The End of Cosmology

[Tormod]

Scientific American has taken it all-out and headlined this on their March issue frontpage:

 

The End of Cosmology?

An accelerating universe wipes out traces of its own origins

 

Full article available online:

The End of Cosmology?: Scientific American

 

I am going to read through it but I have to admit I was a bit surprised when I read the headline. If anything, if cosmology wipes itself out then my guess it is would be instantly recreated...because what is cosmology but the search for origins and a philosophical understanding of our relationship to the universe? I don't see that ending any time soon.

 

Thoughts?

[Essay]

I think they're just saying that any evidence (that a civilization might use to deduce a cosmology) will be unavailable in the distant future.

:hihi:

 

Think how lucky we are now!

:)

[Tormod]

Yeah see that was my point. Cosmology isn't dependent on evidence IMHO. Only when it's coupled with astronomy and made into a science does it require scientific evidence. Cosmology has been around for a long time without needing any evidence apart from the observed movement of the sun, the moon, the planets etc... :hihi:

[Essay]

Well okay, yes, I guess folk cosmologies could still proliferate; I was just thinking of science based cosmologies. I read the article over a month ago, so I'm just going on vague feelings here.

:hihi:

[CraigD]

I’ve gotten a couple of issues behind in my SciAm reading (which I credit partly to the crappiness of my handheld viewer, which takes so long to render/”turn” a pdf file page that I can get distracted and do something else :(), so hadn’t read this 3/2008 article until hearing about it in this thread.

 

It’s the kind of science article its most recognizable author, Lawrence Krause of “The Physics of Star Trek” fame is famed for: conventional science put into popular terms to explain a sound but startling, and not widely discussed, scientific idea. Krause, a real career astrophysicist, is a “rock star” among popular science writers, and with the collaborators and whatever publishing support folk his fame puts at his disposal, puts together a SciAm article as beautiful as any – the “night sky of Earth zero, 5 billion, 100 billion, and 10 trillion years from now” art alone is spectacular, poster-worthy stuff. :)

 

What the article is getting at with its provocative yet scientifically sound and well-explained title is that if, as present best models suggest, the rate of the metric expansion of the universe continues to increase, the amount of information available in any volume of it will steadily decrease. In astronomy terms, this decrease will result in fewer distant galaxies being visible to present-day, or even advanced future telescopes, as increasing numbers of them come to lie outside of an expansion-defined event horizon – though nearby, gravitationally-bound galaxies will move closer together, forming eventually a globular “supergalaxies” of the only practically visible stars to observers within them. Models predict this will occur much faster than the exhaustion of light element “star fuel” results in the end of the stelliferous era, so in about 100 billion years – about 8 times the current age of the univers - stars and physics will be pretty similar to how they are now, but their arrangement in space and the observable sky dramatically different.

 

It’s important to note that this “expansion event horizon” is “soft” compared to others, such the gravitational event horizons associated with black holes. Light from distant galaxies isn’t prevented from crossing it, but redshifted so greatly it’s not practically observable, ultimately to a point where its wavelength is greater than the event horizon, and fundamental physics dictates that the probability of a photon of such light interacting with anything is negligible, and any such detections almost certainly lost in the “noise” of nearby stars (though I can think of a few interesting observatory designs for such an era). As Krause and Scherrer note, astronomy won’t quite be impossible – it will be possible, for example, to use chains of spacecraft to extend the practical radius of observation far beyond the event horizon – but it will be much more difficult than it is now. A newly emerged intelligence like our own, coming to have technology like ours, might be unable to scientifically conclude that anything lies beyond their local supergalaxy.

 

Of course, all these predictions of far future events depends on our present-day theories and models being correct and complete in enough significant details, so may turn out to be dramatically wrong. But you can only scientifically predict with the science you know, and I think Krause, Scherrer, and other proponents of these predictions do a good job of it. My major criticism of this article is that, uncharacteristically for Krause, it sometimes skimps on numbers. For example, nowhere in it do they provide even a rough estimate of the number of stars in the theorized 100-billion-years-from now supergalaxy.

