David Levy

1. Yes, fully agree. 2. No negative. 3. Yes. Unfortunately, I couldn't find the requested no. at the web. However, with regards to the collision rate: Based on the following article - http://hubblesite.org/newscenter/archive/releases/2011/30/full/ "It is a little bit like trying to count car crashes by taking snapshots. If you look for cars on a collision course, you will only see a few of them." If I understand that message correctly - They actually claim that it is very rare to find collided galaxies. Therefore, it's quite clear that they might have the knowledge about the percentage of those collisions. In this case, I would expect them to let us know what they had been discovered, and then offer an explanation for their discovery. Based the following articale - http://www.universetoday.com/90447/determining-the-galaxy-collision-rate/ "When it comes to galaxy evolution, the collision rate is an indicator of how individual galaxies accumulated mass over time." Perfect – fully agree. Unfortunately, they do not offer the no. of the collision rate, as they continue with the following: "While it’s pretty much a standard measurement, there’s a large margin with no information of how often it might have occurred in the very distant past. By taking a look at in deep-field surveys made by NASA’s Hubble Space Telescope, astronomers were able to get a general look – one that showed a merger rate of anywhere from 5 percent to 25 percent of those studied." So, instead of giving us the collision rate which they have just claimed that it is so important, they offer their understanding/solution by merger rate. Somehow, it is almost impossible mission to verify the real percentage of the collided galaxies with regards to all the galaxies in the Universe. Actually, we could focus on just one cluster – as an example let's use our cluster. We could try to find collided galaxies in our cluster and compare it to the total galaxies no. in the whole cluster. Again – even now, I have no idea what is the real percentage of the collided galaxies (that we can see clearly) in the Universe.

Strange, on 06 Jan 2016 - 8:01 PM, said: "The hot accretion regions surrounding the black holes clearly show their locations, and each black hole shows jets in radio". So, yes we can see the jets, but where is the whole mass of the two galaxies??? Don't you think that it proves that collision actually destroy the whole body of the two collided galaxies? So how can we claim that: "the most massive galaxies in the universe and the suppermassive black holes at their hearts grew together over time" (by collision), if we see now a real proof that the galaxies had been destroyed completely due to the collision? Also, what about spiral galaxies? How can we claim that they can grew by collision, if we know by 100% that collision should destroy their shape?

Dear Strange I'm sorry for asking too difficult questions. You do not waste your time for nothing. I do remember your valuable answers and I do appreciate all your effort. For example - With regards to the black hole, you have already claimed: Therefore, I have used your statement that it is unknown how black holes can grow to be so massive. Actually, I didn't find even one article which can offer any real solution for that process. With all the respect, simulation can't be the only replacement for our willing for real evidence. Somehow, it seems that the science set the target and now they just need to place the arrow on the spot. You claim: Why they do not try to find if that process is feasible? Why they put so much activity in order to detect direct evidence of such mergers? Why they do not try to find some other solutions? The science is using an example of car crashes in order to highlight the merging process of galaxies - So let me ask the following: Is it feasible that a crash between two cars can create a new truck? Sorry, but so far I didn't get a real answer if two smalls galaxies with two small black holes can set a bigger galaxy with merged black hole and merged stars. And so far we all know that collision can't be an answer for massive spiral galaxy growing activity. There are many other open issues with regards to that collision/merging process. However, as I do not want to upset you, I will not ask you any more questions about collisions. (Never the less, more questions to come on other aspects of this tread...) Thanks Great article. However, we would expect that each supper massive black hole had been in the past is a core of some type of galaxy. What we see is just a left over from the galaxies mass. So where is all the mass of the galaxies? Therefore, even if we get a merged black hole due to collision, it confirms that most of the galaxies mass is ejected into space in that process.

