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bmpbmp
2003-Sep-25, 03:52 PM
Isnt this bad and dangerous for us

http://edition.cnn.com/2003/TECH/space/09/25/space.cannibal.reut/index.html

Reacher
2003-Sep-25, 03:59 PM
Um, how, exactly?

I can't see it being dangerous to us. Care to clarify how you think this will affect us?

This kind of thing has been observed before. Well... that or I've read that article before. I'm certain, though, that I have read about other galaxies chowing down on their neighbours. I'm not worried about it, but I'm not an expert in... well, anything.

Eta C
2003-Sep-25, 04:00 PM
No. Chill. Relax. Have a beer if you're over 21 and don't plan to drive for several hours.

This event is clear on the other side of the galaxy. We couldn't observe the dwarf galaxy because of the dust and other stuff in the galactic center. It's not likely to cause any observable effects over here.

bmpbmp
2003-Sep-25, 04:05 PM
stars in sagitarious or maybe milky way to explode or have a bad effect also doing damage to the milky way with earth in it

Reacher
2003-Sep-25, 04:11 PM
Well, from my understanding, Sagittaruis is just getting torn apart. No exploding, no bad effects. I mean, the term 'eaten' is not literal. The Milky Way has no intestines. And the effects on the Milky way will be minimal, i think, especially im our neck of the... galaxy. It would have been mentioned in the article if it was dangerous.

bmpbmp
2003-Sep-25, 04:13 PM
Coulnt it cause a chain reaction affecting the earth or milky way i mean if they are merging together and stuff

Reacher
2003-Sep-25, 04:15 PM
What kind of chain reaction? It's probably on the other side of the galaxy anyway. If any stars were to explode, which I severely doubt they will, it will affect us in absolutely no way. Except a pretty little light in the sky.

Rue
2003-Sep-25, 04:17 PM
CNN makes it look like this has only just begun to happen but it most likely is a process that has been going on for a long time, and will continue for a long time to come.

Now perhaps this thread will turn into a big bang debate. If galaxies are moving away from each other how do they collide?

bmpbmp
2003-Sep-25, 04:17 PM
The milky way explode or get chomped down or something,,,

I am confused here

Reacher
2003-Sep-25, 04:26 PM
I noticed.

bmpbmp
2003-Sep-25, 04:29 PM
will continue for a long time..I am very confused about the article and how this would have no effect on us. How many light years away is it and how long would it take to reach us here on earth..

Grey
2003-Sep-25, 04:32 PM
stars in sagitarious or maybe milky way to explode or have a bad effect also doing damage to the milky way with earth in it
Remember that galaxies are mostly empty space. Even when galxies collide, the individual stars pretty much just pass by each other without much effect. Even if the overall structure of the galaxy is changed dramatically (and for that to happen to the Milky Way in this case, the Sagittarius galaxy would have to much, much bigger), the stars are unaffected. So the net result here will just be that the Milky Way will incorporate some new stars. And, as others have pointed out, the Milky Way is a pretty big place and this on the other side. Even if there were something cataclysmic going on over there, we wouldn't be affected.

Reacher
2003-Sep-25, 04:33 PM
This will not affect us because there is no reason for it to affect us.

And what do you mean 'For this to reach Earth?' For what to reach Earth? Nothing will reach Earth. The Milky Way will not be digested by something already half digested. It will not explode.

Also, when I say digested, I don't mean it literally.

bmpbmp
2003-Sep-25, 04:47 PM
A star or something in sagiterius explodes or something how long would it take to reach the earth.

Also What do you mean by half eaten...If the milky is going into the sagitarious inst sagitarious coming into us to...

Come someone explain my ilogic in a non scientifc way that I may understand what is going on.

Thanks

Musashi
2003-Sep-25, 04:51 PM
A star or something in sagiterius explodes or something how long would it take to reach the earth.

For what to 'reach' earth? The light? a long, long time. For any effects? Never.

Reacher
2003-Sep-25, 04:52 PM
Well, as is said above, basically, from what I know, Sagittarius will continue to move into our own galaxy, and the stars will probably not interact, because a galaxy is mostly empty space. Sagittarius will lose it's shape, and it's stars will be sucked into our galaxy. I don't see why you think something has to explode.

And by digested, I meant that Sagittarius is no threat to the milky way, what with being half disintegrated and all. Also, it's really, really small by comparison.

ToSeek
2003-Sep-25, 04:53 PM
Two points:

1. The Sagittarius Galaxy is 78,000 light years away. (http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1995MNRAS%2E277%2E%2E781I&db_key=AST)

2. The "being eaten" refers to the loss of structure by the galaxy. Individual stars would scarcely be affected. Think of it as a stick floating along a stream that feeds into a much larger river. The stream loses its identity in the river, but the individual stick will just continue to float.

Reacher
2003-Sep-25, 04:54 PM
Go ToSeek!

See, I was looking for an analogy like that.

Tensor
2003-Sep-25, 05:01 PM
A star or something in sagiterius explodes or something how long would it take to reach the earth.

Since it is on the other side of the Milky way, about 100,000 years.


Also What do you mean by half eaten...If the milky is going into the sagitarious inst sagitarious coming into us to...

The dwarf galaxy is colliding with the Milky Way. The dwarf is being pulled into the Milky Way by our galaxy's greater gravity (although, the motions of both galaxies play a part in the collision). The collision is about half way through. The phrase "the Milky Way is eating the dwarf galaxy" is just a way of saying that the stars of the dwarf galaxy will end up becoming part of the Milky way.



Come someone explain my ilogic in a non scientifc way that I may understand what is going on.

Thanks

Hope this helped.

Reacher
2003-Sep-25, 05:04 PM
Stars are exploding all the time... Well... They have exploded, so if it were a cataclysmic event for the earth, we'd all be dead already.

Captain Kidd
2003-Sep-25, 05:14 PM
I think they kinda stretched the whole food simile there.

The act of cannibalism…
…the scientists said they were able to capture the totality of the Milky Way's meal
…our galaxy is slurping the stars of Sagittarius as if they were a stellar strand of spaghetti.
Gees, it sounds like Nancy wrote this.
Somebody correct me if I’m wrong but bmpbmp, nothing’s getting destroyed. What’s happening is that our galaxy is absorbing Sagittarius like a sponge absorbs water, the water’s still there, just captured by the sponge. Most of those stars will probably just start orbiting like all the other stars already in the Milky Way, some might sling off on their own course and become, for lack of a better term, one star galaxies. (That’s pure personal speculation as I am not an astronomer and don’t even play one on TV.) Oh, one or two might get gobbled by a black hole, another couple might actually hit another star, but there won’t be “an Earth-shattering ka-boom.” A few might have their, if any, planets stripped from them if they wander in too close to another star.
But the whole ‘eating’ thing was somebody with less astronomy sense than I trying to describe what’s happening in cool layman’s terms. And judging from the average weight of Americans these days, food terms would be widely understood. ;)

So, quoteth dgruss23: remain calm.

Anyways, if all the odds line up and dozens of stars explode, each sending a spike of energy that will all converge on earth at the same time with enough energy to kill us all; you’re great-great-…-great-grand kids will be dead from old age.

