MigL

Yes it does cut both ways; I never said it didn't. I've known plenty of people who had no 'barriers' to obtaining the best 'money is no object' education. Yet their 'everything should be handed to me' attitude allowed them to not even try, and they drop out halfway through 1st year University. There are many barriers to an education, or expanding our knowledge; the worst ones are of our own making.

Why is it always barriers imposed by, or the fault of society, when someone fails ? What part does personal responsibility play in this ? Markus Hanke taught himself GR ( and many other aspects of Physical Science ). It was not provided for him, but he wanted it and he got it. Barriers did not hinder him. You, yourself, have displayed a questioning attitude. One of the best ways to learn about things you know little about. Yet others come here with the attitude that what little knowledge they have , is all there is. They ask no questions, but make conjectures and proclaim results which more learned members quickly dismiss. And yet their attitude, not barriers, allows them to double down and insist they are right ( until they are banned ). A good attitude, and a willingness to learn, go a long way in these days of internet access and on-line courses.

There are two long range forces, gravitational and electromagnetic, and two very short range forces, color and weak ( flavor ). As far as we know, Dark Matter interacts with all other matter, including itself, gravitationally, but does not interact via the Electromagnetic force at all ( or only extremely weakly ). That means we cannot detect it by electromagnetic means ( no visible, radio, infrared, uv, x-ray or even gamma emissions ), but its gravitational interactions with matter and itself, will produce 'falls' or orbits around its center of gravity. It could also be captured by BH event horizons when it intercepts them. Dark Matter particles may get very close to each other, or even collide, but, since they don't interact via the color force, they will not clump together like quarks in nucleons, or protons and neutrons n the nucleus due to residual. And since they don't interact electromagnetically, they won't clump like electrons and protons in atoms. So I see very little chance of being able to localize a large enough mass of Dark Matter that it would be able to collapse to a BH. One type of neutrino is being investigated as a candidate for Dark Matter, so there is the possibility that it also interacts via the weak ( flavor ) interaction, but again, this interaction does not produce bound states.

And I though Zap and his YouTube friend had done a good job of explaining. OK, one more time... The Earth is orbiting the Sun at a radial distance of 150 million km. We now start compressing the Sun. When it is half its current size, the Earth still feels the same gravitational attraction and remains in orbit at 150 Mkm. When it is one tenth of its current size, the Earth still orbits at 150 Mkm, and feels the same gravity. When it is 1/1000 of its current size, the Sun still has the same mass, and the Earth is still orbiting at the same radius of 150 Mkm, so it still feels the same gravity. However, when the Sun is compressed past its Schwarzschild radius, 2GMsun/c^2 , or about 6 km across, it is enclosed by an event horizon, which means that, for the mass of the sun, a 3 km radial separation requires an escape velocity faster than the speed of light. https://en.wikipedia.org/wiki/Schwarzschild_radius IOW, the event horizon goes black because no light can reach us any longer. Yet the Earth is still happily orbiting at 150 Mkm, and feeling the same gravity. So, to recap, if our Sun was a Black Hole, at the current distance from the sun we would feel exactly the same gravity as we currently do. If we were to move closer to the Sun, since as a Black Hole it is vastly smaller, we would feel an increase in gravity, until we get to about 3 km radial separation, at which point no force in the universe could keep us from falling into the event horizon ( its gravity would be THAT strong ). Yes, mass is directly proportional to Schwarzschild radius, but I'm not sure I follow or understand the rest of your questions. Please re-phrase or clarify.

What's really sad is that, centuries later, you still don't understand it. Maybe you should have some humble pie with your Thanksgiving dinner; ask proper questions and stop being so derisive.

Sure came in handy for I Newton.

As Joigus says, the gravity produced by a BH is no different than from any other equivalent mass. If expansion can overcome the gravity of galaxy clusters, it can similarly overcome the gravity of a BH composed of the masses of the equivalent number of stars in that galaxy cluster. There is no upper limit on BH size. There is only a limit to how much you can feed them. Once they 'eat' all close by mass via their accretion disc, they can't overcome farther out stable orbiting material, and stop growing. Direct collapse, however,without going through star lifetimes, is a totally different mechanism.

Lesson to be learned … Dye your hair. ( nobody looks good with white hair, and the flies really show )

Well, since Markus has expressed his desire to join a Monastery, I think that definitely answers the OP question. But, some words to Markus... ( no offence meant, just trying to lighten the mood ) A young monk arrives at the monastery. He is assigned to helping the other monks in copying the old laws of the church by hand. He notices, however, that all of the monks are copying from copies, not from the original manuscript. So, the new monk goes to the head monk to question this, pointing out that if someone made even a small error in the first copy, it would never be picked up! In fact, that error would be continued in all of the subsequent copies. The head monk, says, “You make a good point, my son.” He goes down into the dark caves underneath the monastery where the original manuscripts are held in a locked vault. Hours go by and nobody sees the head monk. The young monk gets worried and goes down to look for him. He sees him banging his head against the wall and wailing. “We missed the R! We missed the R! We missed the R!” “Father!” cries the young monk. “What’s wrong?” The head monk with tears in his eyes replies, “The word is CELEBRATE!"

