Better than 90% of the shitposts on this board

Hey Veeky Forums. I have a question about black holes and special relativity.

Now, in special relativity, velocity addition becomes really fucking weird when objects approach at high speeds. For example, two spacecraft that are travelling towards each other at 99.999% (from the perspective of a third stationary observer) will be measured by the third observer to be closing distance at a rate slightly under 2c. However, from the perspective of the crew aboard one of the spaceships, the other spaceship is NOT approaching at 2c but rather .999999c. I understand this is due to a bunch of weird relativistic effects, but this isn't my main question. I want to know what happens when try to apply this rule to the curved spacetimes of general relativity, or if this is even a valid question to ask.

For example, rotating black holes possess a region extending from the event horizon called the ergosphere, where spacetime is "dragged" in the direction of the black holes spin. The environment is so extreme that it is impossible for any particle, even light, to stand still in this region. Now, from the perspective of a stationary outside observer, the matter swirling around in the ergosphere is travelling faster than the speed of light from their vantage point. This seems to contradict special relativity's claim that you can never observe an object as travelling faster than the speed of light, although I understand that curved spacetimes fall under general relativity's realm. Now for my questions, I'll post more later but these are some of the ones that have been bugging me the most.

Other urls found in this thread:

ocw.mit.edu/courses/physics/
gothosenterprises.com/black_holes/charged_black_hole.html
twitter.com/SFWRedditGifs

What's with all these shit posts on this board?

Here's the only good suggestion you're going to get: actually study modern physics before reading wikipedia and asking ill-founded questions on it.

Need a hug bro?

7/10

1. The ergosphere is in many ways similar to the event horizon. Both possess a surface where light beams can become trapped and (theoretically) never escape. As an external observer watches an object fall towards the event horizon, time slows down and the object takes an infinite amount of time to cross over the event horizon (although from the object's perspective it falls right on through without noticing anything strange). Would a similar process take place for the ergosphere? I don't see why it wouldn't. Would the angle of entry affect the amount of time dilation observed?

Also, does this mean that one side of the ergosphere would be completely dark while the other would be immensely blueshifted? If you positioned yourself at an angle directly in line with the rotation of the black hole, there's no way that light emitted in your direction but travelling against the direction of rotation within the ergosphere would ever be able to reach you, right?

>Asking actual physics related questions
>Shitposts

Fuck off moron, contribute to the thread or leave.

Oh well please enlighten me professor, not all of us have in-depth knowledge of general relativity.

2. Now, what the fuck would an object observed travelling through the ergosphere even look like? When matter is travelling towards you, its clock will tick faster and the light emitted by it will be blueshifted. But from what I understand an external observer will see objects within the ergosphere approaching them at velocities exceeding the observer's local speed of light. How do length contraction and time dilation factor in to this? I know that inside the ergosphere matter is still travelling below the local speed of light, but outside observers will still see matter being dragged around speeds exceeding their own local speed of light.
Basically, if I see a dildo in the ergosphere travelling towards me at speeds that I measure to be greater than C, what would the dildo look like?

stop. you're flooding the board

>t.first year physics undergrad

why did you reply to the same comment 3 times? you know there's a unique poster count, right? there's 4 posters, those are
and you.

Stop flooding the board.

Thank you for the kind bump then.

3. Since objects can leave the ergosphere by extracting rotational energy from the black hole, does this mean that an object sent into the ergosphere could beat a beam of light travelling the same distance in flat spacetime? Since any object seen travelling faster than light in one reference frame can be seen as travelling backwards in time in another equally valid reference frame, how is causality not violated here? I understand that general relativity and special relativity describe different regions of spacetime, but I don't get why objects travelling within the ergosphere would not be seen as travelling backwards in time. I'm sure I've made several mistakes and incorrect assumptions in my questions, but I would love for someone with more knowledge on the subject to help me better understand ergospheres and spacetime in general.

Also, I can't wait until the Event Horizon Telescope come online in the next couple of years, I'm really looking forward to seeing the amazing pictures it produces of our galaxy's black hole.

>I'm sure I've made several mistakes and incorrect assumptions in my questions, but I would love for someone with more knowledge on the subject to help me better understand ergospheres and spacetime in general.
ocw.mit.edu/courses/physics/

Well unfortunately I don't have the mathematical background required to properly understand the material, although I would love to actually take the course on general relativity. Would I benefit at all by purchasing the textbook and taking the course, or get lost like a complete retard?

are you trying to go straight for advanced classes without first learning calculus or classical physics?
no. first do calculus 1/2 and physics 1/2/3. THEN you can think about relativity.