Sigma_Orionis
2003-Sep-25, 05:50 PM
Well bmpbmp one way to look at it is like this :

according to this (http://www.iac.es/gabinete/noticias/2001/mar08i.htm) The Saggitarius Dwarf Galaxy is 15 Kiloparsecs from the center of the Milky Way, a KiloParsec is 3262 Light Years aproximately that means that the Dwarf Galaxy is about 48930 light years, since this is hapening on the other side of the galaxy, and we are about 30000 light years from the center of it this (as ToSeek rightly mentioned) means that this is going on at about 78000 light years away from us, now, what's a light year? it's the distance it takes light (which has a speed of abour 300000 kilometers per second) to travel in one year. that means that whatever we are observing there right now happened 78000 years ago!

As a lot of people here have pointed out, Galaxies are mostly empty space, this is because the distance between stars is so large, it is measured in Light Years. One can then conclude that it's VERY unlikely that two stars could collide.

Finally if there was the even slightest possibility that something were to happen to our sun, or to us as a consecuence of this event, it will take about 78000 years to reach us if whatever happened traveled to here at the speed of light. I don't know about you, but I don't think I will be around here that long :)

Pretty cool though, I didn't know that a galaxy had been detected that was closer to the Milky way than the Large Magallanic Cloud

[Editted several times for clarity]
[Editted again to clarify something else]

bmpbmp
2003-Sep-25, 06:38 PM
if it happened 78000 years ago as you mentioned then it will be reaching us now

Rue
2003-Sep-25, 06:51 PM
...whatever we are observing there right now happened 78000 years ago!


Does anyone know why this happens.

BTW: there is a new image posted with the CNN story.

Sigma_Orionis
2003-Sep-25, 07:03 PM
if it happened 78000 years ago as you mentioned then it will be reaching us now

No it would not, the light it emits would be reaching us right now, not the object (if there was any). The object would move a LOT slower than it's light.

If an object like a star, or something large enough to damage us were moving towards us, it's gravitatonal effect would have been noticed a long time before the object actually arrived. This is one of the arguments that invalidate all of the Planet-X hoopla, something that big has a measurable gravitational effect.

Madcat
2003-Sep-25, 07:06 PM
Hey, that's pretty neat. Our Galaxy is beating up the little galaxy. Muhuhahahaha! Soon we shall rule this pathetic bubble! :evil:

bmpbmp
2003-Sep-25, 07:20 PM
I understand now that this is nothing to worry about but I am confused about the thoery of light to reach us and object to actually reach us...

Can someone clarify this issue with this as an example

ToSeek
2003-Sep-25, 07:44 PM
Hey, that's pretty neat. Our Galaxy is beating up the little galaxy. Muhuhahahaha! Soon we shall rule this pathetic bubble! :evil:

Yeah, but the Andromeda Galaxy is headed our way to teach us a lesson, and it's a lot bigger than we are.

bmpbmp
2003-Sep-25, 07:46 PM
When

Tau
2003-Sep-25, 07:47 PM
Yeah, but the Andromeda Galaxy is headed our way to teach us a lesson, and it's a lot bigger than we are.

No prob, we've got plenty of time before the match with Andromeda. If we gobble up some smaller galaxies in the meantime, we can take 'em on! :x

Captain Kidd
2003-Sep-25, 07:51 PM
I understand now that this is nothing to worry about but I am confused about the thoery of light to reach us and object to actually reach us...

Can someone clarify this issue with this as an example

bmpbmp, first, just out of curiosity, what is you native language? You sentence structure gets interesting at times. Either that or you're leading us on...

Anyways, I think I understand what you're asking.
We see it now because how much faster light travels than objects.
Hmm, example...
How about this:
Err, ok. Consider light like a fighter taking off from an aircraft carrier. The figher originates from the carrier, both are headed in you direction but the aircraft is going to get to you way sooner then the carrier will.

The Bad Astronomer
2003-Sep-25, 07:56 PM
Perhaps this article I wrote (http://www.badastronomy.com/bitesize/invader.html) in 1998 might help?

I gently suggest to people that if you see something you're not sure about, do a web search first, or search my site.

Captain Kidd
2003-Sep-25, 08:03 PM
Hmm, example...
How about this:
Err, ok. Consider light like a fighter taking off from an aircraft carrier. The figher originates from the carrier, both are headed in you direction but the aircraft is going to get to you way sooner then the carrier will.

Work called for a few minutes and I hit the wrong button.
If I may continue.

Light is just a single photon and travels at.. well light speed. Matter takes energy to get moving. So the light from the star race out ahead of them (and behind, above, below, left, right, etc, etc). So when the light finally gets here after all that distance, the star that produced it has barely moved closer, relative speaking.
There's a ton of stuff if you'll Google for say "light speed" or something along those lines.

bmpbmp
2003-Sep-25, 08:57 PM
Call me stupid but this travel thing still confuses me

aporetic_r
2003-Sep-25, 09:08 PM
If I may attempt a reply...

When we look in a telescope and see what is happening on the other side of our galaxy, we are seeing something that happened 78,000 years ago. Now let's say that we looked in a telescope tomorrow and saw a star way over there blowing up. That means that the star actually blew up about 78,000 years ago, and the light has been travelling towards us all this time. Now let's say that we looked in a telescope tomorrow and saw that star exploding, and also saw a big chunk of star heading right towards us. The image we are seeing is light that has been travelling for 78,000 years, but the actual chunk of star travels much more slowly than light, so it would take the chunk of star a LOT longer to get here - probably millions of years longer. But that would not happen, anyway. When the news says that one galaxy is eating another, it does not mean that there are any actual collisions. Stars are not bumping into each other. Instead, the galaxies are just moving through each other. It is weird to think about, but space is so incredibly big that glaxies could pass right through each other and their stars would probably never touch. Does that help? Please note that I sacrificed accuracy for clarity.

Aporetic

bmpbmp
2003-Sep-25, 10:09 PM
Astronomers have mapped the Sagittarius galaxy to show in detail how its debris wrap around and pass through the Milky Way, which contains Earth.

bmpbmp
2003-Sep-25, 10:27 PM
http://www.astro.virginia.edu/~mfs4n/sgr/

What does the scientist mean buy the folowwing i dont understand it but it sounds pretty hefty...


The study's map of M giants depicts 2 billion years of Sagittarius stripping by the Milky Way, and suggests that Sagittarius has reached a critical phase in what had been a slow dance of death.

"After slow, continuous gnawing by the Milky Way, Sagittarius has been whittled down to the point that it cannot hold itself together much longer," said 2MASS Science Team member and study co-author Martin Weinberg of the University of Massachusetts. "We are seeing Sagittarius at the very end of its life as an intact system."

Does this mean we are at a unique moment in the life of our galaxy? Yes and no.

"Whenever possible, astronomers appeal to the principle that we are not at a special time or place in the universe," Majewski said. "Because over the 14 billion-year history of the Milky Way it is unlikely that we would just happen to catch a brief event like the death of Sagittarius, we infer that such events must be common in the life of big spiral galaxies like our own. The Milky Way probably dined on a number of dwarf galaxy snacks in the past."

On the other hand, Majewski and his colleagues have been surprised by the Earth's proximity to a portion of the Sagittarius debris.

"For only a few percent of its 240 million-year orbit around the Milky Way galaxy does our Solar System pass through the path of Sagittarius debris," Majewski said. "Remarkably, stars from Sagittarius are now raining down onto our present position in the Milky Way. Stars from an alien galaxy are relatively near us. We have to re-think our assumptions about the Milky Way galaxy to account for this contamination."

freddo
2003-Sep-26, 12:25 AM
You know, all I could think of when i read the title of that article, was...

