Home | Join! | Help | Browse | Forums | NuWorld | NWF | PoPo   
Singular
Saturday. 1.18.14 6:12 pm
Regarding black holes: they're mostly mathematical. The only physical parameter they have (that we can see) is mass. The event horizon is defined as the surface (sphere) inside of which all matter and energy are inexorably attracted to its center. But that's just the thing, there's no actual horizon. It's not like you hit a wall as you fall in*. It's only a mathematical definition, dependent completely on the mass.

*Our understanding is, of course, incomplete.

For any mass M, there's a radius R such that if you could stuff M inside of a sphere with radius R, you'd have a black hole. That may seem like a weird way to define it, but what I'm saying is that the configuration of matter INSIDE that radius is not important. If the mass M is distributed between three separate chunks of matter, and they're all close enough to be inside a sphere of radius R "drawn" around their center of mass, then they are a functional black hole. Such a configuration would be impossible to maintain very long, anyway; you know that after a certain amount of time, they'll fall into each other at the center.

Of course, you can't see it happen.

An interesting effect of this is that an event horizon has a tendency to grow in anticipation of incoming mass. Imagine a black hole of mass M and radius R. Now say we have a "shell" of mass M hovering somewhere outside of that radius. If we were to let it fall in, the new mass of the black hole would be 2M and the new radius would be R2. (I don't want to say 2R because I'm pretty sure it's not a one-to-one relationship. Let's just say it's a bigger radius.) But, if we slowly let the shell fall in, when do we say it's a part of the black hole?

--
--
--

Well, obviously, when the shell comes inside the new radius we defined, it meets the criteria from before. Even though it's still pretty far away from the center, we have mass 2M inside the corresponding radius R2, and that's all we need. So, we've gone from a black hole of size R to R2. When did that happen? Did the size jump up suddenly when our shell crossed the R2 line? Surely not. This next part is harder to describe without some pictures, so hold on to your seats.

The event horizon is described as the surface behind which an outgoing photon could never escape, due to the intense warping of spacetime. So in weird cases like this, where the horizon seemingly grows as if it's sentient, we go back to that definition. Imagine a bunch of lamps floating near our black hole, in a line stretching between R and R2. Each one emits photons that can be seen far away. And let's say our shell crosses R2 at time 0, for simplicity. As our shell closes in, the photons from the lamp closest to R are unable to escape after a certain point, because even though they started at or after T1 (which is before 0), they couldn't go fast enough to get past R2 by the time R2 became the new horizon. If you have another lamp that's farther away from R, then those photons have a little more time to get out, but even they're trapped if they leave after a certain time.

Our observer (who is very far away) can see from the photons that the lamps are getting snuffed out, one by one, until all the lamps inside of R2 are dark (as we'd expect from the inside of a black hole.) Thus, we can see that the horizon doesn't just jump between sizes, but expands smoothly at a rate dependent on the speed of the falling shell.

Isn't that creepy? Even creepier is in the case where the shell never falls in, like if it just stops and floats above the horizon or if it turns around and speeds away. In that case, you might expect the horizon to expand and then shrink again, but no! It never moves at all.

It knows the future.



In other news, I'm 22 now, it's a new year, I'm a Bible talk leader and a senior, I'm still single, and I have awesome people in my life. See you around! I'll fix typos later, I've gotta go.

Comment! (5) | Recommend!

Substance
Sunday. 11.10.13 5:25 pm
My posts here have definitely been declining in frequency and in...variety, I suppose. I like hearing from you guys, but I've definitely lost most of my interest in blogging. In some ways, I don't need to anymore. I suppose a large part of my interest was based on loneliness. Not that I was lonely, exactly, but there haven't been many people in my life that I can talk to about...all this stuff. Everything. I shared on here because I needed to share. But now I have people in my life who take an interest in all that stuff. People who I can and do talk to about everything.

