The researchers combined the light spectrum from the red giant along with data from NASA's Kepler Observatory to calculate the mass of 70,000 red giant stars along the Milky Way's mantle, up to 50,000 light-years away.
Astronomers have long predicted that the oldest stars in our Milky Way galaxy are in the center of the galaxy, while the younger objects are found in the outer regions. Now the astronomers have mapped their prediction in detail, thanks to the SDSS 2.5-meter telescope at the Apache Observatory in New Mexico.
The findings were presented at the American Astronomical Society meeting in Kissimmee, Florida by a team led by Melisha Ness of the Max Planck Institute for Astronomy in Heidelberg, Germany. The researchers created the first ever growth curve of the Milky Way showing how the galaxy evolved from its infancy to the bright spiral galaxy we see today.
A group of astronomers used the SDSS to determine the mass of red giants, bright stars nearing their end, and scattered throughout the galaxy. The older a red giant star is, in general, the lower its mass. However SDSS cannot measure mass directly. As the team of researchers described at the American Astronomical Society meeting, they combined the light spectrum from the red giant along with data from NASA's Kepler Observatory to calculate the mass of 70,000 red giant stars along the Milky Way's envelope, up to 50,000 light-years away.
On the map, which you can see above, the focal point from which the lines come out is at the point where the earth is located. To his right the older stars (red) around the center of the galaxy and to his left the younger stars (blue) in the outer parts of the disk. As the researchers in the group say, the Milky Way galaxy has grown outward over time.
More of the topic in Hayadan:
About a third of the stars in the Milky Way have moved
A high-resolution tour of the center of the Milky Way
Astronomers estimate that there are about one hundred billion Earth-like planets in the Milky Way
90 תגובות
But the paradoxical question is: why does it only happen to one side?
Why is the distance between the stars, in the eyes of the flying twin, 5 light years and not in the eyes of the star that flies in front of it at the same speed and at the same time?
Why in terms of the flying twin - the flight time is 5 years and not in terms of the star in front of it?
The answer on the wiki and elsewhere: switching reference systems and acceleration.
My answer: clock synchronization.
You have to go to sleep, but if you want, try to answer what is the reason for the central premise underlying the paradox:
Why, if each system sees the other's time as moving slower, would a clock moving in a straight line along a synchronized system see its clocks as showing a higher time than its own?
Good night.
Israel
That is, one twin matured by ten years while his brother matured by twenty years. It is interesting, but there is no paradox.
Without synchronizing clocks, and without accelerations....
certainly
Israel
Now - we will change directions. Again 5 years will pass in terms of the flying twin and 10 in terms of the resting twin.
I'm right?
Definitely
Israel
If so, then do you agree that in terms of the flying twin - the flight time is 5 years?
agree
Israel
Do you agree that the distance between the stars, in the eyes of the flying twin, is 5 light years?
Yes
Israel
In the example I gave - do you agree that the stationary twin matures by 20 years?
No, but they are not in a hurry. Not relative to each other and not relative to other systems.
The solar system is an example of a non-inertial system.
What exactly does it matter to us?
Israel
"You can see the star-twin system as one inertial system." – Their relative speed is zero?
Miracles
The star-twin system can be seen as one inertial system.
In such a system if all the starting conditions are the same for both bodies, the final result is also the same.
But let's solve the problem. There is a difference between the twin and the star: the star's clock is synchronized with the earth's clock, the twin's clock is not. It only resets at the moment it changed to show 0 like the earth, but this is a singular moment.
But as mentioned, this is only half the solution, or actually a third. The next question is: why, if each system sees the other's time as moving slower, would a clock moving in a straight line along a synchronized system see its clocks showing a higher time than its own?
The next question is: if the time of the "moving" clock is always lower - and a photograph from both sides will show this - how can the "moving" clock claim that the clock time of the synchronized system is actually lower? After all, we have photos from both sides that show the opposite!
As you can see the solution is in synchronization, not in changing reference systems and not in acceleration, although it can be argued that when the twin rotates the times of the synchronized system change for it and so do the distances due to Lorentz contraction.
In my opinion, this argument goes too far and cannot be mentally verified with "evidence" such as photographs from range 0.
And it can also be seen that the solution to the twin paradox is not so simple.
And all this is just a promo for the Paradox of the Rings.
Israel
'And you can't look at them as one system? Why?" – I didn't understand 🙂 Are you claiming that speed has no effect?
"And what is the difference between the twin and the star, why if they both started at time 0 are the same distance and the speed between them is the same, they will end the journey at different times?". Read again:
"(1) In the system of the stars - the distance between them is 10 light years.