Cop that Astrology!!!

Shame it's not the actual constellation....

Checkmate
2003-Sep-26, 12:52 AM
Astronomers have mapped the Sagittarius galaxy to show in detail how its debris wrap around and pass through the Milky Way, which contains Earth.
Sure, but the chances of it having a significant effect on the earth are extremely unlikely. To give you an idea of the distance between earth and any other stars in the Milky Way, just look at a picture of it, taken from earth. It looks like a big, white blob because you're looking at it from the side, for one thing. But you might not think your planet is actually part of that blob, because it's relatively small in the sky. That's because of Earth's distance from any other star in it. It's a LOT of space! The chances of something hitting the Earth out of all that space are extremely small. Don't worry about it.

(Somebody correct me if I got something wrong here.)

bmpbmp
2003-Sep-26, 12:55 AM
But what if it did hit earth what would happen and how long would it take from that far to hit earth ..

I am still very confused on the time in space theory

Musashi
2003-Sep-26, 12:58 AM
What if what hit the earth? The entire Sagitarius Galaxy? I am still confused as to what you are so concerned with.

I am not sure if you have grasped the simple idea that light travels faster than matter. Light travels extremely fast. If I were to shine a flashlight at you and throw a baseball at you, at the exact same time, you would see the light well before the baseball hit you in the head.

Someone, somewhere asked you what your native language is... I didn't see an answer, but I would like to. Could you also explain how you missed out on elementary school, middle school, and high school?

bmpbmp
2003-Sep-26, 01:12 AM
but I dont grasp the concept of what people were saying in this post about the travel times and years of all this

Musashi
2003-Sep-26, 01:22 AM
Do you grasp the concept of answering what you native language is?

Travel times of what?

What we see is when we observe galaxies, is light. Sagitarius is 78,000 (or whatever) lightyears away. That means it takes the light from Sagitarius 78,000 years to travel from Sagitarius to Earth. Now, light travels much faster than matter. I do not know what the velocity of the Sagitarius Galaxy is, but lets just say .01 c (that means it reavels 100 times slower than light). That means that Sagitarius would take 7,800,000 years to get to earth, if it traveld at .01c. Now, that also assumes that it is moving on a path that would have it intercept our Solar System. And event then, galaxies are mostly made up of empty space. Our solar system could pass right through Sagitarius without causing anything to happen. But, all of that is millions of years in the future, so calm down.

bmpbmp
2003-Sep-26, 01:26 AM
I mentioned above I am english

So if I understand right that we just recieved the light of this impact and the actual debris from it or the time that it will actuallyreach us is still thousands of years away from now minimum

Do i have it yet

Musashi
2003-Sep-26, 01:31 AM
getting it.

First of all, it was not an impact. Second of all, there is no debris. Third of all, its not thousands of years, its millions. Fourth of all, there really isn't anything that is going to 'reach us.'

bmpbmp
2003-Sep-26, 01:38 AM
Ok I get it now but the article makes it sound like something is coming our way...

Also I dont understand one thing, If we got it now and it happened 78000 years ago then why wouldnt it take 78000 years to reach us but instead it will take 780 000 years to reach us

Isnt pluto in sagitarious and pluto isnt 780000 years away from us

Musashi
2003-Sep-26, 01:43 AM
Wow.

No, Pluto is not in Sagitarius.

Pluto is in our Solar System.

Our Solar System is in the Milky Way galaxy.

bmpbmp
2003-Sep-26, 01:46 AM
But I dont get one thing if this is so far away why is the news and scientists making such a fuss when they wont even be alive 780000 years from now

Musashi
2003-Sep-26, 01:46 AM
Can you show me wher eexactly in the article is says that something is coming toward Earth, or is going to happen to Earth?

And to respond to your other point,

light from sagittarius takes approx. 78,000 years to reach Earth.

mass from that same spot would take around 7.8 million years to reach Earth.

So, if we now saw something coming at earth from that spot, it would take 7.8 million minus 78,000 years to reach Earth, or 7.722 million years.

Musashi
2003-Sep-26, 01:49 AM
But I dont get one thing if this is so far away why is the news and scientists making such a fuss when they wont even be alive 780000 years from now

What, exactly, do you mean by 'making a fuss?'

They are excited about it because it is interesting. The aritcle does not imply that the scientists are afraid of it, or that other people should be afraid of it.

And it is 7.722 million years, not 780,000 years.

bmpbmp
2003-Sep-26, 01:51 AM
I finally understand now

Musashi
2003-Sep-26, 01:52 AM
You're welcome.

bmpbmp
2003-Sep-26, 01:54 AM
What is to be the effects on the earth millions of years from now when this reaches us

Musashi
2003-Sep-26, 01:55 AM
Spoke to quick I guess...

When WHAT reaches us?

The Supreme Canuck
2003-Sep-26, 01:57 AM
I think he means when Saggitarius gets here.

Musashi
2003-Sep-26, 01:59 AM
Why would he think that Sagittarius is coming here?

bmpbmp
2003-Sep-26, 02:00 AM
I mean if sagitarious collapses and the stars merge into the milky way the collapsing stars will eventually reach into the milky way close to earth,,,what will the effects be on earth

The Supreme Canuck
2003-Sep-26, 02:01 AM
Why do you think they will come close to Earth?

Musashi
2003-Sep-26, 02:01 AM
Why will the stars come here?

Being in the Milky Way Galaxy does not mean that they will be close to Earth.

bmpbmp
2003-Sep-26, 02:08 AM
it said that the milkyway is moving into and collapsing sagetarius so to me that means either sagitarious and its stars will be destroyed or they will become part of the milky way and as the milky way keeps moving they will get closer to earth

Musashi
2003-Sep-26, 02:11 AM
If they become part of the Milky Way, and they move with the Milky Way, and Earth continues to move with the Milky Way, then they will not get close.

What do you think would happen?

ocasey3
2003-Sep-26, 02:12 AM
bmpbmp, if I might make a suggestion, please try not to start your posts in the subject line. Your first comments are often not very clear.

wedgebert
2003-Sep-26, 02:18 AM
it said that the milkyway is moving into and collapsing sagetarius so to me that means either sagitarious and its stars will be destroyed or they will become part of the milky way and as the milky way keeps moving they will get closer to earth

Why would the stars be destroyed?

bmpbmp
2003-Sep-26, 02:20 AM
I am so darn confused

The Supreme Canuck
2003-Sep-26, 02:21 AM
About what exactly?

bmpbmp
2003-Sep-26, 02:27 AM
what happenes when galaxys merge like this

Musashi
2003-Sep-26, 02:29 AM
What do you think happens?

bmpbmp
2003-Sep-26, 02:35 AM
I dont know i figure that one destroys the other

The Supreme Canuck
2003-Sep-26, 02:35 AM
Do you mean if two stars collide they will destroy each other?

bmpbmp
2003-Sep-26, 02:40 AM
yes that is what i mean i am right arent i

wouldnt the milky way destroy sagitarious and even though sagitarious is a hell of a lot smaller wouldnt it damage part of the milky way

Musashi
2003-Sep-26, 02:40 AM
Galaxies are mostly empty space. Two galaxies could merge without causing disater.

If a star entered our solar system, we would be in danger, but anything short of that isn't going to affect us (basically).

