The Farthest Object in the Universe

It's completely mind-boggling the amount of time that has passed since the beginning. Even 1,000,000 years is an immensely long time, but then start measuring it in billions and billions of years... it's insane.

a reply to: PrivateSi

You would be nearer the truth (or what we think it is) to imagine yourself living on a raisin in a cake in an oven. As the cake rises, all the raisins move away from one another. Raisin A moves away from raisin B at a certain speed, while raisin C, which is farther away, moves away somewhat faster. This makes it look to you as if you're at the centre of an accelerating expansion and recession, but it does the same for people living on the other raisins too.

Admittedly the cake has a geometric centre, which the universe lacks... How's your Reimann geometry?

UHhh...Do people realize that the science world does not know for sure if the Big Bang is actualy realy real?

Amazing pictures from hubble though.

a reply to: Jobeycool

The science world doesn't know if ANY of its theories are really real. No theory is 100% confirmed. That doesn't make them invalid though, what is your point exactly?

a reply to: Jobeycool

UHhh...Do people realize that the science world does not know for sure if the Big Bang is actualy realy real?

UHhh... No. Care to explain why this is so?

Keep in mind that the Universe is 13.82 billion years old.

Do we have concrete proofs that time has always been the same since the "start" ?
What if what we call a second was during 2 seconds some eons ago ?
What referential are they using to date all cosmics events ?

a reply to: thefedge

Have you heard of the Cosmological Principle? It's the idea that you take any slice of the universe and it should look and behave relatively like any other slice of the universe. The idea that time has always worked at the same rate could be considered an extension to that. There is no proof showing that time has functioned at any other rate so there is no reason to assume it has changed.

a reply to: Krazysh0t

The proof for the time not to have been always homogeneous is the big bang, no ?
It's like science bases its theories on a frame,although it knows that the frame has to be exceeded in order to give a full view ?
Sorry if i'm being unclear.

a reply to: thefedge

Do we have concrete proofs that time has always been the same since the "start"?

We do not. On the contrary, thanks to the late Professor Einstein, we have concrete proof that time moves at different speeds relative to different observers.

However (also thanks to the good professor), we know that the speed of light has always been the same as it is now.

We can estimate the size of the universe using various techniques. When we do this, we find the most distant visible objects are about 13.8bn light-years from us. Since light always travels at the same speed, this means the universe is 13.8bn years old. It's pretty simple, really.

a reply to: Astyanax

Just a note to thank-you Astyanax for using easy to visualize examples for explaining complex processes and things. I used to love Carl Sagan and his COSMOS series for the same reason.

What's interesting to me is that the scientists commenting on this "young" galaxy speak of things that are going to happen to it as it matures/ages. Since the light from this galaxy took so long to reach us, is it possible that all of these things have already happened and that this galaxy has "died" already? (I don't know if whole galaxies die, but I always have a hard time with words when attempting to wrap my mind around cosmic incredibleness.)
-cwm

a reply to: carewemust

Since the light from this galaxy took so long to reach us, is it possible that all of these things have already happened and that this galaxy has "died" already?

I don't know how or if galaxies die either, but it must certainly have gone through many changes in 13bn years.

By the way, your question implies that true simultaneity is possible over cosmic distances. It isn't -- Einstein put an end to that too, when he abolished absolute time. With the special exception of observers in the same inertial frame of reference, one's present is always the other's past or future, depending on which observer the light from an event reaches first.

a reply to: thefedge

Well there is still an overall assumption that time has remained constant since the Big Bang. The reason I brought up the cosmological principle is because it applies the Null Hypothesis to the idea that we don't SEE anything that would cause time to have been at a different rate previously in the universe, so there is no reason to believe it is so.

Guys, there is no universal, absolute time. Time flows at a different rate depending on local gravity and how fast you're travelling with respect to something.

