How is it possible for Galaxies to collide if the Big Bang theory is to be believed?

Question

If the Universe began from one point and is exploding outward, it would seem that there wouldnt be any collisions at all. Yet we have photographic evidence of these occurences. How is this so?

Contrary to what some here are saying, I do not have anything against the Big Bang Theory. I'm motivated to ask solely in the spirit of learning.

Answer 1

Even after the period of inflation just after the Big Bang, not everything would be moving outward from a single point. So some clumps of matter (that eventually would become galaxies) would be moving in different directions.
Plus the gravitational influence of existing galaxies (including the "kick" delivered to interstellar dust clouds and stars by supernovas) would impart random motion to galaxies. Once 2 of them get close enough to each other, their mutual gravitation could pull them together to collide or side-swipe each other.

Scientists don't believe that the universe started at one specific point. Not like blowing up stick of dynamite that has a discreet location.
Its complicated, and worth researching. Check out www.astronomy.com for some fairly easy-to-read articles on inflation theory, etc.

Answer 2

There are several credible theories regarding the beginning of OUR universe. However, it is a near certainty that neither space nor time existed at time zero. These developed as the universe developed and expanded.

One concept why different object travel at different velocities and directions is that near the initial time zero, that there were inconsistencies in the primordial singularity.

But there are several subsequent forces that could explain this feature of our universe. Don't forget that Einstein theorized (almost a certainty) that time and space is curved by massive objects. Most people convulute this fact with gravity.

Accordingly, even if the PS was totally consistent, different objects could assume different velocities and directions according to the curvature of the space inwhich they are located and the accompanying mass of the object. Gravity, which is a totally different force, would have an impact in a more local sense. Gravity, compared to the other forces (that we know of), is relatively a very weak force.

Another theory, Entropy, states all matter and energy progresses, naturally, to a more disordered state. Therefore, although it appears the nebulae coalescre into the more ordered state as stars, they are actually evolving into more disorder.

Briefly, I hope that you will realize that most cosmological events are not simple events manifest from a simple theory, but rather a complex interacting of many different thoeries that are based on probability rather than certainty. But this is another story.

Answer 3

You do a small mistake in thinking:
The theory of the Big Bang does NOT postulate that all movements were perfectly regular into all directions.

Besides, you may know about super forces caused by super novae and or supermassive black holes. The sudden constellation of a cluster of galaxies (sudden in astronomical sense) can cause a single galaxy to go another direction, hence collisions do happen.

btw ... I do doubt that theory of Big Bang, too ... however, I am not a professional scientist who would be able to deliver evidence for any other theory ... but I do understand your doubts.

Answer 4

Bender :

Galaxies are formed through spiraling gas clouds and
nebulae that generate gravity of varying dimensions. When
galaxy is formed, gas and dust in the region of this cloud is
sucked into the center of the galaxy core fueling the grav-
ity and the spin of the Galaxy. Sometimes, under certain
circumstances, Galaxies will gravitate toward each other
due to opposing gravities. .One Galaxy having a greater
spin and density of stars will attract , gravimetrically ,
the smaller less dense galaxy of stars .... even from
several hundred lightyears away. And when it happens ..
talk about worlds colliding! Gravity distortions can be felt
thousands of light-years away

Answer 5

If the big bang theory is right, we are expading, but that doesn't mean that gravity of near galaxies cant make us rotate over the center of our universe (the place with the most of the mass) and over other places with lots of mass. So, expading is just the beginning but there other forces that can change our trayectory in the midtime. Remember that there are black holes and other very densed object in space that may drastically change the routes of planes, solar systems and so on.

Answer 6

Not exploding, expanding. There's a difference - like blowing up a balloon rather than popping it. That said, although everything on the whole is moving away from everything else, the gravity in galaxy clusters is enough to overcome that overall movement in favor of some random movement within the cluster (which is moving away from everything else as a whole). So a close-by galaxy's gravity will overcome the expansion.

Answer 7

Trust the answer that says they don't know for sure but may attempt to give some explanation.
Ultimately you have to decide whom to believe.
Education is an honourable thing Just don't forget your a child of the universe too.Hugh Ross has some interesting prospectives if you have an open mind. Fingerprint of God is his book.

Answer 8

Space time on the scale of the universe is expanding, but local galaxies close enough to feel each other's gravitaional pull can still fall toward each other.

Answer 9

Dam jhstha beat me again, I always find my answer written before I can start typing! I agree with every thing besides your dislike of the big bang, I mean HAVE YOU SEEN WMAPs BACKGROUND RADIATION PICTURE!!! its practically the big bang itself!

nice going not often someone else knows what there talking about.

Answer 10

Not all things move out at the same velocity or in a linear path . Also, subsequent gravitational forces come into play.