Musashi
2003-Sep-26, 02:41 AM
Do you realize that galaxies and stars are two different things?

The Supreme Canuck
2003-Sep-26, 02:42 AM
Galaxies are mostly empty space. Two galaxies could merge without causing disater.

If a star entered our solar system, we would be in danger, but anything short of that isn't going to affect us (basically).

Exactly. The chances of coming anywhere near a star passing through the galaxy are phenominally low.

bmpbmp
2003-Sep-26, 02:45 AM
but arent they stars in sagitarious that will come into our solar system

Musashi
2003-Sep-26, 02:45 AM
TSC:

Do you mean if two stars collide they will destroy each other?

bmp:

yes that is what i mean i am right arent i

wouldnt the milky way destroy sagitarious and even though sagitarious is a hell of a lot smaller wouldnt it damage part of the milky way

If two stars collide, there will be trouble for the stars. But talking about stars colliding and then saying the the Milky Way is going to destroy the Sag Galaxy is jumping to the wrong conclusion.

Musashi
2003-Sep-26, 02:46 AM
Yes, stars will come into our Galaxy. (What do you mean by system? No stars are coming into our solar system!!!!!!!!!!)

bmpbmp
2003-Sep-26, 02:49 AM
i mean arent stars coming into our galaxy with the meger of sagitarious and canuck said it is bad

Checkmate
2003-Sep-26, 02:56 AM
If you read my earlier post, I said that our solar system is PART OF THE MILKY WAY. It's not like the Milky Way will move closer to the Earth. The collapsing stars won't "reach in close to Earth." In fact, it's unlikely there will be any "collapsing stars" at all.

As for your confusion over speed of light, what we're saying is: "This stuff we are observing on the other side of the galaxy happened 78,000 years ago, but it has taken 78,000 years for the light produced by that event to reach our telescopes." The other side of the galaxy is about 78,000 light years away. A light year is the distance light travels in a year. That's a very LARGE distance, because light travels extremely fast.

In case you didn't know, light travels. You don't see anything happen until the light reaches your eye. You have to wait for the light (reflected or otherwise) to reach your eyes. You don't usually have to wait long, because light travels VERY fast, but in astronomy, you're dealing with very large distances. Did you know that the sun is about eight light minutes away from the earth? That's right, when you see the sun in the sky, you're actually seeing what it looked like eight minutes ago.

Now, let's say there's an object, say, ten light years from Earth (I'm not saying there necessarily is, this is only an example). It produces light, and some of that light is heading towards earth, and consequently towards your eyes. It also produces some matter, traveling at, say, one hundred miles per hour, heading towards earth. Since light travels a LOT faster than one hundred miles an hour, you would see this matter before it actually hit the earth, because the light from that matter (or lack of light, perhaps) hit the earth and your retina faster than the matter itself did.

As usual, somebody correct me if I got something wrong. 8)

Checkmate
2003-Sep-26, 02:59 AM
Hmm, I think I posted late because I spent all that time writing the article. I was responding to one of your earlier posts, but it took several minutes for me to write the article and post it... :roll:

The Supreme Canuck
2003-Sep-26, 03:00 AM
If two stars collide, there will be trouble for the stars. But talking about stars colliding and then saying the the Milky Way is going to destroy the Sag Galaxy is jumping to the wrong conclusion.

Guess I could have worded my question to bmpbmp better...

Okay, here's what will happen. In about 7.722 million years, stars from the Saggitarius and Milky Way galaxies will pass by each other. They will most likely not collide. If they do, the stars get destroyed. But, again, the chances are extremely small that this will happen. More likely, the stars from the Saggitarius galaxy will never touch the stars from the Milky Way galaxy and will either pass through the Milky Way or will be captured by it.

bmpbmp
2003-Sep-26, 03:01 AM
ok so that mean what was written above if we saw it now from 78000 years it will reach in 78 millions years minus 78000 which is still millions of years from now

Checkmate
2003-Sep-26, 03:11 AM
ok so that mean what was written above if we saw it now from 78000 years it will reach in 78 millions years minus 78000 which is still millions of years from now
From what I recall, Musashi was only making an example saying that. If there is an object travelling, from the event, at a hundred times slower than the speed of light (which is still pretty darn fast) towards the earth, then yes, it will take approximately 7,792,200 years for the object to hit the earth from when it was observed.

(UPDATE: my calculation was a bit off)
(ANOTHER UPDATE: you know, my last one was correct. Geez.)

The Bad Astronomer
2003-Sep-26, 03:12 AM
bmpbmp, I would strongly urge you to read up on some basic astronomy. I think it would help you understand these things immensely. A good place to start is AstronomyNotes.com (http://www.astronomynotes.com). There are diagrams and good explanations of astronomy there.

bmpbmp
2003-Sep-26, 03:13 AM
so things travel slower than 100 times less than the speed of light

Checkmate
2003-Sep-26, 03:15 AM
so things travel slower than 100 times less than the speed of light
Not necessarily. That was only an EXAMPLE.

bmpbmp
2003-Sep-26, 03:16 AM
so its possible that it would reach us quicker than that,

but in our lifetimes or not possible to be that quick

Checkmate
2003-Sep-26, 03:19 AM
It's really fast, but it's possible. Though there is some dispute, Einstein said nothing can travel faster than the speed of light. Slightly slower, possible, but unlikely.

Musashi
2003-Sep-26, 03:20 AM
Unless something can travel 1000 times the speed of light, nothing will be here before you die of old age.

bmpbmp
2003-Sep-26, 03:23 AM
ok but in this case here how fast is it traveling, is it faster than the speed of light or slower

Checkmate
2003-Sep-26, 03:25 AM
ok but in this case here how fast is it traveling, is it faster than the speed of light or slower
One hundred times SLOWER, remember?

Musashi
2003-Sep-26, 03:25 AM
Well, nothing travels faster than the speed of light... and most things that aren't light travel much much much slower..

I don't know how fast the galaxies are closing, maybe someone else does, but I would say that, as a guess, .01 or .001 c sounds good to me as an upper limit.

Checkmate
2003-Sep-26, 03:27 AM
Oh, I thought he meant in the example. #-o
Slower, definitely.

Tensor
2003-Sep-26, 03:28 AM
bmpbmp, I would strongly urge you to read up on some basic astronomy. I think it would help you understand these things immensely. A good place to start is AstronomyNotes.com (http://www.astronomynotes.com). There are diagrams and good explanations of astronomy there.

Not to mention the Website attached to this Bulletin Board. 8)

Checkmate
2003-Sep-26, 03:29 AM
And remember, the chances of any Saggitarius matter going on a direct course to the earth is EXTREMELY unlikely.

The Supreme Canuck
2003-Sep-26, 03:30 AM
The chances of Saggitarius matter coming anywhere near the solar system is extremely small. Don't worry about it.

(Sorry, it needed to be repeated)

Musashi
2003-Sep-26, 03:31 AM
bmp, you must read this:

http://www.astronomynotes.com/galaxy/s10.htm

Here is an excerpt I find particularly pertinent:


Galaxy Collisions and Mergers
Modern research into galaxy formation is also exploring the role that mergers and collisions of galaxies plays in the structure of galaxies. The distances between galaxies is large, but compared to the size of the galaxies, the distances are not extremely large. Stars inside a galaxy do not collide because the distances between them are hundreds of thousands to millions of times larger than the sizes of the stars.

