/sci/ - Science & Math

because if you break physics you break physics

because the speed of light is constant, therefore relativity.

>>3832977

Can you explain this in more detail? I understand partly the theory behind it, but not fully, or why it would work.

Also while I'm on sci, how do radiometers work?

>>3832962
>explain why something travelling faster than the speed of light travels back in time

It doesn't. Where are you getting such shit-teir concepts from?

The theory of special relativity only works (is defined) for objects going less then (some equal to) light speed. You cannot just take these same equations, and apply them to faster then light travel, that is fucking retarded and all you get is nonsense.

you start at "1"
you travel faster than light (outside the black light cone) to 2
you travel to 3 slower than light (or faster, watever.)
the light cone is now as shown
now you travel faster than light again to 4

>>3832994
Because the speed of light is the speed of information in laymans terms. So if something is traveling over the speed of light, the effect is happening sooner, than the cause, from the viewpoint of a far away examiner. I know that this isn't scientific, so don't bitch about this post please.

>>3833014

I've heard it talked about quite a bit by some friends who are alot more educated in physics talking about it all, but they couldn't explain it properly.

>>3833014
>It doesn't
I guess ytou now better than all them scientuist people

see >>3833015
for how.

>>3832994
The main point is that the faster you travel the slower the times passes, up to the space speed limit of C when the time literally stops. If you somehow managed to travel at C you would get to whatever destination instantly, because of time dilation you are experiencing. If you traveled faster than light the time should go backwards because it already stops at C.

Your answer lies in here, OP:

http://www.bibliotecapleyades.net/ciencia/time_travel/esp_ciencia_timetravel02.htm

>>3833035

Would the distance you have to travel decrease to zero as you approach the speed of light? I read something about space contracting but can't remember if this was correct or not.

>>3833015
this also shows why "bypassing" c by going through wormholes or teleporting also equals time travel.

I'm understanding this a bit.

Basically, when you travel faster than light, you are travelling faster than time, so you're going backwards? Excuse the poor writing, can't put this into words properly.

>>3833024
Well they were fucking wrong.
They are making stupid assumptions, that lead to fucking nonsense.

Equations (+ certian branches of physics) are only defined for certian inputs/systems. You cannot just use them all willy nilly and expect to work for every senario.

Basically, what they are doing is equivalent to divison by 0. You cannot divide by 0, the equations break down. Our notion of divison is incapable of handling such a concept. It is implicitly noted DON'T DIVIDE BY 0, you get fucking nonsense!

Similarly, if you try to use special relativity for objects going faster then the speed of light, YOU GET FUCKING NONSENSE. It is noted mutiple times by einstien and others, the equations of special relativity weren't ment to handle objects going faster then the speed of light. YOU GET FUCKING NONSENSE!

>>3833073
Nope, our equations cannot be applied to FTL objects. Special Relativity breaks down.

\thread

>>3833081

So all the moving back in time stuff is completely wrong because it's worked out using theories that weren't meant for objects moving FTL?

>>3832962
because you will arrive somewhere before the information that you have arrived there arrives there, since information can't excede c

there are more mathematically rigorous ways to define it but if you only did A level physics idk how to explain it easily, other than do say if you travel faster than C you've created a space like interval rather than a time like one

The main idea of special relativity is the relative simultaneity -- whether event A occurs before, after, or at the same time as B can depend on what reference frame you're working in. If A precedes B by long enough for light to get from A to B, then A precedes B in all reference frames. But if you'd have to travel faster than light to get from A to B, then there are some reference frames in which B comes before A.

>>3833081
you do not understand physics, please learn some before you comment on this. its a consequence of Lorentz invariance, if a theory is Lorentz invariant, sending information from one point to another faster than light would take to travel between the points causes time travel, no matter the details of the theory.

>>3833097

Yeah most people I asked said it's hard to explain to somebody who's only done A level as theres alot more I need to know to understand the theories.

>>3833097

But say event A happens and i'm standing there. If i rush to person at B faster than light and tell them that it's going to happen, i'm not going backwards in time because that event has already occurred regardless of if i get to a person before the light does.

