Common misconceptions about the big bang

[Evolution_Not]

That's not what I said.

That's correct, I am saying
that, not to any one specifally-sorry

 

[camanintx]

So any direction we look we will see everything receding from us, so we are at the
center of the universe.

Aren't we always the center of our own universe?

 

[Mr Spinkles]

So any direction we look we will see everything receding from us, so we are at the
center of the universe.

Yes, any direction we look we will see everything receding from us. But that doesn't mean we are the center of the universe; according to the big bang theory, no matter where you are in the universe, everything is receding from you, so there is no center. You can try this idea out for yourself: if you make marks on a rubber band, and stretch it, you will find that, from the perspective of any of the marks, all the other marks are receding (and the marks farthest away are receding fastest).

 

[Evolution_Not]

Yes, any direction we look we will see everything receding from us. But that doesn't mean we are the center of the universe; according to the big bang theory, no matter where you are in the universe, everything is receding from you, so there is no center. You can try this idea out for yourself: if you make marks on a rubber band, and stretch it, you will find that, from the perspective of any of the marks, all the other marks are receding (and the marks farthest away are receding fastest).

I believe your talking about expansion of the universe?
In which case the marks on the rubberband representing galaxies would expand also
beyond any gravity and would have ceased to exist long ago.

 

[Mr Spinkles]

I believe your talking about expansion of the universe?
In which case the marks on the rubberband representing galaxies would expand also
beyond any gravity and would have ceased to exist long ago.

The marks on the rubber band don't expand very much, but in any case it is merely an analogy. The key thing to keep in mind is that it is the space between (clusters of) galaxies that is doing the expanding.

 

[Mr Spinkles]

For starters, the big bang is NOT...

1) ...'over'. It's still happening, right now. Space is expanding as we speak, causing the distances between galaxies to increase.

3) ...going to slow down, turn into a 'big crunch', and cause another big bang. This theory has been thrown out due to recent studies which show that the expansion of space is accelerating. The universe will never (as far as we can tell) collapse back in on itself.

Now, here's what the big bang IS:

1) The big bang is directly observable. We can see it happening, right now. In any direction we look, we can see galaxies receeding from us.

I have to disagree with the certainty by which you make the above claims.

What is observable to use is only observable because of light. It takes time (lightyears) for what we are observing to reach us. In many ways, we are looking into the pasts of these galaxies. Because we are looking at the past, we have no way (currently) of knowing whether the galaxies are still expanding right now.

But if we look at galaxies at various distances, we can measure the expansion at nearly all times throughout the universe's 14 billion year history, including times pretty close to "right now". Note that we can't confirm that the Sun exists "right now", since all information from the Sun takes ~10 minutes to reach us. The fact that we can't detect the expansion "right now" is no more troubling than the fact that we can't detect the Sun "right now".

 

[nutshell]

But if we look at galaxies at various distances, we can measure the expansion at nearly all times throughout the universe's 14 billion year history, including times pretty close to "right now". Note that we can't confirm that the Sun exists "right now", since all information from the Sun takes ~10 minutes to reach us. The fact that we can't detect the expansion "right now" is no more troubling than the fact that we can't detect the Sun "right now".

The sun is 10 minutes away. The nearest galaxy is 25,000 lightyears away. How can you know it's still there right now? I can wait 10 minutes for the Sun - can you wait 25,000 years?

 

[Mr Spinkles]

The sun is 10 minutes away. The nearest galaxy is 25,000 lightyears away. How can you know it's still there right now? I can wait 10 minutes for the Sun - can you wait 25,000 years?

No, I can't, but if galaxies are capable of disappearing, they could disappear billions of years ago (thus making their disappearance observable today) just as easily as "now".

Do you think that we should take very seriously the possibility that, after billions of years, galaxies have started disappearing "now", in violation of known laws of physics?

 

[Evolution_Not]

The marks on the rubber band don't expand very much, but in any case it is merely an analogy. The key thing to keep in mind is that it is the space between (clusters of) galaxies that is doing the expanding.

If galaxies are receding according to the Doppler Red Shift then it is due to the basic laws of
physics. That being the case it would mean an intolerable situation for an atheist
as this would mean that the earth or very near by is center of the universe. I.E.
Special. So the space expansion theory was concocted. Do atoms expand?, is our solar system expanding? They would be if space expansion was a fact.

