Eh, the odds of actually colliding with anything is low enough. Plus the night sky would probably be even more breathtaking. I’m in
I think there’s maybe more risk with the solar system being thrown off balance with other gravitational forces pulling things out of orbit. Even if earth just gets pulled away from the sun a little we are screwed. Or even the moon pulled away from earth somewhat.
Even if earth just gets pulled away from the sun a little we are screwed.
I get what you’re saying, but had to laugh at the use of “a little” here. The goldilocks zone in the solar system is roughly the between the orbits of Venus and Mars, and we’re almost right in the middle of it, so “a little” is like 150 million km.
I would imagine that the first issue we would experience would be that the moon would be pulled out of Earth’s orbit first and then we lose the ocean tides and the stable tilt of the earth. It would probably get worse from there.
Goldilocks zone is basically just where life can survive.
Even if we stay within the Goldilocks zone doesn’t mean that most of the species alive today won’t go extinct because it fucks up the seasons or the magnetic poles or tilt of the earth, etc.
Maybe we’ll get lucky and it’ll counter global warming
Just keep scooting away a little every year, problem solved
Could the other galaxy please pull us just the correct distance away from the sun to cancel the effect of global warming?
Given the vastness of space, this is a lot less likely than you might think, and the process itself would likely take millenia anyway.
It’s even safer. The odds that it’s coming directly at us to “collide” is low. Moving towards us doesn’t mean it’s moving directly at us. If you’re driving down the road, all cars going in the other direction get doppler shifted. They’re coming towards you, they pass beside you (hopefully), and then they’re moving away from you.
Oh no! We might not survive the collision to hundred fifty thousand years from now!
If it’s billions of light years away it might be just a little longer than that.
*must be
ELI5?
If something is red shifting, it’s accelerating away from you. If something is blue shifting, it’s accelerating towards you. An entire galaxy accelerating towards you is somewhat concerning.
Redshift comes from relative velocity (and other effects), not acceleration. Andromeda’s light is blueshifted as it’s moving towards us, but it’s not accelerating.
On top of that, we’ve found that basically everything is redshifting as the universe expands. So to see a blueshifting galaxy would mean something potentially unnatural.
You know how the sound of things moving from you changes? Towards you the pitch is higher, away from you it is lower. The same happens with light. We know how some things should look like, so if they are more toward red or blue, we know their speed relative to us. Blue = towards us = “we will collide” (you also do not collide with every car with a siren where you hear that effect).
I know you can’t see this comment but maybe someone else will find it useful
Just like how a siren changes pitch when it’s coming from a vehicle passing by due to the Doppler effect, the same thing happens to moving light sources due to relativistic effects.
Usually astronomical objects are redshifting because the universe is expanding and are thus receding away from Earth’s frame of reference. Most of them are forever unreachable even if we could travel at the speed of light.
Something blueshifting means it’s coming closer from Earth’s frame of reference. In some cases, this could result in the galaxy colliding with ours, such as the hypothesized collision between the Andromeda Galaxy and the Milky Way
If it’s blue shifting from that distance, then it’s likely some advanced technology is moving it in our direction.
There’s not many other explanations for that.
Could it potentially be an object orbiting around the cosmic center that just so happens to have an orbital path that crosses us?
I have to admit that astronomy is what caused me to change majors, but that’s because I stopped going to class when the lesson was, “This is a terrestrial planet, it’s rocky,” and my first exam was like, “If it’s 5:45pm in Tanzina on October 15th, how many degrees is the moon above the horizon?”
Since the speed something is moving away is dependent on the distance, something billions of light years away is absolutely not going to be moving towards us, regardless of its local orbits.
Had to do AM because it’s below the horizon in the PM.
So blue is moving toward you?
I was always a bit confused with the explanations in high school. But I also got a D in physics so maybe I’m just dumb.
Blue shift, it’s moving towards you, the photons are being “compressed” to a higher, bluer frequency. Redshift, the light is being “stretched” to a lower, redder frequency. Both only noticeable at significant fractions of the spped of light, relativistic speed.
Something ominous about the post is that a cosmic object that is moving towards you at a steady rate is consided “blueshifted” in the past tense, it’s velocity is steady. If a galaxy is “Blueshifting” in the present tense, then that galzy is somehow accelerating at you, which is impossible unless it’s under direct control by an entity, presumably a kardeshev level 3 civilization.
Isn’t the rate of expansion in the universe increasing, and at an uneven rate at that? Meaning it could just as easily be an as of yet unknown natural phenomenon?
You see an hughe comet in the sky…but which stand still and it gets bigger and bigger.
isnt andromeda gigantic in the night sky but weve got too much light pollution to see it normally?
anyway retvrn to alien
Milky Way is going to collide with Andromeda… over the course of millions of years, and due to the distance between stars and other objects the two galaxies are just going to merge with each other and very few things will actually make physical contact.
Well, if they collide (and merge), they’ll also fling a lot of stars into the void, but we aren’t too sure anymore that’s actually gonna happen. NASA explains why (YT, 2:30min).
