/sci/ - Science & Math » Thread #11355434

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Anonymous Sun 02 Feb 23:03:48 2020 No.11355434 View Reply Original Report

Quoted By: >>11355438 >>11355477 >>11356339 >>11356715 >>11357693 >>11357720 >>11357979 >>11359640

If an object A were traveling at 0.9c and another object B were traveling at 0.9c in the opposite direction, to an outside observer, would they pass each other at 1.8c?

Anonymous

Anonymous Sun 02 Feb 2020 23:05:25 No.11355438 Report

Quoted By: >>11355444 >>11355455 >>11355575

>>11355434
Yes.

Anonymous

Anonymous Sun 02 Feb 2020 23:07:22 No.11355444 Report

Quoted By: >>11355476

>>11355438
Then how could one not say that is their relative velocity?

Anonymous

Anonymous Sun 02 Feb 2020 23:12:02 No.11355455 Report

Quoted By: >>11355467 >>11355469

>>11355438
how about if I’m observing object B from object A in the scenario above. Would I also percieve object B as moving at 1.8c?
t. 130 iq brainlet

Anonymous

Anonymous Sun 02 Feb 2020 23:19:02 No.11355467 Report

Quoted By:

>>11355455
no you fucking idiot. In the frame of reference of object B you are standing still and the other object would be coming at you at some relative velocity defined by the Lorentz transformations. I'm not going to do the calculations for you though. It would be coming at you at below c speeds though

Anonymous

Anonymous Sun 02 Feb 2020 23:19:05 No.11355469 Report

Quoted By: >>11355720

>>11355455
No. The simple addition of velocities isn't true in general, but is a limiting case of working with low velocities. The general formula for adding velocities is
$\frac{v+u}{1+\frac{vu}{c^2}}$
which reduces to v+u for low velocities, and at maximum velocity reduces to (c+c)/(1+1)=c

Anonymous

Anonymous Sun 02 Feb 2020 23:21:13 No.11355476 Report

Quoted By: >>11355484

>>11355444
Because thats not how velocities add in SR. Have you considered reading your textbook?

Anonymous

Anonymous Sun 02 Feb 2020 23:21:49 No.11355477 Report

Quoted By:

>>11355434
no

Anonymous

Anonymous Sun 02 Feb 2020 23:22:12 No.11355478 Report

Quoted By: >>11355485 >>11355486 >>11356351

so if you're on a spaceship going at c it would be impossible for you inside the ship to walk towards the cockpit, or rather the ship would stretch infinitely to keep this clearly limited theory afloat.
don't tell me you brainlets truly believe this

Anonymous

Anonymous Sun 02 Feb 2020 23:25:33 No.11355484 Report

Quoted By: >>11355491 >>11355497 >>11355498

>>11355476
>Because thats not how velocities add in SR. Have you considered reading your textbook?
>because that's not how we do things. have you considered reading the 'how we do things' manual
Your professors could all agree that at those speeds, the other object would turn into a mule and take a fat shit on your lawn, and you'd believe it, because you're supa smaht

Anonymous

Anonymous Sun 02 Feb 2020 23:25:53 No.11355485 Report

Quoted By:

>>11355478
Going at c is the relativistic equivalent of classical infinite speed. In classical physics, if a ship goes at infinite speed, can you walk towards the cockpit? It's an ill-posed question, because ships cannot travel at infinite speed in classical physics.

Anonymous

Anonymous Sun 02 Feb 2020 23:26:11 No.11355486 Report

Quoted By:

>>11355478
First of all, things with mass don't get to c, so the question you're asking is inherently unphysical. Secondly, if let's say you're traveling at 0.999c you would still see your spaceship in the same size, everything would look normal to you inside the spaceship, but everything outside would look quite strange

Anonymous

Anonymous Sun 02 Feb 2020 23:27:51 No.11355491 Report

Quoted By: >>11355501

>>11355484
Imagine being proud of ignorance

Anonymous

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Anonymous Sun 02 Feb 2020 23:29:18 No.11355497 Report

Quoted By: >>11355501

>>11355484
>hurr hurr learning things from books is for retards
>I know it's wrong, though

Anonymous

Anonymous Sun 02 Feb 2020 23:29:44 No.11355498 Report

Quoted By:

>>11355484
It follows from the Lorentz transformations, which follow from Maxwell's equations, which are about as experimentally sound as equations can get

Anonymous

Anonymous Sun 02 Feb 2020 23:30:12 No.11355501 Report

Quoted By: >>11355509

>>11355491
>>11355497
My point is that consulting the textbook for all knowledge is about as unthinking as you can be.

