At the Center of the Milky Way

Comments and questions about the APOD on the main view screen.
Zygote from Mars
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At the Center of the Milky Way

Post by Zygote from Mars » Sun Oct 23, 2005 8:08 am

At the Center of the Milky Way
Credit : Rainer Schödel (MPE) et al., NAOS-CONICA, ESO
Explanation: At the center of our Milky Way Galaxy lies a black hole with over 2 million times the mass of the Sun. Once a controversial claim, this astounding conclusion is now virtually inescapable and based on observations of stars orbiting very near the galactic center. Using one of the Paranal Observatory's very large telescopes and a sophisticated infrared camera, astronomers patiently followed the orbit of a particular star, designated S2, as it came within about 17 light-hours of the center of the Milky Way (about 3 times the radius of Pluto's orbit). Their results convincingly show that S2 is moving under the influence of the enormous gravity of an unseen object that must be extremely compact -- a supermassive black hole. This deep near-infrared image shows the crowded inner 2 light-years of the Milky Way with the exact position of the galactic center indicated by arrows. The ability to track stars so close to the galactic center can accurately measure the black hole's mass and perhaps even provide an unprecedented test of Einstein's theory of gravity as astronomers watch a star orbit a supermassive black hole.

Zygote from Mars
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Time Travel

Post by Zygote from Mars » Sun Oct 23, 2005 8:15 am

This explains why time travel is possible to move forward in time and not backward. Everything has been moving forward since the Big Bang and matter can not jump back on itself.

keithh
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Re: At the Center of the Milky Way

Post by keithh » Sun Oct 23, 2005 12:16 pm

Zygote from Mars wrote: Explanation: At the center of our Milky Way Galaxy lies a black hole with over 2 million times the mass of the Sun. Once a controversial claim, this astounding conclusion is now virtually inescapable..
Zygote, how could you resist the temptation? In this context, surely the word "inescapable" deserves its own link.

Here's a candidate: http://www.duke.edu/~teb/stars/blackhole.html

Here's another: http://www.paleothea.com/Myths/Ariadne.html

S. Bilderback
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Post by S. Bilderback » Sun Oct 23, 2005 3:51 pm

There is one thing known to escape a Black Hole - Gravity.

Ideas to ponder:

If gravity is a attractive force pulling one gravity field to another, why doesn't gravity pull it's field back on itself?

What is the speed of gravity, is it instantaineous or the same as the speed of light?

Edy Bevk
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Re: At the Center of the Milky Way

Post by Edy Bevk » Sun Oct 23, 2005 4:42 pm

Zygote from Mars wrote:At the Center of the Milky Way
Credit : Rainer Schödel (MPE) et al., NAOS-CONICA, ESO
Explanation: At the center of our Milky Way Galaxy lies a black hole with over 2 million times the mass of the Sun. Once a controversial claim, this astounding conclusion is now virtually inescapable and based on observations of stars orbiting very near the galactic center. Using one of the Paranal Observatory's very large telescopes and a sophisticated infrared camera, astronomers patiently followed the orbit of a particular star, designated S2, as it came within about 17 light-hours of the center of the Milky Way (about 3 times the radius of Pluto's orbit). Their results convincingly show that S2 is moving under the influence of the enormous gravity of an unseen object that must be extremely compact -- a supermassive black hole. This deep near-infrared image shows the crowded inner 2 light-years of the Milky Way with the exact position of the galactic center indicated by arrows. The ability to track stars so close to the galactic center can accurately measure the black hole's mass and perhaps even provide an unprecedented test of Einstein's theory of gravity as astronomers watch a star orbit a supermassive black hole.
8)
Hi,
don't know if I am doing this well now, if this is the place to react to APOD 23 Okt.
If you put , so to say, the APOD of 23 Okt. on top of the APOD 25 August then you get the idea that 23 Okt is the end of the supposed bar of the Milky Way.?
We can imagine to see in the APOD of 23 Okt the end of the bar of the artist's picture of 25 August.
So once again in other words: you "see" ( APOD 23 Okt.) that one end of the bar that is lifted into our direction.
The picture of 23 Okt. as you quote is an old ESO picture. Shouldn't you put/link these two together?
( I don't know if this mail comes to the right place. To get into this kind of systems I am always terribly clumsy,)
edy
Retired language teacher. When 65 started astronomy as a hobby. SOC member went with Powerpoint Cassini to Slovenija.
Interested in history of Copernic, Brahe,Kepler.

Storm_norm
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no

Post by Storm_norm » Tue Oct 25, 2005 9:30 am

S. Bilderback wrote:There is one thing known to escape a Black Hole - Gravity.

Ideas to ponder:

If gravity is a attractive force pulling one gravity field to another, why doesn't gravity pull it's field back on itself?

