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/sci/ - Science & Math

>you can't go faster than the speed of light relative to any other solid object

OK what if I go 7.c and another spacecraft goes .7c in the opposite direction as me? Now we are going 1.4c relative to each other

checkmate relativityfags
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>>10380971
nope, even if a “stationary” observer sees him going 1.4c relative to you, then in YOUR reference frame you still see him going <c. look up relativistic velocity transformations
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>>10380974
>nope, even if a “stationary” observer sees him going 1.4c relative to you,
that's all that matters

after one year we would objectively be 1.4 light years from each other
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>>10380976
>one year
Whos year we counting here? The passage of time varies widely between the different frames of reference.
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>>10380976
no, distances are not objective. length contraction changes the distances the different observers see
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>>10380987
>Whos year we counting here?
stationary observer going 0c relative to both
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>>10380989
then fine, after 1 year the stationary observer sees them 1.4 ly apart. this does not contradict relativity
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>>10380998
>then fine, after 1 year the stationary observer sees them 1.4 ly apart. this does not contradict relativity
yes it does since we went 1.4 times the speed of light

>you can't go faster than light, unless you do, then we will say it does not count

relativity cope
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>>10381003
relativity brainlet
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>>10381003
based as fuck
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>>10381003
b(rainlet)ait
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>>10381003
why do you think they went 1.4c? both were going .7c, to know their velocity relative to each other you have to transform to one of their frames of motion. then you can add the velocities relativistically
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>>10381003
>>you can't go faster than light, unless you do, then we will say it does not count
true
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>>10381003
none of the three observers ever observe the others going more than c though. it’s all fine, people have thought about this for over 100 years, and if you don’t understand then read one of their books
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>>10380976
>being this retarded
Of course youd be 1.4ly apart, youre both going in opposite directions at 0.7.
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Just shine a laser pointer at the moon and wave it about. The spotlight will travel across the surface faster than c from your point of reference. It's over for relativityfags.
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>>10381035
nothing travels faster than c tho
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>>10381030
>Of course youd be 1.4ly apart, youre both going in opposite directions at 0.7.
then explain how to me you can go 1.4ly in one year and not be going faster than light
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>>10381003
Think about what the time dialation effects for each traveling party would do. I have confidence you can figure this out. The stationary observer saw two ships travel .7 light years in 1 years time. No relativity violations here. The travelers frame of reference is who you should be worried about.
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>>10381056
b(rainlet)
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>>10381040
who went 1.4 ly?
say we're in the reference frame of the stationary observer S where A is going left at .7c and B is going right at .7c. in B's reference frame, S is going .7c and A is going v<c. let me calculate it: [eqn]v=\frac{c-v'}{1-v'\times v/ c^2}=\frac{0.7c - (- 0.7c)}{1-(0.7\times -0.7)} = \sim .9396c[/eqn]
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>>10380971
Also, to properly answer your question OP, your two spacecraft would be going almost 0.94c relative to an another.
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>>10381093
oops i fucked the middle part of the equation but the answer is correct. let me rewrite it...
in S's reference frame A and B are moving with velocities $v_A$ and $v_B$ respectively. then in B's reference frame, A appears to be going at $v_A'$ and the equation is
[eqn]v_A' = \frac{v_A-v_B}{1-\frac{v_A v_B}{c^2}}[/eqn] and the rest of the equation is correct
[eqn]=\frac{0.7c - (-0.7c)}{1-(0.7\times -0.7)} \simeq .9396c[/eqn]
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>>10381039
This is false. Immaterial objects move faster than light.

Only INFORMATION can't move faster than light. The laser "dot" on the moon can move faster than light over the surface but the actual physical photons just hit different spots of the moon's surface at different times giving the illusion of movement.

Same if you have a giant scissor in space if you close the scissor the dot in the middle where the paper gets cut will go faster than light but that's not a real object just a immaterial construct.

A similar thing is quantum entanglement just like the laser pointer on the moon you can't transfer information faster than light with it and thus it doesn't violate it.

C only stands for the limit of information.
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>>10381122
>stuff i made up, the post
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>>10381122
>Immaterial objects
well in physics we usually only worry about the motion of material objects. in physics we could also define for example a reference frame that is at x=0 for t>1 and x=81082937ly for t≤1; this obviously can't be the reference frame for a physically real object, but nothing prevents you for considering that reference frame.

quantum entanglement is a whole other story and unrelated to your point about shining a laser pointer across the sky and watching the dot reflect back from spacelike separated points
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>>10380971
>transformations

And if two jet planes seperate in the opposite direction both at mach2, that doesn't mean both jets are going at mach4 - they're still going at mach2.

