The technique is called very long baseline interferometry (VLBI). This will create a telescope dish the size of the geographic distances between all the telescopes, that is, a dish the size of
Scientists are preparing a network that will act as a super telescope to study Sagittarius A, an object that is probably the black hole at the center of our galaxy. Its weight is 8 tera iota kilograms, that is, we don't even have a syntactic prefix to describe its enormous mass. To illustrate, its weight is equivalent to 4.5 million suns like ours. And if it is so huge then why is it so hard to see? Because it hides behind half of the galaxy and for that you have to overcome large amounts of light from stars and gas that are in the way and reduce the signals. Oh yes, and another small detail - black holes do not emit light, which makes the investigation even more difficult.
In order to overcome all this, the astronomer Shap Doelman from MIT came up with the idea of connecting together many radio telescopes spread all over the world and creating a kind of super telescope. The technique is called very long baseline interferometry (VLBI). This will create a telescope plate the size of the geographical distances between all the telescopes, that is, a plate the size of the Earth.
Since the core of the galaxy is a populated and bustling place, the gas makes it difficult for radio waves to pass through, "it's like a thick fog that obscures the image of a street lamp," says Avi Loeb of Harvard University. Therefore, the telescopes were tuned to receive a wavelength of 1 mm. Such a short wavelength easily cuts through the fog and gas and gives a less blurry image than a longer wavelength.
Scientists believe that in the cores of most large galaxies there are supermassive black holes. In active galaxies, a huge amount of gas swirls and is swallowed by the black hole, the process creates a hot disk of material that sometimes shines on the billions of stars in its vicinity.
In our galaxy the situation is a little different, the black hole is not a big glutton, and it is satisfied with "small" amounts of gas flowing to it from nearby stars. When the gas falls into the black hole it heats up and radiates, but to a lesser extent than in active galaxies. Radiation of all types of wavelengths is emitted from the area, from radio rays to X-rays.
As mentioned, black holes do not emit light, so what you expect to find is a dark silhouette surrounded by hot, glowing gas.
It will not be easy to see the silhouette. According to the theory of relativity, a black hole with a size of 4.5 million solar masses should spread over an area 27 million kilometers long, and although the great gravity will deflect light rays passing by the hole towards the hole, making it appear twice as large, even from our perspective on Earth , it will show a magnitude of 50 microarcseconds. For illustration, this is the size a football would look like if we put it on the moon.
The research, besides confirming the claim that there are black holes in the centers of spiral galaxies, will also help to investigate models regarding the formation of the Milky Way, as well as test predictions of the theory of relativity.
22 תגובות
Meir Giladi:
I see that you have decided to flood us with new Torah that you instigated.
See reactive to your previous response
Hmmm some of the material is thrown back most of it disappears and its fate is unknown, this has the information paradox that comes into play here.
Not 4.5 million suns or another guess. The black hole simply has no mass of its own. It is simply a consideration of the gravitational forces of the material around it.
Black holes are not collapsing stars. If these were collapsing stars, the gravitational force we would feel if we were standing on the surface of the star would be equal to the gravitational force after the collapse of the star into itself if we continued to stand at the same point in space. The gravitational force of any body such as a star comes from its mass. Because the collapsing star does not contain, due to its collapse, more mass than it had before. The strength of gravity will not change even if the body collapsed. The force of gravity is always calculated as if all the mass was concentrated in the center from the beginning. Although if we collapsed together with the star "and stayed alive" we would feel a huge force of gravity because our distance from the center of the star was shortened to almost zero. Therefore the effect of collapsing stars on Their environment in space before they collapsed and the creation of black holes as a result is complete nonsense.
The gravitational force of the Earth, for example, is calculated as if all its mass were concentrated in the center. The gravitational force we feel is affected by our distance from the center of the Earth, therefore there is a small change in the strength of the gravitational force on the surface of the Earth because it is not a perfect sphere but an ellipse. Therefore, satellites are launched from the equator at a lower cost than at the poles.
The gravitational force of the entire Milky Way galaxy is also calculated as if it were all concentrated in the center. Or rather, in the center of the sum of the gravitational forces. This center is actually the "black hole" and its power is derived from the mass of the stars and the material around it without its own material.
If our distance from the center of the Milky Way is about 25 thousand light years. There will be the force of gravity in which we will be pulled together with the Earth to the center equal to the force of gravity resulting from the mass of the stars and matter in a radius of 25 thousand light years from the center. The stars outside this radius affect us in a different way. Some pull us together with the black hole and some pull us against this force (these are stars we are between and the black hole).
It is therefore a mistake to think that black holes have their own mass. If this were the case, their power would increase in direct proportion to the matter "swallowed" by them and over time they would "swallow" all the matter in the universe.
Because black holes do not have their own mass and in fact at the virtual point in the center of the black hole there will be no gravitational force at all because the distance from the center is 0 and according to the gravitational force formula at a distance of 0 the force is also 0.
