Starship Asterisk*

Today's APOD shows a brilliant and beautifil galaxy 60 million light years away. How do we know it, or indeed any other of these galaxies and far off objects, are still there?

http://apod.nasa.gov/apod/ap070328.html

It's not! It may and probably does still exist but not THERE. Everything is moving. Even if the central mass has violently exploded, 60 million years is probably not enough time for the entire mass to have disintegrated. The galaxy as a whole has moved somewhere else however. Anything beyond that is faith.

JE

nw42jx wrote:Today's APOD shows a brilliant and beautifil galaxy 60 million light years away. How do we know it, or indeed any other of these galaxies and far off objects, are still there?

Actually I would guess that it's not at the location we see it at... It's moved considerably in the last 60 million years so by now it could be at a neighbors house sipping coffee for all we know...

Which makes me ask the question: What does the universe actually look like right at this second? All those far off galaxies and stuff are not anywhere near where we see them because they've been moving for millions and billions of years...and how if a galaxy shed light 13 billion years ago is it now just getting to us? I mean shouldn't it have passed us by a long time ago because we're moving so slow compared to the speed of light because 13 billion years ago we were much closer to it than we are now because the universe is expanding right? Trying to wrap my brain around this gives me a headache...now I need some coffee...

I love discussions on this subject.

Your question is pretty simple to answer but not an easy concept. At this very second the Universe LOOKS exactly like it appears to us in these pictures and with our own eyes. Yet it looks completely different to whatever intelligent life may be living in that 60Mly away galaxy. But you did ask about LOOKS.

If faster than light (FTL) travel were possible for us right now, then the question of how to map the Universe would be more important... because we'd have to know how to navigate and avoid the hazards. We could build a map by inferrence (by using the historically observed distance and movement we do know about) where objects should be... probably. There's still a lot we just don't know or are flat wrong about... I wouldn't want to completely trust it!

As for your 13 Billion question, I think you are a little mixed up about what an expanding universe and relativity really means. It really is difficult sometimes for us to wrap our finite minds around the infinite!

What does the universe actually look like right at this second?

Freebird stated one continuance to your question, here's another:

Are you asking, if one could be omnipresent (all places at all times) what would the universe look like at this exact time?

That's an easy one. It'd look like just what your omnipresent being wanted it to look like.

-Noel

As far as a grand scale goes; I believe that the galactic clusters and superclusters, when viewed from afar, resemble neurons in a vast brain.
http://www.psc.edu/science/2006/blackho ... pdated.jpg in this graphic, noting the approx locations of superclusters of galaxies an of some known larger galaxies (suspected black holes circled)

This animated GIF file shows the suspected early universe as it cools and forms larger scale structures http://www.psc.edu/science/2006/blackho ... s/anim.gif note that near the end it does indeed resemble brain cells.

This is similar to the image I was originally looking for
http://www.space.com/php/multimedia/ima ... 2C+Ontario

Dr. Skeptic wrote:Are you asking, if one could be omnipresent (all places at all times) what would the universe look like at this exact time?

Yes. I mean that a galaxy we see 5 billion light years away obviously has moved. So where is everything right this second...those things are not where we see them obviously so where are they and what does the overall picture of the universe look like right now?

It's like if I wanted to show my friends in California a picture of a street in New York, so I take a picture of it. By the time I walk down the block the positions of the cars and people have changed so my picture is no longer accurate. But if I walked to California with that picture and showed my friends it would not even be close to an accurate representation of what cars and people are on the street and their locations. I'd have to know the speed and direction of every car and person to know where they are now plus there would be no way of knowing what cars and people were just around the corner coming into the scene so I would have no way of portraying an accurate image.

My head is starting to hurt again...

The simple answer is that in a relativistic universe you simply CANNOT know where something "really is". Nothing travels faster than the speed of light. Another way of looking at it is that in every way that could possibly matter it is right where you see it.

If our sun were to pop out of existence, it would be roughly 8 minutes before we would know it. Until that time we would continue to receive light and warmth and orbit it as though it was still there.

I have always found it very interesting that our imagination can travel faster than the speed of light.

-Noel

Nothing travels faster than the speed of light

How about the properties of entangled photons?

When I spot some of those photons I'll let you know, Dr. Skeptic.

Actually, I'm being overly simplistic in my explanation. I really only know an overview of the Theory of Relativity, and even with what little I know it seems to me that theory allows for space-time warp (e.g., in a black hole). But we've had endless discussions of black holes here, and it's clear no one really KNOWS what it's really like out there, so I didn't want to muddy the water.

-Noel

I love discussions on entanglement.