(Italics mine)

Here is more:

Collisions take place over very long timescales compared to the length of our lifetime---several tens of millions of years.

bmpbmp
2003-Sep-26, 03:31 AM
but even if it did it woiuld not be in our lifetime right

The Supreme Canuck
2003-Sep-26, 03:33 AM
It just wouldn't happen. A star would not come anywhere near the Earth or the Sun. And even if one does (it most likely won't) it will not happen until we have been dead and forgotten for millions of years.

Musashi
2003-Sep-26, 03:34 AM
bmp, did you read my link?


When two galaxies collide the stars will pass right on by each other without colliding. The distances between stars is so large compared to the sizes of the stars that star-star collisions are very rare when the galaxies collide.

bmpbmp
2003-Sep-26, 03:38 AM
yes i did
thanks everybody i understand now

russ_watters
2003-Sep-26, 04:37 AM
bmpbmp, just out of curiosity, how old are you? There is a severe disconnect here between the things that you are reading and the things you are saying in response. You aren't grasping some very simple concepts. If you're 10, I can understand it - much older than that....well, I don't know. Are you for real?

freddo
2003-Sep-26, 04:47 AM
bmpbmp stated in another thread that he is 27.

aporetic_r
2003-Sep-26, 05:01 AM
bmpbmp: If I may offer a bit of advice... Please take the BA's advice and read www.astronomynotes.com and some other serious astronomy sites. A couple people in this thread really did their best to help you, but they got pretty frustrated because they had to begin at an extremely basic level. Remember that the people answering your posts are real people with real lives who come here for enjoyment and enlightenment, just like you. You will get better responses from them if you gain some more basic knowledge about astronomy and use that knowledge to ask more detailed and advanced questions. You will also get better responses if you take some more time to put together better posts, with clear sentences and precise questions. People on this board want to help, but you have to meet them half way.

This public service message brought to you by...

Aporetic

Musashi
2003-Sep-26, 05:08 AM
For me, more than the basic level thing, it was the resistence to learning from the answers given that was getting to me...

Checkmate
2003-Sep-26, 06:57 AM
It would have helped for him to acknowledge our answers before bringing some other issue up.

Fraser
2003-Sep-26, 07:25 AM
Okay, one last thought experiment for Mr. Bmp.

First, nothing is going to happen because stars are so far apart.
Imagine one team of like ten people spread out across the East Coast of the US. They will have hundreds of miles in between them. Imagine another team on the West Coast. Now, those two teams start running across the United States until they get to the other coast.

What do you think the chances are that any of those people, running towards and then past each other are actually going to run head long into another person from the opposite team? Very very very small. Not impossible, but small enough that it's pretty much impossible.

That's how galaxy collisions work. Two gigantic groups of stars are attracted to each other through gravity, but the distances between the individual stars are so vast that they don't actually collide. All the stars just dance around each other until they take up a new shape. The individual stars (and their planets) are completely unharmed by the whole process.

Second, this is going to take a long long long time.
I'm not sure the exact time, but the Milky Way has been colliding with Sagittarius for tens of millions of years. If you tracked the position of all the stars when you were born, and then did it again on your 100th birthday, you would have a difficult time seeing any movement of any star in Sagittarius. You'll need to wait millions of years more before this "collision" was complete.

You're safe. Your great-grand children are safe. Everybody's safe.

Jigsaw
2003-Sep-26, 01:44 PM
Musashi: You rock.

That is all.

8)

mr. show
2003-Sep-26, 02:46 PM
we've all been trolled

bmpbmp cannot be serious - I maintain our educational system cannot be this inadequate

parejkoj
2003-Sep-26, 04:19 PM
bmpbmp cannot be serious - I maintain our educational system cannot be this inadequate

You haven't met some of my friends. Same education system, just a little later. It is that inadequate.

bmpbmp: keep learning and reading! It does a body good! :)

Nowhere Man
2003-Sep-26, 04:59 PM
Trolled by bmpbmp? Maybe. If so, he puts more work into it than your typical troll does. I still don't know if bmpbmp is skywatcher or not. The MOs, typing style, and posting style are very similar.

As for educational systems, bmpbmp said he was English. Even so, I bet that modern educational systems are similar, and can produce many different results. And there may be factors that are outside of the educational system.

But I'm not here to talk about that.

bmpbmp asked, regarding the upcoming collision between the Milky Way and Andromeda galaxies, "When?" It will happen about 3 billion years from now. The process will take another billion years, and the result will be an eliptical galaxy. I wouldn't lose any sleep over it if I were you.

Go to Hubble's interacting galaxy gallery (http://hubblesite.org/newscenter/archive/category/galaxy/interacting) for some beautiful pix of galaxy collisions. Read the captions and any other descriptions they have. Some of the pictures are wonderful.

Let me reiterate what Universe Today said: It takes a long time for anything to happen on a galactic scale. As Douglas Adams wrote, "Space is big - really big - you just won't believe how vastly, hugely mind-bogglingly big it is. You may think it's a long way down the road to the chemist, but that's just peanuts to space. " Since nothing can travel faster than light, and galactic distances are best measured in hundreds of thousands or millions or billions of light years, and galaxies are moving at 1/10,000 of light speed (at a guess), the process is a slow and majestic one.

There has been discussion of star collisions, and that threat has been disposed of. What no one has mentioned is a) tides and b) dust/gas clouds.

Tides first. When two galaxies approach, they start feeling each others' gravity. This tends to stretch out both galaxies. When the two are similar in size, you get neat streamer effects like the Mice (http://hubblesite.org/newscenter/archive/2002/11/image/d) or the Antennae (http://hubblesite.org/newscenter/archive/1997/34/). When one galaxy is much larger, the smaller one is stretched out far more than the larger one, and eventually is disrupted and captured by it. This is the situation with the Saggitarius dwarf galaxy.

Now, dust and gas clouds. These clouds are far larger than stars, and so they are more likely to collide when two galaxies meet. This produces areas of star formation, as the gas and dust are compressed by the collision. You can see this in the Hubble photos. Dust and gas clouds will not cause existing stars any trouble, much less make them explode. However, the larger of the new stars will burn faster and go nova sooner. Don't worry, this is normal stellar evolution and also takes a very long time.

One impressive example is the Cartwheel. (http://hubblesite.org/newscenter/archive/1995/02/) Apparently a small galaxy plowed right through the center of the larger one, starting a circular wave of star formation spreading over the entire galaxy.

One thing to remember is that, if a galactic (or even stellar) collision were to threaten Earth in the near future, there is absolutely nothing we can do about it except make whatever peace we can with ourselves and go out with dignity.

Fred

Jigsaw
2003-Sep-26, 05:22 PM
, if a galactic (or even stellar) collision were to threaten Earth in the near future, there is absolutely nothing we can do about it except......send the Enterprise back in time, to before the universe was created, and have Captain Kirk reset the game parameters so no collision can take place...

russ_watters
2003-Sep-26, 05:38 PM
bmpbmp stated in another thread that he is 27. Oh yeah. Duh, I remember reading that. I may even have been the one who asked. Brain fart. :-?

we've all been trolled

bmpbmp cannot be serious - I maintain our educational system cannot be this inadequate I'm going to have to agree. I can't imagine a 27 year old could possibly be this naive, gullible, and uneducated about science (and unwilling or unable to learn).