Anonymous

Anonymous Sun 02 Feb 2020 23:33:38 No.11355509 Report

Quoted By: >>11355524 >>11357649

>>11355501
Have you ever opened up a physics textbook before? Do you think it's just a bunch of formulas listed in a row with no derivation, justification, or historical development given?

Anonymous

Anonymous Sun 02 Feb 2020 23:37:09 No.11355524 Report

Quoted By: >>11355592 >>11357649

>>11355509
yes

Anonymous

Anonymous Sun 02 Feb 2020 23:53:42 No.11355575 Report

Quoted By: >>11355580

>>11355438
no, lorentz velocity transformation.

Anonymous

Anonymous Sun 02 Feb 2020 23:55:47 No.11355580 Report

Quoted By: >>11355590

>>11355575
I understand the difference between Lorentzian and Gallilean velocity transformations. Reread the question.

Anonymous

Anonymous Sun 02 Feb 2020 23:59:44 No.11355590 Report

Quoted By: >>11355611

>>11355580
great, then do the math

Anonymous

Anonymous Mon 03 Feb 2020 00:00:03 No.11355592 Report

Quoted By:

>>11355524
Consider educating yourself

Anonymous

Anonymous Mon 03 Feb 2020 00:06:47 No.11355611 Report

Quoted By: >>11355686 >>11355703 >>11355828

>>11355590
I did the math. If an observer sees an object moving +x at 0.9c and another object moving -x at 0.9c, those objects will be moving toward/away from each other at 1.8c in the observer's reference frame. You should learn how special relativity works before posting here again.

Anonymous

Anonymous Mon 03 Feb 2020 00:36:20 No.11355686 Report

Quoted By: >>11355705

>>11355611
compute A|B relative speed first

Anonymous

Anonymous Mon 03 Feb 2020 00:41:43 No.11355703 Report

Quoted By:

>>11355611
wrong

Anonymous

Anonymous Mon 03 Feb 2020 00:41:59 No.11355705 Report

Quoted By: >>11355718

>>11355686
Not necessary when we're only dealing with one reference frame.

Anonymous

Anonymous Mon 03 Feb 2020 00:44:23 No.11355718 Report

Quoted By: >>11355734

>>11355705
then define
> A B pass each other
in reference frame of C

Anonymous

Anonymous Mon 03 Feb 2020 00:44:29 No.11355720 Report

Quoted By:

>>11355469
I don't know much about advanced maths and physichs, but thinking that c+c=c is tripping

Anonymous

Anonymous Mon 03 Feb 2020 00:47:58 No.11355734 Report

Quoted By: >>11355786 >>11355792

>>11355718
When the x position of each is the same.

Anonymous

Anonymous Mon 03 Feb 2020 01:04:34 No.11355786 Report

Quoted By:

>>11355734
v A|B ~= 0,98 point they pass
((EACH OTHER)) at that speed
only thing that outside C observes all the time is the decrease/increase of the distance between them a the rate 1,8c which is not relative velocity nor velocity at all

Anonymous

Anonymous Mon 03 Feb 2020 01:07:41 No.11355792 Report

Quoted By: >>11355800

>>11355734
v A|B ~= 0,98 is the velocity they pass
((EACH OTHER))
only thing that outside C observes is the decrease/increase of the distance between them a the rate 1,8c which is not relative velocity nor velocity at all, nothing is moving relative to anything else at the speed 1,8c

Anonymous

Anonymous Mon 03 Feb 2020 01:09:32 No.11355800 Report

Quoted By:

>>11355792
Are you sure you are responding to the right person?

Anonymous

Anonymous Mon 03 Feb 2020 01:17:35 No.11355828 Report

Quoted By: >>11356369

was responding to
>>11355611
who claims that
>those objects will be moving toward/away from each other at 1.8c in the observer's reference frame.
which is nonsense sentence

Anonymous

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Anonymous Mon 03 Feb 2020 06:16:27 No.11356339 Report

Quoted By:

>>11355434
Yes the classic contradiction between Newtonian and Einsteinean physics. Einstein was correct and Newtonian only works as a rough estimate that is good enough for many mundane things but relay falls on its face in some of the extremes.