What about the other 90% of galaxies? For example - Spiral galaxies It is clear that collision should destroy the shape of spiral galaxy. Therefore, merged by collision is not even an option for for this type of galaxy. How the science explain the growing of spiral galaxy? What about the black holes merged? In this articale They do not even try to verify this critical issue. How can they discuss about large galaxies merged without understanding if black holes merged is feasible? This is the most critical issue! Why they do not try to simulate this merging process? Without a real proof for black holes merged there is no meaning for any further discussion on gaining mass due to collision/merge. Anyhow, let's see if it is pretty common: It is stated: "Having an accurate value for the merger rate is critical because galactic collisions may be a key process that drives galaxy assembly, rapid star formation at early times, and the accretion of gas onto central supermassive black holes at the centers of galaxies," Lotz explains. Never the less, in the same token it is stated "Large galaxies merged with each other on average once over the past 9 billion years". So, large galaxies merge with each other only once 9 Billion years. It's about 1.35 times from day one of the Universe. With regards to the small galaxies it is three times more often than the large galaxies: So it is: 3 x 1.35 = 4 times. So, at this low rate of collisions how could it be used as an answer for the galaxy assembly? Till now, I have no idea what is the real rate of galaxies collision. Why it is not stated clearly? Instead of giving a direct answer, they use the example of car crash. "These different techniques probe mergers at different 'snapshots' in time along the merger process," Lotz says. "It is a little bit like trying to count car crashes by taking snapshots. If you look for cars on a collision course, you will only see a few of them. If you count up the number of wrecked cars you see afterwards, you will see many more. Studies that looked for close pairs of galaxies that appeared ready to collide gave much lower numbers of mergers than those that searched for galaxies with disturbed shapes, evidence that they're in smashups."" So, they admit that the crashes are very rare, but they think that they have an idea how to overcome. Therefore, let me ask again - Please let me know the current snapshot of the galaxies collisions percentage.

1. You claim: "It looks like a significant amount of stellar mass has been ejected, but most of that returns to collide with the other galaxy again." Let's agree that this is correct by 100%. So, most of the mass returns to collide with the other galaxy. However, we also know that 50% of the stars are located outside the galaxies. The main answer for that was (as expected) - Galaxy collision. So, how could it be that that we are using the same phenomenon as an explanation to a very contradicted evidences? (Whenever we want to show that "the most massive galaxies in the universe and the suppermassive black holes at their hearts grew together over time",- we offer Galaxy-collision and prove that most of the stars stay at the galaxy, and in the same token, whenever it is important for us to show that "At least 50% of the stars are located outside the galaxies" - we also offer Galaxy-collision and prove that most of the stars are ejected away from the galaxy...) 2. In our universe there are billions of spiral galaxies. How many collisions we can see? Is it 0.01 of the total spiral galaxies? 0.001? or less then 0.00000001? Actually, if we also consider the effect of the expansion, Don't you think that the collision ratio should be very low? 3. Please also focus on the description – "…grew together OVER TIME" So it's not that just one collision per galaxy could be good enough. If they need to grew OVER TIME, we need to set many collisions per galaxy. Again and again and again - "over time". If the colisions are so rare, how could it be feasible? 4. Spiral shape – Is it correct that after collision, spiral galaxy should looks like elliptical galaxy? If so, do you agree that there is no way for spiral galaxy to increase its size by collision?

Thanks Based on your reply, the expansion is: 70 km/sec/Mpc, So, let's look at a galaxy which is located at 100 Mpc away from the milky way: - If there are no clusters at all between the two galaxies, do you agree that the expansion rate between the galaxies should be: 70 x 100 = 7,000 km/sec? - However, if there are clusters in between the galaxies, is it going to have any effect on the total expansion speed? In other words, do we have to eliminate the expansion rate for all the spots were the clusters are located? For example, if there are two clusters, and each cluster is at size of 10 Mpc, then the real open space is only: 100 - ( 10 x 2) = 80 Mpc. Therefore, the expansion rate should be: 70 x 80 = 5,600 Km/sec (instead on 7,000 km/sec - without the clusters). Is it correct? Do I understand it correctly? Well, the science has some sort of estimation what is the current size of the Universe. Let's assume that it is 50 Billion Ly from edge to edge. My question is - how long it might take the universe to multiply its size to 100 Billion Ly?

Thanks You might have missed my main point. So let me ask the following: I assume that the expansion is mainly applicable for long distance. So, let's start by looking at a galaxy which is located at 90 Mly away from us. Do you agree that (regardless of all the mass and clusters in between) the expansion rate in space between us should be: 74 x 90 / 3 = 2220 kilometer per second? Is it correct? One more question about the size of the Universe. How long it might take to the Universe to multiply its size due to the Expansion?