Entanglement is a fact, the new record is 93 kilometer of separation. For those that don't know what "Entanglement" is, it is a way of creating reversed polarized pairs or reverse spin photons that if one photon is acted on the other of the entangled pair will respond instantaneously (via unseen dimensions?) regardless of the distance of separation, complete information of the quantum state of each photon is instantaneously transferred by the "sender", who is called Alice, to a "receiver" called Bob.

For amusement purposes, lets say there is a target 1 light year away that is known to absorb photons, 1 light year in the opposite direction there is a entangled photon detector. As soon as the entangled photons, Alice, reached the target, the other half of the entangled pair, Bob, would be reaching the detector creating instantaneous sensing of the photon absorption 2 light years away, in other words, information traveling faster than the speed of light.

Application:

Imagine a super massive star 20 light years away that has a high probability of going hyper-nova. An entanglement source is place 10 light years out directly between the solar system and the star, if/when the star goes hyper-nova, the detector could give 20 years of advanced warning before a visual warning could take place.


http://en.wikipedia.org/wiki/Photon_entanglement

Have you or someone thought of a way entangled photons can be used to transmit information?

Whatever the nature of the connection between entangled particles may be, nearly all physicists agree that it cannot be used to transmit messages faster than the speed of light. All it can do is assure that a random choice by one entangled particle is instantly echoed by its distant partner. This is not the same thing as transmitting information, the experts say, and therefore it does not violate relativity theory.

The above is from this somewhat older article: http://www.cebaf.gov/news/internet/1997/spooky.html

-Noel

Hawkgirl,

Nice analogy ! It carries the details well.

OK, so everything is moving, and it's not where we see it in our present time.
The further away the larger the error a-la intrinsic vectors.

That's just how the universe is. If gravity travels at the speed of light, then our locale won't be sensing influences inexplicable from the visible.

Try this mind-wrap, all speed of light events are not a 'speed'. They simply propagate at the 'Ratio of Space to Time'. The reason it takes light one year to get that far is because we see it when it happened, for It; but as It is a light year away, we see It one year ago from when it happened for It, but for us it is in real time. In this way we see it when it happened for It, but one year later. Unlike watching a man chopping wood across a small valley. The ax splits the wood, he bends to pick up another piece of wood and we then hear the sound of the wood splitting. Light speed events arrive all together and we receive a complete picture in all (sol)spectrums of the event when it happened.

Thinking of light traveling at the 'ratio of space to time' simplifies the subjective nature of perception, and removes the inclination to compete with nature and try and go faster. It also makes the Theory of Relativity more accessible in conceptualization, for me anyway.

To go another step, if gravity is a faster than light speed event, and there is some considerable thought that it must be so; then like the woodchopper, light would be like sound, and gravity like light. The search is on for a clear simple demonstration of this.

As we look further away, we see things equally back in time. It must be this way, because Space-Time is constructed in this fashion, and its qualities operate under those parameters.

So sad, I wanted to go to the Pillars of Creation for this summer's vacation.

ps. I have a photograph of NYC and the WTC is standing there in all its glory, but by the time the photographer walked to LA it's today and NYC is not the same. Same for M87, or SN1987a.
Def Leopard's 'Photograph' will never sound the same!

NoelC wrote:Have you or someone thought of a way entangled photons can be used to transmit information?

Whatever the nature of the connection between entangled particles may be, nearly all physicists agree that it cannot be used to transmit messages faster than the speed of light. All it can do is assure that a random choice by one entangled particle is instantly echoed by its distant partner. This is not the same thing as transmitting information, the experts say, and therefore it does not violate relativity theory.

The above is from this somewhat older article: http://www.cebaf.gov/news/internet/1997/spooky.html

-Noel

Quantum computing.

http://qubit.nist.gov/

Hello All

BMaone23 said

As far as a grand scale goes; I believe that the galactic clusters and superclusters, when viewed from afar, resemble neurons in a vast brain.
http://www.psc.edu/science/2006/blackho ... pdated.jpg in this graphic, noting the approx locations of superclusters of galaxies an of some known larger galaxies (suspected black holes circled)

This animated GIF file shows the suspected early universe as it cools and forms larger scale structures http://www.psc.edu/science/2006/blackho ... s/anim.gif note that near the end it does indeed resemble brain cells.

Very nice images.

People add Early Universe by assuming early universe without reason.

http://thunderbolts.info/tpod/2006/arch ... cience.htm

I guess I should have said "Earlier Universe" so I sit corrected.