It's weird, that always seemed like a cliche to me before. Why would I want people to know everything about me? Blogging is funny because I didn't really know the people who read this. For the most part, you play no part in my life. You're disconnected, so I can say what I want without worry. I won't be judged harshly here. You're not affected by me and my life except as a viewer. There's power in that disconnection. I can get feedback without being truly open. On the other hand, if I told my friends a few years ago what I was writing at that time, they either wouldn't care (referring to my especially abstract and long-winded posts) or they'd feel hurt, or think less of me. They'd make me face the parts of me that I don't want to acknowledge. So I only show them what I want them to see, and I show you some of the rest. Some of it. It gives the semblance of transparency, but what's the point of a window behind a wall?

That's the biggest thing I've been coming to grips with this semester: being open. It probably seems obvious to some of you. Being open is good so you can know how to become better. It seemed obvious to me, consciously, but I didn't really apply it. I didn't want to change, I wanted to be comfortable. So of course I'd be reluctant to get into all that. Now my priorities are different. My spiritual family is there to help me mature in Christ, but they can't be much help if they don't know me. But I don't LIKE being open. I'm OK with admitting I'm wrong on some stuff, but there are other things I'd rather just leave alone. Probably some things I can't even think of right now because I subconsciously skirt the problems. The same way that a person can argue a point, thinking their view is the ONLY thing that makes sense, until someone else sees the fault and points it out. This still happens to me all the time, even though I've gotten much better at examining my own viewpoints. So even though it makes me uncomfortable and sometimes outright ashamed, I talk to the people I call brothers and sisters. Especially with my roommates, I try to be as forthcoming as I can stand, and then a little more. Sometimes that's what it takes to elicit repentance and change. A lot of times, actually. Even though these are the people I live with and see all the time, it's worth it to open myself to their judgement, because I know they won't judge me. Some of them are the same as me, and can relate. And they all love me, as I love them. We just want to grow. But that's a different point.

The point is that I don't need to be anonymously open anymore. In fact, I can't really, because the stuff I really want to talk about seems pretty senseless to most of the world. It's striking to me, how alien I've become, even in this society that seems so familiar. That's another reversal: my friends become strangers, and strangers become my friends.

---

On something of a lighter note, part of my blogging capital comes from my random enthusiasm about stuff. I just feel the occasional need to explain and discuss something...at length. You can probably gather that from some of my longer posts. So the decline of my posts can be attributed in part to my change of taste! I like to talk about spiritual stuff, get advice, and stuff like that more than I used to. And I have the perfect environment for that! :D

Which reminds me, I want to talk about how Event Horizons expand next time. Peace.

Comment! (6) | Recommend!

Flipped
Friday. 10.25.13 11:26 pm
Today I am weary. It's not easy! Rewarding, definitely. But not easy. Today was hard. My night-vision's been spoiled and I gashed my toe on a treacherous stone.

I wake and something is amiss
The world is different in my sight
Since last I laid my head to rest
I’ve mixed my left side with my right

Reversal is accompanied
by new contours I can’t ignore;
Shadows where they ought not to be
and Light where there was none before.

When left is right and right is wrong,
what I thought true has truly changed.
And now the darkness’ crooning song
I know to be a wail of pain.

I journey through the world I knew
And reckon with my sanity
My state of mind has been made new
From old perceptions I am free

I gaze upon my looking glass
that plane dividing false from true
and with your help it comes to pass
Instead of me I just see You.


This isn't easy. And I should thank God for the people that are there for me, to love me and help me grow. For the people who take me in and treat me like their son (sometimes quite literally,) or push me higher, or even just open up about their lives so I can learn from them.

For the sunlight.

Comment! (6) | Recommend! (1)

Reversal
Sunday. 9.29.13 12:36 am
I remember a long time ago, I was having a discussion about non-denominational churches with someone. Maybe it was Jon! It was pretty far in the past. During this discussion, I remember saying (or maybe just thinking) that these "new" churches were sort of suspicious. Religion definitely evolves over time, but I believe then and now in an absolute truth. So for all these groups to be diverging and making their own doctrinal paths seemed pretty foolish to me.

