theoretically (galaxies colliding)

[Gatekeeper777]

not to mention the unkown orbits of bodies in the ort cloud only a few bodies have been discovered there and they estimate that there are thousands there the size of pluto. the orbits can take thousands of youears to compleate so you never know what can happen considering that planetary observation is still very promitive. Also you must take inco account of a varied gravitational flux by passing planets on ort cloud objects as well as passing stars.
They all have a gravitational effect on extra-planetary bodies. All it takes is just a tiny tug and its like a pool table on the break and earth is behind the 8 ball.
Any cosmologist or geologist will tell you its only a matter of time.

[Oneironaut]

Well yeah, it's only a matter of time before the Earth gets hit by something, but something the size of Mars seems pretty unlikely. We haven't been hit by something that big in at least 3-4 billion years (when the universe was a much much much much more hectic and chaotic place), and Earth only has another 5 billion years or so left.

It's not just a tiny tug that will send a large, planet-sized object from the Oort Cloud into the inner solar system. It would take a huge push, according to Isaac Newton. Most of the things out there are smaller and more reactive to small tugs, which is why we see so many comets and so few giant ice planets coming out of nowhere.

In any case, I don't see interplanetary collisions as a serious threat to our species. In all likelihood, a huge collision is not going to happen in the next couple hundred years, and if we don't wipe ourselves out by then I'm sure we'll have the technology to prevent or at least flee such a collision.

[Gatekeeper777]

they have allread worked out the numbers to avoid a collsion. they need at minimum 5 years notics. in otherwords at the curent point in time its immpossible cuz most times we only have a month if we are lucky.
An object the size of mars unlikely but the object to hit earth ond kill off the dinosaurse was only expected to be 1 km and you know there are thousands of them. as well as hundreds of long orbiting and short earth crossing comets and astroids.

On July 9, 2002, MIT astronomers discovered 2002 NT7, a 2 km-wide space rock in a curious orbit. Unlike most asteroids, which circle the Sun in the plane of the planets, 2002 NT7 follows a path that is tilted 42 degrees. It spends most of its time far above or below the rest of the solar system. Every 2.29 years, however, the asteroid plunges through the inner solar system not far from Earth's orbit.

After a week of follow-up observations, researchers did some calculations. There was a chance, they concluded, that 2002 NT7 might hit our planet on February 1, 2019. The odds of impact: 1-in-250,000.

also see..
News Article: 1997XF11 and its possible hazard to the Earth.

[iwantFUEGO]

I dont believe that space is infinite...

I lean more toward believing in dimensions.

If you observe carefully, physics is very consistent in the universe.

Our atoms have particles orbiting them and also exhibit attractive forces.

What if our universe is nothing more than than the "liver" of some crazy huge being that lives in the dimension above us... and in the dimension below us, there are whole civilizations living on 50% of the atoms in our bodies.

What if these "galaxies" are actually specialized inside of a huge cell to carry out different functions just like in our cells. Do you really think that we as humans will ever be able to see that big of a picture?

Thats like the civilization on our atoms trying to see us....

:S5:

[Amun]

galaxies wouldnt collide.


...the multiverse is constantly growing. it has only been growing since the day it was created. erverything is moving father appart.......i dont really think that would be a realistic thing to expect.

but hell, im no astronomer....

[420ultimatesmokage]

they have allread worked out the numbers to avoid a collsion. they need at minimum 5 years notics. in otherwords at the curent point in time its immpossible cuz most times we only have a month if we are lucky.
An object the size of mars unlikely but the object to hit earth ond kill off the dinosaurse was only expected to be 1 km and you know there are thousands of them. as well as hundreds of long orbiting and short earth crossing comets and astroids.

On July 9, 2002, MIT astronomers discovered 2002 NT7, a 2 km-wide space rock in a curious orbit. Unlike most asteroids, which circle the Sun in the plane of the planets, 2002 NT7 follows a path that is tilted 42 degrees. It spends most of its time far above or below the rest of the solar system. Every 2.29 years, however, the asteroid plunges through the inner solar system not far from Earth's orbit.

After a week of follow-up observations, researchers did some calculations. There was a chance, they concluded, that 2002 NT7 might hit our planet on February 1, 2019. The odds of impact: 1-in-250,000.

also see..
News Article: 1997XF11 and its possible hazard to the Earth.

Even worse is apophis, it is going to have a 1 in 45,000 chance of hitting earth in 2029
99942 Apophis - Wikipedia, the free encyclopedia
Impact event - Wikipedia, the free encyclopedia

[slipknotpsycho]

see i never knew they were always colliding tho o.0

[madeline]

Galaxies have in the past and still DO collide and there are also large objects in our solar system that can still do us harm even though they are not currently in line to hit us. Gravity changes all the rules of nice and neat orbits and anything passing by can knock them out of their current and presumably safe orbits. Even a passing star can stir up the oort cloud and send a planetary size comet our way...it's not a matter of if, but WHEN!

[Gatekeeper777]

a rogue comet the size of pluto coming at me at 67,000 miles per second still will mess up your day, but the odds of it actually happening in my lifetime are relitively low.

[Bob the Awesome]

I dont believe that space is infinite...

I lean more toward believing in dimensions.

If you observe carefully, physics is very consistent in the universe.

Our atoms have particles orbiting them and also exhibit attractive forces.

What if our universe is nothing more than than the "liver" of some crazy huge being that lives in the dimension above us... and in the dimension below us, there are whole civilizations living on 50% of the atoms in our bodies.

What if these "galaxies" are actually specialized inside of a huge cell to carry out different functions just like in our cells. Do you really think that we as humans will ever be able to see that big of a picture?

Thats like the civilization on our atoms trying to see us....

:S5:

Holy crap I've seriously thought up the same thing before... that's insane. I remember telling my friends that idea when I was in 9th grade, they all thought I was insane.