But I don't think that we can use the argument that an ancient or steady state universe model would necessarily require it be a brighter universe. The argument "Where is all that light?" doesn't hold water in either model. If it did, then we would be able to detect and measure the expansion of light in the present visible universe. If Light were to be able to fill the void and brighten it, it would be doing so and be measurably growing brighter now. But light can not be seen directly. Only its source and reflection can be detected.
If you go to the dark side of the moon while it is on the far side, the only visible light would be star light. Once your eyes were allowed to adjust to the darkness you would see that you could see the landscape from the reflected starlight. That is because the photons are everywhere, light is everywhere right now, it just needs something to reflect it to show its presence if the source isn't local.

Hello BMAONE23

Read this link, not that I agree with it.

RUFUS'S GALAXY WEB PAGE
The Steady State Galaxy Theory
An Alternative To
The Big Bang Theory
http://www.galaxytheory.com/#SHA

I disagree with many parts, but it is a better option than the BiG Bang theory with all its ad hoc ideas.

If you get a chance read Prof Neil Turok, CambridgeUniversity, science journal on recyclic universe.

In thinking this morning about your posting,

<<Which makes me ask the question: What does the universe actually look like right at this second? All those far off galaxies and stuff are not anywhere near where we see them because they've been moving for millions and billions of years. . .Yes. I mean that a galaxy we see 5 billion light years away obviously has moved. So where is everything right this second...those things are not where we see them obviously so where are they and what does the overall picture of the universe look like right now?>>

Ahh, the pureness of Idealism, unmuddied by the compromises which Space-Time imposes upon perceptions. Are you looking for instantaneous star charts, updated in realtime, with calculated vector analysis of personal intrinsics vs external intrinsics to show interception/collision-avoidance/arrival possibilities for navigational purposes, and, a need-to-know desirability arising from the curiosity of 'how does everything fit together in this universe'. I too would like to know where everything is. One solution in a psychological sense is to 'surrender' to allowing everything to be where it is and be warmly OK with things as they are, and trust like Dr Pangloss, that all will be well in this best of all possible worlds. This allows the freedom to do things, without worrying about things which are beyond my lifetime possibility of interacting with, or, over which I have no influence. Part of me wants to reach very far, much beyond the pragmatic sphere of influence I actually have. Thus is the 'human condition'. As I move thru this world and discover 'my power' (a-la Carlos Casteneda and the 'Don Juan' series of books) and how that relates to reality, a confidence and acceptance builds with discovery, that reaches from the inner mind to the outer limits.
The next step is, through surrender, the intelligence which pervades the universe can be listened to and heard and conversed with. Where else do those inspirations of great depth come from out of the blue?

It must have been another poster, Hawkgirl, who was asking about 'How can we measure motion', is there something against which we can make an absolute reference to measure motion or acceleration. The universe answered yes, the border of our awareable universe; but the next response was to use what that 'border' manifests, Inertia ! If a gyroscope of sorts was made and connected with a computer memory to track its path on a galactic GPS for example, then by 'history' one would have a reference base to construct a 'baseline' for future reference.
Inertia is oriented to the shell of our awareable universe, as a Foucault Pendulum does its best to remain undisturbed in its relationship with that 'sphere'. Using Inertia/Momentum as the 'anchor' in the sea of space-time will create the universal reference grid to plot absolute motion against for all components within the system of perception.

A further thought was, we need more women in science. Your 'whole brain' approach to subjects is needed more than ever. One Googleing session discovered Amara Graps' website, she got involved in Helioseismology and participated in that effort some years ago. Next she was working on 'wavelets', which is a 'hologramatic approach' to problem solving. As each small element in a hologram contains a complete dataset of the entire hologram, beit a small scale representation of the whole, a wavelet likewise contains a dataset for the entire largescale structure. The widespread applications for wavelets is astounding.
Instead of getting caught up in fighting in the trenches of BBT vs Dobsonian Cosmology or the Standard Solar Model (SSM) vs the Electric Sun Model (ESM) for example, she went further and worked on leading edge investigations which would look directly into the heart of the matter, whatever that would turn out to be. Last I checked I do not know what she is doing now, besides teaching at the American University in Rome. She is someone I would do well to emulate.

kovil wrote:Hawkgirl,

Nice analogy ! It carries the details well.

OK, so everything is moving, and it's not where we see it in our present time.
The further away the larger the error a-la intrinsic vectors.

That's just how the universe is. If gravity travels at the speed of light, then our locale won't be sensing influences inexplicable from the visible.

Try this mind-wrap, all speed of light events are not a 'speed'. They simply propagate at the 'Ratio of Space to Time'. The reason it takes light one year to get that far is because we see it when it happened, for It; but as It is a light year away, we see It one year ago from when it happened for It, but for us it is in real time. In this way we see it when it happened for It, but one year later. Unlike watching a man chopping wood across a small valley. The ax splits the wood, he bends to pick up another piece of wood and we then hear the sound of the wood splitting. Light speed events arrive all together and we receive a complete picture in all (sol)spectrums of the event when it happened.