>>3833095
not necessarily, there are plenty of relatavistic theories that include objects which can exceed c

>>3833081

That's going a bit too far. Special relativity doesn't explicitly exclude the possibility of things travelling faster than the speed of light, it merely requires that anything moving travelling faster than the speed of light would be very abnormal. The possible existence of tachyons which travel faster than the speed of light has been contemplated by physicists for a while.

That said, you're not entirely wrong either. The possibility of neutrinos travelling faster than the speed of light (as CERN has appeared to observe) is closer to being a violation of special relativity, in which case, we can't assume that it would lead to time travel.

Furthermore, even if we do have tachyons, that doesn't mean we can use them to send any useful information back in time, let alone send actual physical objects back in time. It just means that causality gets kind of fucked up.

>>3833116

Someone answer to this post.

everyone in this thread seems to be confusing "time travel" with "observation of what looks like time travel". The first is much more paradoxical than the second. the second would still be able to occur if the universe obeyed newtonian mechanics. In fact, it could even happen in our universe since light can be slowed down with materials. For example, make a large glass wedge that is shaped such as to bend all the light from one side of it towards an observer on the other side. If someone traveled near the speed of light from the thick side of the wedge to the thin side, they could be observed as traveling backwards in time.

>>3833116
you are going back in time, if you weren't you would have arrived there after the event happened
if you try and think of spacetime being sheet of paper, if you fold it so two edges are touching then you can shoot a beam of light around the curve surface of the paper but you can alternately jump through the part where they are touching
if you send the beam of light then jump through the touching parts you have left before the informatin that you have left arrives so you must have left before you sent the message

>>3833136
see
>>3833100
In the reference frame he described the scenario in, he is not going back in time. But there is another reference frame in which he is.

>>3833116
in that case its not time travel, you need to return to A for it to be time travel, because you will be able to get to A before you left. going FTL in one direction (such as because the expansion of space) does not cause time travel.

>>3833131
this

special relativity only excludes things passing c either way, you can't accelerate past it or decellerate below it
things that travel faster than c have to have some special properties though, just as light requires the property that it is massless to travel exactly at c

>>3833161
nope.gif

>>3833161

But why? Regardless of if i travel faster than light, i would still return after the original event has taken place.

>>3833095
Yep

>>3833107
Lorentz invarnace is not ment to be used for FTL objects, it was explictly set up to REPRESENT A SYSTEM WHERE NOTHING CAN GO FTL.

Yes, you can plug in FTL values and get fucking nonsense, just like when you deivide by 0 you get fucking nonsense. This is not a correct way to use Lorentz invairence though. Do you not understand range of validity kid?

metaphysics nonsense the lot of it

for an outside observer to experience the effect before the cause isn't timetravel it is a matter of perception

omg lighting timetravels because i can see the lightflash before the sound which has an upper speed limit

timetravel is moving through time, and as such can be defined as being able to prevent it's own departure (paradox and all)
tell me how this follows from any particle moving faster then c

>>3833170
the development of lorentz invariance doesn't involve any restrictions on speed
just as an equation where you do not divide by anything doesn't put any restrictions on anything

you would be correct if there were any restrictions placed on speed but there isn't
you just need to use some special little tricks to get physical values for speeds greater than c, just as you can't get physical values when you plug in c itself directly into a lorentz transformation yet light is allowed by relativity

>>3833169
if you could constantly move at FTL from A to B to A without accelerating, you would get to A after you left, but because you have to accelerate it changes your reference frame and so when you turn around and go back to A, you can get there before you left. as in the pic by >>3833015

tl;dr - you need to change your frame of reference to time travel.

>that doesn't mean we can use them to send any useful information back in time
Who cares? That's not at all the point (aside from the OP's thread). It's not supposed to happen, preiod. So if it does then it has some pretty radical implications.

>It just means that causality gets kind of fucked up.
Yeah, just that. What's the big deal about causality being fucked up, anyway? So what if effect precedes cause? Right?

Sheesh.

>>3832962
The thoery of Special Relativty is designed to explain the physics of objects moving Less then light speed. It is known to work great for obejcts less then light speed. This is has been experimentally confirmed countless times.

