I thought a thick skinned sphere was one possibility. Not sure where that thought came from at the moment. My imagination is fairly active. Merged post follows: Consecutive posts merged You beat me to it.

if the universe ends up being a 3-D sphere, couldn't it have a center?

Time is bound to space so we do not have to deal with an extra dimension. The math works out well. Time, like the speed of light, is constant. But only relative to its current location or frame that it is in. Bent space, because of gravity, will change the duration of one second relative to another frame. Your speed relative to other matter will also change the length of time segments.

Would that "something" be a God?

Walking into my home without knocking.