Action Vs Reaction

[rewind]

Robbo,
dark matter is the mater theorized due to the imbalance of glaxies and solar systems gravitational pull and centrifugal force.

Essentially, I dont know how, scientists worked out out that the centrifugal forces exerted on the outside planets/ starts/ systems un the solar systems/ galaxies were such that it counter acted, and outweighed the gravitational forces that theoreticly held them inplace.

In principle this would mean that they would be flying out this way and that, rather than sticking in the places that they do.

They then theorized that there must be something 'holding' the planets/stars/systems in on the outer rims, and this 'something' was dark matter.

The only problem is that theoretically, it cant be measured, observed, cought or anything. the only proof of its theoretical existance, is that these galaxies and solar systems are not spinning themselves apart when they should be.

(atleast, thats my understanding of dark matter)

the thing with black wholes, and peoples fasination about them, is that essentially they are just an object of such high mass, that its gravitational forces pulls in and crushes/destroys anything near it, so why do people see them as gateways and portals etc? are these people just stupid?

the other thing, is if anti matter and matter are supposed to be opposites, how come that it takes so much matter to create anti-matter, and how can it create it at all, if anti-matter cant create matter, the same should be true of matter

 

[Robbo]

Robbo,
dark matter is the mater theorized due to the imbalance of glaxies and solar systems gravitational pull and centrifugal force.

Essentially, I dont know how, scientists worked out out that the centrifugal forces exerted on the outside planets/ starts/ systems un the solar systems/ galaxies were such that it counter acted, and outweighed the gravitational forces that theoreticly held them inplace.

In principle this would mean that they would be flying out this way and that, rather than sticking in the places that they do.

They then theorized that there must be something 'holding' the planets/stars/systems in on the outer rims, and this 'something' was dark matter.

The only problem is that theoretically, it cant be measured, observed, cought or anything. the only proof of its theoretical existance, is that these galaxies and solar systems are not spinning themselves apart when they should be.

(atleast, thats my understanding of dark matter)

Well, I don't think the above can be your understanding of dark matter rather you acknowledge the effects of dark matter.

the thing with black wholes, and peoples fasination about them, is that essentially they are just an object of such high mass, that its gravitational forces pulls in and crushes/destroys anything near it, so why do people see them as gateways and portals etc? are these people just stupid?

No, they aren't stupid Rewind, anything but, it might do you well to consider reading up a little more on the subject and maybe look at what happens when somebody starts to feel the effects of the black hole's gravitational pull in slowing time down for that person ..... the idea of a portal to another place/dimension/whatever you wanna call it, is a natural theoretical consequence of a singularity where classical physics breaks down.

the other thing, is if anti matter and matter are supposed to be opposites, how come that it takes so much matter to create anti-matter, and how can it create it at all, if anti-matter cant create matter, the same should be true of matter

I'm pretty sure anti-matter could make matter, leastwise I haven't heard of it being dispelled.
To manufacture anti-matter, it takes vast amounts of energy but that's because it has to mimic those first few moments of the big bang where the temperature was insanely hot, insanely hot.

 

[Bon]

Not to mention, the second antimatter is created it has to be contained in a perfect vacume in a magnetic feild so it cannot react with anything.

This in its own must give it a limited sheld life.

 

[chrizwheatley]

Another little thing i had been thinking about which is kind of the same was these theories, what will happen towards the ends of our universes life or if it will happen.

Some think that eventually the universe will end with a 'big crunch'. Meaning it will eventually get so big and the energy will run out that it will end up like an elastic band and shrink back into itself, kinda like a black hole? Some think it will do the opposite and just keep getting bigger until the energy just runs out, the suns die until no light or nothing that they call the 'big freeze'.

I think they both sound good but there are a million ways it could happen.

Do you think these fit within the action vs reaction thread?

 

[Tony Harrison]

I never realised nick brockdorrf was one of their script writers ????

Preach on, Brother!

 

[Robbo]

Another little thing i had been thinking about which is kind of the same was these theories, what will happen towards the ends of our universes life or if it will happen.

Some think that eventually the universe will end with a 'big crunch'. Meaning it will eventually get so big and the energy will run out that it will end up like an elastic band and shrink back into itself, kinda like a black hole? Some think it will do the opposite and just keep getting bigger until the energy just runs out, the suns die until no light or nothing that they call the 'big freeze'.

I think they both sound good but there are a million ways it could happen.

Do you think these fit within the action vs reaction thread?

Once again Chriz, I think your questions tend to reveal the fact you haven't really understood some of the fundamentals of this subject matter.

As for millions of ways the end can come, in fact, the speculation was only three ways.

a) The universe continues expanding

b) It stays the same, neither expanding nor contracting

c) It eventually contracts

In 1929, Ed Hubble discovered the universe was expanding because he was able to measure the frequency shift in moving galaxies and in doing so, realised we (galaxies) are all moving away from each other.

This red shift is much like the Doppler shift when you hear a siren go past but with galaxies, it is an emergent property of light rather than sound.

This discovery quashed any idea of a static universe and it only remains for the astro-physicists to decide between an ever expanding universe and a contracting one that leads to the big crunch as against our universe's genesis, the big bang.

For our universe to contract, we have to discover a lot more mass and at the moment, the required gravitational attraction to pull us all back in, just isn't there.
Maybe dark matter is the missing mass but this as I have said before has yet to be confirmed in any way other than from a pen and paper.

Chriz, keep reading mate and you'll eventually get there but I think it's gonna be a close run thing between you understanding it all and the big cunch.

JK ......

 

[Igotya]

I was under the impression that scientists had already calculated the rate of expansion and found it to be slowing allowing them to roughly estimate when said expansion would stop I may be totally wrong and I bow to robbo who from previous posts I have read is far more qualified than me to answer this but if my memory is correct it's millions of years away

 

[Robbo]

I was under the impression that scientists had already calculated the rate of expansion and found it to be slowing allowing them to roughly estimate when said expansion would stop I may be totally wrong and I bow to robbo who from previous posts I have read is far more qualified than me to answer this but if my memory is correct it's millions of years away

Firstly, scientists had calculated rates of expansion, I suppose the most famous of which was Hubble who was the first person to discover the expanding universe (and other galaxies) and he achieved this by measuring the red shift of the light from the other galaxies with respect to our own.

But recently, it's been discovered that instead of the rate of expansion slowing down as first thought, it seems it's speeding up.
The reason for this?
Well, dark matter and dark energy make some guest appearances but I'm afraid it's only speculation at the moment and the jury's still out on that one.

As for when the big crunch may (or may not) happen, don't worry too much about that, it's not millions of years, it's billions.