Sorry MSC. I mistakenly quoted your reply to Pussstmpy. ( I just fell off my nit-picky high horse )

It IS currently inhabitable and will remain so for some time, as it means 'suitable to live in'. You probably meant uninhabitable ( unsuitable to live in ). I think most understood what you meant, but I'm feeling nit-picky today.

Just how big Black Holes can get. Massive enough to affect galaxies in a cluster. And possible effects of Dark Matter in their creation. https://www.msn.com/en-ca/weather/topstories/monster-black-hole-is-caught-feeding-off-galaxies-trapped-in-its-spider-s-web/ar-BB19LywO?ocid=msedgntp

When did the Bible become 'the word of God' ? It is simply an imperfect interpretation by men, sometimes centuries later, of events. Religions ( most ) have constantly changed through the ages; so has the interpretation. I am not a believer, myself, but don't look down on believers. Science is based on facts and observations. Religion relies on an entirely different thought process; it does not require explanations or experimental observations. It relies on FAITH. Science does NOT.

And you have never disappointed. Looking forward to continuing the discussion.

Sorry, edited my post to add content. I most certainly did not mean support as in charity. I have given examples of emotional support that Religion gives the believer in previous posts. But then you'd have to actually read the whole thread to find out where people like Zapatos and I stand on the issue. Incidentally CV is Latin fo Curriculum Vitae, or 'course of life' literal translation. Otherwise known as an elaborate Resume, which typically means 'Summary' of relevant education and work history.

Neither is Religion mandatory, Joigus. Most of us on this forum chose to abandon Religion. I grew up Roman Catholic, and received the sacraments of Baptism, First Communion and Confirmation; I've managed to avoid Matrimony and I'm hoping to put off Last Rites as long as possible. My parents were not very religious, and I soon found that I didn't need Religion; I had a strong family for a support system whenever I was troubled. The fact that I personally don't need the support that Religion gives some people, does not give me the right to deprive them of whatever support the Church may give them. Live and let live, seems to be a fitting motto in quite a few situations. Mine is Dirty Harry getting ready to shoot someone. Does that make me a murderer ??? ( the rest of your post is nonsense also )

What a difference 35 years make ... 1982 2016 Now that Jimmy showed me how its done. Thanks Jimmy, you're a saint. ( how does Benedict Cumberbatch always manage to look so damn cool ! @ 56 sec in the 2016 video )

I don't fear Religion. There is no thought police, and people will think and believe whatever they wish. I fear people who use Religion to instill fear in others for their own ends.

That list you presented, Joigus, along with many other reasons you left out, are why you ( and many of us also ) have no need for Religion, and see it as something that has caused more harm than good. And it is easy for us to be so rational when our life isn't falling apart But what about the parents with a sick child, who is going to die from cancer ? If religion ( and 'false' hope ) gives them reason to keep going and not lose their minds, who are we to take that comfort away. That is one example of many I could give you. If people 'believe' there is a higher purpose, even one they are not aware of, they are more inclined to keep trying in the face of adversity. Hope, even false hope, inspires and drives people. For us, we realize it's just a 'crutch' to lean on, but none of us know if we'll need one also when we're in their shoes. ( and I hope you never have to find out )

If Religion is what makes you feel good about yourself, should we question that, or consider it psychological abuse ? How is it different from a person who feels they are one gender trapped inside the opposite gender ? The scientific markers and evidence are there that you are one particular gender, yet that person 'feels' better about themself as the opposite gender. And, as a society, we've decided that that's OK, and beneficial to express and act ( sex reassignment surgery ) on those feelings. Why is Religion then, with all scientific evidence against it also, psychological abuse that people need 'help' and 'advice' with ?

It wasn't that long ago that Religious people were asking themselves that same question regarding non-believers. And they sent out Missionaries to convert them. Is that what you had in mind ?

That's the problem with Religions ( aside from political commentary ) and reminds me of an Emo Philips joke Once I saw this guy on a bridge about to jump. I said, “Don’t do it!” He said, “Nobody loves me.” I said, “God loves you. Do you believe in God?” He said, “Yes.” I said, “Are you a Christian or a Jew?” He said, “A Christian.” I said, “Me, too! Protestant or Catholic?” He said, “Protestant.” I said, “Me, too! What franchise?” He said, “Baptist.” I said, “Me, too! Northern Baptist or Southern Baptist?” He said, “Northern Baptist.” I said, “Me, too! Northern Conservative Baptist or Northern Liberal Baptist?” He said, “Northern Conservative Baptist.” I said, “Me, too! Northern Conservative Baptist Great Lakes Region, or Northern Conservative Baptist Eastern Region?” He said, “Northern Conservative Baptist Great Lakes Region.” I said, “Me, too! Northern Conservative Baptist Great Lakes Region Council of 1879, or Northern Conservative Baptist Great Lakes Region Council of 1912?” He said, “Northern Conservative Baptist Great Lakes Region Council of 1912.” I said, “Die, heretic!” And I pushed him over. ( reading it back to myself, it does seem much funnier in an Emo Philips voice )

UNofficial jokes go in the .science sections ( usually Physics or Biology ). It's hilarious what some people try to pass off as science.

Haven't you guys ever heard of Lyme Disease ? Stop playing with ticks.

You're such an optimist … I only recognize degrees of uncertainty.