Imagine that you live on a hypothetical planet very close to a black hole (like that planet in Interstellar), and that both you and the black hole existed from the beginning of the universe. Because of the very strong gravitational time dilation, your time flows extremely slowly, and the universe will appear to be much younger than for an equivalent observer far away from any strong source of gravity.

a reply to: Krazysh0t



I don't really know what to say about this. I could go on a rant...but it's too hot.

a reply to: MarioOnTheFly

Rant? Why would you rant about new scientific discoveries?

a reply to: Krazysh0t

The freakon thing is 20 pixels(give or take a few pixels) how can they know what it is?

Nevermind how far it is, when it was formed, etc.

Also, Didn't they recently say the Big bang didn't actually happen? how are we still measuring things "since the big bang" when it was dis-proven?

originally posted by: PsychoEmperor
a reply to: Krazysh0t

The freakon thing is 20 pixels(give or take a few pixels) how can they know what it is?

Nevermind how far it is, when it was formed, etc.

Are you being facetious, or do you really not know about things like red shift, gravitational lensing, and luminosity?

Also, Didn't they recently say the Big bang didn't actually happen? how are we still measuring things "since the big bang" when it was dis-proven?

No they didn't say that. They said that the singularity may not have existed, but they said the Big Bang definitely happened.

originally posted by: Krazysh0t


Are you being facetious, or do you really not know about things like red shift, gravitational lensing, and luminosity?

Which one of those makes me seem smarter? I pick luminosity, that's what I'm being...

originally posted by: Krazysh0t

No they didn't say that. They said that the singularity may not have existed, but they said the Big Bang definitely happened.

So... what banged?

originally posted by: carewemust
a reply to: Astyanax
What's interesting to me is that the scientists commenting on this "young" galaxy speak of things that are going to happen to it as it matures/ages. Since the light from this galaxy took so long to reach us, is it possible that all of these things have already happened and that this galaxy has "died" already? (I don't know if whole galaxies die, but I always have a hard time with words when attempting to wrap my mind around cosmic incredibleness.)
-cwm

Yes, it is possible. It's a pretty small galaxy really, so it likely either wouldn't have a long lifespan or it would get swallowed up by a larger galaxy with a stronger gravitational pull. Also, it is almost certain that this has already happened. While studying this galaxy, it is like viewing a window into the past. And this particular point in the past is VERY close to when the Big Bang happened, so there is a whole universe of events that have happened between then and now.

originally posted by: PsychoEmperor
Which one of those makes me seem smarter? I pick luminosity, that's what I'm being...

Redshift

Some redshifts are an example of the Doppler effect, familiar in the change in the apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer. Another kind of redshift is cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth. Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields. Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field. However, redshift is a more common term and sometimes blueshift is referred to as negative redshift.

This galaxy's redshift z value is 10.7 by the way. The greater the redshift, the further away from us it is.

Gravitational lens

A gravitational lens refers to a distribution of matter (such as a cluster of galaxies) between a distant source and an observer, that is capable of bending the light from the source, as it travels towards the observer. This effect is known as gravitational lensing and is one of the predictions of Albert Einstein's general theory of relativity.[1]

Luminosity

In astronomy, luminosity is the total amount of energy emitted by a star, galaxy, or other astronomical object per unit time.[1] It is related to the brightness, which is the luminosity of an object in a given spectral region.[1]

Astronomers use these things and more to identify those small blips in the telescope. It may look like a red blob of pixels to you, but that doesn't give you carte blanche to dismiss the claims of scientists who have been trained to detect these things. Instead of pretending you know better than scientists, how about actually researching the topic to see how they go about identifying that mass of pixels as a galaxy?

originally posted by: Krazysh0t

So... what banged?

Dunno. Some scientists think the Singularity still exists, and some don't. Either way, no one knows for sure. The closest we can see back to the Big Bang is the Cosmic Neutrino Background which can take us back to when the universe was just a few seconds old, but even THAT isn't far back enough to see what started it all or what existed before or at t=0.