Can Cosmology Offer Hope for Humanity's Future Beyond Our Solar System?

[wolram]

Since the speed of light has been proven to be an absolute limit on the speed of travel, it is obvious humans will never reach beyond our solar system, humans may do some fantastic parallax measurements, but beyond them we will never have any thing other than a rubber ruler to measure with.
Worm holes may be an attractive conjecture to give hope of traveling beyond our SS, but are they even real?
So if one gives cosmology some realistic bounds of discovery what will it ever tell us?

 

[wildman]

It has told us a lot. The Universe came into being 13 billion years ago and it has expanded and evolved into a wonderfully beautiful place. It is hardly futile.

 

[Astronuc]

Space is big. You just won't believe how vastly, hugely, mind- bogglingly big it is. I mean, you may think it's a long way down the road to the chemist's, but that's just peanuts to space.

Nothing travels faster than the speed of light with the possible exception of bad news, which obeys its own special laws.

There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.

In the beginning the Universe was created. This has made a lot of people very angry and has been widely regarded as a bad move.

The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair.

Douglas Adams, The Hitchhiker's Guide to the Galaxy

I strongly recommend reading Douglas Adams, The Hitchhiker's Guide to the Galaxy series:
1. The Hitchhiker's Guide to the Galaxy
2. The Restaurant at the End of the Universe
3. Life, the Universe and Everything
4. So Long, and Thanks for All the Fish
5. Mostly Harmless
6. And Another Thing...

and posthumously - The Salmon of Doubt


They provide an appropriate perspective.


The universe provides a lot of things to explore and discover. We just have to be very clever.

Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so.

Douglas Adams, "Last Chance to See"

 

[wolram]

It has told us a lot. The Universe came into being 13 billion years ago and it has expanded and evolved into a wonderfully beautiful place. It is hardly futile.

A crazy model where very few thing are real/known tell us this, sure if you want to believe in fanasy.

 

[marcus]

Since the speed of light has been proven to be an absolute limit on the speed of travel, it is obvious humans will never reach beyond our solar system, ...

You underestimate us

 

[Nabeshin]

Since the speed of light has been proven to be an absolute limit on the speed of travel, it is obvious humans will never reach beyond our solar system, humans may do some fantastic parallax measurements, but beyond them we will never have any thing other than a rubber ruler to measure with.
Worm holes may be an attractive conjecture to give hope of traveling beyond our SS, but are they even real?
So if one gives cosmology some realistic bounds of discovery what will it ever tell us?

For clarification, are you trying to state that because we cannot ever reach the objects in question (distant galaxies, usually, for the sake of cosmology), we cannot draw conclusions from our measurements of them? (which are, as you note, aside from parallax, very indirect)

 

[zankaon]

Would end to funding lead to the end of cosmology? That is, would the futility of pursuit of funding be consistent with the futility in the pursuit of cosmology? Or are we in an electronic Golden Age of analysis, whether applied to math or science?

 

[shoehorn]

Futility implies that there is a goal which has not and will not be achieved. What, precisely, do you think that goal is Wolram?

 

[marcus]

futile:
1 : serving no useful purpose : completely ineffective...
2 : occupied with trifles : frivolous
...
http://www.merriam-webster.com/dictionary/futile

According to Wolram, it may have no purpose, may be purely for fun, a grand frivolity.
But I still think that's a good question to be asking, Shoehorn. Wolram what would you say the purpose of cosmology is?

 

[Chalnoth]

Since the speed of light has been proven to be an absolute limit on the speed of travel, it is obvious humans will never reach beyond our solar system,

No, it isn't obvious. Not yet. In order to cross light years of distance, what we need is a way to obtain a nearly-continuous acceleration for very long periods of time (e.g. years). If we can do that, then we can travel the stars, given:

1. We have the desire to undergo the enormous cost of any such mission.
2. We can build a ship that is capable of surviving the journey.
3. We don't mind going on missions that last decades to the people on board.
4. We don't mind all such trips being purely one-way trips. No visiting possible.

 

[marcus]

Chalnoth, I think Wolram's obviously wrong about never exploring beyond solar system. With robot surrogates, who can deal with 1000-year ship-time trips, it doesn't even have to be expensive.

But that is a minor irrelevance! It doesn't bear on the main point of discussion. Cosmology isn't about Milkyway galaxy. Wolram may well be mistaken about not exploring the galaxy. So what? There are still limits. Cosmology treats a much much larger scale. Quite possibly no exploration or contact at those billion LY distances. And that is not why we study cosmology! It is not a preparation for exploration or contact.

So if we grant that it is not preparation for exploration or contact, what is it for? What's the practical benefit?

One answer is that cosmology is really good science and it predicts things that we then observe. So it leads to new physics.
It predicted the CMB, which was then observed, and by studying the CMB we can learn about space and matter under extreme conditions. It helped predict Dark Matter, which we can now see and map by lensing. Finding what constitutes DM will extend particle physics.
Cosmology is a major source of new knowledge about the nature of space, time, and matter.