(2) In the system of the flying twin - the distance is 5 light years.
Which of these claims do you disagree with?"
And you can't look at them as one system? Why?
And what is the difference between the twin and the star, why if they both started at time 0 are the same distance and the speed between them is the same they will end the journey at different times?
The solution is in what I said. starts with s.
Israel
The star system, and the twin system.
If a twin flies towards a star, what other system is here?
Israel
"In this system only"???? but …. but …. But there are two systems here!
And I said:
"We will look at the star-twin system. They move in front of each other at the same relative speed at moment 0 according to their clocks."
Can you tell what is the difference between the two in this system alone?"
So why don't you answer this question and introduce additional factors?
The answer is half the solution.
Israel
I said that in Earth's system there is a star 10 light years away. The spacecraft flies at gamma = 2, so the distance appears to be half as small.
Why not the other way around?
Israel
I explained the difference:
(1) In the system of the stars - the distance between them is 10 light years.
(2) In the system of the flying twin - the distance is 5 light years.
Which of these statements do you disagree with?
Miracles, once again:
"We will look at the star-twin system. They move in front of each other at the same relative speed at moment 0 according to their clocks."
Can you tell what is the difference between the two in this system only?
again:
"If when the twin passes by the star and takes pictures of its time and vice versa, won't the photographs from both sides show that the time of the twin is lower than the time of the star? (Our debate in the paradox of the rings)".
Which answers your question:
What photos? We reset clocks in the suit - these photographs were taken on Earth. What other photo is there?
And to your question:
What does "why" mean? This is a conclusion from special relativity that is supported by experiments.
The conclusion of the theory of relativity is that each system sees the opposite system's time as passing more slowly. As we can see, only in one system it is possible to measure - and also photograph - a lower time. This is the paradox.
If you cannot explain why in one of the two systems it is possible to record a lower time, you will not be able to solve the paradox.
But the main thing is the first section:
"We will look at the star-twin system. They move in front of each other at the same relative speed at moment 0 according to their clocks."
Can you tell what is the difference between the two in this system only?
Israel
"1. Why is it that from the point of view of the star the distance to the twin is 10 light years and from the point of view of the twin only 5?" (a) From the point of view of the distant star the suit occurs near the Earth, which is 10 light years away. (b) From the point of view of the spacecraft - the distance between the sphere and the earth and the star is 5 light years (Lorentz contraction). What part do you disagree with?
"2. Why when they meet, the twin time is 5 and the star time is 10? Where is the symmetry?" – There is no symmetry.
"3. Why, even though the twin time is lower - and the photographs from both sides show it - can he claim that time in the Earth-Star system moves more slowly?" – What photos? We reset clocks in the suit - these photographs were taken on Earth. What other photo is there?
"4. Why does time move slower in general, and why exactly in the twin system will the photographs show this?" - What does "why" mean? This is a conclusion from special relativity that is supported by experiments.
Miracles
We have 3 watches: the KDA, the Star and the Twin.
When the twin passes over the land, both clocks show 0.
Because the earth is in sync with the star, the time on the star clock is also 0 when the twin sets out.
Let's look at the star-twin system. They are moving towards each other at the same relative speed at time 0 according to their clocks.
Questions:
1. Why in terms of the star the distance to the twin is 10 light years and in terms of the twin only 5?
2. Why when they meet, the twin time is 5 and the star time is 10? Where is the symmetry?
3. Why, even though the twin time is lower - and the photographs from both sides show it - can he claim that time in the Earth-Star system moves more slowly?
4. Why does time move slower in general, and why exactly in the twin system will the photographs show this?
Israel
No - the twin comes from Earth which is 10 light years away.
Assume that the twin does not start on Earth but resets its clock at the moment of the suit. From the distant star the distance is 10 light years but as for the spacecraft the distance is only 5 light years.
Miracles
You write "As for the second twin, the distance is only 5 light years. Therefore - he will eventually mature in 10 years."
But also regarding the star to which the twin flew, the distance is only 5 light years from it, isn't it? They fly in front of each other at the same relative speed, don't they? Why then do 10 years pass in him, while only 5 in the twin?
You also said what I claim: it has nothing to do with changing reference systems, or the twin turning around. The time dilation exists even without changing the reference system.
Anyway, what you need to explain is:
1. Why if the time in the star passes faster than in the twin, the opposite does not happen, because of the symmetry.
2. If when the twin passes by the star and its time is photographed and vice versa, won't the photographs from both sides show that the time of the twin is lower than that of the star? (Our debate in the Paradox of the Rings).
