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The unimaginable vastness of the universe


Alan McDougall
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Hello people I know my little essay is a statement but it is a statement of how really huge the universe our home realy is.

 

 

The unimaginable vastness of the universe

 

Author Alan McDougall

 

The distances in space are unimaginably vast beyond human comprehension. If I try, tell an uninformed nonprofessional that it is so many kilometers to the Sun or moon, will these people be able to comprehend these vast unbelievable distances.

 

The moon and sun are a mere two light seconds and eight light minutes respectively from the earth. Light travels at 300 000 kilometers a second or seven times around the earth in the same time. The moon is a mere 400 00 kilometers and the sun about 156 million kilometers from the earth respectively, next-door neigbours in fact. Even this is near distance on cosmological scale is almost impossible for anyone to truly comprehend. What about our nearest neibour, Alpha Centauri only 4.2 light years away and the next nearest star to the sun. Just around the corner on the vast cosmological scale.

 

It helps if one understands that the fastest object ever made by man “(spacecraft voyager at 100 000 kilometers per hour)” would take 80,000 years to get there. Then if you understand how amazingly fast that object actually goes one might begin to gleaning some understanding of how far away Alpha Centauri is. Moreover, Centauri is our next-door neighbor!

 

Then we can move further. Let us say, Epsilon Eridani, 10 light years away. That is over twice as far - Voyager would take close to 200,000 years to get there. All evidence of human civilization would be pretty much gone in a few thousand years, given an average society lifespan of about 1000 years or less, We're talking 200 societies coming and going before Voyager makes it to Epsilon Eridani. Moreover, Epsilon Eridani is right next door.

 

The Andromeda galaxy, The galaxy nearest to our own milky way galaxy is mere two million light years away.. Voyager would take forty thousand billion years (40,000,000,000,000) to get there. That is over 3300 times longer than the current postulated age of the universe, and that's our nearest galactic neighbor. There are galaxies that are estimated to be12 billion light years from earth and the strange objects called quasars even future at 14 billion light years.

 

To reach far galaxies with a Voyager like spacecraft would take almost an eternity and it is obvious that this cannot be the ultimate method of crossing the universe. I foresee instant teleportation or some type of mind/spiritual means as the method used by advanced humanity in the very distant future to explore the universe.

 

Maybe they are not far at all, right next to us in an parallel universe or alternate dimension only requiring a portal to visite our reality

 

"The universe could be a sphere of infinite radius"

 

By Alan McDougall 15/9/2007

 

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I am not sure this is really a subject which causes problems for most of our members. I would imagine that on average, someone who is a regular visitor here is more likely to be the kind of person able to comprehend and/or visualise these kinds of distances.

 

OTOH, looking at that link posted by Arch2008 and reading down the right-hand column gives a very entertaining insight.

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In the context of Christianity, seeing how God created air friction, gravity and other nasty things that make it pretty hard to get off Earth to begin with, I'd be pretty amazed if he designed the universe with FTL travel in mind. It's like he doesn't even want us to go to space, as it's a cold, hostile place where lethal bursts of radiation and pieces of rock swoosh about, rather than a warm place filled with candycanes. God seems like the kind of dude who really wants humans to work their asses off if they want to get anything done.

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Saronya

 

I disagree, now it is two that can comprehend, you and the big guy. You knew and forgot to tell us and the big guys will not only. As for finite little "mortal "me the vastness of the universe is uncomprehensible

 

Go to this amazing link and you will get a new perpective of how tiny earth and our sun really really really is!!!!!,

 

 

http://www.rense.com/general72/size.htm

What do you think?

 

Alan

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just because you can't imagine itdoesn't mean nobody else can.

 

there are many many people who work with vast scales(or the opposite, tiny ones) that necessarily have a very good sense of proportion outside that of a normal person.

 

i for instance deal with very tiny things(atoms and such) but i deal with them in vast vast quantites. when i started i couldn't get my head round the scales and my estimates were often off by several orders of magnitude, but by working with them regularly i now have a good sense of proportion on it and can make quite accurate estimates.