[HydrogenBond]

There are some conceptual problems with the acceleration expansion of the universe. First, the data we receive from far distances is not real time data, but historical data. This implies if an object is billions of light years away, and we receive its signal today, all we can say is billions of years ago this object was accelerating. It tells us nothing of today, since the signal of what is happening today, will take billions of years to reach us. If it pulled a u-turn 1 billion years ago, we can't know this from the historical data, since this data is too old to tell us anything about it more recent history. It is ancient history data of a time long past.

 

One of the models to describe the expansion of universe, compares the space-time expansion to an expanding bubble or foam where everything is expanding relative to each other. If we assume this is true than the closet data should be the same as the more distant data. While the closest data should be the closest to us in real time, i.e., less historical. The question is, does the closest data show the same level expansion-acceleration? The closet galaxies are actually blue shifted or contracting toward us. This data is less historical, so based on the bubble expansion relative to galaxies, it should be closer to the real time nature of the universe, and less biased by ancient history of or what had been.

 

Let me give an analogy. We have three astronauts each with a watch that are all set at the same time. We also have a fourth watch which we will leave on the earth at mission control. We give them each the same project which is to build a shelter that will take one month. The first astronaut we place on the moon, the second on Mars and the third on one of Jupiter's moons. Each astronaut sets up a camera to show their progress. At exactly the same time on their watches, JAN 1, 2056 at 12 noon, they all begin their projects. Because of the time delay of the video signal, the person on the moon will appear to start first and the person on one of Jupiter's moon will appear to start last.

 

We know they are all in synch because they are all wearing the same hi-tech watch which has been certified to keep perfect time. But the time delay in the video signal is creating the illusion their watches are off. The uniform expansion of space-time assures all the watches are the same. Our best bet to assure we are observing the real time and not historical progress due to signal time delay, is to focus ourself on the astronaut on the moon, since his progress is closest what they are all doing in synch time.

[Mike C]

To All

 

Maybe what that article means is an 'end' to Cosmogony (BBT) rather than cosmology.

 

The cosmology is protected by the 'Laws of Conservation' like the SSU. So it cannot end.

 

The BBT does not comply and so it is not protected. Ha ha.

 

Mike C

[CraigD]

There are some conceptual problems with the acceleration expansion of the universe. First, the data we receive from far distances is not real time data, but historical data. This implies if an object is billions of light years away, and we receive its signal today, all we can say is billions of years ago this object was accelerating.

No simple bolometric or spectroscopic data can directly reveal that an object is accelerating, only the radial component of its velocity. Hence Hubble's law makes no statement about a relationship between distance and acceleration, only between distance and velocity.

 

It’s also critical to note that

• The metric expansion of space does not involve a classical acceleration, ie: [math]\frac{\Delta v}{\Delta t} = \frac{F}{m}[/math]. No force is involved.
  
• The measured “cosmological” redshift supporting these “de Sitter-like” models is not classical or relativity-adjusted Doppler effect due to the relative velocity of the sending and receiving bodies, but due to the “lengthening” of space. This substantially, but not incalculably, complicates its description
  

Both the simple signal time HydrogenBond mentions, and these more complicated factors, are included in theoretical models of the universe. These models are complicated, but mathematically rigorous, not reliant on intuitive satisfaction.

 

As has been noted in many threads, claims like the following

It tells us nothing of today, since the signal of what is happening today will take billions of years to reach us.

strongly contradict the relativity of simultaneity, a essential concept of modern physics. The concept that spatially separate events absolutely do or do not happen at the same time or on a particular order, though intuitively appealing, is ultimately meaningless and unhelpful.

The closet galaxies are actually blue shifted or contracting toward us. This data is less historical, so based on the bubble expansion relative to galaxies, it should be closer to the real time nature of the universe, and less biased by ancient history of or what had been.