 

[painted wolf]

um... no that isn't what it means.

it means that in relation to us its moving away... not that we are in the middle.

wa:do

 

[rocketman]

wa:so

wa:so?
hehe

 

[Evolution_Not]

1937 THE OBSERVATIONAL APPROACH TO COSMOLOGY- Edwin Hubble
pg 51 "The unwelcome supposition of a favored location must be avoided at all cost"
pg 59 "to escape the horror of a unique position"
pg 54 "There must be no favored location in the universe, no center, no boundry;
all must see the universe alike"
"The assumption of uniformity has much to be said in it's favour. If the distribution were not uniform, it would either increase with distance, or decrease. But we would not expect to find a distribution in which the density increases with distance, symmetrically in all directions. Such a condition would imply that we occupy a unique position in the universe, analogous in a sense, to the ancient conception of a cental earth.......
pg 50 "The hypothesis cannot be disproved but it is unwelcome and would be accepted only as a last resort in order to save the phenomena. Therefore, we disregard this possibility and consider the alternative, namely, a distribution which thins out with distance."
"To this principle has been added another proposition...that all observers, regardless of their location will see the same general picture of the universe. The second principle is a sheer assumption.....Nevertheless, it leads to a rather remarkable consequence, for it demands that, if we see the nebulae all receding from our position in space, then every other observer, no matter where he may be located will see the nebulae all receding from his position. However, the assumption is adopted...."

 

[Mr Spinkles]

If galaxies are receding according to the Doppler Red Shift then it is due to the basic laws of
physics. That being the case it would mean an intolerable situation for an atheist
as this would mean that the earth or very near by is center of the universe. I.E.
Special. So the space expansion theory was concocted. Do atoms expand?, is our solar system expanding? They would be if space expansion was a fact.

No, not necessarily. The expansion of space is a tiny effect compared to the strength of gravity at close range. The effect of the expansion is thus only really significant in the massive voids of empty space between gravitationally bound clusters of galaxies. Earth is not the center of the universe because, according to big bang theory, galaxies are receding in all directions with respect to ANY point in space. [edit: recall the expanding rubber band example--from the perspective of ANY mark on the rubber band, all other marks are receding away; each mark appears to be the 'center' of the expansion; other analogies are raisins in rising dough, or points on an inflating balloon]

 

[nutshell]

No, I can't, but if galaxies are capable of disappearing, they could disappear billions of years ago (thus making their disappearance observable today) just as easily as "now".

Do you think that we should take very seriously the possibility that, after billions of years, galaxies have started disappearing "now", in violation of known laws of physics?

But what if the galaxies aren't disappearing one at a time - what if there's been one big destruction somewhere that is ripping apart the universe right now - it just hasn't reached us yet? I don't claim to be a science person, but what I've stated is possible, isn't it?

 

[Mr Spinkles]

But what if the galaxies aren't disappearing one at a time - what if there's been one big destruction somewhere that is ripping apart the universe right now - it just hasn't reached us yet? I don't claim to be a science person, but what I've stated is possible, isn't it?

Yes, I concede that it is possible.

 

[rojse]

I have a question:

In another thread, a poster stated that the centre of the universe was everywhere. Is this correct or not?

 

[Mr Spinkles]

I have a question:

In another thread, a poster stated that the centre of the universe was everywhere. Is this correct or not?

You could say it that way. However, it seems to me that the best way of saying it is that the universe has no center.

 

[rojse]

You could say it that way. However, it seems to me that the best way of saying it is that the universe has no center.

Thank you.

 

[Evolution_Not]

No, not necessarily. The expansion of space is a tiny effect compared to the strength of gravity at close range. The effect of the expansion is thus only really significant in the massive voids of empty space between gravitationally bound clusters of galaxies. Earth is not the center of the universe because, according to big bang theory, galaxies are receding in all directions with respect to ANY point in space. [edit: recall the expanding rubber band example--from the perspective of ANY mark on the rubber band, all other marks are receding away; each mark appears to be the 'center' of the expansion; other analogies are raisins in rising dough, or points on an inflating balloon]

Evidently you are not comprehending what the father of astronomy is saying-Edwin Hubble . So I will put it in different words for you. Oh crap, based on the red shift in any direction we look everything is receding. No blue shift of any galaxies etc coming towards us. We can't
except what our intruments are telling us so lets concoct a theory, a work around so
we wont have the earth as the center.
Steven Hawkings admits the same thing, so keep believing a lie because its in a text book.

 

[rojse]

Evidently you are not comprehending what the father of astronomy is saying-Edwin Hubble . So I will put it in different words for you. Oh crap, based on the red shift in any direction we look everything is receding. No blue shift of any galaxies etc coming towards us. We can't
except what our intruments are telling us so lets concoct a theory, a work around so
we wont have the earth as the center.
Steven Hawkings admits the same thing, so keep believing a lie because its in a text book.

If everything is expanding in the fashion you say, where the effects of gravity are less than the expansion of the universe, why isn't the earth itself flying apart? And, for that matter, why aren't you?