It is currently thought that nothing can go FTL. It is also currently not known if Special Relativity works for anything going FTL (if that is even possible).

To blanantly assume the special relativity works for FTL is wrong, not scientific, and not justified by what we know of the universe.

\thread

Nothing travels back in time.

How does distance play in to this? Would I have to travel a considerable distance in order to notice difference in time change?

>>3833218
This.

>>3833147

I don't get it.

If you throw a baseball and then run fast enough to catch it, that doesn't mean you've travelled in time. It just means you're faster than baseball.

>>3833178
>claims physical answers are metaphysical
>wants physical answer to a metaphysical question

>>3833194
>lorentz invariance doesn't involve any restrictions on speed

I don't think you actually understand lorentz invariance as well as you think.

>>3833218
incorrect

>>3833226
if you travel only slightly faster than c, you would have to travel very far to only go back 1 s, if you can travel instantly, you can travel as far back as you want by only moving 1mm, or 1 plank length, or watever.

>>3833246
I think you have only a feeting knowledge of what the lorentz transformation looks like and no idea how it got there
look up a derivation of the lorentz transformation, you'll notice that nowhere are any restrictions placed on speed

>>3833015
I'm confused at this diagram...none of the axes make sense as time, and if they are both space then the "light cones" don't show any information. so...wtf is going on there?

>>3833170
>>3833218
But it is possible to make "objects" (if you'd call them that) that don't carry information, such as shadows or (under special conditions) light pulses in a medium, move faster than light. In those cases, it makes perfect sense to apply the Lorentz transforms.

>>3833218
\thread

>>3833258
Yeah, I just noticed he drew the diagram wrong. I'll draw you a correct one.

>>3833015
>>3833068
>>3833100
>>3833107
>>3833153
>>3833161
>>3833194
>>3833212

are the only people (or person) in this thread who knows what he is talking about.

>>3833256
>implying "c" does not appear as a parameter you input into the lorentz equations

>implying this doesn't restrict the values of v

>>3833261
>Apply the lorentz transformations to FTL objects

Nope. Also, you do realize that you can't always use lorentz transformations right?
SPECIAL RELATIVITY ONLY APPLIES TO INIERTIAL REFERENCE FRAMES. Please learn how to use GR.

>>3833277
it doesnt restrics v, it says :

if you are below c you need an infinity amount of energy to get to c,
if you are at c, you are always at c
if you are above c, you stay above c.

that covers all the values of v.

I am not going to argue any further, but, the value of C is predetermined from Maxwell's equations. That should be clue enough.

>>3833284
where the hell did we start using gravity in this thread?

>>3833285
>assume axiom A
>A implies not B
>OH I NO GUYZ LETS TRY PLUGGING B INTO THIS EQUATION

the lorentz factor has a term 1/sqrt(1-v²/c²)

claims there is no v restriction

pic related

>>3833218
\Thread

Why the fuck are people still posting?

>>3833293
>doesn't understand physics
>wants attention
>greentext random shit

>>3833293
where exactly did not B come in?

>>3833296
because it is incorrect

>>3833267
>>3833015

>>3833277
>implying c is some arbitrary value
>implying its exictence alone places restrictions on v
>wtfamIreading.tiff

look guys, I know a lot of you mean well but most of the nonsence in this thread about special relativity not allowing speeds greater than that of light and god knows what else is just misinformed and based on faulty understanding of the foundations of special relativity

I advise you, if you are interested in the subject to brush up on your maths and pick up a copy of Landau and Lifshitz' Course of Theoretical Physics Vol. 2 - Classical Theory of Fields

once you have read that and have a good understanding of relativity you can return and spread your now informed views and opinions

>>3833284
I didn't mean to imply that you could use the Lorentz transforms to describe a reference frame of the FTL shadows/light pulses. What I'm saying is that you can describe the FTL shadows/light pulses using more than one reference frame. For example, the lab reference frame and some slower-than-light train's reference frame. If the shadows/light pulses are changing over time, observers in those two frames may not agree on the order of the changes; they may be time-reversed between the two frames.