Israel
Suppose the twin flies to a star 10 light years away, at such a speed that gamma = 2. Approximately - the remaining twin will mature in a little more than 20 years. As for the other twin, the distance is only 5 light years. Therefore - he will eventually mature in 10 years.
*Note that due to symmetry - on the way the Earth moves away from the spacecraft at gamma = 2, close to the speed of light. And because the star and the earth are in the same frame of reference - the speed with which the star approaches the spacecraft is also close to the speed of light. Hence the 5 years towards.
**To understand that there is nothing to do with acceleration - let's think about what happens when we increase the acceleration more and more. Time slows down rapidly and let's exaggerate and assume that time has stopped completely at this point. Therefore - as the acceleration increases, the effect on our experiments is smaller.
Miracles
If the explanation is so simple, bring it.
Floating point
The twin "paradox" is not really a paradox. The solution is simple to understand and I don't understand why to get involved 🙂
I lost the desire to talk to you. thanks for the answers.
N.C.
Can you show me where you asked?
Make a clear list of everything you want me to explain.
And here is what I ask you:
Why is it that after a twin returns from his journey he does not find to his surprise that he is the same age as his brother as Newton claims?
Or, mercifully, find to his dismay that he is actually older?
There is no symmetry between you, they explain to him: you experienced acceleration and you are the one who turned around and changed reference systems (the explanation in Wikipedia and other places).
If you answer this question, we may be able to move forward and see why changing reference systems or acceleration has nothing to do with solving the paradox.
Israel,
All in all, I asked you to explain in simple words why there is a difference between the twins. Where is the symmetry broken? Don't want to explain? Not bad.
Point C.
What is that "essential element of the twin paradox" other than synchronization that creates the paradox?
And why "your scholarly explanation does not work if you are the twin on the spaceship and the planet is the one that moves away from you and then returns"?
Of course, "my scholarly explanation" also works in the opposite case!
You.. you know my learned explanation?
(Do I know him?)
😀
Miracles
It actually seems paradoxical: if all three factors started at time 0, and each system sees time in the opposite system as passing more slowly, then how is it that the time in one system - the twin - is lower than that of the opposite system and both sides agree that it is lower?
My claim is that this has nothing to do with changing reference systems, which is the explanation in Wikipedia, or acceleration, which is the explanation in many places, including certain physics books. Only for synchronicity.
The explanation of how this happens is long and winding, but it seems to me that we have summed it up.
Israel, there is an essential element in the paradox of the twins, and it is to find what is the difference between them. If there is no difference between the twins then any argument (synchronization, reference systems, whatever you want) works even if we switch roles between them. And then when they meet then A is younger but also B is younger.
So you have a scholarly explanation that differs from Wikipedia, great. Why does your scholarly explanation not work if you are the twin on the spaceship and the planet is the one moving away from you and then coming back?
By the way, if there is perfect symmetry, then it is guaranteed that when the 2 twins meet, they are exactly the same age. In my opinion, this is what is happening in your question of the rings (by the way, any symmetrical path the twins do will reach the same result), and I am actually very satisfied with this puzzle because no math is needed!
Israel
What you described is correct. There is nothing here that seems paradoxical.
Miracles
If the twin passes planet A (without accelerating) at time 0 according to both clocks, and the clock of planet A is synchronized with the clock of planet B, then the twin will reach B at a time higher than its clock.
There is no exchange of reference systems here, only synchronization.
Israel
I don't understand what this has to do with sync. One twin flies and returns, and is younger than his brother.
Miracles
The "paradox" happens because of the movement, and it is that although each side sees the other's time as going slower, only one of them's time is moving slower. And as I mentioned, it is not related to changing reference systems or acceleration, but synchronization.
Israel
that's not the point. The "paradox" happens when the twins are in the same reference system. During the movement it is not interesting.
Life
good week..
good week..
good week..
good week..
sit down.. enough!
Eliyahu Hatshebi..
Miracles
If you look at the half of the paradox, that is, the hurrying twin simply passes clock A, which is synchronized with clock B, on his way to him, you will see that his clock will tick slower than theirs even if you do not switch reference systems.
Israel
The twin "paradox" is not related to accelerations. The explanation of reference frame switching is correct.
Why complicate? 🙂
Israel Shapira
Now I understood why the twin is in a hurry. He tries even before Shabbat to find a prayer cycle adjusted to the Martian clock for Raphael and David. Immediately after the Havdalah prayer this coming Shabbat, they fly there. They meet at gate 6 in Netavg. I assume you remember the prayer for a good and blessed week Elijah the Prophet... which was broadcast on Channel A at the end of Shabbat.