Nowhere Man
2003-Sep-26, 05:38 PM
, if a galactic (or even stellar) collision were to threaten Earth in the near future, there is absolutely nothing we can do about it except......send the Enterprise back in time, to before the universe was created, and have Captain Kirk reset the game parameters so no collision can take place...
:o Before? ROFL...

BTW, the previous message went on rather longer than I'd planned. Took all of lunch hour, it did. #-o

Fred

Musashi
2003-Sep-26, 11:33 PM
Thanks Jigsaw. :)

Reacher
2003-Sep-27, 03:14 PM
Yeah, I think I'll just be ignoring our friend Mr Bmpbmp from now on.

digitalspector
2003-Sep-28, 04:51 AM
ouch...



painful thread.

Tau
2003-Sep-28, 06:34 AM
No need to get nasty. I think bmpbmp is just a newbie to natural science and astronomy. He still hasn't got an idea of the scale of these events.

On any good astronomy education site, there is a discussion about the cosmic scale before any lessons are given. I think bmpbmp should start with sites like this (http://www.astronomynotes.com/chapter1/s2.htm), then look for specific info.

(Link leads to Astronomy Notes, Copyrighted, 1998 - 2002 by Nick Strobel)

digitalspector
2003-Sep-28, 07:19 AM
Tau... true enough


and point noted.

But I to have been proposed to be of "troll-istic" sense.

bmpbmp can find the information his/she seeks. It is out there....I know this ....because I am a newbie.....and yes most of my questions are answered by simple googlizing I do like to here personal answeres. Once I get one, though I drop it, where-as Bmpbmp continues the questioning....So who knows.

russ_watters
2003-Sep-29, 01:41 PM
No need to get nasty. I think bmpbmp is just a newbie to natural science and astronomy. He still hasn't got an idea of the scale of these events. How newbie is reasonable for a 27 year old? Most 14 year olds have more common sense and learn more science in junior high than bmpbmp seems to know. I know it sounds mean, but its true. I still remember learning the scientific method and concepts like precision vs accuracy (with arrows on a target for visual aid) in 8th or 9th grade physical science. Hell, most younger kids learn a lot simply out of curiosity. It seems almost as if bmpbmp has never even heard the word "science." I just can't believe its possible.

The Bad Astronomer
2003-Sep-29, 05:29 PM
Folks-- please either stick to the thread topic, or hold your peace. If you think we are being trolled, fine, but I would prefer that you not assume bmpbmp is a troll until proven otherwise. This falls under ad hominems.

LTC8K6
2003-Sep-29, 06:02 PM
Edit: PM'd the BA instead.

Blondin
2003-Sep-29, 07:33 PM
What the heck? I go away for 4 days and the Milky Way collides with Sagittarius?

But seriously...

Take it easy on Bmp. I meet lots of people at public observing sessions who have even more confused ideas. I blame our education system. Even more importantly I blame our media for hyping every crackpot, weirdo claim and not giving equal time to the level-headed, analytical response.

For a little light-hearted help in memorizing some of the facts about our galaxy here is a little ditty by Eric Idle:
http://www.open.hr/space/lands/galaxy.html
Download and play the .mp3 - it's a toe-tapper!

numbskull
2003-Sep-30, 05:02 PM
For a little light-hearted help in memorizing some of the facts about our galaxy here is a little ditty by Eric Idle:
http://www.open.hr/space/lands/galaxy.html
Download and play the .mp3 - it's a toe-tapper!

One of my favourite ditties. That and "Always Look on the Bright Side of Life".

kanon14
2003-Sep-30, 10:32 PM
i'm not trying to make it even more confusing, but what are the odds that the gravitational force of the stars from Sag trigger the Kuiper Belt Objects and thus driving them towards Earth, or perhaps hitting Earth.

Is it possible?

Musashi
2003-Oct-01, 01:09 AM
IMO, the odds are extremely low. First, the stars would have to get to the Kuiper belt area, and I don't think that is going to happend anytime soon, if ever.

kanon14
2003-Oct-01, 03:20 AM
but for a star in Sag. they'll be at least 100X more massive than Jupiter, so it does not have to get "into" the Kuiper Belt. the icy bodies would still feel the gravitional effect

Musashi
2003-Oct-01, 03:30 AM
OK, you tell me how close they have to get, and when that will happen.

kanon14
2003-Oct-01, 04:13 AM
i just did a simple calculation showing that for the KBO to have a significant velocity while entering the inner solar system, a single star from Sag has to get to about 1AU away from the KB, then the KBO will be getting into the inner solar system at the speed of about 20km/s in bout 200 yrs later, but i did not enter the acceleration given by Jupiter and Sun while it's within the solar system and also assuming there is only one star can get close to the KBO

but for how long the stars from Sag to come to that close. i have no idea

AGN Fuel
2003-Oct-01, 04:24 AM
IIRC, someone once likened the chances of two stars colliding during a galactic merger as being comparable to dropping a handful of snails at random across mainland Australia and then expecting them to bump into each other! :o

I think that bmpbmp needs to read some simple texts to help get a grasp of the size of the various hierarchical components in our galaxy. For the novice, it is worth keeping these comparisons in mind:

Distance from Earth to the sun - roughly 8.5 light minutes.
Diameter of our solar system - roughly 10 light hours.
(So the time it takes light to travel the distance from Earth to the sun as opposed to crossing the whole solar system may be compared to the difference in taking a shower as opposed to a very good night's sleep).
Distance to the nearest star outside our solar system - 4.3 light years.
(So the difference between the size of our entire solar system and the distance to the nearest star can be thought of in terms of the difference between a single good night's sleep and the time to complete a typical university degree)
The diameter of our galaxy, the Milky Way - roughly 100,000 light years.
(So, the difference in distance from the nearest star to across the whole galaxy is similar to the time to complete a university degree compared to the time required for our species to evolve from hunter/gatherer to spacefarer).

In short, the galaxy is mind-numbingly VAST!

SarahMc
2003-Oct-01, 04:37 AM
One of the best sites I know of for demonstrating the vast distances is The Distance to the Nearest Star (http://www.anzwers.org/free/universe/stardist.html) and the pages associated with it that illustrate the distances across the galaxy, between galaxies, local groups and superclusters - The Universe within 12.5 Light Years (http://www.anzwers.org/free/universe/12lys.html)

I introduced my kids to these pages one night after I had them out observing a year or so ago, and they were asking about distances to stars and galaxies. Maybe bmpbmp will find them usefull (or anyone else that needs a graphical representation for someone else).

kanon14
2003-Oct-01, 04:48 AM
let alone stars collision, is it possible that these stars could trigger something that can affect us in any way? such as the KBO i mentioned above
is it even possible?

Peter B
2003-Oct-01, 08:34 AM
let alone stars collision, is it possible that these stars could trigger something that can affect us in any way? such as the KBO i mentioned above
is it even possible?

In the short term, no.

In the long term, it's possible.

By "short term" I mean "up to about 10 million years".

By "long term" I mean "over 100 million years".

By "it's possible" I mean that: our Solar System might pass through a dust-rich part of the Milky Way galaxy, which could cool the Earth; or our Solar System could pass near a region of large hot stars with the chance that one might go super-nova and irradiate Earth; or our Solar System could pass near a star which disturbs the Kuiper Belt and triggers a relatively high number of comet strikes.

Jigsaw
2003-Oct-01, 01:52 PM
See, the trouble is--what you're dealing with when you're talking to woowoos--is that they have the ability to hear selectively.