Changing mach2 to .7c doesn't change the fact that you're mistaking velocity for 'displacement from each other', rather than 'displacement from origin'.
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>>10381003
>yes it does since we went 1.4 times the speed of light
What? No you didn't.
If you and your brother meet on the side of a 2 lane road with a 50mph speed limit, and you both take off in opposite directions going 49mph, you would be 98 miles apart in one hour.
Who would the cop give the speeding ticket too since, by your reasoning, this means the speed limit was exceeded.
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>>10380976
>after one year we would objectively be 1.4 light years from each other
That moment when I realize anon doesnt understand literally the first principle of relativity
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>>10381271
>opposite directions going 49mph, you would be 98 miles apart in one hour.
>Who would the cop give the speeding ticket too since, by your reasoning, this means the speed limit was exceeded.
so you don't understand relativity at all or what is being asked?
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>>10381108
get outa here with your equations and actual physics!
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>>10381003
>yes it does since we went 1.4 times the speed of light
2 cars go each at 70 mph
after an hour they are 140 miles apart
hurrr durrr they went over 100 mph
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Okay so I put a racecar on a train. The train travels at 0.99c and the racecar is accelerated to 0.99c. Now my car is going 1.98c. CHECKMATE!
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>>10381719

Oh shit!
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>>10381719
1.98c relative to who?
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>>10380976
what if the space between us is expanding
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>>10380971
The speed of light is a rate of induction. The light itself is not moving. What we call the speed of light is the perturbation of the medium at the speed of 299 792 458 m / s.

Tesla had some devices that supposedly had transmission faster than the speed of light. But when you get to the speed of light, time goes out the window and you may as well post on /x/ because you're entering a zone where measurements kind of don't work.
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>>10381719
Physical matter can't travel that fast. Only non physical phenomena. Teleportation technically could beat it.
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>>10381003
Retard. The person at 0c sees both going .7c, the fact that they're 1.4ly apart from eachother is insignificant.
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>>10383195
>The speed of light is a rate of induction. The light itself is not moving. What we call the speed of light is the perturbation of the medium at the speed of 299 792 458 m / s.
wat

how is the light not moving when you shine it and it goes from the earth to the moon
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>>10380971
>OK what if I go 7.c
You can't just go at .7c, that's meaningless. You have to go at .7c relative to something.
Relativity says any thing you're going at xc relative to has x<=1.

So what if we have infinite spacecrafts, each one going at 0.7c relative to the next?
They all think they are stationary and the adjacent ones are going at 0.7c.
The adjacent ones think their adjacent ones are going at 0.7c too.
>derp 0.7nc n>=2 cant even relate
Relativity says that's fine because the first one sees "the adjacent one seeing himself as stationary and seeing the next one going at 0.7c" as the adjacent one "going at 0.7c and seeing the next one going at 0.2c" and after infinite adjacencies it all adds up to 1.
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>>10383335
It's a wave. And What is a wave...
A wave is an effect not the source.
A wave is what something does and not what something IS.
The wave hits matter and it is illuminated.
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>>10383363
what's waving
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>>10383373
Light I suppose, but then what is the source of light itself? I have no clue. But I can guarantee a wave is not the cause but just the effect.
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>>10383378
>But I can guarantee a wave is not the cause but just the effect.
how can you guarantee that
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>>10383381
If a fat kid jumps on the pool, do you proclaim the waves on the pool to be the fat kid? I hope not, No it's just moving water.

If someone yells at you do you proclaim the sound waves to be the person themselves??

No a wave is like a shadow. Not the actual thing.
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>>10383195
>The medium
And what medium would that be?
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>>10383373
Electric and magnetic feilds
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>>10380971
u cant
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>>10383413
Spacetime would be the “medium”, although that is disingenuous. It’s probably better to say that emr doesn’t need a medium when thinking of it like a classical wave.
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>>10383426
>u can't
can and did
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>>10380989
FUCKING HOW?
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>>10381108
wait you using latex in 4chan?? teach me the ways i must flex
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>>10381003
If a stationary observer watches a northbound train going 20 mils an hour north, and another going 2o miles an hour south, is either of the trains going faster than 20 miles an hour?
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>>10381035
Please tell me you are trolling.

>What makes up the "point of light" you see traversing the moon? Is it photons traveling from you to the moon, then hitting the moon and being reflected back to you so you can see it? Are the photons sliding along the surface of the moon following the spot of light? If they were, how would you be seeing them?
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>>10381276
That cannot possibly be the first moment you realized this.
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>>10383373
Obama and Romney.
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>>10383413
The medium is the stuff between the source of light and gross matter, e.g the sun is source and moon is illuminated.
Call it quantum fluid, ether, Tesla called it a super rarefied gas, or a primordial atmosphere, whatever makes most sense to you call it what you want. The medium is simple and easy for people minds to grasp. But we are observing waves. not the actual source of the waves, so the field perturbation we observe must be via a medium that is effected from lights source, there cannot be nothing to cause a wave. If there is no water at the beach you cant see any moving water lapping on the shore which people call Waves, the water is the medium.

>>10383450
Space-time no that term is confusing and not really helpful. Time is only a measurement of change itself, And Space has no properties, acts o nothing and does nothing. Coupling a measurement of change (time) with an empty box of nothingness does not solve nor answer anything.
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>>10385803
>t. pseud
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>>10385811
What part of that whole post was pseudo you troll. It Makes sense to me.
Unless you disagree that time isn't a measurement?
Or disagree that space can't actually do anything?
Or do you disagree that water can be a medium?
You retarded or something?

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