>>3833312
>assume you can't go faster than the speed of light
>use that to derive lorentz invariance
>plug in values faster than the speed of light.

Yes, lorentz invariance is dependent upon c being a maximum speed. If instead you took "nothing can go faster than 1.1c" as your axiom, you would get a different equation

>>3833322
ok, il admit, that picture is slightly better than mine.

>>3833352
>assume you can't go faster than the speed of light
>use that to derive lorentz invariance

what? Lorentz invariance is not derived from assuming you cant go faster than light, it is derived from the fact that light speed is the same in all reference frames.

>>3833352
no
you start off by assuming that c looks the same in all frames
that is not the same as c is the maximum speed

at no point do you assume c is a maximum speed limit
a result of assuming that c is the same in all frames is that it is impossible to accelerated something to c in a finite time

>>3833322

trying to interpret your diagram here
the blue crosses are they supposed to represent light cones and as such such be drawn as 3d cones?

also i do not see any values decreasing on the t axis, from the red frame of reference you can move everywere at once, but were are you going back in time

also what allows you to lorentz transform the axis
the internet gets me the pic formula for lornetz transform

or should these axis also be moving in a 3d plan, representing complex number results?

cause if that is the cause how does complex time result in timetravel

>>3833352
the equation would look exactly the same but with c -> 1.1c

>>3833342 here,
To use a concrete example, take a laser and point it at the moon. It's easy to make the spot on the moon travel faster than light. This doesn't violate SR in any way because no information is being transmitted from the starting point of the spot to the end; it's all a projection from the earth.

Now suppose midway through my sweep across the moon, I make the laser pointer change color. In my reference frame, I make a point that starts out red, travels FTL across the moon, and turns to green halfway.

Now let's observe the same situation from a spaceship moving rapidly in the direction in which I'm sweeping the laser beam. If the spaceship's moving fast enough, then in the spaceship's reference frame, the spot starts out green, moves across the moon in the opposite direction, and turns red midway.

>>3833338
>>3833338
And where in "Classical Theory of Fields" do they say the range of v can include values greater then c?

O'WAIT! THEY FUCKING DON'T. THEY ALWAYS SAY THE EQUATIONS ARE ONLY DEFINED FOR Less the FTL values of v.

It is your shitty assummption that v can be FTL, even though we have no experimental evidence to support such a range of v.

Trollin or stupid?

>>3833408
they also say nowhere that v is restricted to <= c

and it isn't just my assumption, there are many relatavistic theories that include v's > c

it is YOUR shitty (and uneducated) assumption that v must always be less than or equal to c
your assumption is incorrect

the experimental evidence only points to c being a speed limit for things traveling below c
you cannot accelerate things past c
you cannot decelerated or accelerate things from c to speeds =/= c
there is no experimental evidence to say that speeds cannot exceed c
infact quite the opposite is true, these neutrinos could be evidence that speeds > c are infact true
this does not spell the end for relativity, it spells the end for a lot of these uneducated opinions based on pop-sci and hearsay that c is the maximum speed for everything

>>3833395
The light cones aren't really important, I mainly included them because they were drawn wrong in the other diagram.

>also i do not see any values decreasing on the t axis
The four black arrows are the four steps in our cosmonaut's journey across space and time. In the fourth arrow/step, notice that in the red coordinate system, his starting point has a higher t value than his ending point.

>also what allows you to lorentz transform the axis
After he shuts down the FTL drive at the end of step 2, he fires his conventional drives. So during step 3, he's moving at a speed slower than light relative to his motion in step 1. When he fires up the FTL drive again for step 4, it moves him at infinite speed in the rest frame he had during step 3 (the green frame).

>>3833408
and since you seem to be convinced that there is some reason speeds greated than c cannot exist, give me an example of where they are disallowed

since you say that everything is only defined for speeds less than c it should be an easy task

What you're describing is about as likely as punching a wall hard enough to turn it into candy.
Yes the internal structure of the wall can be changed by force, no we don't know what happens if you apply infinite force,
BUT WE'RE RRETTY SURE THATS NOT IT.

