Red shift problem?

[Graham4C]

hi all,
Id like to discuss the "Red shift"...

To my knowledge, the red shift is the only "evidence" to show that the universe is expanding i.e the matter is moving further apart.
(By the way, i would greatly appreciate it if someone could explain the red shift / hubbles law for the benefit of readers of this thread - i uderstand it but id rather have someone else explain it...)

Anyway, it is cited that because the red shift shows matter moving further apart, it must have started at a central point, or singularity, i.e the Big Bang.

I think there is a problem with this theory lying in gravity. For those who arent sure, the force of gravity is the attraction between all matter in the Universe.
Isaac Newton (correct me if im wrong) showed that this force is measurable - it is directly proportional to the sum of the masses of two objects, and inversely proportional to the square of the distance between their centres.

PROBLEM NUMBER 1

Firstly, we have an issue with the Big Bang - using data provided by NASA regarding the estimated mass of all visible matter, and Big Bang theory, it is possible to work out what the gravity at point of singularity (Big Bang) would have been:

Proposed mass of Universe – 1.59 x 1055kg
The approximate diameter of an atom – 10-12cm
= 10-14m
Singularity size (a billionth this size) – 10-23m

Therefore, the total gravitational force = 1,07 x 10 to the 91 using Newton’s law of Universal Gravitation.

Note that these figures are not my own invention, im merely doing the math.

The force required to accelerate the matter outwards would be greater than 1,07 times ten to the power of 91!!

Would anyone like to suggest where this force would come from? And its not valid to say that the laws of matter do not operate in singularity - thats not science, and at the time of the Big Bang, the matter would no longer be in singularity...

PROBLEM NUMBER 2

This deals with the red shift...

If the red shift is valid, all matter in the universe is moving away from us. This is often cited by scientists as proof for the Big Bang.
BUT, according to NASA, our nearest neighbor galaxy, Andromeda, is moving towards us at a phenomenal rate.
This would be due to the gravitational pull of the galaxies on each other.

Calculations then show that the galaxies will collide in so many milions of years.

Now, if Andromeda is moving towards us, then it is patently NOT moving away from us. Hence, a red shift will not occur when studying any star in the Andromeda galaxy.

Scientists go one further than this to say that galaxies collide with each other ALL THE TIME!
Once again, if they are moving towards each other, they are patently NOT MOVING FURTHER APART.

This means that the red shift is more than inconclusive, but completely unreliable. The movement of galaxies is explained by pure gravity. We can see that everything is not expanding, and there is evidence for that. The red shift SURELY CANNOT be given as evidence for the Big Bang.
And since it is the only "evidence" for the Big Bang, surely the theory holds no water...

these are merely my thoughts, please give constructive arguments rather than rants based on nothing
but any thoughts are appeciated nonetheless

 

[ClearSky]

i would greatly appreciate it if someone could explain the red shift

No problem. The color of light is determined by its wave length. When space expands over time, the wave length also expands, i.e. it becomes bigger. Bigger wave lengths mean a color shift towards the red. Therefore, when space expands, all light waves become 'redder' during their life time. The longer a certain light ray exists, the redder it becomes.

Therefore, when you assume that the light from far galaxies already travels a long time, and when space expands, the image from the galaxy is shifted to the red the more, the further away the galaxy is.

Proposed mass of Universe – 1.59 x 1055kg
The approximate diameter of an atom – 10-12cm
= 10-14m
Singularity size (a billionth this size) – 10-23m

Therefore, the total gravitational force = 1,07 x 1091 using Newton’s law of Universal Gravitation.

No, that's not the right way to calculate the singularity. The numbers are all wrong. The 10^55 kg are the mass of the VISIBLE universe only, the Hubble volume. The universe itself is much bigger. It's size is unknown, it's probably infinite in size. Likewise, scientists assume that the singularity was probably already infinite in size. It is a common misconception to understand the singularity as some sort of "point". It was not small, it was just extremely dense and hot, and consisted not of atoms, but of radiation.

Now, if Andromeda is moving towards us, then it is patently NOT moving away from us. Hence, a red shift will not occur when studying any star in the Andromeda galaxy.

Scientists go one further than this to say that galaxies collide with each other ALL THE TIME!
Once again, if they are moving towards each other, they are patently NOT MOVING FURTHER APART.

This means that the red shift is more than inconclusive, but completely unreliable.

You're confusing two things. The galaxies are not moving away from us. In fact they tend to move towards each other due to gravity. It's the space itself that is expanding, i.e. all distances increase over time.

The reason science assumes for the observed red shift of far away galaxies is the long time span their light needed to reach us. During that long time the light has gone red due to the permanent space expansion. For the same reason, we're seeing events in those galaxies - such as supernovae - happen in slow motion because the light from those events became stretched over time.