Cosmology has always been predictive. Ptolemy and countless others predicted planet motions and eclipses. (That's what the Cosmology of that time did---predict events in the sky---just as it does today.)
And Cosmology has always driven the invention of new mathematics. Hipparchus. Aristarchus. Archimedes. Kepler. Newton.

And it continues to predict events in the sky, just different events. Matt O. here at PF writes that instruments will soon be able to detect the gradual increase in redshift. As galaxies get farther away, the Hubble law says their redshifts should increase. There is a predicted increase which we should be able to check. (Another potential confirmation that redshift does reflect the expansion of distances as predicted by GR.)

 

[Chalnoth]

Another important point is that even if there were no practical results that stem directly from the scientific conclusions, merely building the instruments required to answer the scientific questions requires that we develop entirely new engineering techniques, techniques that are, as a rule, made public. So even without any results from the research conclusions, we get spin-off results that tend to be highly beneficial to society.

But heck, I don't care about that. I want to learn more about cosmology because I think it's so incredibly fascinating!

 

[Carid]

I think it was Stephen Weinberg who, when asked by a board of Pentagon generals what was the military purpose of particle physics, replied that it gave America something worth defending. Is cosmology any different?

 

[Mentz114]

If physics is about making mathematical models whose predictions fit observed data - then cosmology is great physics. It is amazing that the Einstein tensor for the FLRW space-time can be fitted to the SET (EMT) for dust, and that a relationship between the expansion rate and the energy density can be found. This and the models that have grown out of it is one of the most fascinating areas of research and data is constantly being gathered to test the theories.

Futile ? On the contary, as Chalnoth puts it, it is 'incredibly fascinating'.

 

[wolram]

I guess every considered opinion about cosmology is right, as Marcus said, we could send robot probes into deep space but will we ever? we all know political opinion changes several times in our own life time, how could we hope for continued funding of an experiment that would take 10s of years.
My biggest concern is the rubber ruler, we can take thousands of measurements using light
as the ruler ,but will we ever know if light is playing tricks with us until after some deep space probe results?
Cosmology is not useless as many have said, even the spin offs in the science of building the equipment is valuable, how we value any results measurements from the cosmology of today is the question of futility.

 

[atyy]

beyond them we will never have any thing other than a rubber ruler to measure with.

What is the rubber ruler?

Is General Relativity futile? If it isn't, then cosmology cannot be futile. General Relativity demands that we do cosmology, since each solution of Einstein's equations is an entire universe. I don't think GR is the final word, but futile?

 

[vanesch]

Most things we care about are futile. The difference between different human beings is that they appreciate different kinds of futilities. Once you've reproduced, you are futile yourself... and even without reproducing, if the human species is considered futile.

What's *not* futile ? Maybe your immediate pleasure. In that case, some people enjoy cosmology, as others enjoy watching a football game. The market opportunities may be different, agreed.

 

[atyy]

Maybe your immediate pleasure. In that case, some people enjoy cosmology, as others enjoy watching a football game.

Is this a scientific statement? Cosmology is surely more like baseball!

Edit: I confess the game in which the Red Sox broke their curse was quite entertaining.

 

[Chalnoth]

I guess every considered opinion about cosmology is right, as Marcus said, we could send robot probes into deep space but will we ever? we all know political opinion changes several times in our own life time, how could we hope for continued funding of an experiment that would take 10s of years.
My biggest concern is the rubber ruler, we can take thousands of measurements using light
as the ruler ,but will we ever know if light is playing tricks with us until after some deep space probe results?
Cosmology is not useless as many have said, even the spin offs in the science of building the equipment is valuable, how we value any results measurements from the cosmology of today is the question of futility.

One way to get a handle on what the universe looks like far away from us is to look at light that is deflected off of dust elsewhere in the universe. There have been, for instance, some measurements of supernovae from observing them lighting up dust far away from the explosion. There are also measurements of how galaxy clusters interact with the light from the cosmic microwave background (the Sunyaev-Zel'dovich Effect).

Another consideration is to look at the universe in things other than electromagnetic radiation. Observations of high-energy cosmic rays are beginning, with the Auger observatory reporting some interesting results that appear to show that a significant portion of the highest-energy cosmic rays may be coming from relatively nearby quasars. There are also gravitational wave experiments in the works. One day, we may even be able to measure the cosmic neutrino background (the idea here is basically the same as the cosmic microwave background, just with neutrinos, though neutrinos are vastly more difficult to measure, particularly at the low energies required to observe this background).