>>3833434 here,

Reading >>3833395 again I realize you might be trying to plug in the FTL speeds into those equations. That's not valid. During steps 2 and 4, when he's using the FTL drive, the cosmonaut doesn't have a rest frame. In all reference frames, he is moving FTL, although different frames will disagree on whether he is aging or getting younger.

>>3833342
What you are descirbing is not FTL travel. You are descibing a shitty illusion that only dumb people are fooled by. You can use lorentz tranformation on the obejcts making these illiusions because NOTHING IS ACTUALLY TRAVELING FTL.

You can indeed take a laser beam, shine it on surface and sweep out a "spot" that appears FTL. However, the "spot" you view at one location, is not actually the same spot you view at another locations. YOU ARE VIEWING TOTALLY DIFFERENT SPOTS, MADE OF TOTALLY DIFFERENT PHOTONS. No photon or "spot" is traveling FTL.

The problem is, when you look at all the differnt spots, YOU LITERALLY THINK THEY ARE THE SAME SPOT MOVING ALONG THE SURFACE. WTF? Do you not understand how fucking retarded that is?

Its like you drawing a line on a piece of paper, and constantly erasing the end on the line, It gives you the illisuons that "the line is moving across the paper". However, what you are really doing is making a new line.

>>3833472
That's just metaphysics. "X is the same as Y" doesn't exist in the laws of nature. I think that most people wouldn't call the laser spot a "real" moving object. But some people would call FTL light pulses in a medium moving objects.

What really distinguishes this from a "real" object moving FTL is that if moon cats fuck with the laser spot at point A, it doesn't affect the laser spot at point B. The same applies to the FTL light pulses. This is often summarized by saying these things carry no information.

>>3833508
should be
>X is the same object as Y

If you shoot two electrons at each other, and they scatter off each other, and you observe two electrons coming out, the laws of physics don't give you a way to figure out which electron was the "original" one.

>>3833450
>>3833434

ah thanks that helped

tho some remarks, does this then assume that your ftl drive is somehow instant and no lorentz transformation takes place right before and after both ftl travel periods?

>>3833442
I don't think you understand how science or physics works. You need proof to "believe" something. YOU NEED EXPERIMENTAL PROOF!

If you decide just to believe shit without experimental proof to support your claims, YOU AREN'T DOING SCIENCE OR PHYSICS! (have fun in your religious bullshit kid). You already sound as dumb as a christian.

There is no proof that anything can travel FTL, so allowing v to go FTL is not a conclusion you can make scientifically. Futhermore, Special relativity was expressly developed with c as the light speed limit.

It was one of the restrictions used when making the theory. If this restriction were not present WE WOULDNT GET SPECIAL RELATIVITY. We would get a totally different theory with a different framework.

If we ever do discover FTL, WE wont use special relativity (since it is fundementally embedded with a lightspeed limit). We will use a different theory, that approximates to special relativity in the proper instances.

>>3833508
>"X is the same as Y" doesn't exist in the laws of nature

You aren't very bright are you?

>>3833545
Lorentz transformation isn't a physical process, it just gives us a different way of describing the same events. I can take a situation in which a truck is moving past me, Lorentz transform it, and get a situation in which I'm moving past a truck.

The principle of relativity says that doing a Lorentz transform doesn't change the laws of physics. So if you have a machine that can take you from rest to FTL in the red frame, it should also be able to take you from rest to FTL in the green frame. It doesn't matter how quickly you go from rest to FTL or what steps you take in between.

Also, if by instantaneous you meant the way the FTL drive was drawn as having infinite speed, that's not necessary either. A drive with any speed faster than light can be Lorentz transformed into a time travel machine; you just need a bigger Lorentz transform.

>>3833571
yet again, c being a maximum speed limit is NOT involved in the derivation of special relativity
relativity will still be used if ftl particles are discovered (it's still used and they are already theorised)
there is no reason to assume speeds could not excede c so why would we dissallow the possibilty that they do?
what if, back in newtons day we decided 'well, we've never seen anything excede 100mph, therefore we shall disallow objects with speeds exceeding 100mph, theres just not enough experimental evidence to back it up'?
no, that is not how physics is done

>>3833571
>It was one of the restrictions used when making the theory.
no it wasnt. what the hell are you talking about. do you even know why SR was developed? or who developed it for that matter?