So, although the galaxies move towards us, the distance to them also increases when the space between them and us is big enough so that the space expansion exceeds the gravity movement. As to the Andromeda galaxy, you can not see any red shift with such close galaxies. It requires huge time spans, such a billions of years, for light to become noticeably red shifted when space expansion is the reason.

Of course, the real reason is that God filled the universe with light that looked just as red shifted as if it had already traveled billions of years.

Hope this brief explanation helps. A good and easy introduction into this matter is the Yale freshmen course that someone else has posted here some time ago:

http://open.yale.edu/courses/astronomy/frontiers-and-controversies-in-astrophysics/home.html

 

[gluadys]

You're confusing two things. The galaxies are not moving away from us. In fact they tend to move towards each other due to gravity. It's the space itself that is expanding, i.e. all distances increase over time.

Graham4C

ClearSky is absolutely right on this point. Many people mistakenly think of the Big Bang as propelling matter through space from a centre point where the Big Bang happened. But it is not a question of matter being propelled through space. It is space itself that is expanding.

Also, the red shift is not the only evidence favoring the Big Bang. In fact, so long as the red shift was the only evidence available, the theory remained hotly contested.

What tipped the scales in favour of the Big Bang was the discovery of the cosmic background radiation: a phenomenon predicted by Big Bang theory but unexplainable under rival theories.

 

[Graham4C]

I have heard of the discovery of cosmic radiation, but that is not proof of the big bang. You could think up an infinite number of theories that explains cosmic radiation, yet it does not prove them.

okay, here's another thing - about space...

The universe consists of clumps of matter due to gravity - this much is agreed upon by almost everyone regardless of religion, etc.
Where there is no matter, there is nothing, i.e empty space. We call it 'space' because is really is just empty space between matter.
So here is the point - if space is indeed just a place where there is no matter, how can you say it expands?

 

[ClearSky]

I have heard of the discovery of cosmic radiation, but that is not proof of the big bang. You could think up an infinite number of theories that explains cosmic radiation, yet it does not prove them.

There is no such a thing as "proof" in science. You can only disprove a theory when it contradicts our observations. You can never prove a theory.

The background radiation is assumed to be huge evidence for the Big Bang because of two reasons. First, it has exactly the temperature that it had when it was caused by a Big Bang, with an accuracy down to a fraction of a percent. Second, there are not an "infinite number" of consistent theories to explain background radiation otherwise. In fact there is none that I would know of.

if space is indeed just a place where there is no matter, how can you say it expands?

The usual example to explain expansion is: Imagine someone puts a valve to the earth, and begins to pump it up. The surface of the earth will then expand. Meaning that all distances on the surface will grow bigger over time.

That's the same as the expansion of the universe. All distances grow bigger. Space without matter is not somehow "exempt" from the expansion.

 

[Graham4C]

The usual example to explain expansion is: Imagine someone puts a valve to the earth, and begins to pump it up. The surface of the earth will then expand. Meaning that all distances on the surface will grow bigger over time.

That's the same as the expansion of the universe, only that it happens in 3 dimensions.

the two are not the same. If you put a valve on the earth and pumped, it would expand because of the pressure of the air on the crust - both are matter. Space is merely empty space, not matter so again ill ask, how can it expand?

The background radiation is assumed to be huge evidence for the Big Bang because of two reasons. First, it has exactly the temperature that it had when it was caused by a Big Bang, with an accuracy down to a fraction of a percent.

How would you possibly work that out? You surely cannot know what the temperature was at the big bang

and about the theories, i could say it was given off by colliding galaxies, stars, comets, or that it is just something put there by God. All of these could be valid as there is no way to disprove them

 

[ClearSky]

the two are not the same. If you put a valve on the earth and pumped, it would expand because of the pressure of the air on the crust - both are matter. Space is merely empty space, not matter so again ill ask, how can it expand?

Well, if there were no matter, you could not measure any distance, and so in some sense you could indeed not say that it expands or not. However I think this is more a philosophical and not a scientific question.

In our real world, we have matter in the universe and can measure distances between galaxies. Thus, we can very well determine that the distances grow and thus space expands. We can also determine the difference between 'real' galaxy movement and space expansion.

How would you possibly work that out? You surely cannot know what the temperature was at the big bang.

We can not "know", but very well calculate the temperature. According to the Big Bang theory the background radiation escaped at a certain time when the universe became transparent. Calculating the temperature for this event is pretty straightforward. It was slightly below 3,000 K. The Big Bang has been simulated in a computer model recently, the Millenium simulation in Garching. The simulation ended up with a universe exactly like that what we have today.