Life
If he does not hurry, his time will not be shortened.
point.
I looked for the question about the twin paradox on wikipedia, but couldn't find it. Can I have a link?
What I did find is a common explanation for the solution to the paradox:
"Actually there is no symmetry between the two. The twin who remains on Earth remains all the time in the same reference system - that of Earth. In contrast, the traveling twin changed reference systems. Initially it was in a system moving at speed v+ relative to the Earth, but then it reversed its direction and moved to a reference system moving at speed v-. In this rotation, it was he who activated the engines, and not the Earth, and therefore in this period of time he accelerated, while his twin brother moved at a constant speed.'
Another common explanation is that the younger twin experienced acceleration while his older sibling who was left behind did not.
It is hard for me to agree with these two explanations. The solution to the paradox in my opinion is only in the context of the simultaneous relationship. I think it is possible to build a certain scenario where the older twin is the one who accelerated and his younger brother did not, and still the results will be the same as before.
We will try to see how your riddle relates to the twin paradox and what is the difference between the twin that moves and moves, as if there is such a thing:
For this purpose, we will consider two planets 10 light hours apart that are relatively close to each other and their clocks are synchronized with each other. The rushing twin passes (without accelerating, it just continued its flight from before) at moment 0 in the planetary clocks near Planet A and its time at this moment is also 0. Its speed is almost the speed of light, so the gamma factor is equal to 10.
According to the paradox, he will reach Planet B in one hour according to his clock, and a little over 10 hours according to the clocks of the planets.
Suppose the observer in the telescope on planet A looks at the clock on planet B at moment 0. The time he will see will be 10 hours.
The rushing twin that passes by Planet A at moment 0 according to its clock, will see the same thing because two observers at the same point and at the same moment will always see - and photograph - the same thing (miracles, our debate in the paradox of the rings).
When he reaches Planet B, his time will be one hour and the time on Planet B will be 10 hours.
That's why he saw on the way the Planet B clock spinning 20 times faster than his clock, or 2 gamma.
What happens to an observer on planet B at time 0 according to his watch who is looking at planet A?
He sees the Planet A clock showing 10 o'clock, but the hurrying twin has not yet reached her. It is about 1990 light hours away from it in the planetary system, about 199 light hours in its system (longitudinal shortening) and the time that the observer from Planet B sees on his watch is -199 hours.
When the rushing twin arrives at Planet B, the time on his clock is one hour and the time on the planet's clock is 10 hours. Therefore, the rushing twin clock advanced by 200 hours, while the planetary clock only advanced by 10. The twin clock as seen by the observer on Planet B is ticking at a faster rate than the planet clock in the same ratio of 20:1.
Israel I forgot the most important part - your answer about the clock is correct! 10 out of 10 on this section.
Israel,
The question is based on the entry "The Twin Paradox" in Wikipedia. You didn't answer about the connection to the twin paradox. Maybe "everything works out" is supposed to be the connection? I did not understand. As a minimum, tell why what is true for the movable twin is not true for the stationary twin.
Regarding your question, I don't understand what "everything works out" or "how it works out", but I have a vague feeling that it is very close to what I asked you to answer! In short, I asked first 🙂
Israel Shapira
Referring to the twin in a hurry, the question arises, why is he in a hurry? What is chasing him? Is he rushing to the meeting or is he running away from the tax authorities? And maybe he wants to go shopping for Saturday? What is his fax number?
Two years more, two years less, what does it matter?
(what does it matter?)
we will jump
Nice question you asked, where is it from?
My head says: the clock in front of you moves faster than yours. If you're interested in how many times (it's ok, I know you're not but you have no choice): 2 Gamma. This is what my algebra yielded.
And now a question for you: if the rushing twin moves towards the distant planet where it makes a U-turn and comes back everything works out. His watch moves slowly, the time on the planet moves fast, everyone is disappointed.
But how does it work out from the perspective of that distant planet? After all, she also sees his clock moving faster than hers, especially if the viewers are using the Hubble Turbo telescope where the clock is seen right in front of you?
for miracles
Nice, nice, and the truth is that I was too lazy to check 1056 or 1054 and I switched to 1056
So 1054!!!!!!!
Thank you for responding gently and not oppressing me for my ignorance.
Good day miracles!!