Why? What is wrong in my calculation?

O.K. If that is correct then it might generate some significant distortion in the expansion rate as follow: Let's assume the following: Our cluster is like a ball shape with a radius of 3 Mly. The closest cluster to ours has the same features. Let's assume that the distance between the centers of those clusters is 9Mly. The expansion rate is about 74 kilometer per second per 3 million LY. So, as the clusters are not affected by mutual gravity force, then technically the expansion rate between the centers should be as follow: 74 x 9 / 3 = 222 kilometer per second. However, the distance between the closest edges of each cluster is only 3 MLY. Let's assume that at each edge there is a galaxy. (Galaxy A – in our cluster, and Galaxy B in the other cluster) So, as stated, the expansion rate doesn't affect the whole mass in each cluster due to gravity force. Therefore, in order to compensate the effect of the gravity force in each cluster, those two galaxies should move away from each other at a speed of 222 kilometer per second. That set a conflict. How could it be that two galaxies at a distance of 3 MLY move away from each other at a speed of 222 kilometer per second due to expansion, while the expansion rate is only 74 kilometer per second per 3 million LY? So, we should see significant distortion in the expansion rate between edges of clusters all over the universe. Do you agree?

Thanks I'm not sure that I fully understand why it is stated: http://www.scienceda...90202175320.htm "... the largest, most massive galaxies in the universe and the supermassive black holes at their hearts grew together over time." Why they claim that the galaxies and the suppermassive black holes grew together over time? Based on what evidences? In the articale which you have pointed it is stated: http://iopscience.iop.org/article/10.1088/0004-637X/691/2/L142/meta "Research on supermassive black holes (BHs) in galaxy nuclei centers on the growing evidence that BH growth and galaxy evolution are connected (Ho 2004)." But they do not give any further explanation about the idea that suppermassive black holes grew together over time. They mainly focus on the impact of light deficits Ldef: "This Letter reports tight mutual correlations between M•, σ, and the light deficits Ldef that define cores in elliptical galaxies. These point more directly to formation processes. In particular, we find a correlation between the fundamental observables Ldef and σ that is as tight as the well-known M• – σ correlation" But I still do not see a conection between this light deficits to the statement that suppermassive black holes grew together over time. It is also stated: "To set the stage, we recall that it is difficult to understand how cores can form in galaxies that are made by major mergers." So, without getting deep into the merging process, what is the key evidence for the idea that suppermassive black holes grew together over time? Why they also use the word "grew"? In the dictionary it is stated: "undergo natural development by increasing in size and changing physically (of a living thing)" Galaxy is not a living thing. So why grew? Why not: increase, enlarge or become great.

Thanks Now it is clear that the gravity force eliminates the expansion of the universe in our cluster (at a distance of at least 2.5 Mly). So what is the real size of our cluster? in other words, until what distance this gravity force eliminates the expansion? Is it 5 Mly? 10 Mly, above? In the same token, Do you agree with the following: There is no expansion in all the clusters in the universe. The expansion works only in the open space between the clusters. Would you kindly direct me to an article which explains the connection between gravity clusters and universe expansion?

So do you mean that the gravity eliminates the expansion of the universe? I assume that at a distance of 2.5 million Ly, the gravity force between the two galaxies is virtually zero. So, how could it be? In the same token, as you mention the gravity force, let's look at the Triangulum Galaxy which is located near Andromeda. https://en.wikipedia.org/wiki/Triangulum_Galaxy However, it isn't expected that Andromeda should collide with Triangulum. Actually it is expected that the Triangulum galaxy should also collide with the milky way. So how could it be those two galaxies "prefer" to collide with the Milky Way instead of with each other? Why gravity doesn't work between so closed galaxies?