As the article that started this thread describes, nearby galaxies are blue shifted because they are gravitationally bound, tending over billions of years to grow closer together until an entire local supercluster of galaxies becomes a “supergalaxy”, not because data about them is “less historic”. Redshift observation clusters of galaxies so distant that the light we are currently receiving from them was emitted when they were billions of years younger than our galaxy show similar movement. There is no “bias” of these very old images of the universe: other than the population of stars in them containing more metal-poor population II and III stars than our galaxy, the fundamental mechanical nature of physics evidenced by the motion of these distant, ancient galaxy clusters is not much different than our nearby, young cluster.

 

The Krause and Scherrer article does not address skepticism of the widely accepted theory of the metric expansion of space, but rather shows a surprising consequence of it. If you reject mainstream cosmology, the article has, IMHO, very little of interest to offer you – though I still recommend it on the merit of the prettiness of its illustrations (available, unfortunately, only in the sciamdigital.com and print versions).

[LaurieAG]

If anything, if cosmology wipes itself out then my guess it is would be instantly recreated...because what is cosmology but the search for origins and a philosophical understanding of our relationship to the universe? I don't see that ending any time soon.

 

Thoughts?

 

I agree Tormod,

 

The first sentence says it all, in all its truthful glory.

 

One hundred years ago a Scientific American article about the history and large-scale structure of the universe would have been almost completely wrong.

 

Has anybody collected any empirical evidence to verify this factoid and can we just assume that today everything is almost completely right? It would be interesting to see some figures on the relationships of the scientific 'truths' of periods of time 100 years apart and their relative realities.

 

After all, we then might be able to tell if our universe of scientific knowledge is actually expanding, if the limits are being restricted/falsified/countered (contracting) by the 'anti'/fallacious scientific knowledge that we know it contains, or if only large parts of it are disappearing (or are about to dissappear) down their own black hole of localised hubris.

[Thunderbird]

In short, it erases all the signs that a big bang ever occurred. To our distant descendants, the universe will look like a small puddle of stars in an endless, changeless void. What knowledge has the universe already erased?

 

This view goes as far as these event horizons, information is lost to our present observations past these points, however this view is not taking in to account that our point of view will not remain static in space time for the next few billion years.

 

 

One constant in the universe is that information and energy in the universe is constantly evolving and moving though a series events in space time.

 

We can assume from observations of the cyclical nature of energy and information that our view point will also pass though many yet unseen event horizons.

[CraigD]

From “the End of Cosmology?”

• The quickening expansion will eventually pull galaxies apart faster than light, causing them to drop out of view. This process eliminates reference points for measuring expansion and dilutes the distinctive products of the big bang to nothingness. In short, it erases all the signs that a big bang ever occurred.
  
  
• To our distant descendants, the universe will look like a small puddle of stars in an endless, changeless void.
  
  
• What knowledge has the universe already erased?

This view goes as far as these event horizons, information is lost to our present observations past these points, however this view is not taking in to account that our point of view will not remain static in space time for the next few billion years.

While the quoted bullet-point items don’t mention it, the article later states:

Ambitious future observers might also send out probes that escape the supergalaxy and could serve as reference points for detecting a possible cosmic expansion. Whether it would occur to them to do so seems unlikely, but in any event it would take billions of years at the very least for the probe to reach the point where the expansion noticeably affected its velocity, and the probe would need the energy output comparable to that of a star to communicate back to its builders from such a great distance. That the science-funding agencies of the future would support such a shot-in-the-dark is unlikely, at least if our own experience is any guide.

IMHO, the authors are stretching artistic license pretty thin in their guesses about billionth century ([math]10^9[/math]th C) science-funding policies, but can be forgiven this, as the goal of this article is not so much to speculate on future human history as to illuminate an under-discussed consequence of present day cosmological theory.

 

One possible [math]10^9[/math]th C human history, I suspect the most widely believed one among present day humans, is that there won’t be any human history in the billionth century – in short, that no terrestrial life, except possible some low-to-non-intelligent extremophiles, will be present anywhere in the universe. For almost entirely emotional reasons - because it makes me happier to do so, without doing any apparent harm to others or myself - I chose to imagine a different history, in which a cultural, if not a genetic, continuity from our current historic past to this hundred-million times more distant future exists – that in principle, a [math]10^9[/math]th C “human” might use their culture’s equivalent of a library to read this very hypography thread, if their interests so lead them. In short, I believe in the preservation of data, and the end of effective library burnings.