 

similarly, cosmologists and the like are used to dealing with the vastness of the universe. it will be equally easy for them to comprehend the distances in the universe as it is for me to comprehend a couple of molecules in relation to a swimming pool

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"Maybe" "Maybe" "Maybe"

This does not bode well as your third reply in your own thread.

 

Is there anything else to discuss, or did you just want to post a proclamation of what is not possible? I do not think there is a good chance that a sensible discussion of "mind/spiritual" means of crossing the interstellar gulf will take place here.

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just because you can't imagine itdoesn't mean nobody else can.

 

there are many many people who work with vast scales(or the opposite, tiny ones) that necessarily have a very good sense of proportion outside that of a normal person.

 

i for instance deal with very tiny things(atoms and such) but i deal with them in vast vast quantites. when i started i couldn't get my head round the scales and my estimates were often off by several orders of magnitude, but by working with them regularly i now have a good sense of proportion on it and can make quite accurate estimates.

 

similarly, cosmologists and the like are used to dealing with the vastness of the universe. it will be equally easy for them to comprehend the distances in the universe as it is for me to comprehend a couple of molecules in relation to a swimming pool

 

Indeed.

I for one always had trouble grasping the distances in Space.

When I got to 8th grade, it all clicked after a lot of reading, research, and discussions with my science teacher. Not everyone can imagine, but if you get the right background, and if you out a lot of effort into actually trying to get it, it all will make sense. I'm living evidence of that.

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The distances in space are unimaginably vast beyond human comprehension.

 

Unimaginable? I imagine the Universe as much more vast than we could ever know. I can imagine an infinite meta-universe with infinitely many universes like ours, an extension of the scale of nature that we see within our own universe.

 

I disagree, now it is two that can comprehend, you and the big guy.

 

What big guy?

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Or rather "we", seeing as it turns out I am not some kind of unique specimen.

 

I think all of us (except Alan) basically hold the same viewpoint.

His view is rather close-minded and based on assumptions, while our opinions are based on actual experiences.

(I just realized that most of what I said is an assumption...uh oh...)

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Sar,

 

You look at tiny things, then tell me what is the most powerful microscope on earth?

 

Oh I am "not going the god route by the way", however, to really comprehend the vastness of the universe you would need to view it from a great obsever platform, something just like your microscope in reverse.

Edited by Alan McDougall
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A reminder that this is the Astronomy and Cosmology section, not Spirituality and Mysticism.

 

I want to introduce an idea which might be supportive of what Swansont is reminding.

 

that is the idea of operational definitions. since so far (until moved) this is a physics thread, it should be possible to say in practical terms what the terms mean.

 

I can't see, personally, what vastness can mean besides VOLUME.

it has certain poetical and rhetorical overtones but basically I think the idea is volume (or extent generally) and so the question being discussed is

can you imagine the volume of space?

 

and a lot of people would answer "Yes, of course. what do you want to know about it?" Others would say yes provisionally but they would want to have it specified whether you meant the observable part, that we see objects that are in it-----or the whole. and what you were assuming for the average density (because that is important, it factors in to a constructive effort to imagine and answer questions about---- how much matter, stars etc, per unit volume)

 

But we can get down on this question and require more definition if people see the need for it. What does it mean operationally or practically to IMAGINE the volume of space.

 

I think in a physics subforum thread it means you can picture it well enough to answer some basic questions about it. It means having a mental picture that you can work with. Like solve a simple homework problem about it.

 

And that is tougher because most people don't get given enough information in school so they can think concretely about the standard model of space. they have to pick it up on their own by reading! If the education curriculum gave us all some more basic cosmology facts, we could get more traction. I mean facts about the standard model because that's what you should understand before you go off into individual variants. The standard model is what you get at websites like Ned Wright's, or in a typical undergraduate course in general astro and cosmo. Or what you get in that Lineweaver SciAm article that SFN people seem to like pretty much and most have read.

Since it is the version that you normally hear about everywhere you go, it is good to start out by understanding the basics of the standard picture.