I still wander how it could be that we don't know. How could it be that we are so clever to have deep visibility of the first second after the big bang, but we have no idea what came first. Especially, as it is there, infront of our eyes.

http://www.space.com/17884-universe-expansion-speed-hubble-constant.html "The most precise measurement ever made of the speed of the universe's expansion is in, thanks to NASA's Spitzer Space Telescope, and it's a doozy. Space itself is pulling apart at the seams, expanding at a rate of 74.3 plus or minus 2.1 kilometers (46.2 plus or minus 1.3 miles) per second per megaparsec (a megaparsec is roughly 3 million light-years)." So, the expansion rate is about 74 kilometer per second per 3 million LY. Let's verify if it is correlated with some other evidences. For example – Andromeda galaxy which is located 2.5 Million LY from Earth: https://en.wikipedia.org/wiki/Andromeda_Galaxy "The Andromeda Galaxy (/ænˈdrɒmɨdə/), also known as Messier 31, M31, or NGC 224, is a spiral galaxy approximately 780kiloparsecs (2.5 million light-years) from Earth" Therefore, the expantion rate between the Milky Way and Andromeda (at 2.5 Miilion LY) should be as follow: 74 * 2.5 / 3 = 61.5 kilometer per second. However, it is stated Andromeda is approaching the milky way at 110 Kilometer per second. "The Andromeda Galaxy is approaching the Milky Way at about 110 kilometres per second (68 mi/s).[95]It has been measured approaching relative to our Sun at around 300 kilometres per second (190 mi/s)[1]as the Sun orbits around the center of our galaxy at a speed of approximately 225 kilometres per second (140 mi/s)." Therefore, by adding the expansion rate to the measured approaching speed, it is clear that the real velocity between the two galaxies should be: 110 + 61.5 = 175.5 kilometres per second. Do you agree with this calculation?

http://www.scienceda...90202175320.htm "A pair of astronomers from Texas and Germany have used a telescope at The University of Texas at Austin's McDonald Observatory together with Hubble Space Telescope and many other telescopes around the world to uncover new evidence that the largest, most massive galaxies in the universe and the supermassive black holes at their hearts grew together over time." Hence, please advice if you agree with the following: 1. Galaxies and supper massive black hole grew together over time. 2. There is no need for galaxies collision in order to increase the size of a galaxy. 3. The Milky Way galaxy is growing together with its black hole. 4. In the past, the Milky Way was quite smaller in its size (as well as its black hole). Is there any way to verify the growing rate of the Milky Way? If so, we can technically calculate what was the real size of the Milky in the past - let's say 10 billion years ago (assuming that there were no collision with any other galaxy).

Why? Why don't you accept those photos? The image is very clear.

Please see the following photos. http://www.easynotecards.com/uploads/1175/86/_6ea8c384_144fee962ba__8000_00000610.jpg http://www.wolaver.org/Space/galaxycollision.jpg http://www.spaceanswers.com/wp-content/uploads/2013/01/Black-holes-collide.jpg https://fsmedia.imgix.net/ee/4a/b8/00/990f/4ff6/bc33/e2f0101d8247/an-illustration-of-two-spiral-galaxies-with-their-black-holes-on-a-collision-course.jpeg?w=700&dpr=1&auto=format&q=75 It's looks to me that significant amount of the stellar mass had been ejected to space.

How do we know that black holes can merge? Do we have any evidence for that? Actually, a collision between two spiral galaxies (at a similar size) should eject to space significant amount of their stellar mass. So, technically, (if we accept the idea of black hole merging), there will be a new merged galaxy with double size of BH but with much less stellar mass. This could violet the following proportional: "Each bulge contains a central black hole, whose mass is proportional to the bulge stellar mass 1–5 , MBH ≈ 0.001Mbulge. Therefore, could it be that the idea of merging galaxies isn't feasible? Fully agree. However, There is a solid proof that the B.H and stars are growing together. "most massive galaxies in the universe and the supermassive black holes at their hearts grew together over time." So, if There is not matter flowing into galaxies from the great voids between galaxies, How could it be that the B.H increase its size on a daily basis while the stellar mass in the galaxy is also growing proportional to the B.H size? Somehow, the B.H is increasing its size without "eating" the stellar mass of the galaxy. What could be the scource for that new matter (for the B.H and for the stellar mass)?

