Thread: Question about the Big Bang

A SCIENTIFIC THEORY is based upon facts, laws and hypothesises, is testable and falsifiable, has no evidence that can't be worked into the theory (has never been demonstrated to be false) and due to the overwhelming amount of evidence in support is considered the best hypothesis (all theories are hypothesis but not all hypothesises are theories) available. It is however not considered proven as proof is considered impossible in science. Science is based upon probability not absolute certainty.

Originally Posted by injest

Honest question, people, I really don't know that much about it.

but from what I understand, the Big Bang says that there was a big explosion and everything in space is moving away from this point. And if something in space is moving, it will keep moving until something acts on it..

so how could we be on a collision course with another galaxy?


http://news.yahoo.com/milky-way-gala...194656925.html

The big bang refers to a singularity of all mass in the entire universe merged into a point so small it literally takes up NO space. This is postulated in Einstein's theory of general relativity.

It exploded in something like a millionth of a millionth of a millionth of a second and expanded very fast. This is called "inflation".

SO, the big bang does not relate to a collision of 2 galaxies. BUT, we are indeed on a collision course with our nearest (and larger) neighbor, Andromeda. It's expected to occur in about 4 billion years. The Milky Way and Andromeda are the two largest galaxies in our local group and it's believed both have absorbed other galaxies in the past.

In fact, we are absorbing two small galaxies now, called the Larger and Smaller Magellanic Clouds.

Originally Posted by Trinnity

In fact, we are absorbing two small galaxies now, called the Larger and Smaller Magellanic Clouds.

No. The Magellanic Clouds are 160,000 light years away. No absorption going on yet.

Originally Posted by mutmekep

The centers of most galaxies are black holes , massive ones .
A black hole to put it simply it is gravity that went mad , because those holes are massive they don't suck as much matter as smaller ones so all this matter rotates them creating galaxies .

That's wrong.

Super-massive black holes are at the center of most if not all galaxies. Beyond a certain point (even horizon) the gravitational pull from the SMBH is not enough to pull in the other elements in the galaxy. But the gravitational attractions do keep the galaxy together. A Black hole will pull in anything that's within it's even horizon.

Additionally, as a SMBH gets denser, it's pull is stronger, enlarging the event horizon.

Originally Posted by fmw

While gravity has a tendency to want to pull things together, most objects in the universe are far enough away from other objects that gravity alone can't get the job done.

Thus "dark matter" gets involved in the situation.

Originally Posted by fmw

Dark energy is not as popular as the multi universe theory. Many physicists turn their noses up at something that is invented and isn't detectable. The purpose of dark energy is to complete some mathematical equations that help explain things we don't understand about the universe. My own view is that we need to understand those things without inventing undetectable masses. Many would agree with me.

Dark energy IS detectable. It can be seen as it affects the optical aspect of how we see some objects through our space telescopes. Not sure I'm explaining that well.

Originally Posted by fmw

No. The Magellanic Clouds are 160,000 light years away. No absorption going on yet.

Wrong~

Milky Way Already Colliding with Magellanic Clouds!

February 4th, 2008,

Astronomers from CSIRO have recently discovered, with the help of radio telescopes at Parkes and Narrabri, that gas coming from the Large and Small Magellanic Clouds is penetrating through the material disk of the Milky Way right over to the other side. Such gas flow observations may eventually provide data that would reveal the ultimate fate of the little galaxies, in the near vicinity of our Milky Way.

The leak of matter was dubbed HVC306-2+230 and is spanning all the way from the Magellanic cloud to the material disk of our galaxy, piercing it in a location about 70 thousands light-years away, near the Souther Cross. According to CSIRO astronomer Dr. Naomi McClure-Griffiths, from the Australia Telescope National Facility, such a discovery represents an important find for the astronomical community, especially while taking into consideration the fact that gas features are very hard to spot from great distances.

Originally Posted by injest

Honest question, people, I really don't know that much about it.

but from what I understand, the Big Bang says that there was a big explosion and everything in space is moving away from this point. And if something in space is moving, it will keep moving until something acts on it..

so how could we be on a collision course with another galaxy?


http://news.yahoo.com/milky-way-gala...194656925.html

This wont move in one direction forever. It will depend on objects gravetational pull to the other objects around it as to what direction things will move. If there is more gravitational force for an object to move one direction it will. Or, an object may influence its movement slightly even if the graviational pull is slight. So not everything is moving away from everything else.

I noticed much nit picking as I skimmed the replies etc. Still M=most of the replies were very good! I absolutely love cosmology and astronomy, next to custom Harley Davidson’s, preferably pre 1960 machines. The iron in those big Vtwin jugs (cylinders) were forged in the heart of second generation stars as was all elements heavier than He and H.

Anyway, as some members said the big bang was the universe suddenly expanding faster than the speed of light (inflation) from an singularly type ’point’. Still the BB did not arise out of a traditional singularity. It was different than a singularity created from a black hole (according to theory). Space, time, all the fields of energy, gravity, mass, literally everything was created about 14.7 billion years ago in the BB. Again some members were correct in saying that stuff is not expanding from the center point where the expansion began. More accurately every thing is expanding away from everything else, and anywhere is the center of the universe. So when two galaxies collide for example try to cop a visual and envision everything expanding away from everything else, not every thing is expanding from a certain point. Yes it is counter-intuitive! So since there is no center point galaxies can collide as can planets or stars or even dust particles. As far as the expansion goes a fantastic and strange thing is happening. Instead of everything slowing from the initial expansion like scientists expected, everything is speeding up, the objects that are 'farthest away' are moving the fastest. That is truly whacky! Gravity should be slowing all mass in the universe down and eventually pull everything back in making a big crunch that would create another big bang.

That is where the dark energy comes in to play and its literally a made up thing. No one has ever seen it or tested it. it’s a theoretical guess. Lastly there is dark mass. As it stands today our universe is missing almost ALL ITS MASS! So our wonderful secular scientists also made up dark mass. Gots to love that science eh? Well I do love it but too much faith is put into it IMO.

Reva

Originally Posted by Trinnity

Wrong~

I am wrong indeed. I was assuming a galactic diameter of around 30,000 light years. I checked with an astronomer I know. He pegs the galactic diameter closer to 100,000 light years and agrees the Milky Way is in the process of eating the Magellanic Clouds. Thanks for the correction and please accept my apologies for the bad information.