Yehuda
Yehuda
1054, no? 🙂
Riddle to Israel Shapira:
A clock is coming straight at you (!) at half the speed of light. With a telescope you can see its hands. A similar clock rests next to you. Do the hands of the flying clock move slower, faster or at the same rate compared to the stationary clock? And how is the answer related to the twin paradox?
It's a bit too vague for me.. Isn't there something more recent? Maybe some supernova that was discovered in the last few months and can be viewed? Have any of the commenters ever seen a new supernova in a telescope?
Surely one can watch one that has already exploded. Do you know the Cancer Nebula?, the one that exploded in 1056 and many saw it then and also its beautiful remains today!
Exact location on Wikipedia
Good night
Yehuda
Yoda
Supernova Refsdal returns for a visit this year:
http://gizmodo.com/this-is-how-we-know-a-supernova-is-coming-in-2016-1743763465
And my intention is: since the lifespan of a supernova can reach months and years, is it possible to observe one after you already know that it exploded and what its location is?
To Israel Shapira my friend
I will try to answer all the questions
And of course in order of importance
A. The promised Turkish coffee is still guaranteed
Maximum in a year or two there will be a total solar eclipse in the USA and I will try to visit you and treat you to coffee (if you don't surprise me before then of course in our holy land).
B. Regarding the expansion of the universe, we all agree that it is also inside the galaxies, but for some reason you tend to reduce its strength inside the galaxies because of gravity, whereas I claim that there is almost no gravity in the galaxy and the expansion of the universe is not even aware of the existence of this production - "galaxy" and therefore the expansion of Hubble is actually the same size as outside the galaxy .
third. And as for watching a super nova, there's nothing simpler than that. You just have to look for the galaxy where a poor star was lucky enough to explode. This happens in the nearby galaxies about once a year, for example in the Large Magellanic Cloud in 1987 and a year or two ago in the Whirlwind Galaxy and the Milky Way in 1056, so you have to wait patiently and when the star The whole galaxy will explode, talk about it, and then you only have to point the telescope and look at the stars of creation!
d. Did you understand that Shapira?
God. No one knows who the next supernova will explode and where.
and. I wrote a fictional story about a race of supernovae exploding super novae for an astronomy thesis. Appears here on the science website "Dissertation in Astronomy"
All the best!
Sabdarmish Yehuda
Life
I have not forgotten him, nor the Turkish march of our father Moshino Abolafia Amzlag in the Shashash Championship of the Zaranoga III Pass.
But before going to sleep, a serious question for Yoda and the forum on matters of astronomy:
How can I observe the supernova directly, whether with a home telescope or some other telescope?
thank you and good night.
Israel Shapira
Regarding the coffee, you forgot the Turkish march of our father, our king, our righteous Messiah, Wolfgang Amadeus Mozart, and the most important thing is that it will be in C major
Yoda
Who is this who has returned from a distant land? What am I, a nice bird?
Still in the US, in the end.
A blizzard.. 25 degrees in California, golden sun is shining, everyone is wearing short shirts.
Regarding expansion - according to Pushing, it should apply to everything, including the Milky Way, and this is what our articles claim. The thing is the quantity. In my understanding, the expansion of Hubble is that of space-time itself, and within the galaxies gravity holds the stars together, therefore the expansion is small.
Like a lake can expand and grow without affecting the size of the boats or fish in it.
Did you understand the satellite and half the coffee thing?
And speaking of coffee, what about the Turkish coffee you promised me?
Dear Israel
Welcome back, from a distant land.
And for miracles
I will further examine your claim about rotating bodies and falling bodies, but the question we are discussing here: does the cosmic expansion of the universe also take place within the galaxies or not??
We would be happy to hear the learned opinion of the new Israeli entrant.
so good night
Yehuda
Yoda
The sum of the forces does not zero - according to Newton a satellite in orbit is accelerating.
You can see this clearly if you look at his condition after half the coffee. Its tangential speed is the same, but in the opposite direction.
The same thing will happen if you simply accelerate it against the direction of the original velocity: the velocity will first decrease to 0, and then increase to v-.
Yehuda
I will ask like this (and I am not sure of the answer): does a clock in free fall look like a clock resting in the same place?
It is clear that the balance of forces is zero, but spacetime is still that of a gravitational field.
Miracles
I claimed that the sum of the forces acting on a satellite in a circle is zero! That is, the gravitational force is reset by the centrifugal force
Yehuda
Are you claiming that a satellite in orbit is in 0 gravity? The equation for calculating the change of time due to gravity does not depend on speed. Therefore - I think you are wrong.