 

[Graham4C]

Well, if there were no matter, you could not measure any distance, and so in some sense you could indeed not say that it expands or not. However I think this is more a philosophical and not a scientific question.

??? why shouldnt u be able to measure distance in space? we can quite easily measure the difference between two points or from one clump of matter to the next.

We can not "know", but very well calculate the temperature. According to the Big Bang theory the background radiation escaped at a certain time when the universe became transparent. Calculating the temperature for this event is pretty straightforward.

So in otherwords, it is being calculated based on the THEORY? Thats invalid

The Big Bang has been simulated in a computer model recently, the Millenium simulation in Garching. The simulation ended up with a universe exactly like that what we have today.

That by no means makes it accurate. the computer merely does calculations based on input data. It is extremely easy to input leading data in the situation

 

[Walpurgis]

3000K is below absolute zero. Surely that would assume a negative pressure?

In what way is 3000 less than 0?

 

[Hnefi]

Proposed mass of Universe – 1.59 x 1055kg
The approximate diameter of an atom – 10-12cm
= 10-14m
Singularity size (a billionth this size) – 10-23m

Therefore, the total gravitational force = 1,07 x 1091 using Newton’s law of Universal Gravitation.

Note that these figures are not my own invention, im merely doing the math.

The force required to accelerate the matter outwards would be greater than 1,07 times ten to the power of 91!!

I'm afraid those calculations are completely wrong. Newtons theory of gravitation is only an approximation. It breaks down when distances become very small or forces become very large, so calculating the force of gravity at the beginning of the big bang can not be done using Newtonian mechanics. The theory of relativity brings us closer, but also breaks down when approaching singularities. There currently is no working theory that can calculate gravity within an event horizon. Put simply: when you approach a singularity, the laws of reality as we know them break down and cease to be valid. We need a theory of quantum gravity to describe singularities.

Would anyone like to suggest where this force would come from?

There is no law of conservation of force. Force can be created by any number of causes.

And its not valid to say that the laws of matter do not operate in singularity - thats not science, and at the time of the Big Bang, the matter would no longer be in singularity...

Actually, it is valid to say that, because the laws of physics simply break down. The equations we use to describe reality do not give any meaningful results in such extreme conditions. The brightest minds in the world are working on a solution to that problem, but none exists yet, so no definite answers regarding the actual moment of the big bang can be given - we can only say what happened a certain time after the initial "bang".

If the red shift is valid, all matter in the universe is moving away from us. This is often cited by scientists as proof for the Big Bang.
BUT, according to NASA, our nearest neighbor galaxy, Andromeda, is moving towards us at a phenomenal rate.
This would be due to the gravitational pull of the galaxies on each other.

Calculations then show that the galaxies will collide in so many milions of years.

Now, if Andromeda is moving towards us, then it is patently NOT moving away from us. Hence, a red shift will not occur when studying any star in the Andromeda galaxy.

Scientists go one further than this to say that galaxies collide with each other ALL THE TIME!
Once again, if they are moving towards each other, they are patently NOT MOVING FURTHER APART.

It's true that Andromeda is moving away from us. It is also true that when observing Andromeda, we do not see a red shift. Instead, we see a blue shift. This is consistent with the big bang theory.

Consider this: imagine a dotted balloon covered with crawling insects being inflated. As the balloon inflates, the insects will be moved apart from each other, and the further apart they were from the beginning, the faster they will move away. But insects have legs and like to crawl. Thus, if two insects are sufficiently close to each other and are crawling towards their neighbour, they will manage to crawl faster than the expansion of the balloon can force them apart. The net effect is that they will eventually collide, eventhough on average, all insects are moved away from each other.

What I'm trying to say is that for things that are relatively close to each other (such as Andromeda and the Milky Way), the relative velocity of the objects can be higher than the expansion of space between them. Therefore, these objects can move towards each other just fine.

This means that the red shift is more than inconclusive, but completely unreliable. The movement of galaxies is explained by pure gravity. We can see that everything is not expanding, and there is evidence for that. The red shift SURELY CANNOT be given as evidence for the Big Bang.

Unfortunately, the movement of the galaxies can not be explained by gravity alone. They do move away from each other on average, and they move faster the farther apart they are. Gravity alone cannot explain this.

And since it is the only "evidence" for the Big Bang, surely the theory holds no water...

As others have mentioned, there are other lines of evidence. Cosmic background radiation is one such example. It was predicted in the 1940's as a consequence of the big bang theory and was observed some twenty years later. The temperature, polarization and anisotropy of the radiation is consistent with the big bang. You'll have to turn to a real physicist or other scientific source for more detailed information.

 

[Graham4C]

Quote:
Originally Posted by Graham4C
3000K is below absolute zero. Surely that would assume a negative pressure?