 

I guess I will risk a suggestion. This might work. We could have a thread explaining the very most basic basics of how to imagine the vastness of space. And just keep people out of it who don't have constructive suggestions and who are just having a spam fight.

 

in the simplest terms the basics would probably be

1. the CMB, what it is, what it means to be at REST relative to CMB---i.e. no doppler hotspot

 

2. universal time for observers at rest relative CMB, how you can think of measuring the distance to some far galaxy with the help of a chain of such observers, so you get the distance NOW (the CMB gives a concept of simultaneity which is a big convenience). each observer can be equipped with a radar distance range device to get the distance to his immediate neighbor. the point is to have a lot of observers so you can get the whole distance (as a sum of increments) almost all at once. before the sucker changes.

 

3. What the Hubble parameter H is. It is the ratio of recession speed now, to distance now. You multiply an objects distance from us at the present moment by H(now) and it will give you the recession speed at the present moment. To think about H correctly and rigorously, as it is actually defined by the pros, you need a universal time concept like what step 1 and 2 give.

 

the chain of observers are all at CMB-rest so that their clocks will agree. that way you can be sure what you mean by the instantaneous present distance to something, and give the Hubble parameter an unambiguous meaning.

 

4. the present value of critical density. which if the present average density of matter and energy in space is equal critical, then the geometry of space is exactly flat----the sum of interior angles of big triangles out in empty space is 180 degrees (as long as they don't get too close to stars and black holes which bend lightrays out of shape, as long as they stay clear and keep out of trouble :) )

 

5. the current critical density is easy to calculate from G, c, and the present value of H. it is simple arithmetic.

 

I would say if you can calculate the current value of the critical density then you really understand a lot of cosmology. You can almost stop with that.

 

6. but if you want to go on, Omega is the ratio of the REAL density to the critical. and if it is more than one, like if it is 1.01, that means the real density is one percent more than critical and space is finite volume

 

Laugh all you want, this is the standard LCDM model. there are two cases of it, space infinite and space finite. If the real density is one percent more than crit, we are in the finite case! And I can tell you the radius of curvature at the present moment.

 

It is the Hubble radius c/H divided by the square root of Omega minus 1. this is where it seems a little magic, but you get used to it.

 

7. Knowing the radius of curvature, you can easily compute the volume. The current spatial volume of the universe.

 

So that is the course outline for a short course for college freshmen on Imagining the Vastness of Space.

 

The main thing you really want them to do is get to the point of #5 where they can calculate the critical density. Forget about why the formula works (the Friedmann equation, too much to get into in a short course) just accept the formula for now and calculate.

 

Modest sense of power and accomplishment just from being able to calculate "rho_crit" by yourself

from handbook values of G, c, and the Hubble parameter Hnow

Calculating rho-crit from scratch on your own. Nice.

 

After that, points #6 and #7 are just trimmings. the radius of curvature (assuming Omega = 1.01) and the spatial volume.

 

Anyway that's my personal view of the main issue. I'd make imagining the vastness into a practical operational-defined process. Interested if others, like Klaynos or DH, Sayonara, or Swantsont, have some ideas. Would you take a different tack from this?

Edited by Martin
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Sar,

 

You look at tiny things, then tell me what is the most powerful microscope on earth?

 

Oh I am "not going the god route by the way", however, to really comprehend the vastness of the universe you would need to view it from a great obsever platform, something just like your microscope in reverse.

 

I fail to see how that question is even relevant but then again I fail to see how this topic is relevant to a science forum.

 

Electron Microscopes can have a resolution of 0.002nm or greater, however just because you can see something doesn't mean you can comprehend its scale.

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People I insist the universes immensity is beyond human comprehension.

 

Go to this link for the slide picture

 

http://www.naturalhistorymag.com/0404/0404feature_slide1.html

 

 

 

"I have visted other forums, but few jump in and cratch their heads for something negative to say, without giving a newbie the space to to ground themselves" .

 

I see I am "closed minded", man!! how far off reality can one get, you make this assumption on my very first thread knowing absoltuley nothing about me.

 

Just wisper the word and I will go elswhere!