Cheers p
The example you gave of a sphere at the bottom of a bowl is problematic because there are no such structures in the great cosmological space. But we both agree that it is also necessary to compare the magnitudes of displacements involved.
The gravitational force between an extreme star and the center of the galaxy is expressed in millimeter particles per second towards the center, while the expansion of the universe is kilometers from the center outward. It is clear that the expanding universe of Hubble is not even aware of nor does it care about the tiny movement of gravity.
And your example of a gatekeeper at the entrance to the galaxy made me smile.
On the second issue of expansion above the speed of light. The usual explanation is that bodies are unable to move away above the speed of light, but the entire universe actually does and this already happened in the first second of the big bang. You try to continue it even today…. It seems to me that you are very bold...
My opinion is that the speed of light was greater then.
Let's conclude that you and I agree that something squeaks in the statement that the spread of Hubble does not exist in the vastness of the galaxy as well.
All the best
Yehuda.
Yehuda
Draw your attention that even if the sum of the forces is zero, it does not mean that they are unrelated. Put a ball at the bottom of a bowl and you will find that the sum of the forces acting on it is zero, yet it is at the bottom of the bowl unable to move in any direction.
Therefore there is no evidence from what you said.
However - I tend to agree with your problem, how come Hubble's law will only work between galaxies and not in the content. Is there an end guardian of the galaxy who won't let him in without a note from the manager?
I wonder if anyone has tested the possibility that there is no dark matter. The dark matter is meant to explain why the galaxies do not break up (since the tangential speed of the stars is too high). But suppose they are really in the process of disintegrating? So no need for dark matter.
And the galaxies are indeed in the process of disintegrating due to Hubble's law.
We seem to be guessing without any real research tools.
in another matter. If Hubble's law is valid, let us assume that there are other galaxies so far away that the rate of their receding is greater than the speed of light. In other words - the space added to the distance between us increases at a rate greater than the speed of light.
Conclusion: the light emitted from them tries desperately to reach us - but fails. With each passing moment, it erases less space than the space that was added.
That is - there are galaxies that we can no longer see. Not because our telescopes are too weak but because the light cannot reach us.
Of course it is also the other way around: the light from our galaxy will no longer be able to reach them.
Do you have anything interesting to say about it?
Chaim P
First of all, I appreciate the discussion you are having about something unacceptable and it seems to me that despite the disagreement between us, we understand the dispute better and that is the main thing.
Well, until the middle of your comment (the quote from Astropedia) we have no disagreement. But from here on our paths diverge.
The quote from Astropedia is a bit problematic. I will repeat it:
"The Astropedia website claims that according to general relativity, Hubble's law does not operate between "strongly" related bodies such as solar systems or galaxies..." End quote.
Let's check what is meant by "strongly"? After all, the connection created by gravitation is completely reset by the centrifugal force. So zero forces are "hard"??
And even if we ignore the fact that they reset, then let's see what kind of movement it is:
Well, let's calculate the centrifugal acceleration, (which is equal to the acceleration of gravity) The size of this acceleration is the peripheral speed of the galaxy (230 km per second) squared, divided by the radius of the galaxy (50,000 light years times the number of km in a light year (about ten to the 13th power) ).
Calculated and we get about ten to the power of minus 13 km per second squared!!!
Do you think that the expansion of the universe at the size of a kilometer per second does not matter at all from a tenth of a millionth of a mm!!!!!!!!!! Between us lives, the expansion of the universe is not even aware of the reality of the galaxy at all. This is my humble opinion. Food for thought, isn't it??
Please respond gently, Saturday evening today!
All the best, and I enjoyed responding to you!!
Sabdarmish Yehuda
To Judah
Here is a copy from the Astropedia website,
"Today's best estimates, based on a variety of measurement methods, regarding the value of Hubble's constant are about 72 km/s per mega-persec"
I break down the expression step by step to avoid a mistake:
1: 72 km/s to megapersec.
2: 72 km per second per million persec.
A peach is equal to 3.26 light years. so:
3: 72 km per second per million times 3.26 light years.
4: 22.09 km per second per million light years.
The radius of the Milky Way is 50,000 light years, which is 1/20 of expression 4.
Therefore, the speed of expansion is approximately 1 km per second - assuming that Hubble's law is active within the galaxy.
(You were right. In my previous calculations I fell victim to ambiguity on the Wikipedia website)
The Astropedia website claims that according to general relativity, Hubble's law does not operate between "strongly" related bodies such as solar systems or galaxies...
If the galaxy is indeed growing - then either my hypothesis is correct or Hubble's law is indeed operating within galaxies....
