/sci/ - Science & Math

>>5472668
>0K just means that the entropy cant change when you add or take away energy.
sory, i was thinking of beta, the closer you get to 0K the smaller energy change would cause the same change in entropy until any infantismal energy change would cause a large change in the entropy.

again with this shit?

>>5472559
no, negative temperature does not let things go back in time. negative temperature means that as you increase the energy in the object, the entropy decreases. thats all.

>>5472574
yes you can.

>>5472583
any system with a upper bound to energy can have negative temperature, even if the system is in equilibrium. have you even studies statistical mechanics?

>>5472622
that complete bullshit and you/her has no idea what you/he is talking about.
- you dont adjust the 0 point, you can go as low as you want
- temperature is not energy, its the ratio between change in energy and entropy.

>>5472648
temperature only relates to the motion of atoms in a perfect crystal or ideal gas. 0K just means that the entropy cant change when you add or take away energy. please dont talk about things you dont understand.

>>5433719
>if you are planning to

>>5433687
>where did i imply that?

>>5433604
ARE YOU FUCKING KIDDING ME?
you know nothing.

>>5433438
problems:

>energy needed
we need as much energy on start up as is used by the entire world in 1 year.

>materials:
it needs negative mass matter, which we dont have (unless the 5D GR theory NASA is testing works out, then this isnt a problem)

>structure:
in order to make this work, you need a 1 atom thick shell of this negative mass material around your ship. we have no way to even theoretically do this at the moment.

>Radiation:
if you are planning to goat or over the speed of light the ship will be bathed in su much radiation it will instantly be destroyed.

>Causality:
using such a device above light speed would cause paradoxes (even with its "no time dilation" condition) and we dont know how nature deals with it (all currently theoretically possible paradoxes are somehow prevented by nature).

>Steering:
you have no way of telling the warp drive to stop from inside the ship, so you need structures at the end point to tell it to stop, meaning we have to travel the the location with other technology anyway.

I think that covers it.

>>5419059
4. Brains have mass, volume, and other physical properties, but experiences do not.
o lord. this is gold

the other arnt bad too.

>>5418883
;_;.

dont be mean to me, i have autism. (sci diagnosed)

>>5418906
what calculator do you own that doesn't group digits together as 1 number?

>>5418879
>>5418886
it doesn't matter. you still have to account for both cases

>>5418863
seeing as he had a calculator, and i happen to have the formula memorized, its [3] [/] [1][6]. then it should give the answer.

but even with no calculator, 3/16 = 30/160 = 15/80 = (15+0.25*15)/100 = (15+15/4)/100 = (15+3.75)/100 = 0.1875

im going to look like an ass if that's not correct.

>>5418204
there are multiple things you can have, but cant tell others if you have it.

like "lisp". if you have a lisp, you cant say it.

another good one is hippopotomonstrosesquippedaliophobia. the fear of big words.how are you supposed to day it if you fear it??

same with some other stuff, comatose, death. cant say it.

>>5418848
>i have a 1 boy and 1 girl
>is your boy the eldest?
>lol i dont know? maybe.

>>5418758
is that what i think it is?

yip. it was.

Its retards like that that make all engineers look bad. (who the fuck is an "expert" yet hasn't memorized their formula sheets yet?)

well since its a wedding, just rip this off.
http://www.youtube.com/watch?v=BipvGD-LCjU

>>5416443
physical motivation:
the whole equation is just ma = F
so you can see that the terms in the bracket is acceleration of the point in the fluid. but this comes from 2 parts, 1, from how the velocity at the point changes with time (the first term (dv/dt)) and secondly how the velocity changes as the point moves due to this velocity.

as motivation: if the fluid was moving at a constant rate, nabla v would be 0, since there is no variation in velocity as the point moves.

to determine how the velocity changes as the point moves, you must take the derivative in some direction, but that direction is just the direction the fluid is moving (because the point is moving with the fluid), so its v*nabla.

>>5415934
in fact, i had to go look for a video response to show how much i hate him
http://www.youtube.com/watch?v=gwni-WAV4io

>>5415922
no, one of my friends was obsessed with that so i know about all the retarded shit in it. not only is there no proof, it cant predict anything and even contradicts current experiments. he makes around 10 errors in his derivations and even misrepresents data 2 times to make it look legit. (he compares the "strength" of the forces in a way that you cant, and in one place he shows 2 numbers which differ by a factor of 100, but said its the same order, becasue he fucking show one as a fraction and the other as a percentage). he uses special relativity at the edge of a blacvk hole, which means his answered are off by around 50%, he switches between einstiensian relativity and Newtonian relativity depending on which one gives the answer he wants, and completely leaves out the fact that according to his own theories a proton would decay on 1 femptosecond, while releasing a shitton of energy the whole time. He also lies about how his paper was the best at some conference since the conference wasn't even about physics and no one there probably knew what the fuck he was talking about.

fuck i hate him.

>>5413736
a perfect crystal does not have a upper bound for its energy, so it can never have negative temperatures. you can only have negative temperature in a system such that at some high energy all the particles are in some highest state, which would mean entropy = 0, they point where the entropy starts decreasing with added energy is where the temperature jumps from positive to negative.

>>5413375
>>5413389
no, the no motion thing is only in classical mechanics anyway, even at 0K there would still be motion when you consider quantum mechanics. plus temperature isnt about the motion of the particles in general, it just happens to correspond to it in the case of an ideal gas or other simplifications.

>>5413345
zotero logged in automatically for me, here is the paper if you want it.

https://dl.dropbox.com/u/46685978/52.full.pdf

>>5413338
it does seem to show some new theoretical properties of such materials, I still have to read the actual paper but it seems interesting. im not aware of <0K material being shown to act like dark matter before.

>>5413331
see
<span class="deadlink">>>5410174[/spoiler]
for source and other neat stuff.

>>5413326
>rewriting the laws of physics in the process
where the fuck do people get this shit? this was done many times before, negative temperatures are NOT NEW. this is just a more advanced application of old technology. this is one of the first things you learn in statistical mechanics, is the re anyone on sci with even undergrad level science education?

this better be a direct quote from some shit news site.

>how far away (in time)

lightyears