A better question would be to ask what the collision speed is between two trains hitting head on each going 0.8c.

Anonymous

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Anonymous Mon 03 Feb 2020 06:21:56 No.11356351 Report

Quoted By:

>>11355478

If you managed to actually get your space ship to go at 1c it would, by an internal reference point, instantly teleport to it's destination or at least to its deceleration point. By an external reference you would still be traveling at a rate of one light year per year. So no you could not walk to the cockpit while travailing at 1c.

If you where unable to decelerate you would simply be in an eternal time dilation status.

Anonymous

Anonymous Mon 03 Feb 2020 06:30:41 No.11356369 Report

Quoted By: >>11356654

>>11355828
How is it nonsense?

Anonymous

Anonymous Mon 03 Feb 2020 09:44:43 No.11356654 Report

Quoted By: >>11357247

>>11356369
no object is moving in relation to another object with 1.8c
mutual speed is not velocity
https://en.wikipedia.org/wiki/Faster-than-light#Closing_speeds

Anonymous

Anonymous Mon 03 Feb 2020 10:15:46 No.11356715 Report

Quoted By:

>>11355434
No.

It will always be less than c:

https://en.wikipedia.org/wiki/Velocity-addition_formula

Anonymous

Anonymous Mon 03 Feb 2020 17:06:57 No.11357247 Report

Quoted By: >>11357448

>>11356654
Your own link proves me right. Thanks for playing.

Anonymous

Anonymous Mon 03 Feb 2020 17:19:22 No.11357279 Report

Quoted By: >>11357439

I could never comprehend that shit and to be honest, I don't think many people do anyway.
Imagine a sun, one photon at one end of it would go at the speed of light in one direction, the other one would go the opposite direction at the same speed.
Yet relative velocity can never be more than c.
So what the actual fuck?

Anonymous

Anonymous Mon 03 Feb 2020 18:42:24 No.11357439 Report

Quoted By: >>11357443

>>11357279
It doesn't make sense to think of relative velocity in a light beam's reference frame, since time and space along the direction of motion are collapsed to 0 at the speed of light. More important is that the speed of light is the same for all sub-lightspeed observers

Anonymous

Anonymous Mon 03 Feb 2020 18:48:14 No.11357443 Report

Quoted By: >>11358029

>>11357439
It seems contradictory is all.
I know it's impossible to observe c > 1.

Anonymous

Anonymous Mon 03 Feb 2020 18:53:04 No.11357448 Report

Quoted By:

>>11357247
there is no velocity between objects to measure in the first place in that nosense formulation, not understanding it doesn't make you right, it makes you retarded.

Anonymous

Anonymous Mon 03 Feb 2020 20:18:55 No.11357649 Report

Quoted By:

>>11355509
>>11355524
it's rare to see a self own this brutal

Anonymous

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Anonymous Mon 03 Feb 2020 20:43:28 No.11357693 Report

Quoted By: >>11358572

>>11355434
Daily reminder if you are interviewing at this company, they expect you to answer this question in 15 seconds.

Anonymous

Anonymous Mon 03 Feb 2020 20:58:04 No.11357720 Report

Quoted By: >>11357959

>>11355434
From an outside observer they'd pass each other at .9c, duh

Anonymous

Anonymous Mon 03 Feb 2020 22:38:55 No.11357959 Report

Quoted By:

>>11357720
looooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooow iq

Anonymous

Anonymous Mon 03 Feb 2020 22:46:39 No.11357979 Report

Quoted By:

>>11355434
No you would travel through time faster, and lengths contract.
You can never reach c if you got mass

Anonymous

Anonymous Mon 03 Feb 2020 23:19:21 No.11358029 Report

Quoted By:

>>11357443
nah bro u just gotta wait a little more time for the light to arrive

Anonymous

Anonymous Tue 04 Feb 2020 04:14:07 No.11358572 Report

Quoted By:

>>11357693
jews doing algorithmic trading, is it 2008?

Anonymous

Anonymous Tue 04 Feb 2020 19:03:30 No.11359640 Report

Quoted By:

>>11355434
Thus
c=0

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