What is the speed of gravity, is it instantaineous or the same as the speed of light?
no no, if you instantly removed the Sun from the solar system, it would take the earth 8 minutes to feel that the sun isn't there.

Storm_norm
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theory

Post by Storm_norm » Tue Oct 25, 2005 9:48 am

I guess the evidence is mounting for a very fast paced center with a huge black hole. But....... we can't forget that the distances are still even more massive. Normal Stars living out their normal lives, EVEN at the center.

craterchains
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Post by craterchains » Tue Oct 25, 2005 1:07 pm

S. Bilderback wrote:There is one thing known to escape a Black Hole - Gravity.

Ideas to ponder:

If gravity is a attractive force pulling one gravity field to another, why doesn't gravity pull it's field back on itself?

What is the speed of gravity, is it instantaineous or the same as the speed of light?
Now THAT is a great question!
Just how do we figure it out :?:

Does gravity travel at the same speed as light? Doubtful, as we note other aspects of gravity's effects.
"It's not what you know, or don't know, but what you know that isn't so that will hurt you." Will Rodgers 1938

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Post by orin stepanek » Tue Oct 25, 2005 1:57 pm

Does gravity have a speed? Is it constant? Seems like the greater the attraction the greater the acceleration toward it.
Orin

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BMAONE23
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Post by BMAONE23 » Tue Oct 25, 2005 4:53 pm

Gravity should be a constant but only effective upon things which fall into its relative sphere of influence. The central black hole of our galaxy has a gravity well that is effective over a 70,000 LY area while the Andromeda galaxy effects over 200,000 LY.

S. Bilderback
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Post by S. Bilderback » Tue Oct 25, 2005 11:38 pm

One way to measure the speed of gravity would be to have a mass traveling near the speed of light and measure it's effect as it passes close to a stationary object.

S. Bilderback
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Re: no

Post by S. Bilderback » Tue Oct 25, 2005 11:48 pm

Storm_norm wrote:
S. Bilderback wrote:There is one thing known to escape a Black Hole - Gravity.

Ideas to ponder:

If gravity is a attractive force pulling one gravity field to another, why doesn't gravity pull it's field back on itself?

What is the speed of gravity, is it instantaineous or the same as the speed of light?
no no, if you instantly removed the Sun from the solar system, it would take the earth 8 minutes to feel that the sun isn't there.

That is only true if the speed of light and the speed of gravity are equal. If the speed of gravity is instantaineous, we would see the Sun get smaller for 8 minutes as the Earth continued on a straight line away from where the Sun was.

Storm_norm
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Re: no

Post by Storm_norm » Tue Oct 25, 2005 11:53 pm

S. Bilderback wrote:
Storm_norm wrote:
S. Bilderback wrote:There is one thing known to escape a Black Hole - Gravity.

Ideas to ponder:

If gravity is a attractive force pulling one gravity field to another, why doesn't gravity pull it's field back on itself?

What is the speed of gravity, is it instantaineous or the same as the speed of light?
no no, if you instantly removed the Sun from the solar system, it would take the earth 8 minutes to feel that the sun isn't there.
That is only true if the speed of light and the speed of gravity are equal. If the speed of gravity is instantaineous, we would see the Sun get smaller for 8 minutes as the Earth continued on a straight line away from where the Sun was.

I am saying that if gravity moved as fast as light, that it takes 8 minutes for gravity to have an effect on the earth, right? I am just making sure no one here is saying that gravity can move faster than light. if gravity has a speed limit of the speed of light, than gravity would stop its influence on the earth 8 minutes after the sun were removed.

S. Bilderback
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Post by S. Bilderback » Wed Oct 26, 2005 12:49 am

I'm saying it is possible that the speed of gravity could be faster than the speed of light. In the String Theory the gravity model has the graviton as an open ended loop, to over simplify, it means part of gravity exists outside of our 4 dimensional world allowing it "violate" the laws of general physics.

A quick lesson in accelerometers, matter can be created, atomic collisions can be like crashing two tricycles together and getting a bulldoze, a couple airplanes and a gross of flashlights as the byproduct.

This has been done, particles created in an atom smasher from a single source have been separated, set in different locations and when let's say one of the electrons is forced to change it's energy state, a "connected" electron in the other location will have an instantaneous reaction - they still have a connection by a common string connected via a different dimensional state.

Gravity may follow this same principle, instantly jumping though other dimensions from point to point.

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Post by Empeda » Wed Oct 26, 2005 7:47 am

This is true, but the important part is the jumping dimensions....

In our 'physical' world, the speed of light can be view as the speed of information transfer.

So if the sun did suddenly disappear into a puff of logic, the earth WOULD still continue in it's 'orbit' for eight minutes, because to all intents and purposes, to us mere earlings, the sun would still exist, in the same way that distant galaxies 'exist' eventhough we see them as they were 12 billion years ago.
I'm an Astrophysics Graduate from Keele University, England - doesn't mean I know anything but I might be able to help!