But even before we go to these other options, there are a multitude of ways to measure the properties of cosmology just with telescopes that observe radiation. We've got the anisotropies in the cosmic microwave background, we've got the polarization of the CMB, we've got supernova observations, we've got galaxy cluster counting experiments, we've got baryon acoustic oscillations, we've got cosmic shear observations, we've got weak and strong gravitational lensing of massive systems, we've got X-ray images of clusters, we've got infrared and sub-millimeter images of extremely distant galaxies, we've got 21cm experiments to detect the epoch of reionization, and I'm sure I'm missing a number of things. The point is, though, that by measuring the exact same theoretical parameters using all of these various analysis techniques, we get independent checks that we're not totally mistaken as to the nature of what's going on.

If there was a fundamental flaw in the big bang theory, for instance, then we wouldn't expect different experiments that measure entirely different observables would agree. And yet they do agree, again and again and again. So we can be pretty darned confident that the overall picture is at least approximately accurate.

 

[wolram]

Calnoth, no matter what i say i am sure you will have confidence in your models, the crux of the matter is, we could have sent deep space probes 20 yrs ago, may be a multi unit mission that consisted of amplifiers dropped at x distances and the primary probe, instead of messing about with the moon and mars, to me they are small value targets.
By now the probe would be giving real value information, if as Marcus suggested it could accelerate continuously, not to difficult once one had the fuel in 0g.
As for THE model, i await the Ligo results, i am sure there are all ready people working on why gravitational radiation is suppressed.

 

[Chalnoth]

Calnoth, no matter what i say i am sure you will have confidence in your models, the crux of the matter is, we could have sent deep space probes 20 yrs ago,

No we couldn't. Not any that would have been of any use in cosmology. Any actual cosmological mission would be a multi-million year mission. So I don't see why this would help us any. And besides, more than enough independent cross-checks of our models are available without moving an inch. But apparently you didn't pay any attention to that part.

The fact of the matter is that in any scientific discipline, we can't just make up any experimental we would like to be able to perform and say that we won't accept a theory until that result is performed, because no matter the discipline, there are always large numbers of conceivable experiments that just can't be performed in reality. So though it might be nice to be able to travel to some other region of the universe and observe things, we just can't do that. Our models must, therefore, be constrained by what we can observe right here on Earth. Fortunately that turns out to be quite a lot, more than enough to provide us with a large number of cross-checks on our models.

As for THE model, i await the Ligo results, i am sure there are all ready people working on why gravitational radiation is suppressed.

No. It's just that the current sensitivity isn't good enough. The gravitational wave signal would have actually had to be pretty darned large for current detectors to catch any. We'll only start to be genuinely surprised that we don't see any if the next generation also provide null results.

 

[matt.o]

Might we turn the question around and ask is quantum mechanics futile because we'll never be able to shrink ourselves down to 10^-10 m sizes and observe quantum tunneling?

 

[mgb_phys]

History is pretty futile because we haven't got time machines.

 

[wolram]

Chalnoth quote
No we couldn't. Not any that would have been of any use in cosmology. Any actual cosmological mission would be a multi-million year mission. So I don't see why this would help us any. end quote.

I was waiting for some thing like that ,so we will all ways only have our models and will never be able to go out into the universe to test them.

And of course we are sure our models are correct, forgive me but that seems circular thinking to me.

 

[wolram]

Might we turn the question around and ask is quantum mechanics futile because we'll never be able to shrink ourselves down to 10^-10 m sizes and observe quantum tunneling?

You would have to ask some else about that, but i think the quantum world is more accessible to us.

 

[Chalnoth]

I was waiting for some thing like that ,so we will all ways only have our models and will never be able to go out into the universe to test them.

Why does that matter when we can perform so many independent checks right here on Earth?

And of course we are sure our models are correct, forgive me but that seems circular thinking to me.

Okay. You really should read up on what the evidence is. Here is an excellent essay that provides a broad look at the evidence:
http://www.talkorigins.org/faqs/astronomy/bigbang.html

The key thing to pay attention to is the independence of the various observations.

 

[turbo]

You underestimate us

You misunderestimate us. With enough taxpayer money we can reach the stars, or maybe Mars, or perhaps even the Moon (again). If the Sun doesn't throw a tantrum, maybe we can get those Moonies back in one piece.

 

[heldervelez]

To the OP I say that Cosmology will tell us what to expect in the future to the Earth and to the Mankind. Future is not like the Present neither equal to Past eras.
Cosmology is not futil, only in a bad road. Do not underestimate the Mankind. We are the Life keepers. Our responsability.
Take 'c' as an absolute limit: it is a property of the Space.

 

[Chalnoth]

To the OP I say that Cosmology will tell us what to expect in the future to the Earth and to the Mankind. Future is not like the Present neither equal to Past eras.

I don't really see how. Astrophysics has some stuff to say, provided we live long enough. But I don't see how cosmology has anything at all to say about the future of the Earth or mankind.

Cosmology is not futil, only in a bad road.

On a bad road? In what way?

 

[heldervelez]

Cosmology is a study not only of Present conditions, but also of Past, and also the Future conditions. Unlike History we can read also about future.
Trying to explain why past climate on Mars was warmer, watered. Why past climate on Earth was warmer?
Bad road ? probably a dark road.