A woowoo will hear only this part--

By "it's possible" I mean that...our Solar System could pass near a star which disturbs the Kuiper Belt and triggers a relatively high number of comet strikes.
--and will completely ignore this part--

In the short term, no.

In the long term, it's possible.

By "short term" I mean "up to about 10 million years".

By "long term" I mean "over 100 million years".
So the end result is that you now have a woowoo who insists that he heard someone say, "Yes, it's possible for a storm of comets to come out of the KB and hit the Earth..."

aporetic_r
2003-Oct-01, 02:11 PM
How about this?

It is unlikely, but possible, that a barrage of KBOs could be forced directly toward Earth by a rogue star about 1AU away.

It is unlikely, but possible, that an as-yet-undetected comet or other such body will smash into the Earth within your lifetime.

It is unlikely, but possible, that you will die a slow, painful death from radiation overdose when the North Korean government decides to attack the western US with nuclear weapons rather than accept the inevitable collapse of its regime.

It is unlikely, but possible, that you will be blown up, shot, beheaded, or otherwise murdered in an act of violence, rather than dying peacefully in your sleep due to old age.

It is unlikely, but possible, that you will be killed while crossing the street today.

It is unlikely, but possible, that you feet are currently being gnawed off by rabid chipmunks.

So here are your options:

1) Curl up in the corner wearing boxers and a stained white tanktop, crying and rocking back and forth while you bemoan the unlikely, but possible horrors of existence. (In which case you'll probably just starve yourself to death).

2) Enjoy the time you have, knowing that you'll probably live to a ripe old age of enfeeblement and incontinence and get to bat disrespectful kids over the head with your cane, then die peacefully in your sleep due to natural causes.

Aporetic

bmpbmp
2003-Oct-01, 02:15 PM
http://news.bbc.co.uk/1/hi/sci/tech/3142582.stm


"Remarkably, stars from Sagittarius are now raining down on to our present position in the Milky Way.

"Stars from an alien galaxy are relatively near us. We have to re-think our assumptions about the Milky Way galaxy to account for this contamination."

AstroSmurf
2003-Oct-01, 02:22 PM
http://news.bbc.co.uk/1/hi/sci/tech/3142582.stm


"Remarkably, stars from Sagittarius are now raining down on to our present position in the Milky Way.

"Stars from an alien galaxy are relatively near us. We have to re-think our assumptions about the Milky Way galaxy to account for this contamination."
Yah, trust the BBC to pick the most colourful statements.

"near" means "within 1000 light-years"
"now" means "now, give or take a million years or so"

Don't take my figures as canon, I'm just estimating the order of magnitude of this thing.

The real significance of this is that some of the stars that we see and already know about didn't originate in the Milky Way. No new stars have been found, but we need to reassess our assumptions about some of them.

2003-Oct-01, 02:44 PM
Brown in and dens my Q
.1 the 1st view of SAG, is looking "IN"
and of course the story is looking thru
"THE CENTER OF THE GALAXY" at the Fer side
------------------------------------------------------
2 now we are given the cross sex
instead of looking thru the center
we do a 90 (CCW) and git PROfile{$}
=============================
3: and the CORK screw
do not forget that #
net is for today {pleas wait}?
::::::::::::::::::::::::::::::::::::::::::today ? = 10/1
..30 .... 2P.. 130.............5 20.............................|.T&1
.... ok: ALLRIGHT? I'LL look it up and right now..ALLrignt {2:14 A.M.}
.... the file "EQZ" clearly states that the LULL@1st.1/4 is AFTER....
.... by TWO DAYS.. So when ive a connection i'll search out Quakes...
.... EDIT/COPY?LINK and start a new Against for 3&4? so later 4this1
..30 .... 2P.. 130.............5 20.............................|.T&1
.... ok:ok so these ritch asian kids {youknow Phase T mineUS x}......
.... (& count N) of the actuall foot mov(Y) {etc} are displaying ....
.... their new hand helds. Stub Antenna about erraser size.. Anywhen.
.... yesterday one walks past to the junction of E/W hall & N/S hall?
.... looks at her miniscreen looks South looks back at 'er miSC &...
.

Nowhere Man
2003-Oct-01, 07:00 PM
<gibberish>
Well, that kills THIS thread for me...

Fred

sts60
2003-Oct-01, 08:06 PM
http://news.bbc.co.uk/1/hi/sci/tech/3142582.stm


"Remarkably, stars from Sagittarius are now raining down on to our present position in the Milky Way.

"Stars from an alien galaxy are relatively near us. We have to re-think our assumptions about the Milky Way galaxy to account for this contamination."
bmpbmp, is there a point you're trying to make here? What is your opinion of this item?

You do understand the "now raining down on us" and "near" are only in the astronomical sense, not in the We're-All-About-to-Die sense, right?

bmpbmp
2003-Oct-01, 08:33 PM
actually sts i did understand it in the bad way

SirThoreth
2003-Oct-01, 08:50 PM
http://news.bbc.co.uk/1/hi/sci/tech/3142582.stm


"Remarkably, stars from Sagittarius are now raining down on to our present position in the Milky Way.

"Stars from an alien galaxy are relatively near us. We have to re-think our assumptions about the Milky Way galaxy to account for this contamination."


What it means, bmpbmp, is that not all the stars in the Milky Way galaxy came from the Milky Way galaxy. Some of the ones we can now see in the sky came from Sagittarius.

What any astronomer or astrophysicist who wants to research the formation of the Milky Way has to do, now, is to take that fact into account.

SirThoreth
2003-Oct-01, 08:53 PM
<Weird Stuff>

OK, had you through part two, I think. Can someone translate, or does HUb' get easier to understand with time?

Archer17
2003-Oct-01, 08:56 PM
..actually sts i did understand it in the bad waybmpbmp - you ought to read some of the astronomy links posted earlier in this thread by the BA and others so you get some background on the way outer space is. Work your way up by learning the basics so that when you read something like that BBC item you'll understand it in the right way.

TriangleMan
2003-Oct-01, 09:09 PM
OK, had you through part two, I think. Can someone translate, or does HUb' get easier to understand with time?

Here's an old thread (http://www.badastronomy.com/phpBB/viewtopic.php?t=2554) on Hubbish.

mr. show
2003-Oct-01, 09:18 PM
Folks-- please either stick to the thread topic, or hold your peace. If you think we are being trolled, fine, but I would prefer that you not assume bmpbmp is a troll until proven otherwise. This falls under ad hominems.

point taken

kanon14
2003-Oct-02, 12:58 AM
let alone stars collision, is it possible that these stars could trigger something that can affect us in any way? such as the KBO i mentioned above
is it even possible?

In the short term, no.

In the long term, it's possible.

By "short term" I mean "up to about 10 million years".

By "long term" I mean "over 100 million years".

By "it's possible" I mean that: our Solar System might pass through a dust-rich part of the Milky Way galaxy, which could cool the Earth; or our Solar System could pass near a region of large hot stars with the chance that one might go super-nova and irradiate Earth; or our Solar System could pass near a star which disturbs the Kuiper Belt and triggers a relatively high number of comet strikes.

bue neither the sun nor the earth will be around for that long

kanon14
2003-Oct-02, 01:03 AM
See, the trouble is--what you're dealing with when you're talking to woowoos--is that they have the ability to hear selectively.