>>3833539
Your statement has no bearing on this topic.

You can distingish that differnet spots are made of different photons, you can PHYSICALLY find this. It isn't some metaphysical bullshit. YOU CAN EXPERIMENTALLY FIND THAT THE DIFFERENT SPOTS ARE PRODUCED BY DIFFERENT PHOTONS (SETS OF PHOTONS).

Do I really need to dumb the whole thing down for you? Is this not implicitly evident to you?

>>3833617
>there is no reason to assume speeds could not exceed

1) It has never been observed

THAT IS A GOOD ENOUGH REASON.
Do you really not understand science?

>>3833645
there is no theory or assumption or anything that would stop something from moving faster than c, is this not a good enough reason to think it may be possible?

>>3833645
>Observed by two separate labs and teams
>Not observed

Pick one

>>3833657

We're free to think anything is possible, but unless we actually observe something that suggests it is possible, it's unjustified.

>>3833660
>two

Whoa, whoa. Explain this bullshit.

>>3833631
>YOU CAN EXPERIMENTALLY FIND THAT THE DIFFERENT SPOTS ARE PRODUCED BY DIFFERENT PHOTONS (SETS OF PHOTONS).

Please describe your "isthisthesameoradifferentphotonometer."

What if I reduce the intensity of the laser beam so that only one photon is fired, then I place mirrors on the moon that reflect the photon into an interferometer, and I repeat the experiment enough times that the statistical distribution of results can only be explained by the photon having an amplitude to take both paths? What then, motherfucker?

>>3833617
>we should assume shit without evidence
>thinks this is proper science

Until you have experimental evidence to supprt something IT IS BULLSHIT.

There is no reason to believe that I am not fucking your mom as we speak. Therefore It must be a scientifically valid theory right? Should I cum in her mouth or vagina?

You need to go back to grade school kid.

>>3833682
does it give you a boner calling grown men "kid" over the internet? just because sci is on 4chan does not mean its a place for pedophiles.

for all you fucktards here who think that c being a maximum speed limit is used in the derivation of the special relativity, I'm gonna derive it right here

we take two events, one when we emit a photon and one when we recieve it, we assume c is the same in all frames, so we have
(d here means delta, not differential)

c dt - dr = 0
and since c is the same in all frames, for these two events in the K' system
c dt' - dr' = 0

if we call these quantities the interval, S we can say that

c^2 dt^2 - dr^2 = S^2
c^2 dt'^2 - dr'^2 = S'^2

if we now take the differentials of each side (d is now differential)
c^2 dt^2 - dr^2 = ds^2
c^2 dt'^2 - dr'^2 = ds'^2

since ds=ds' when ds=0 we can conclude since they are of the same order that

ds = a ds'
but this a can't depend on anything so we have
ds = ds'

suppose the K' system is moving relative to K then we have
dr = 0
and so

c^2 dt^2 = c^2 dt'^2 - dr'^2
dt^2 = dt'^2 - dr'^2/c^2
dt^2 = dt'^2(1-(dr'^2/dt'^2) 1/c^2)
dt = dt' sqrt(1- v'^2/c'^2)

I'll let you do r for yourself, well done you now know where the lorentz transformation came from

>>3833676
minos and cern

>>3833660
I love how you jump to such shitty conclusions. You must be a christian. How many times do you go to church a week?

Please show me where those scientific teams said they observed FTL travel? Citation?

NO WHERE in there paper/seminar/press relase DID THEY ONCE MENTION AN FTL interpretation for there findings. They decided to actually do science, and not jump to shitty conclusions, unlike you.

It was shitty people like you, who don't know how to science, that decided to start spouting FTL bullshit. People like you give scienists and science a bad reputation.

>>3833720

Minos discovered that neutrinos oscillate, not that they travel faster than light.

>>3833707
>claims to prove SR without assuming v < c
>takes the square root of a negative number

Nope.