Please see the following statement: http://www.sciencedaily.com/releases/2009/02/090202175320.htm "Astronomers love tight correlations," Bender says. "They tell us what is connected with what. The new observations give us much stronger evidence that black holes control galaxy formation, at least at their centers." So, if the black holes control galaxy formation, does it mean that B.H should come first? (or at least, there must be some order in the development of galaxies). Actually, in the title It is stated: "A pair of astronomers from Texas and Germany have used a telescope at The University of Texas at Austin's McDonald Observatory together with Hubble Space Telescope and many other telescopes around the world to uncover new evidence that the largest, most massive galaxies in the universe and the supermassive black holes at their hearts grew together over time." So, the galaxies and supper massive black hole grew together over time. This is a key message. It is almost as a living body. – Grew together over time! So, if we take for example the ratio between our hart to our weight, we should get a perfect proportional in average. Therefore, as all parts in a living body grew together over time, then also "most massive galaxies in the universe and the supermassive black holes at their hearts grew together over time." It is like a child galaxy which is growing day by day to become a mature galaxy… Do you agree?

Thanks However, we don't have to make too much intensive research. The answer might be in front of our eyes. So what can we learn from the following statement about spiral galaxy? "Each bulge contains a central black hole, whose mass is proportional to the bulge stellar mass 1–5 , MBH ≈ 0.001M bulge." Let's add to that factor that the supper massive black hole had been created before the stars as was introduced by the T.V program. ---(We shouldn't underestimate a scientist as Lawrence M krauss, even if his message had been given in a science T.V. program). So, based on that information do you agree with the following conclusions? - There is a clear order in spiral galaxy. - The first step for spiral galaxy is to create a black hole. - This black hole should be massive enough and rotatable to have the power (including electrical/magnetic energy) to create all the stars and the unique formation of spiral galaxy. - We have to figure out how the Sun had been migrated to its current location - as Lawrence M krauss had been stated in the T.V program. (I highly advice you to watch this special program).

Thanks Let's start with the first sentence: "Virtually all massive galaxies, including our own, host central black holes ranging in mass from millions to billions of solar masses." Why it is stated: "all massive galaxies"? Why not: "all disc shape spiral galaxies"? Later on it is stated: "Galaxies come in two basic types: ‗football-shaped‘ ellipticals and ‗disk-shaped‘ spirals (Fig. 1)." How could it be that they don't see the main difference between those galaxies? If I understand it correctly: All disc shape Spiral galaxies host central black holes. All of them! However, there is no valid proof for black holes in all other types of galaxies. So, why they don't say it clearly? Please see the following explanation about spiral galaxy: "Each bulge contains a central black hole, whose mass is proportional to the bulge stellar mass 1–5 , MBH ≈ 0.001M bulge." This is the most important information about spiral galaxy. There is a very specific proportional between the bulge stellar and the black hole in all types and size of disc shape spiral glaxies. What can we learn from this fix proportional? How could it be that in all types of disc shape spiral galaxies we have the same proportional? Don't you see that it could be a key element for our understanding of spiral galaxies?

In the following video: http://www.sciencechannel.com/tv-shows/how-the-universe-works/videos/how-the-universe-works-milky-way it is stated: "...Some people believe that black hole in the center helps to initiate star formation". My question is as follow: Is there any possibility to initiate star formation without black hole?

Yes, Please look at the following video. http://www.sciencechannel.com/tv-shows/how-the-universe-works/videos/did-a-black-hole-create-the-milky-way However, It is quite short video. In the full T.V. program, they have offered an evidence that black hole should be a seed of any spiral galaxy including the Milky way galaxy. Lawrence M krauss have stated in this program, that it is a key element for our understanding of spiral galaxy. He also adds that we need to figure out how the Sun had been migrated to its current location. Therefore, we can't ignore this key question. The science must take a decision. What came first in spiral galaxy? Stars or Black hole? If it is black hole - then we must reset our current theory about how spiral galaxy had been formed.

How could it be? Don't you think that it is a mandatory requirement for our understanding of the spiral galaxy mechanism? Is there any verification which the science is doing in order to revile the mystery? Thanks If a black hole had been formed before the galaxy became a spiral, how could it affect our understanding of the evolvement of spiral galaxy?

Black hole or stars?