The material that is accelerated towards the black hole and falls into its event horizon and swirls with acceleration and is finally thrown back into space in the form of two jets perpendicular to the plane of rotation. Why perpendicular? Because only perpendicular to the plane of rotation of the stars is the force of gravity the smallest, because the stars rotate in the plane of a disk around the center, therefore only perpendicular to the disk is the force of gravity weaker and the material can escape.
This article is in terms of changing the perception of the popular knowledge in science on the subject. The conventional wisdom is that black holes are stars that have collapsed in on themselves and that black holes have a huge mass.
I predict in advance the wave of reactions in the rescue that will come to strengthen an entrenched and unfounded Torah.
To begin with, I aim at those few who think outside the box...
Bijumbom = troll. Cute, but a troll.
A. Ben Ner
Thank you
to Bijumbom
I will try to answer your questions even though I am not an expert.
1. The density of matter in the dust clouds - in the space of the galaxy there are quite large distances between the stars. For example, our sun is about 3 light-years from the star closest to it (Alpha Centauri) and about 8 light-years from the second star near it (Sirius). (A light year = (approximately) to 9000 billion kilometers or approximately to 1 and thirteen zeros after it in kilometers). In the expanses of the galaxy there are also areas of dust clouds scattered over huge volumes. This dust is the result of ancient stellar explosions, explosions also known as supernovae. These dust clouds block some of the radiation that hits them. The percentage of blocked radiation depends on both the density of the dust and the frequency of the radiation. frequencies
Some, mainly those with a short wavelength, are blocked more and others, with a longer wavelength, are blocked less. That's why the research was done on radio rays with a wavelength of about 1 cm, which are long waves and have a high penetration capacity, compared to visible light rays, for example - on the one hand, and on the other hand, can still be received and photographed by compact antennas.
2. Regarding the satellite photography, it is clear that the processing of the signals received in the measurements and their presentation in some graphical way, either as a graph or as a color image, is done with the help of a computer.
A. Ben-Ner
Could you please respond to the other questions I wrote in response 13
Thanks
to Bijumbom
Below is the meaning of the first line in my previous response:
Tsal = should be
Avi Leib = name of a well-known Israeli astrophysicist, who serves as a professor at Harvard University-USA. His name was written by mistake in the article
As Avi Loeb.
A. Ben-Ner
Thank you for responding to my question, but in your legacy I still did not understand several things, including the entire first line with the initials - I lost you, sorry -
By the way, I also noticed according to your attitude that you are quite knowledgeable about this subject, what is meant by the density of the material in the dust clouds and what is the connection of the radio waves in satellite photography?
Is the satellite photography done using radio waves, and if so, how exactly is it received in the image? Because I assumed it was done using a combination of magnifying lenses?
In short, I'm sorry for driving you crazy, but if you could sort out the mess for me and perhaps explain to me how satellites work and where radio waves and a mirror lens come into play in this matter (after all, it only reflects what is seen, how can such a thing be interpreted with massive magnification.
Thank you in advance, sorry for my growing curiosity
to the point
You're right, I was wrong.
Made me remember the words of the teacher in high school math classes
Note: Tsal "Avi Leib" and not "Avi Loev" as it was written by mistake.
to Bijumbom
The hiding or blocking ability of the material in the galactic medium depends on the density of the material in the dust clouds, the angular size of the stars that are between us and the center of the galaxy (that is, what part of the sky they hide from us) and of course the frequency being tested and the intensity of the emitted radiation, of the frequency being tested. It turns out that the density of the material in the dust clouds is thin enough to allow partial penetration of the radio radiation. This is how the radiation "bypasses" the stars that are between us and the center of the galaxy, "optical bypass".
In an article published on this website on 03-05-09 by Avi Leib ("Hundreds of black holes roam the galaxy...") there is a reservation about the existence of hundreds of "medium" black holes in the galactic space. If a picture of a gravitational clouding of the radio radiation is discovered, around the center of Apple, this will be a strong confirmation application for the above assumption.
very interesting
The word population is also used in mathematics to describe a group of objects or items, and in astrophysics, to describe the stars that populate the sky. In the same degree of personification, it can be said that the star resides in...
To the writer - Yael Petar
I would also like to receive an answer from you regarding my question
The really intriguing question is: how is it possible to really see through the stars that stand between us and the giant hole?
I think this is also what "point" meant, from the first comment
I'd like to receive an answer
Populated from the word population = living beings. Its name is a kind of controversial metaphor
populated by stars and other sweet things.
When they say populated, they don't always mean creatures...
In my eyes, the strange is the observer...
What I really like about this article is the sentence: "Because the core of the galaxy is a populated and bustling place,"
Inhabited by what, little green aliens or maybe angels? A strange sentence, no doubt.
It seems to me that in the current context - translating the word Baseline to "baseline" instead of "starting line" would convey the idea in a more intuitive way.
:-O what a COPY PASTE!!!!
If there is a star or several standing between us and the black hole, I find it hard to believe that it would even be possible to detect anything.