/sci/ - Science & Math

3 dimensional energy dependent vector field actually

>>10128594
One-dimensional vector.

>>10128594
thanks anon , you just stalled my brain for a sec there

>>10128599
how is it energy dependent ? is it something to do with entropy ?

>>10128594
Time in zeroth component of 4vector.
I had to complete captcha for this, i dont even know who is bigger retard you op or me.

>>10128594
If time could be stopped, would/could expansion still happen, since it's not motion?

>>10128594
It's a raster

>>10128605
Dependent on the energy of a particle moving as it approaches c

>>10128605
Not that anon but a system with hypothetical "zero energy" would be static and unchanging.
Just a guess freshly pulled from my arse.

>>10128735
>>10128605
If there's 0 energy in a system there's 0 transfer of energy, 0 change of entropy etc, time is hard to define but using thermodynamic definitions if theres 0 change in the thermal variables of a system than no shift in time occurs. Of course in a practical situation time will be passing externally but within the system there's no change that can be observed as a function of time, thus time does not shift.
All of this was pulled directly out of my ass though time is very hard to quantize

>>10128594
It's made up, it can be whatever the fuck you want it to be.
>>10128735
>>10128738
>At the center of time there is no time

0 vector

>>10128771
>center of time
There's no shift in the value of time

>>10128776
I'm basically saying it doesn't exist.

Infinite dimensional vector

>>10129156
that’s called a wavefunction

it's a tensor

>>10129202
Sure if you take space time, it's just a wavefunction

>>10129212
dis

but, it's often convenient to deal with it as a vector instead

>>10131064
why did you bump this retard thread? seriously.
ITT a bunch of highschoolers being like "hey i learned this cool math word, 'tensor', now im smart"

>>10128594
actually got that one on my last physics test
t. highschool

>>10131070
bump-brother

>>10131070
uhh I'm actually studying tensors anon don't judge

>>10131788
yeah, tensors are fucking dope, but there's not one high schooler who can possibly understand them is my point (well, unless they're doing some insane level tutoring or something)

>>10131789
This is /sci/ what else is there to do but mention things other people don't know in order to sound cool?

>>10131788
Ok, then. Tell us what you know.
I expect to see the universal property of the tensor product.
Or else.

>>10131814
I'm not that far in the book anon, I just got past the introduction to Einstein notation and using it with the kroenecker delta and Levi civitas symbol

>>10129212
>>10131064
>>10131788
>>10131824
If you were actually knowledgeable about tensors, you would know that time is not a tensor. It's a coordinate.

>>10131843
it's almost like this is a shit thread full of bait replies and you fell for one of them

>>10132374
the absolute state of /sci/

>>10128594
It's a cube

>tfw

Time is a coordinate in spacetime. Coordinates are scalars.

>>10128594
>>10128599

Einstein discovered that space and time are inseparable (i.e. they are components of spacetime), right?

Would it be accurate, then, to say that any object is a 4D vector in spacetime with a constant vector length of c (in some mathematical space)?

>>10128738
>If there's 0 energy in a system... no change can be observed as a function of time, thus time does not shift

Okay, that all makes sense conceptually... but there are no real systems that behave this way.

Because our universe is expanding, and because the energy density of dark matter remains constant... and because the entire universe is diffuse with CMB radiation... with sensitive enough equipment we could measure the redshift of CMB photons over the time interval in question.

A measurement

>>10128594
Neither time is what passes along a time-like curve. For [math](X, g) [/math] a Lorentzian spacetime, a tangent vector [math] v \in T_xX [/math] is called
[math] \bullet \mathbf{timelike} [/math] if [math] g(v,v) < 0 [/math];
A curve [math] \gamma:\mathbb{R} \to X [/math] is called timelike if all of its tangent vectors [math] \dot{\gamma} [/math] are.

it's actually a distortion - man-made - non-natural - violation. so it won't matter what you call it.

>>10128594
Multilinear map

>>10128594
It might not be the most wise (or scientificaly correct) way to describe time, but I always liked to treat it as one of components of vector. One component would be your spatial velocity, and second would be your temporal velocity. Resultant vector would have the lenght of c.

>>10128594
Time is whatever you want it to be

>>10128594

time is a component of a vector.

>>10128594
No

>>10128594
time is linguistic you stupid fucking faggot god I hate this board

is pi a real number or a complex number or a concept.
Stupid question
/thread

>>10131070
BTW what's the difference between tensor and vector and pseudovector?
As far as I understand scalar is just one dimensional vector and vectors can be thought as list of scalars. But what's the deal with pseudovectors and tensors? They seem to be functionally identical to vectors.

spacetime - space = time

>>10136250
time describes a physical phenomenon, not some platonic entity.