[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

View post   
File: 93 KB, 400x399, frodo.jpg [View same] [iqdb] [saucenao] [google]
6186319 No.6186319 [Reply] [Original]

>pleb /lit/fag here
>reading a brief history of time
>in chapter two, hawking says that three dimensional orbits are four dimensional straight lines, then moves on without showing how he/einstein came to that conclusion

can someone help?
here, I'll even make fun of myself so i can just get the answer and go
>>lol where do you work a cafe
>>books plz 0k starting
>>lol ur poetry is bad

>> No.6186321

Any body who claims the existence of anything other than 3D is wrong

>> No.6186333

>>6186321
>>space-time is a single dimension

>>implying that four dimensional geometry isn't just using four coordinate axis instead of three

>>implying length, width, breadth and time are not four dimensions

>>implying hair color, eye color, skin color, height, weight, and favorite book is not a six dimensional array

jesus christ man, come on

>> No.6186338
File: 1.26 MB, 260x197, mfw.gif [View same] [iqdb] [saucenao] [google]
6186338

>>6186321
>>6186333

>> No.6186385

bump for answers

four dimensional geometry is beyond me. Is it because the solar system is also moving?

>> No.6186392

>>6186321
>i don't get it, therefore it's wrong

>>>/x/

>> No.6186393

>>6186321
>biology major detected

>> No.6186418

>>6186321
you mean 3 dimensional space

>> No.6186431

>>6186319
Basically in the presence of gravity, 4 dimensional spacetime is bent. All objects travel in straight lines, but the spacetime itself is bent so things travel in orbits.

I always use the analogy of a golfcourse green. Like the golfball will always travel "straight" even if the green dips. Even if it dips so far the ball circles around in a circle around a depression, the ball is still going straight, its the just surface is on is curved.

Move the analogy up one dimension and there you go.

Tldr: gravity is a curving of space

>> No.6186432

>>6186333
You sound like me after I learned about vector spaces in linear algebra. One kid was saying in physics that the "fourth dimension" doesn't exist and its all bullshit made up, that was a fun conversation.

>> No.6186435

>>6186431
ah, shit, that makes a whole bunch of sense. I'm working my way through the Elements currently, trying to grasp all the basics of geometry, so I'm not at Non-Euclidean yet. That makes a whole bunch of sense, now that "straight line" means something different than it does in plane geometry. Thanks! honestly, the most pleasant interaction I've had with /sci/

>> No.6186436

>>6186319

This is not a smartass answer, but you can't just explain high-level physics to someone casually. A lot of concepts just don't translate into english. In order to properly explain it, you have to have the sufficient math knowledge.

That being said
>>6186431
this guy did about as good of a job as you can get for layman's.

>> No.6186439

>>6186319
As to why einstein came to that conclusion, fuck I guess he's einstein bro.

He wrote a short book generalizing the concepts of special and general relativity, and kept most of the rough math out of it. It does a great job explaining what the fuck he did to get where he did. There's pdfs of it somewhere, check it out.

>> No.6186442

>>6186432
Is that wrong? I'm a much bigger reader than a mathematician, but I think i'm actually grasping these things correctly...

>> No.6186445

>>6186435
I haven't touched non-euclidian shit yet either. Apparently solving shit in general relativity is no joke either.
Inb4
>2014-.1
>no knowing general relativity

>> No.6186450

>>6186436
I've read up on symbolic logic in preparation for my foray into mathematics, i was disappointed when "A brief history of time" was mostly just graphs with pictures. Because of the existence of "a briefer history of time" which supposedly takes out all of the "hard math," I assumed there'd be a formula or two.

>> No.6186452

>>6186442
Lol no bro. I get what you mean, from the lin algebra sense of dimension as the "minimal number of vectors needed to span whatever". People like to think that dimension is a mystical word when its pretty basic.

>> No.6186461

>>6186450
A brief history is good for getting you interested in shit. But what I've learned is jumping in and knowing the math gives you a wonderful new perspective.

A retarded example is I always KNEW objects fall at the same acceleration. But intuitvely it seems wrong. More mass, more force, more acceleration. Right? Lelno. Just jacking around with newtons gravitational law reveals why shit accelerates the same. Was one of those "I GET IT NOW" moments.

>> No.6186468

>>6186452
Yeah, alright. I think I'm actually making some progress on math, I came here last year asking for textbook recommendations and have been working my way through them, though I decided that I needed to take a few steps back before I could really comprehend it

>>tfw decide to do calculation on the variability of the fractal circle based on the radius of the interior circles
>>tfw holding multiple complex symbols in my head at once like tightly wound strings
we're all going to make it bros

>> No.6186475
File: 270 KB, 804x964, 1384288870518.png [View same] [iqdb] [saucenao] [google]
6186475

>>6186468
I..I don't think I'm that far yet.

>> No.6186487

>>6186475
I bet you know how to do stuff that's actually useful though. I've just made math into a hobby

>> No.6187394

bump because i thought this thread was cool