That's great and all, but I'm asking a specific question that does not require me to have in-depth knowledge of general relativity or advanced mathematics and physics. I'm sure most of my questions can be answered by someone knowledgeable in the subject in a way a retard like me would understand.

introductory calculus and introductory physics is not "advanced mathematics and physics". you SHOULD have taken it if you have any interest in STEM at all, unless you're underage

if you don't care about the topic, then why would someone care about giving you a shitty mostly-false layman explanation of it?

Holy shit please for the love of God stop whining and spamming. You've fundamentally misunderstood a crucial component of what makes the ergosphere different than the event horizon.

Object do *not* rotate in such a way as to travel faster than the speed of light in the ergosphere. The ergosphere is a region where an observer would need to rotate with the black hole--which you correctly understood, must be in the same direction as the black hole rotates--in order to maintain a fixed radius. There are no *static* observers in the ergosphere, but there are *stationary* observers in the sense they can fix their radial distance from the black hole center so long as they rotate about it.

Particles aren't trapped in the ergosphere, rather they must rotate to some extent with the black hole to maintain their radial distance. There is no way for an observer to maintain a fixed radial distance without rotating along with the black hole in this region. It's similar to an event horizon in that, if you refuse/have no mechanism to rotate with the black hole, you have no way to propel yourself radially outward and will fall into the blackhole inevitably. In fact, the ergosphere bulges outward from the event horizon along the plane of rotation--the event horizon is contained in the ergosphere, the two line up at the poles. The energy extraction mechanism you've mentioned involves escaping the ergosphere by increasing your rotational velocity.

No particles, photons, or observers are traveling faster than the speed of light in any reference frame in any instance--ergosphere or not.

If it's something you're passionate about, you really should make an effort to learn the mathematics and physics behind general relatively. Or at least check out some info other than wikipedia--I feel like the wording there may've mislead you a bit.

Fair enough. Still, that would take months of learning and study, and in the meantime I would like a crappy but somewhat satisfying layman explanation.

I'm no expert on general relativity but I will have a crack anyway, bc that's what everyone else on the internet does

>Time dilation in the ergosphere
I think by the time you're in the ergosphere the gravitational time dilation would be so extreme anyway that the effect of time dilation from the ergosphere might not be very significant

>Also, does this mean that one side of the ergosphere would be completely dark while the other would be immensely blueshifted?
The light particles in the ergosphere experience the same frame dragging that you do, you'll still witness the light travelling towards you at C if you too are inside the ergosphere

>does this mean that an object sent into the ergosphere could beat a beam of light travelling the same distance in flat spacetime?
I doubt at any point the ergosphere's fram dragging will allow a particle to go faster than C, if it enters at 0.9c in the same direction as the dragging the particles new speed measured by an outside observer will probably be more like 0.9999c, still less than light would travel

lol moron

Objects can move relatively away from each other at faster than speed of light, without violating relativity. They, essentially, stop existing to each other.

This is what has happened to the unobservable universe, and will continue to happen, as the universe's expansion accelerates. Eventually, we won't be able to see any of the currently red-shifted galaxies, and it will appear as though ours is the only one (which, by then, will have merged with all few blue-shifted galaxies.)

What the fuck is an "inner" event horizon?

I think you post this multiple times a day throughout Veeky Forums.

It seems to be a subtle troll attempt acting as a meme, which is masquerading as a somewhat serious reply.

I see it everywhere.

>However, from the perspective of the crew aboard one of the spaceships, the other spaceship is NOT approaching at 2c but rather .999999c
mind=blown

>What wavelength is magenta!?

Half the posts on Veeky Forums just seem to be folks attempting to disprove the value of science - like some sorta swarm of internet bullies attempting to beat up on the nerds. (Cuz I guess that isn't the trend IRL anymore, or something.)

But I think this guy is genuinely confused, maybe, possibly. Relativity and quantum physics generate more misnomers and confusion than anything, thanks to Hollywood always taking fantastic sounding shit out of context.

>all people who mock me must be the same person and "meming"

Not saying, you have to take this low effort two word post seriously, but you sound a bit paranoid

...nvm, I thought you were on about OP.

I'm not even the user he's replying to.

It's just that I have two different threads open at the moment, which feature identical posts:

I've also seen it several times over the past week in other threads.

Yes...

It's like some sorta meme magic...

It's the same formatting every time: all lower case with no punctuation and placed directly under the link.

It's either the same person or a new meme.

The identical formatting indicates the former.

Are we supposed to explain memes to you or do I have to spout "summer!"? I dont come here for this sort of shit.

Wow, I didnt expect that much autism. I thought I would get a "not an argument" as if that was the point, but such a mental breakdown, wow!

bump

What is a ring singularity?