 

In this imagined future [math]10^9[/math]th century, interested humans, having access to effectively many orders of magnitude more telescope data than we [math]10^{1.323871}[/math]th centurians, would know a great deal about the universe at large, even if the observations that built that knowledge were no longer possible. I imagine they’d know a great deal more about physics and cosmology, and about subjects that no human living today can imagine, than any human living today can imagine.

 

It’s quite possible and reasonable, IMHO, that among the greater human knowledge of physics would be improvements on present day theory invalidating the predictions made in a 3/2008 Scientific American article, and the night sky of whatever natural or artificial place a given human called home would look very different than that article’s beautiful illustrations.

 

My beliefs, which I have but can’t prove, label me, I think, an optimist, a trait not incompatable with a naturalistic scientific worldview.

[Mike C]

As an after thought, cosmology cannot end because as long as there are stars and galaxies in the sky, than the science of these observations has to exist.

 

Regarding the observed redshifts, my opinion is that this is a relation between the RS's and the apparent distances implied that would include the angular sizes with the higher RS objects that implies distance.

 

Mike C

[HydrogenBond]

Both the simple signal time HydrogenBond mentions, and these more complicated factors, are included in theoretical models of the universe. These models are complicated, but mathematically rigorous, not reliant on intuitive satisfaction.

 

The question is, can mathematically rigorous proof support illusions? Math is a faithful horse that we can lead anywhere ever we wish. We start with a goal in mind and then find math proof.

 

Let me give an example. Say we assume that gravity is due to the repulsion of matter by space. This is erroneous, but if we assume this to be true, one could come up with sort of the reverse math of what we currently use to express gravity. The math will allow us to create the illusion this assumption is correct because the math works out using this assumption and it can be used to make predictions. Do we assume our assumption is true simply because the math appears to say so? In physics the answer appears to be yes, allowing mutually exclusive options. Common sense is not so generous, it would say, we need to test the theory to make sure this is real and not just a math illusion, even if math alone is sufficient for many.

 

As has been noted in many threads, claims like the following

Quote: Originally Posted by HydrogenBond

It tells us nothing of today, since the signal of what is happening today will take billions of years to reach us. strongly contradict the relativity of simultaneity, a essential concept of modern physics. The concept that spatially separate events absolutely do or do not happen at the same time or on a particular order, though intuitively appealing, is ultimately meaningless and unhelpful.

 

If the theory of simultaneity is correct let us test it to make sure it is not just an math illusion. It should be impossible to coordinate all the watches in the example I gave, placing astronauts on the moon, mars and one of the moons of jupiter doing the same task at the same time. Even if the watches change slightly, when we bring them back to earth, that little change will not be anywhere near the time delay we will experience due to the transmission of signals over those distances. Light speed is the same independent of reference. So we are off by less than 1%. The observable universe is still ancient history. The data says long-long ago it was accelerating-expanding quickly. But long ago it was not doing this quite as much. Closer to our own time in history it looks like it is getting closer again. No math illusion just common sense. We bring the watches back to fine tune.

 

I am going to digress, but this is important for understanding abstract thinking. Art typically anticipates and proceeds changes in the way culture looks at reality. Abstract art started in the late 1800's and the early 1900's and anticipated the change into abstract thinking. If you look at abstract art there are no set rules for clarity or proportion. It doesn't even have to look real or be anything. It can also employ special affects that would not be possible in the real world such as the stairway to nowhere.

 

This art movement anticipated the movement toward abstract thinking and sort of gave a glimpse into the mind of abstraction. It uses the same tools as the classical artist or thinker, i.e., paint=math. I am not saying all math is an illusion, it is a faithful horse that goes where we wish it to go. It can be used to help create reality art or abstract art.