Thinking of light traveling at the 'ratio of space to time' simplifies the subjective nature of perception, and removes the inclination to compete with nature and try and go faster. It also makes the Theory of Relativity more accessible in conceptualization, for me anyway.

To go another step, if gravity is a faster than light speed event, and there is some considerable thought that it must be so; then like the woodchopper, light would be like sound, and gravity like light. The search is on for a clear simple demonstration of this.

As we look further away, we see things equally back in time. It must be this way, because Space-Time is constructed in this fashion, and its qualities operate under those parameters.

So sad, I wanted to go to the Pillars of Creation for this summer's vacation.

ps. I have a photograph of NYC and the WTC is standing there in all its glory, but by the time the photographer walked to LA it's today and NYC is not the same. Same for M87, or SN1987a.
Def Leopard's 'Photograph' will never sound the same!

Two questions.

1. Has gravity a speed or is it instantaneous?

2. One way or another, if gravity is faster than light, will the Universe still have the remains of light "flying around" after the mythical Biblical "end of Time", when gravity "stops" & slowcoach light is not told about it? I suspect two answers are popular:- a/Who cares? b/Pray you miserable sinner. Is there a rational answer?I mean if Time stops everything stops? The other seven dimensions, or is it seventeen, can't help us?

Third question (sorry about that)

3. If the end of time is not instantaneous everywhere, but starts "at the other end" of infinity will the Milky Way galaxy continue to exist when half the universe is gone?

Hawkgirl wrote:

nw42jx wrote:Today's APOD shows a brilliant and beautifil galaxy 60 million light years away. How do we know it, or indeed any other of these galaxies and far off objects, are still there?

Actually I would guess that it's not at the location we see it at... It's moved considerably in the last 60 million years so by now it could be at a neighbors house sipping coffee for all we know...

Which makes me ask the question: What does the universe actually look like right at this second? All those far off galaxies and stuff are not anywhere near where we see them because they've been moving for millions and billions of years...and how if a galaxy shed light 13 billion years ago is it now just getting to us? I mean shouldn't it have passed us by a long time ago because we're moving so slow compared to the speed of light because 13 billion years ago we were much closer to it than we are now because the universe is expanding right? Trying to wrap my brain around this gives me a headache...now I need some coffee...

As you will see from my post above, I'm pretty simple-minded (perhaps because I don't drink coffee, only tea). But being so, I found this Atlas helpful:-

http://www.anzwers.org/free/universe/index.html

also this about the BBT:-

http://map.gsfc.nasa.gov/m_uni/uni_101bb2.html

And btw if you see harry or Harry of "smile & live another day", run!!!!

he'll get you all tied up with Plasma Cosmology:-

http://en.wikipedia.org/wiki/Plasma_cosmology

Sorry harry, just smile & live another day.

And headaches cured by coffee are a sign of caffeine withdrawal & so of addiction. But there are worse things than coffee, I guess......

Hello toejam

I have been asked to make a 007 movie.

SMILE AND LIVE ANOTHER DAY.

====================================

IF YOU FEEL PAIN IN THE HEAD, RELAX AND HAVE WATER.

======================================

Position of the super galaxies.

I do not know if this link is crank pot or not.
http://astro.uwaterloo.ca/~mjhudson/research/threed/

There are some good questions on this thread , some good answers , and some not so good answers

First, as has already been noted, what you regard as simultaneous may not be what someone else, somewhere else, regards as simultaneous. That's one of the counter-intuitive results from (special) relativity.

And as simultaneity is inextricably tied to most of the good questions in this thread, the answer to them is "it depends on where you are and when you are ... and each observer will give perfectly valid, but different, answers".

Next, the speed of gravity hasn't been experimentally measured, as far as I know.

However, the theory of (general) relativity (GR) has been tested, and has passed every test so far, with flying colours. In GR, the speed of gravity is c, so as GR has passed every test (so far), the "speed of gravity is c" is certainly fully consistent with all experimental and observational results to date.

Then there's entangled photons. As was noted, entangled photons do not create an inconsistency with SR, as there is no transfer of information.

On philosophy, one of the nice things about good theories in physics is that you are free to choose any interpretation (mind picture) you wish ... just so long as there is no experimental difference (even in principle). One mind-bending example: with the appropriate care, you can imagine the universe to be contracting, not expanding.

On alternatives: a good many astronomers would love to have a decent alternative to the concordance model of cosmology (a.k.a. the big bang theory), but, sadly, none of ones what you will find in the many websites purporting to be such pass even the most simple of (observational) tests.

I've split posts from this thread that are waaay off-topic, into another thread, in the Asterisk Cafe: Discussion of alternatives to concordance cosmology.