On another matter - your statement regarding the ellipse is not appropriate. If I move the earth to an orbit 1 km away from its orbit - its speed will not match the new orbit and it will make an extended ellipse that will move away from the previous ellipse. But that is not the case. There is a wrong assumption in your thinking: I am moving KDA not all at once, but continuously, for a year. The result is that the thousand meters between the routes will develop into something bigger, inevitably. If this force continues continuously, consistently, persistently - the galaxy will disintegrate. Actually the question is more serious: why did the galaxy thicken in the first place.
What turns out to me from all this is:
1. Hubble's law does not work inside galaxies.
2. Are galaxies expanding? There are still many intergalactic gas clouds that fuel galaxies and expand them.
It seems to me that I have a positive solution to the disintegration problem and that is the movement in a more elliptical orbit. It seems to me that a small deviation of the distance will make the track more elliptical and not necessarily lead to its disintegration. After all, it's clear that if you haven't reached the escape speed, then "you won't escape" (:)) but... We will keep thinking.
Good Day
Yehuda
Cheers p.
A farsec equals about 3.2616 light years. point. That means about 3 and a quarter light years and not as someone here expressed (probably carelessly) 326 light years!
Therefore write down before you that you made a hundredfold mistake in your calculations. That means the radius of the galaxy should increase by 1000 meters every second. (as I claimed) and not by ten meters (as you claimed)
But... I'll admit and I won't be ashamed, that it doesn't make my situation any easier towards your claim that our beloved galaxy will fall apart!, on the contrary. And must in some way reduce/change the force of gravity. It is not possible that a change of a few kilometers will completely disintegrate the galaxy and it is not possible that it was originally built under contemptible and uncompromising laws of gravity. The laws must be such that they direct the heavenly bodies to a stable path even if they deviate a little from this path. This is my opinion!
You gave me food for thought (at least for this weekend)
So please respond gently (and without jokes)
Good night
Sabdarmish Yehuda
I will join Yehuda and Ben-Ner's discussion.
I heard your evaluations and criticisms of each other.
Yehuda, you are an idiot :). (LOL. Just kidding about your requests for gentle responses).
As a matter of fact, let me add a new hypothesis that answers all the data in the article: the galaxy is still absorbing gas clouds from the surrounding space. (That's how it was created in the first place!). It's an ongoing process. Little by little the edge of the galaxy thickens. New stars are formed from baryonic matter. (I do not support Ben Nun's hypothesis that dark matter becomes a bully).
As for Yehuda's words: the Hubble constant is 0.21 km per second per million light years. (70 km per second per million farsecs which is 326 million light years) that is: about two hundred meters per second per million light years.
The radius of the Milky Way is about 50,000 light years. That means that the rate of expansion of the galaxy is about 10 meters per second. This is assuming that Hubble's law applies to the intragalactic medium. Does it apply?
If it applies, it means the galaxy is slowly being torn apart. So how did it arise in the first place?
For those who do not understand, I will try to explain: what will happen if I move the Earth away from the Sun to a distance of 1000 meters? Will the earth stay in the new orbit that is 1000 meters larger than the previous one? Answer: No! The Earth will move further away, because its speed is too high for the new orbit. In order to keep him on the new track, I also had to reduce his speed!
Well, yes, if Hubble's law had worked at the intragalactic level - a galaxy would not have formed in the first place.
walking dead
I agree that it should be tested a little if the pressures in the early universe also compressed solid matter. It could be true (:))
Yehuda
I just wanted to ask, and equally why not examine smaller scales as well. I certainly don't think this is true, and I know of no evidence to support this idea.
In short, maybe the dinosaurs weren't that big, and some of the mountains on Earth are just plains that swelled up.
So please forgive me and Walkin Dead for the heresy and respond gently.
walking dead
Describe to you what I think when I see large fossils of extinct scorpions and dragonflies?, were they small when the universe was compressed and now that the universe has expanded, have their remains also "expanded"? , maybe I'm not brave enough to say what you fearlessly said. walking death
Yehuda
Shouldn't you then also continue this regarding people, stones, trees, buildings and bicycles?
Are there effects of the expansion of the universe on these objects and why are we not measuring them?
By Avner I meant A. Benner. apologetic
Please respond gently this time too (:))
Sabdarmish Yehuda
Avner
Look at how many exercises you, and many other scientists, do, the main thing is not to consider the simple rule that the expansion of the universe is also done inside the galaxies. And not only that, I don't believe that the spread of grief exists even between the stars and the planets and even between the planets and the moons. I believe that two thirds of the annual distance of the moon from the earth (26 mm out of 38 mm) is caused by the Hubble expansion of the universe.. Gravitation does not determine anything here because it is reset by the centrifugal force resulting from the rotation of the moon around the earth.