I thought, "The Church has 2000 years (even more if you count the Israelite heritage) of thought and philosophy riding behind it. Why would people abandon that to try to figure it out on their own?" I was raised in a Reformed Presbyterian church, so I don't know what "Church" I was even referring to. It was pretty foolish.

I didn't actually care about denominations that much, though. I liked the church I was with, and I sort of had a bad image of Catholicism in my mind, but other than that I didn't know what the big deal was. So when I got to college I was more than happy to go to whatever church was nearby, even if it was "non-denom."

HA! That looks like demon. Not really a good truncation.

So I went to this church for a while, and it was alright, but after a semester or so I started to get restless. I NEVER made any friends there. I went with my roommate and maybe a few girls I knew, and we'd leave again afterwards without ever being spoken to or met. I knew a few things about church:

It's something you're a PART of, not something you attend.
Lessons and lifestyles should be based on the Bible, not personal philosophies.
Worship is great but I'm not there to get emotional, so there'd better be more than good worship.
It should be challenging on a personal level, but I should feel loved and welcome.
And other such things.

So I quit going. I was looking for something more, and boy did I find it. I stumbled into a group of guys and girls who did all of the things I mentioned above, and more. They studied the Bible with me, showed me that my faith and my life didn't match Scripture, helped me repent and get right with God, and became my best friends. It was literally life-changing.

And the church I became a part of is non-denominational. Well, sort of. There are a lot of sister churches, where we've branched out and planted ministries all over the world. But the main thing is that we don't care about denominations. There's one Church, and you're either in it or you aren't. Having separate groups based on doctrine seriously undermines the point of the church (as does, of course, having wrong doctrine.) Doctrine is important, and we shouldn't be learning solely from our historical philosophies and stuff like that. We should be learning from the Bible. Period. And if we don't agree on major stuff, then somebody isn't being humble to Scripture.

That's one thing that I've learned. As a religion, Christianity has a rich history (both good and bad) of culture, philosophy, etc. But what good is philosophy by itself? How does a refined culture help me, a sinner? It doesn't. If I don't have a personal relationship with God, my religion is worthless. If I don't abide in the Word, how can he abide in me?

And what's more, that religious history has led us astray. Read the New Testament. Check out what the disciples do after Jesus dies. The first century church was a RADICAL movement. Read those scriptures and then think: have you been to a church that even remotely resembles that heart? There's a big argument these days about the meaning and usefulness of baptism. Go read about baptism in the New Testament. And then read about its history in the church since then. It was only recently that people started "praying Jesus into their hearts." How does that happen? Why do we replace the Law of God with something man-made?

Mark 7:5 --
5 So the Pharisees and teachers of the law asked Jesus, “Why don’t your disciples live according to the tradition of the elders instead of eating their food with defiled hands?”

6 He replied, “Isaiah was right when he prophesied about you hypocrites; as it is written:

“‘These people honor me with their lips,
but their hearts are far from me.
7 They worship me in vain;
their teachings are merely human rules.’
8 You have let go of the commands of God and are holding on to human traditions.”

9 And he continued, “You have a fine way of setting aside the commands of God in order to observe your own traditions! 10 For Moses said, ‘Honor your father and mother,’ and, ‘Anyone who curses their father or mother is to be put to death.’ 11 But you say that if anyone declares that what might have been used to help their father or mother is Corban (that is, devoted to God)— 12 then you no longer let them do anything for their father or mother. 13 Thus you nullify the word of God by your tradition that you have handed down. And you do many things like that.”


Just something I was thinking about today. It's pretty badly put together, I didn't try to reign in the rambling. Thanks for reading.

Comment! (5) | Recommend!

middaymoon's Weblog Site • NuTang.com

NuTang is the first web site to implement PPGY Technology. This page was generated in 0.023seconds.

  Send to a friend on AIM | Set as Homepage | Bookmark Home | NuTang Collage | Terms of Service & Privacy Policy | Link to Us | Monthly Top 10s
All content © Copyright 2003-2047 NuTang.com and respective members. Contact us at NuTang[AT]gmail.com.