KEK

If this is a meme, then I haven't seen it before.

>summer

I've been here for 11 years.

I'm not the user you originally replied to.

I was just trying to figure out if it was a meme or just the same person making identical posts.

Either way forced meme is forced and you're a faggot.

...

I'm not going there, it's full of hyped up 14 year olds.

I'm going to stick around here and discuss science, while drawing up conspiracy theories regarding memes and identical posts.

>I've been here for 11 years
> I haven't seen it before
>forced meme

Holy shit, how dense are you?

>it's full of hyped up 14 year olds
Thats why I thought it would fit better, Mr. Meme

I haven't seen it before, the formatting of the multiple posts is exactly the same and it's been posted around three times in the past few days.

It doesn't seem prevalent enough to be an established meme and the formatting issue indicates that it's being posted by the same individual.

i think the 'forced meme' comment was supposed to be a joke.

Shoulda used :^) lad m8.

I haven't posted any memes, Bum Holio.

I'm not going to use that, ever.

gothosenterprises.com/black_holes/charged_black_hole.html

>now he is repeating the same autistic shit he already posted
>established meme
>formating
Holy fuck, I hope you are just trolling

Kek is also known as kuk, which is also something very close to pol

Ok, let’s take a closer look at this by analysing the entire board.

>pic related

Results:

43.7142857142% of posts begin with a lower case letter.

86.4285714285% of posts do not exhibit a space between the link and the first line.

31. 142857142% of posts do not exhibit proper use of a period/full stop.

Therefore, it is not possible to discern weather the ‘lol moron’ post is resultant of a single user by analysing the formatting alone.

This validity of this intuitive judgement turns out to be indiscernible.

However, we can analyse the lexical density of all the threads on Veeky Forums and compare the phrase ‘lol moron’ with well-established memes, in order to determine whether it is a well-established meme or not.

Three common and well established memes:

‘It’s 50%’ ~ ‘it either happens or it doesn’t’ # lexical density of 1.7142857142857124%

‘austist’ ~ ‘austismo’ ~ ‘autism’ # lexical density of 5.357142857142857%

‘fedora’ ~ ‘tips fedora’ # lexical density of 3.571428571428571%

Now let’s look at the phrase in question:

‘lol moron’ # lexical density of 0.25714285714285715%

This data indicates that the ‘lol moron’ phrase is not a well-established meme.

In addition to this, the ‘it either happens or it doesn’t’ meme is relatively new and subsequently has a relatively low lexical density; although, it is still significantly prevalent.

The ‘lol moron’ phrase is not significantly prevalent, therefore if it is a meme then it must be new.

If it’s a new meme that is not significantly prevalent, then it is very likely that it is being posted by a small number of individuals or a singular user.

If an individual is repeatedly posting an unestablished meme, then we can consider it to be a forced meme.

Therefore, forced meme is forced and user is a faggot.

I certainly like your style and analytic approach to Veeky Forums. However your conclusion that everything that isnt posted as often as common buzzwords and memes is a "forced meme" still strikes me as silly

...

That wasn't my conclusion; read the post again.

>If it’s a new meme that is not significantly prevalent, then it is very likely that it is being posted by a small number of individuals or a singular user

Forced meme:

>having one person or a group of people attempt to spread a meme

This is the most beautifully autistic thing I've ever seen.

yeah, thats just conjecture. The only thing you know is that it isnt posted as often as for example buzzwords and memes. You conclude from this alone that it is a ""forced meme""

I concluded that if it is scantily posted, then it must be posted by a small number of anons or an individual user.

No, you concluded it is a ""forced meme""

Not everything is a meme.
and
memes can be obscure without being forced

I concluded that it is being posted by a small number of anons or an individual user, which would make it a forced meme by default.

This is because the definition of a forced meme is:

>having one person or a group of people attempt to spread a meme

If you want to dispute the intention then we'll call it an 'indirect forced meme by default'.

>Not everything is a meme

That was my original argument.

>memes can be obscure without being forced

Well, thinking about it there's no way to prove intention; therefore, this chain of argument is pointless.

>therefore, this chain of argument is pointless.
exactly.
Thats what I was saying

Yes, I see that now.

My original argument was that it wasn't a meme.

I added the forced meme comment in later on.

>will be measured by the 3rd observer at just under 2c

Stopped reading there.
Special relativity literally requires only highschool algebra and apparently you cant even understand that

If ever you were unsure of which board you were on this post would prove it to be Veeky Forums

Buddy, I'm really not trying to be a dick here, but GAT DAYUM!
>pic related