S. Bilderback
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Post by S. Bilderback » Wed Oct 26, 2005 11:20 am

It has been proven that the speed of information can be breached, here's a wonderful read on the subject.


http://www.metaresearch.org/cosmology/g ... _limit.asp

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Post by makc » Wed Oct 26, 2005 12:33 pm

now why it has bored me to death.

Empeda
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Post by Empeda » Wed Oct 26, 2005 1:05 pm

makc wrote:now why it has bored me to death.
Ah, because the speed of information was breached, and you knew it before you'd finished reading it..... :lol:
I'm an Astrophysics Graduate from Keele University, England - doesn't mean I know anything but I might be able to help!

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Re: According to older ideas the sun removing would be felt

Post by Edy Bevk » Mon Oct 31, 2005 12:05 am

Storm_norm wrote:
S. Bilderback wrote:There is one thing known to escape a Black Hole - Gravity.

Ideas to ponder:

If gravity is a attractive force pulling one gravity field to another, why doesn't gravity pull it's field back on itself?

What is the speed of gravity, is it instantaineous or the same as the speed of light?
no no, if you instantly removed the Sun from the solar system, it would take the earth 8 minutes to feel that the sun isn't there.
According to older ideas the removing of the sun would be felt immediately. That was a problem because then there would be velocity faster than light.
According to Einstein there is no velocity faster than light. At the same impossible moment you would take that good old sun away, you also would have taken away the warp that the sun causes in the spacetime. That means that mother earth would immediately run away straight on for she is held in orbit by that warp.
Who knows better gets the prize.
edy

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Post by crosscountry » Mon Oct 31, 2005 3:23 am

S. Bilderback wrote:There is one thing known to escape a Black Hole - Gravity.

Ideas to ponder:

If gravity is a attractive force pulling one gravity field to another, why doesn't gravity pull it's field back on itself?

What is the speed of gravity, is it instantaineous or the same as the speed of light?


it's not actually gravity that you feel. it's the slope of space-time. you're "standing" on the slope. the bigger the object, black holes included, the more slope.

S. Bilderback
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Post by S. Bilderback » Mon Oct 31, 2005 3:32 am

Experiments using massive orbiting pulsars should reveal an answer in a few years as to the speed of gravity, so far, faster than C looks like the most probable outcome.

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Post by Aqua » Mon Oct 31, 2005 6:00 pm

"There once was a lady named 'Bright', whose speed was much faster than light. She went out one day, in a relative way, and came back on the previous night!"

Praps gravity appears instantaneously everywhere, without having to travel to get there, because it exists in dimensions beyond our local space/time?

craterchains
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Post by craterchains » Mon Oct 31, 2005 9:19 pm

This time, as I have stated previously.
"Does gravity travel at the same speed as light? Doubtful, as we note other aspects of gravity's effects."

The known fact that once in motion, stays in motion, and the more thrust, the more speed, has no proven stop point. Thus, realistically (not relativisticaly, take a back seat Einny) we should be able to use these gravity wells or black holes to sling shot us through and out the other side?!?! Like running a river's currents. 8)

Some one may have all ready built a faster than light gravity drive. But, can we learn to navigate them? :wink:
"It's not what you know, or don't know, but what you know that isn't so that will hurt you." Will Rodgers 1938

S. Bilderback
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Post by S. Bilderback » Mon Oct 31, 2005 11:20 pm

Åqua wrote:"There once was a lady named 'Bright', whose speed was much faster than light. She went out one day, in a relative way, and came back on the previous night!"

Praps gravity appears instantaneously everywhere, without having to travel to get there, because it exists in dimensions beyond our local space/time?
That is what the -Open Loop- theory of the graviton states. Some of its connecting forces don't interact with our 4 dimensional universe.

To test this theory all that is needed is an object of a mass great enough that gravity is the strongest force, send it at (near) the speed of light passed a stationary test object and see when the gravitational field pulls on the test object. If the test object is pulled by gravity before the speeding object passes, the speed of gravity is faster than light.

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Post by harry » Sat Nov 19, 2005 7:42 am

Gravity is part of the medium of space and in many cases gravity controls the speed of light. Where we have extreme garvity such as at the Event Horizin the speed of light seems to be Zero.
Even in labs scientist have bent light and slowed it down by using electromagnets creating the artificial gravity.
Sunspots the very large gravitational convectional currents direct light and matter into the sun spot reducing the amount of light escaping.
So in an open area without external influences light will travel at the speed of light at the same speed as gravity.
If Gravity travels faster than light will go with it. The both go hand in hand.
Harry : Smile and live another day.