 

 

 

 

 

 

by Josh Gough (How many stars are there in the universe?)

 

No one can ascertain the answer to this question with absolute certainty due the immensity of the universe and fact that light from vastly distant galaxies has not even had time to reach the Earth. The reason for this is that even though light travels at approximately 300,000 kilometers per second in a vacuum it will still take billions upon billions of years for it to travel from the outer limits of the universe across the seemingly infinite distance to planet Earth.

 

Yet, in 2003 Australian astronomers set out to answer this very question to the best of their abilities. They used two of the world's most powerful telescopes to observe 10,000 visible galaxies and then extrapolated this data out to the edge of the known universe.

 

The number they estimated was an astonishing 70 sextillion, written as 70,000,000,000,000,000,000,000. 70 sextillion is 7 followed by twenty-two zeroes!

 

More importantly, is there any way for us to even begin to get our minds around a number so large as this?

 

There is if we descend to the Earth for a few moments and use our imaginations.

 

Imagine that you are laying on the beach at night, looking up at the expanse of the sky and stars above you, amazed by the surreal feeling of imbibing the cosmos. Countless grains of sand stretch out in all directions beneath you. Hanging in the sky, the moon acts as a sentinel shining its light on the clouds that creep by it like apparitions. Incessantly the waves roll to the shore in curls, spirals, and tumbles and then recede, pulled by the tugging reins of gravity from the moon.

 

Mesmerized by this thought you walk toward the tide and begin to dig your ankles into the sand beneath your feet as the water splashes over them. Burying your feet in countless minuscule grains of sand as you fixate on those dots of light piercing the night's canopy, you pause to ponder a question that enters your mind.

 

You think to yourself, "What if I were to walk every beach of the earth, digging my feet into every sand bar, then lay myself down and drag my fingers through every smoothed plane of wet sand to build countless sand castles. How many grains of sand could I count? What if I then were to traverse every cubic millimeter of every desert on this planet Earth, diving into sand dunes and shielding myself from devastating sand storms, but through pure magic were able to tally up every last grain of sand on my feet, every grain surrounding me in the dunes, and every grain blown violently at me from the punishing winds? Surely, I would find that there must be more grains of sand on this planet Earth than there are stars in the universe."

 

The Australian researchers would say that you were very diligent yet also very wrong. They estimated that there are at least ten times as many stars in the known visible universe as there are grains of sand along every single beach, and in every single desert on the planet Earth.

 

Inevitably this inspires us to wonder about the possibility of life elsewhere in the cosmos. Dr. Simon Driver, who spoke at the General Assembly of the International Astronomical Union about this calculation, said this when asked about this possibility, "Seventy thousand million million million is a big number ... it's inevitable."

 

Somewhere on a distant planet, with far fewer grains of sand on his or her own world than exist stars in the universe, may lie an intelligent being peering out into the universe amazed by the very same possibilities that you and I have dared to imagine.

Edited by Alan McDougall
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The number they estimated was an astonishing 70 sextillion, written as 70,000,000,000,000,000,000,000. 70 sextillion is 7 followed by twenty-two zeroes!

 

tiny number, in chemistry you deal with mols. 1 mol is 6.022*10^23 atoms or molecules depending on what you apply it to. then you have my field, chemical engineering where you can be dealing with several hundred Mmol, or several hundred times 6.022*10^29.

 

thats getting on a reasonable sized number, then you consider the number of atoms in the earth alone, then the solar system and so on.

 

i'll admit that i have difficulty imagining correctly the number of atoms past planetary scale but this is because it is far outside my usual realm. i'm quite sure i could learn to imagine it more accurately with a little practise.

 

i will say again, it is not unimaginable just because you cannot correctly comprehend it.

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Perhaps our thread starter meant to say:

It's not the factor by which the universe is bigger than something we know, like a house, that we cannot comprehend... it's the fact that this factor is in fact unknown...

 

Or did the threads about the size of the universe have a single constant as an answer? :)

 

I also feel comfortable with large factors, although like most chemists I think at a small scale. If you really fail to imagine small numbers, thinking not in size, but in terms of dilution might work.

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