Interesting theory on the big bang. Need a Sheldon Cooper to agree or offer the anti-thesis.

All galaxies are moving away from each other as a result of the big bang, we know this, right? Can someone answer this for me:

If most galaxies have black holes in their center, sucking everything in, then surely there comes a point when gravity overrides the momentum gained from the big bang, drawing all galaxies back in to one piece of matter (eventually).

Galaxies are colliding and becoming one, which will eventualy happen to our own milky way and our nearest neighbour, Andromeda. So, stop me if im wrong here: more mass = more gravity. Given that in space there is nothing but a void, surely, eventually gravity will override the momentum of the big bang on galaxies draw them all back in to one finite point, like it was prior to the big bang?

That said, gravity is both the strongest and the weakest force in the universe. If only light enough to move objects in space (look at a comets tail always pointing AWAY from the sun, or ION propulsion) is there any way this would override gravity. Lets not forget light in the universe wont last forever?

Im clearly no physicist, but its food for thought and would be good if someone else can offer anything to it.....

According to Hawking, the universe will eventually contract and form a singularity which in turn will create another universe. Our current universe may well be just one of many in an unbroken chain.

you know, i knew id heard the theory somewhere before!

It then begs the question, what does it expand into. Boggles your mind, it realy does

Actually the universe is in a period of accelerated expansion caused by dark energy. The farther objects such as galaxies are away from us, the faster they are moving away from us. It appears that the universe will end in scattered isolation as the big "crunch" (gravity bringing all the mass back together) will never happen. All the suns will die. Protons will break down causing the last ice cream to melt.

NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO,Not My Icecream!

So dark matter is constantly being created? How does that work?

No, dark matter and dark energy are two completely separate things.

Dark matter surrounds the galaxies and causes the stars to orbit their central black hole at a more or less constant speed. Without dark matter, the speed of an orbiting star near the central black hole would be much greater than the speed of a distant star in the same galaxy. Dark matter can be observed by the gravitational lens effect it has on distant stars but cannot be observed directly as it is not affected by electromagnet radiation.

The newest NASA satellites have made very accurate maps of the dark matter.

Wow. That's amazing :)

Do scientists have any idea of what dark matter actually is yet? And is dark energy constantly being created?

Scientists think that the most likely possibility for dark matter is a particle that has mass but does not interact with light or other electromagnetic radiation. In other words, a particle that allows light to pass through it undisturbed. The most likely structure of these particles are WIMPS (Weakly Interactive Massive Particles). Of course their exact nature is still unknown. Scientists have been trying to capture some, but due to their weakly interactive nature, they are hard to pin down ... somewhat like a neutrino.

Another candidate is the MACHO (Massive (astrophysical) Compact Halo Object). The "halo" is the invisible cloud around the galaxies that provides the mass that provides the gravity to equalize the orbital speeds of the stars in a galaxy.

A long discourse along the lines of how they fit into the Standard Model of particle physics is beyond this thread. But there is a lot to read about if you are interested.

http://www.astro.caltech.edu/~george/ay20/eaa-wimps-machos.pdf

However, the dark energy question is somewhat of and "chicken or egg" type question as to which came first, the dark energy pushing the universe apart or the expansion of the universe allowing the dark energy to be created from the "void". Some think that dark energy is a inherent property of space itself.

Perhaps the most logical (even if somewhat speculative) version of dark energy is a continuation of the energy expended during the big bang. It was slowed somewhat while the universal mass was concentrated enough to affect all other mass with gravity, but as mass is dispersed in the expansion of the universe, gravity has a decreasing effect and the force of dark energy can continue unabated.

If you combine these theories with M-Theory of multidimensional space, you can see how a shock wave of two colliding dimensions could create the big bang and provide the energy to sustain it.



Here is a short u-tube on M-theory which shows how modern physics has included extra dimensions to answer some questions about the universe.

http://www.youtube.com/watch?v=HOkAagw6iug

The replacement for the Hubble is the James Webb. He led NASA during the Apollo period. The new satellite is more infrared focused for deep space viewing but has some visible light capability.

Quantum physics has pretty much taken dark matter/energy out of the picture...DE was an invention of scientists to mathematically fill the voids of why the universe is expanding, where as quantum fills the voids with out DE/DM..

I think the universe is a big recycling pit, and has been around for trillions of years, and will be around for trillions more...

http://news.nationalgeographic.com/news/2011/08/110831-dark-matter-proof-gravity-quantum-theory-cern-space-science/

The comet tail is formed because of heating by the sun and the solar wind, not so much by gravity.

No such thing has happened. One guy has one theory about quantum anti-gravity. That hardly takes it out of the picture. This is what one physicist has to say about the "no dark matter theory".

"Evidence for Dark Matter "Very Compelling"

Physicist David Evans called the new study a "very interesting theoretical exercise," but he said he isn't ready to abandon dark matter just yet.

"The evidence for dark matter is now very compelling," said Evans, of the University of Birmingham, who leads the U.K. team for the ALICE detector at CERN's Large Hadron Collider.

For example, in 2006 astronomers unveiled a photo of two colliding galaxies known as the Bullet cluster that purportedly showed the separation of matter from dark matter.

A similar effect was observed in the Pandora cluster earlier this summer, said Evans, who was not involved in the study.

(Related: "Dark Matter Proof Found Over Antarctica?")

Hajdukovic said he is currently expanding his theory to account for these observations. His preliminary calculations, he said, suggest that "what is observed in the Bullet cluster and more recently at the Pandora cluster may be understood in the framework of the gravitational polarization of the quantum vacuum."

CERN physicist Michael Doser agreed that Hajdukovic's ideas are "unorthodox" but did not immediately dismiss the new theory."

it's all just theory, and even you have to admit it was a mathematical fill to make their equations work to show why the universe is expanding instead of contracting... in other words, they invented DE/DM to make their math right... now, instead of looking for the real reason, they are trying to prove themselves right rather than looking for the true reason....

You could not be more wrong. Yes DM/DE is a theory. They have backed up their theories with astronomical observations of both the gravitational effects on light and a more complex analysis using the converging galaxies as described above. "They" represent a combination of the top physicists and astronomers in the business and are the theories taught at major and minor universities around the world.

Your claim that all that has been replaced by one guy's theory using the quantum effects of anti-gravity is simply not true.

one word... theory... you don't know, and i don't know... and quantum does take it away, it's just not accepted yet...