In what way is 3000 less than 0?

uum, ya. forget i said that, i dont know what i was thinking - that was so stupid - was thinking something else

Consider this: imagine a dotted balloon covered with crawling insects being inflated. As the balloon inflates, the insects will be moved apart from each other, and the further apart they were from the beginning, the faster they will move away. But insects have legs and like to crawl. Thus, if two insects are sufficiently close to each other and are crawling towards their neighbour, they will manage to crawl faster than the expansion of the balloon can force them apart. The net effect is that they will eventually collide, eventhough on average, all insects are moved away from each other.

once again, u are asuming that empty space, i.e "nothing" can expand

 

[Walpurgis]

once again, u are asuming that empty space, i.e "nothing" can expand

It's counter-intuitive but it appears to be true. It's not an assumption though - it's the conclusion of a series of tests and calculations.

 

[Hnefi]

once again, u are asuming that empty space, i.e "nothing" can expand

It's not an assumption, it's the result of actual measurements and theoretical predictions. No assumptions necessary.

I should point out that this is not proof of the big bang. There is no such thing as proof in science. It is "only" evidence in favour of the big bang, which strengthens what was originally a hypothesis into an actual theory. Science can only disprove things, and so far noone has been able to actually disprove the big bang whereas the same can not be said of any other theory with the same explanatory power. Therefore, the big bang theory is more or less universally accepted as the best explanation of the early moments of the universe that we currently have.

 

[Graham4C]

okay, could you name and/or describe such tests to me

 

[Hnefi]

okay, could you name and/or describe such tests to me

Such explanations are, by their very nature, long-winded. Also, as I am not a physicist, my own understanding of the area is very limited. I can, however, give you a couple of sources that explain these things in great detail.

Hubble's original paper wherein he showed that distant objects move away from us is publicly available and can be found here. It should be of great interest to you as it contains the primary research data, methods and conclusions on which the modern theories of spatial expansion are based.

There was an experiment made, detailed here, which demonstrated through observation of distant nebulae that the cosmic background radiation was warmer in the past. In other words, the cosmic background radiation is cooling down. That is only possible if it is heating up in some parts of the universe, it is leaking to outside the universe or if the universe is expanding. The first possibility is demonstrably false, the second is absurd and so the third possibility must be accepted.

Those sources are not light reading. They are scientific articles, and they can be quite a pain to read (believe me, I know!). However, they are the best sources for detailed, technical descriptions of these phenomena.

 

[sfs]

How would you possibly work that out? You surely cannot know what the temperature was at the big bang

But you can know what the temperature was at the time the cosmic background radiation was given off, because that had to have happened when the universe became transparent. That happened when it had cooled enough for the ionized gas that constituted the most of the matter of the early universe to recombine to form neutral hydrogen. It is true that is more difficult to predict the current temperature of the background radiation, since that depends on how much it has been cooled by the subsequent expansion of the universe. The first prediction of the temperature (made well before it was observed) was 5 degrees Kelvin.

and about the theories, i could say it was given off by colliding galaxies, stars, comets, or that it is just something put there by God. All of these could be valid as there is no way to disprove them

You can't disprove the claim that God put it there, to be sure, but "God did it" is pretty useless as a contribution to a scientific discussion. Your other suggestions can be ruled out easily, however, since none of the them will produce radiation with a black-body spectrum, and none of them will produce radiation with the right temperature, and none of them will produce radiation with the observed uniformity.

I really have to ask: just how stupid do you think astronomers and cosmologists are? Do you really think they wouldn't have thought of absolutely trivial objections to such an important theory?

 

[ClearSky]

we can quite easily measure the difference between two points or from one clump of matter to the next.

Exactly. And when scientists observe that all distances expand over time, they conclude that "space is expanding".

it is being calculated based on the THEORY? Thats invalid.

I am not sure about the purpose of such posts - do you want to learn about red shift and space expansion, or just drop some personal opinion? If you want to learn, ask and you'll get answers. But if you only want to express an opinion, it would be useful when you beforehand inform yourself about the object of your statements, for instance with the course I've posted a link to. It makes obviously not much sense to argue about Big Bang theory with someone who has only vague ideas what the Big Bang theory is.

 

[MrSnow]

empty space, i.e "nothing"

And this assumes at least two things:
1) space is empty
2) space is the lack of "stuff"; that space is nothing; space does not consist of anything

Why do you assume that space is empty? Why do you assume that space is "nothing"?

 

[MrSnow]

Matter is a form of energy. The pre-big-bang universe would not necessarily have been "dense", per se.

 

[Graham4C]

And this assumes at least two things:
1) space is empty
2) space is the lack of "stuff"; that space is nothing; space does not consist of anything

Okay, then id like to here your idea of what it is