A woowoo will hear only this part--

By "it's possible" I mean that...our Solar System could pass near a star which disturbs the Kuiper Belt and triggers a relatively high number of comet strikes.
--and will completely ignore this part--

In the short term, no.

In the long term, it's possible.

By "short term" I mean "up to about 10 million years".

By "long term" I mean "over 100 million years".
So the end result is that you now have a woowoo who insists that he heard someone say, "Yes, it's possible for a storm of comets to come out of the KB and hit the Earth..."

thx for pointing that out but i do NOT hear selectively. I think you were referring to me since it's me who brought up the KBO question. I'm just asking questions in a nice manner. If you find my question ridicious, then point it out how dumb my argument is, but please don't attack me by saying I only "hear selectively". That does not help the problem
thx

Archer17
2003-Oct-02, 01:17 AM
kanon, you will live to a ripe old age without the sun dying or KBOs affecting our fine planet. Trust me. Keep asking questions, that's why we're here. I'm sure Jigsaw was generalizing, your questions do mimic a lot of the woowoo stuff we are exposed to, but I don't think it was personal. Sometimes we hear alot of the same questions and forget it's different people asking 'em .. don't take offense kanon, I know I speak for more than myself when I say I'm glad you're here asking questions instead of someplace else 8)

kanon14
2003-Oct-02, 01:26 AM
Kanon, you will live to a ripe old age without the sun dying or KBOs affecting our fine planet. Trust me. Keep asking questions, that's why we're here. I'm sure Jigsaw was generalizing, your questions do mimic a lot of the woowoo stuff we are exposed to, but I don't think it was personal. Sometimes we hear alot of the same questions and forget it's different people asking 'em .. don't take offense Kanin, we're glad your here asking questions instead of someplace else 8)
yea i love this site and forum. i've been reading here for a long time but never spoken before, cuz my knowledge in astronomy and physics just isn't good enough to join the discussion. see when i started my first post here i got criticized right away.

Musashi
2003-Oct-02, 01:34 AM
Actually, I liked your first post. It showed that you were thinking. I hadn't thought about other stars getting close enough to fling kuiper objects at us. I just think the odds are low, and the timeline is looooooooooong.

kanon14
2003-Oct-02, 01:41 AM
Actually, I liked your first post. It showed that you were thinking. I hadn't thought about other stars getting close enough to fling kuiper objects at us. I just think the odds are low, and the timeline is looooooooooong.

yea i think the odds are low too given the milky way going peacefully and not interacting with other galaxies. but since merging with other galaxies is quite common in the universe, i was just wondering if such an event really happens, how long would it take for us to notice the effect.

freddo
2003-Oct-02, 01:42 AM
Actually, I liked your first post. It showed that you were thinking. I hadn't thought about other stars getting close enough to fling kuiper objects at us. I just think the odds are low, and the timeline is looooooooooong.

Not only that kanon14- but the question was one that had not been specifically answered - and for that you should be applauded. There's nothing worse than treading continually over old ground.

BTW, since I haven't taken a chance to welcome you to the board - welcome! =D>

Archer17
2003-Oct-02, 01:52 AM
what the Aussie said 8) .. welcome kanon (where's my manners?)

kanon14
2003-Oct-02, 01:52 AM
thx for the welcome :)

Peter B
2003-Oct-02, 07:05 AM
By "long term" I mean "over 100 million years".


but neither the sun nor the earth will be around for that long

Actually, our current information suggests the contrary.

From what I've read, life on Earth in its current form should be able to survive maybe 500 million years more, and life in some form or other should be around for another 500 million years beyond that.

The life span of the Sun can be measured in a couple of billion years before it runs low on hydrogen and swells into a red giant.

Peter B
2003-Oct-02, 07:41 AM
actually sts i did understand it in the bad way

Okay, let's put things in a bit of context, seeing as links weren't helping.

Light travels at 300,000 kilometres per second. So do radio waves.

Multiply that out over a year, and you get a distance of a little under 10,000,000,000,000 kilometres. That's known as a light year, or the distance light travels in a year.

If you send a radio message to the nearest star (apart from the Sun), the message will take 4 1/2 years to get there. If you do the sums, this means the nearest star is about 42,600,000,000,000 kilometres away. That's about 26 trillion miles.

And that's just to the nearest star.

Now this nearest star is called Alpha Centauri. It's not rushing towards us. I doubt it's even moving towards us at any noticeable speed.

In fact, I don't think there are any stars within 100 light years which are moving towards us. How far's 100 light years? You do the sums. :wink:


Okay, next bit:

The Sun, the Earth, the Moon, and the planets form the Solar System. Our Sun is one of very roughly 100,000,000,000 stars in the Milky Way galaxy.

The Milky Way galaxy is about 100,000 light years across. This is (roughly) 1,000,000,000,000,000,000 kilometres. This means the stars in the Milky Way are s p r e a d o u t.

Now our Sun and the Solar System orbit the centre of the Milky Way galaxy. It takes about 200 million years to complete one orbit. As the Solar System is about 30,000 light years from the centre of the galaxy, this means it's moving at roughly 300 kilometres a second around the centre of the galaxy. But remember: so are the other stars around us!

There are millions upon millions of other galaxies in the known universe. Some are like our own Milky Way galaxy, while others are tiddlers like the Sagittarius dwarf.


So:

When two galaxies collide, this means that only the galaxies collide. The stars in each of the galaxies don't collide because they're so far apart. Others in this thread have given practical comparisons of how far apart stars are.

And at the speed stars move compared to each other, it takes millions of years for them to get close to each other.


Conclusion:

SPACE IS BIG. Interesting things outside our Solar System are trillions of kilometres away at the closest. Most of the interesting things are quadrillions or quintillions of kilometres away.

TIMESCALES ARE BIG. Most of the interesting things take millions of years to happen. You are not likely to live that long.

kanon14
2003-Oct-03, 01:52 AM
By "long term" I mean "over 100 million years".


but neither the sun nor the earth will be around for that long

Actually, our current information suggests the contrary.

From what I've read, life on Earth in its current form should be able to survive maybe 500 million years more, and life in some form or other should be around for another 500 million years beyond that.

The life span of the Sun can be measured in a couple of billion years before it runs low on hydrogen and swells into a red giant.

ohh wait... i thought i read "100 BILLION years" lol
yea in 100 million years hopefully the Sun and our Earth will still be around 8)

Jigsaw
2003-Oct-03, 01:53 PM
thx for pointing that out but i do NOT hear selectively. I think you were referring to me since it's me who brought up the KBO question. I'm just asking questions in a nice manner. If you find my question ridicious, then point it out how dumb my argument is, but please don't attack me by saying I only "hear selectively". That does not help the problem
thx

[See big wink smilie -----> :wink:
See big grin smilie -----> :lol: ]

Hey, Kanon14, what's it like, being the Center Of The Known Universe?

[See more big wink smilies -----> :wink: :wink: :wink:
See more big grin smilies -----> :lol: :lol: :lol: ]



Wasn't talking to you, dude. If I had been talking to you, I'd have said, "Yo, Kanon14, whassup?" and then you'd have known I was addressing you. Don't assume it's always "about" you, 'cause most of the time, it ain't. ;)

Welcome to the BABB. 8)

kanon14
2003-Oct-10, 06:06 PM
maybe i thought too much :oops:

Jigsaw
2003-Oct-12, 02:02 AM
It's okay. 8)