Also, sage for non group-theoretical proof of Lorentz transformations.

>>3833676
so you would agree with newton disregarding any solution to an equation that resulted in something traveling faster than 100mph?
remember now that no one then had seen anything travel faster than that

what you should say is that we should allow the possibilty that something can happen as long as they are withing currently accepted theories
(which ftl is)

>>3833720
Citation where either of those teams actually say they observed "FTL travel"?

(Hint: they never made such a claims)

>>3833739
>implying i is a problem when light, with v=c divides by zero
>implying the people who don't know what relativity is are going to know anything about group theory

>>3833739
cannot into imaginary numbers
yes its well known that tacions would have imaginary mass.

>>3833754

>>3833753
>implying an observable quantity (dt) can be imaginary

>>3833740
You really don't understand science do you?
You obviosly can't draw proper conclusions for shit.

Do you even know what a theory is? What a hypothesis is? The difference?
Do you understand the scientific method?

Tell me where your fail stems from, and maybe I can correct you properly.

>>3833740
>disregarding any solution to an equation that resulted in something traveling faster than 100mph? remember now that no one then had seen anything travel faster than that

That would actually be a reasonable assumption until shown otherwise... but your example is false. That barrier had already been broken by cannons.

We did not assume it possible to break the sound barrier until it was demonstrated with jets and rocketry.

Mind you firearms and even a bullwhip were already capable of this, but we did not yet understand the phenomena and did not realize that the bang or crack was the sound barrier being broken.

>what you should say

I said exactly what I mean to say, thank you.

>>3833766
xbox hueg but with seemingly little sag. most impressive

>>3833774
>We did not assume it possible to break the sound barrier until it was demonstrated with jets and rocketry.
there you fucking hypocrite, you are doing the same fucking thing. only with light.

>>3833761
>implying an observable quantity dt' can be infinite
>implying there aren't workaround ways to fix this
>implying there aren't workaround ways to fix i

>>3833766
there is no difference between faster than light travel in special relativity and faster than 100mph travel in newtons theories in newtons days, at least towards what we are discussing

both of these are allowed by the theories
both of these were unobserved at the time (if 100mph was observed, bump it up to 1000mph or w/ever)
neither of these have any reason to be disregarded

YOU don't know how science works

try reading some books on particle physics, see how many unobserved yet allowed particles, that do important things, are bobbing about there in the different variations of the standard model, are you claiming that YOU alone know how to do science and the countless researches of particle physics do not?
are you claiming that ALL theoretical physicists don't know how to do science and that you do?

>>3833825
>SR says nothing can go FTL

>Newtonian mechanics never had a speed limit

Proper assumtpion from Newtonian mech, any speed is possible.

Proper assumtpion from SR, nothing can go faster then c (in inertial frames).

Improper assumption from Newtonian mechanics, nothing can go faster then c.

Improper assumtpion from SR, HUURRR DURRR FTL TRAVEL HAS TO BE POSSIBLE SO MY ANIME SPACE TRVEL FANTASTIES CAN COME TRUE.

No one can possibley be as stupid as you are claiming to be.

0/10

>>3833853
>SR says nothing can go FTL
where, where the fuck does it say that?

>>3833853
SR doesn't say that, didn't you see the previous derivation?
it, at no point, mentions c being a maximum speed

Yo fags!

Traveling faster than light can you see a trail of your past self? or you need another observer for that?

>>3833879
You would have to stop and let the light catch up to you in order to see the trail.

>>3833887

>>3833887

What if you were theoretically moving backwards FTL? When you stopped would you see yourself running backwards?

Or if you ran FTL and did a 180 and stopped, would you see yourself running towards yourself?

Is this the right way to think about it?

Experimenter P (on Earth) fires his neutrino gun towards the Moon. He expects to detect a return neutrino 2.2 seconds later (or whatever).
Experimenter Q (on the Moon) detects a neutrino 1.0 seconds later. He instantly fires a neutrino back to Earth.
1.0 seconds later, Experimenter P is shocked to find that he detected a new neutrino 2.0 seconds later, rather than 2.2 seconds later.