 

The advantage of abstract art is because it is free style, without rules of common sense proportions, it makes it easier for anyone to do. It allows more artists than reality art, since reality art requires more careful sense of reality and proportion. A good painting of a tree can be seen by all. This is reflects our common sense. Abstract art is an acquired taste for a narrower range of taste. With an abstraction, common sense is suspended. It gives us a feeling for alternate reality apart from common sense. It stimulates the imagination more than a sharp portrait allowing one to leave reality further and drift into the ozone layer.

 

This is the state of affairs with all types of abstractions and even some stairways to nowhere. It is still beautiful art that takes skill to do. But by its very nature it not suppose to real or it won't stimulate the imagination. Chaos is a tool that helps the abstract affect. If a person sort of sees a tree, then chaos helps to create a sense of doubt to make sure the abstraction isn't too real. This prevents the art from appearing to go retro so it can look like it is cutting edge leading the charge.

[Thunderbird]

From “the End of Cosmology?”

• [*]

It’s quite possible and reasonable, IMHO, that among the greater human knowledge of physics would be improvements on present day theory invalidating the predictions made in a 3/2008 Scientific American article, and the night sky of whatever natural or artificial place a given human called home would look very different than that article’s beautiful illustrations.

 

My beliefs, which I have but can’t prove, label me, I think, an optimist, a trait not incompatable with a naturalistic scientific worldview.

 

 

I thought you might enjoy this perspective.;)

The Other Syntax

 

Did the universe really begin?

Is the theory of the big bang true?

These are not questions, though they sound like they are.

Is the syntax that requires beginnings, developments

and ends as statements of fact the only syntax that exists?

That's the real question.

There are other syntaxes.

There is one, for example, which demands that varieties

of intensity be taken as facts.

In that syntax nothing begins and nothing ends;

thus birth is not a clean, clear-cut event,

but a specific type of intensity,

and so is maturation, and so is death.

A man of that syntax, looking over his equations, finds that

he has calculated enough varieties of intensity

to say with authority

that the universe never began

and will never end,

but that it has gone, and is going now, and will go

through endless fluctuations of intensity.

That man could very well conclude that the universe itself

is the chariot of intensity

and that one can board it

to journey through changes without end.

He will conclude all that, and much more,

perhaps without ever realizing

that he is merely confirming

the syntax of his mother tongue.

 

***************************

 

a chapter from Carlos Castaneda's book The Active Side of Infinity:

[LaurieAG]

The question is, can mathematically rigorous proof support illusions? Math is a faithful horse that we can lead anywhere ever we wish. We start with a goal in mind and then find math proof.

 

Hello HydrogenBond,

 

Sanctus and I have been having a bit of a look at higher derivatives in http://hypography.com/forums/physics-mathematics/14674-higher-derivatives-how-d-problem-get-2.html#post215792 and both of us think something is wrong.

 

It looks like an improper imaginary unit is becoming evident in some forms of the calculations. Could this be an example how imaginary illusions can creep into a rigorous mathematical proof?

[LaurieAG]

Hi All,

 

There was an error, a missing multiplier, in one of the given equations (on a path that my calcs don't go on) that appears to be the cause of the improper i, when comparing the correct working with the incorrect answer.

 

This is interesting because it shows one basic method for identifying (and correcting) an implicit imaginary unit i, introduced through error, when none should explicitly exist.

 

Put succinctly: if you have an implicit i and you are not working with imaginary units, check your work for errors.

[PhysBang]

Yeah see that was my point. Cosmology isn't dependent on evidence IMHO. Only when it's coupled with astronomy and made into a science does it require scientific evidence. Cosmology has been around for a long time without needing any evidence apart from the observed movement of the sun, the moon, the planets etc... :hihi:

Actually, the theories that you are talking about do use evidence. Just very little evidence. The point of the article is that eventually the great amount of evidence we have access to now will be gone.

 

(The article comes about ten years too late, but since the evidence won't disappear for millions if not billions of years, it's not all that important.)