I think so
Please respond gently.
Sabdarmish Yehuda
Another possible reason for the expansion of the galaxy is implied in the article:
"The older a red giant star is, in general, the lower its mass"
As the stars in the galaxy age, there is a reduction in the galaxy's mass and force axes
The centrifugal, resulting from the rotation of the galaxy, expands its dimensions.
Lesbadramish
A]. I always respond to your words gently.
B]. It must be admitted that the article (also originally in English) is not detailed enough. Anyway, not great
In the article that a decrease in the density of stars in the galaxy was observed, but only the expansion of the galaxy.
Therefore, it is more likely to assume that the expansion is the result of the growth of the galaxy at its edge, as a result
A mass of baryonic matter is added and not the "dispersion" of the galaxy as you explained.
Not Ben Ner
And maybe this proves that the galaxies could only form initially when the expansion of the universe was slower?
But beyond that, my great "love" for dark mass and energy does not allow me to accept as easily as you do your accepted explanation that dark matter works miracles and wonders in the creative joy of the galaxy,
Please respond gently.
Yehuda Sabdarmish
The fact that it is expanding does not mean that in time it will shrink in its core until the black hole may evaporate. Have the physicists already concluded that the universe will expand forever, or that it may at some point shrink back.
Lesbadramish
You are obviously wrong this time. The reasoning is quite simple.
If you were right, and the expansion of the universe was indeed faster than the speed of the collapse of the galaxies
After all, the galaxy would not have been formed at all. The very formation of the galaxy says
which is faster than the expansion of the universe. That is, you are wrong this time. parable.
The explanation for the growth of the galaxy is completely different and is due to the fact that the surrounding dark matter **
The galaxy collapses into the galaxy, compresses and heats up, under the influence of the warming
Decays into baryonic matter that forms young stars. As the mass of the galaxy increases, so does
The rate of collapse of dark matter into the galaxy, its disintegration and transformation into baryonic matter.
This is the explanation for the growth of the galaxy.
Please note: the article does not claim that the density of stars in the galaxy is small, but only that the galaxy is growing
This means that the baryonic mass of the galaxy increases and the radius of the material is also emitted
The light in the galaxy is increasing.
**-Dark matter is a stable neutron gas at a temperature very close to absolute zero.
With the collapse of the dark matter into the galaxy it is compressed, heated and part of it breaks up into protons,
and electrons
Lanti, so this is it, since we are arguing about it!!
About a week ago I listened to a very interesting lecture. The lecturer conveyed the subject of galaxies in an excellent manner but insisted that the expansion of the universe does not exist within the galaxies. When I showed him my calculations on the subject, he insisted that I must have made a calculation error.
Today I am more confident in my calculations.
I believe that it is not far today that the mass and dark energy objects will also pass from the world after eighty years of them troubling science.
Please respond gently (:))
Thanks
Sabdarmish Yehuda
To Sabdarmish Yehuda, you're probably right, and you're not really a mediator with that either.
This is simply the first time this has been proven at the galaxy level.
Is there a big statement in this - probably not
The expansion wins because all the mass we know including black holes makes up 4% compared to 96% of dark matter and dark energy. So that in fact the process that happens is both together when the expansion of the observed galaxy/universe apparently occurs in the light of dark energy that accelerates and expands, while we know that its gravitational force exists only that it does not interact in any way with the materials and elements that are familiar to us. As mentioned, 4%.
Also, holes may have an expiration date, so that in fact it will never "swallow" the entire galaxy.
The movement resulting from gravitation within the galaxy (any galaxy) is tiny relative to the cosmic expansion of the universe. The propagation of the Hubble is about 70 km per second per mega-persec, which is at least 50 km per second per XNUMX thousand light-years of the galaxy's radius. On the other hand, the acceleration of gravity is equal to the centrifugal acceleration and is zeroed by it. So in any case we will only give up with the expansion of the galaxy's grief. I don't understand why they claim that the expansion of the universe is only outside the galaxies, it's really ridiculous!
Please respond gently..
Sabdarmish Yehuda.
Thought-provoking
At the heart of the galaxy according to the explanation is a supermassive black hole. I don't understand which process is happening or both together. The black hole swallows the galaxy and becomes more massive and attracts more matter, or the matter escapes from the galaxy.