The h Bar

heather

12:00 AM

@Mew, o/

Sir Cumference

3:16 AM

Howdy

...Anyone here?

@obe Ya really leaving?

koolman

3:36 AM

Hiii , good morning

user116211

3

A: What is the most efficient way to destroy the universe?

Find antiuniverse somewhere and annihilate it with what we have here. Black holes does not work as they evaporate when growing.

user116211

Why did this 5 years old post come to Late Answers review queue?

Secret

4:10 AM

eye is gleeming Bubble of nothing?

Bernard Meurer

4:26 AM

@Secret You around?

Secret

yup

Bernard Meurer

Do you know Linear Algebra?

Secret

I have done a course on it 3 years ago. Just ask and I will see if I can help

Bernard Meurer

in Mathematics, 1 min ago, by Bernard Meurer

A set being a vector subspace of $\mathbb R^4$ with dim=2 the same as it being a generator of $\mathbb R^2$?

Secret

well, it is true that since the vector subspace is 2 dimensional (it has a basis of two elements, say the unit vectors along x and y (or more generally any 2 linearly independent unit vectors in $\mathbb{R}^4$, say u and v)), then it is going to span all possible values of $u$ and $v$. I suspect then it should be isomorphic to $\mathbb{R}^2$ but let's see if I can construct the isomorphism to show that

Bernard Meurer

4:40 AM

@Secret Does it being isomorphic to $\mathbb R^2$ imply it spanning $\mathbb R^2$?

Secret

yes, as an isomorphism is bijective. Thus it is surjective. That means the inverse map should be able to take any point in $\mathbb{R}^2$ back to the 2 dim subspace. If the map only take the 2 dim subspace to a small set of $\mathbb{R}^2$ then the inverse map cannot recover the whole 2 dim subspace.

Bernard Meurer

@Secret Sweet, got it

Sir Cumference

@Secret Why can't the universe have a happy ending? :(

Goddammit second law of thermodynamics and vacuum decay

You two ruin everything (literally)

Bernard Meurer

2 days ago, by Bernard Meurer

Let's be honest here guys, life's a bottomless pit of pain and suffering

@SirCumference ^

Sir Cumference

@BernardMeurer Damn, so pessimistic :(

user218912

5:04 AM

huh they're not deleting my account. -.-

Bernard Meurer

@obe Who?

user218912

the mods

DanielSank

@BernardMeurer Hey, traitor!

You're math-cheating!

Bernard Meurer

@DanielSank You were taking too long :P

user218912

I requested deletion 27 hours ago but still no e-mail or deletion.

Bernard Meurer

5:06 AM

@obe Why?

Secret

@BernardMeurer Let $a,b\in \mathbb{R}$ fixed constants, Let $k,l\in\mathbb{R}$ and let a basis of $\mathbb{R}^4$ be $\{\mathbf{s,t,u,v}\}$ and a basis of $\mathbb{R}^2$ be $\{\mathbf{c,d}\}$. Suppose the subspace is $S=\{<\mathbf{s,t}>+a\mathbf{u}+b\mathbf{v}\}$. Then define a homomorphism $f: S\rightarrow \mathbb{R}^2$ as follows:

$$f(k\mathbf{s})=k*f(\mathbf{s})=k*\mathbf{c}$$
$$f(l\mathbf{t})=l*f(\mathbf{t})=k*\mathbf{d}$$
$$f(a\mathbf{u})=a*f(\mathbf{u})=a*\mathbf{0}_{\mathbb{R}^2}=\mathbf{0}_{\mathbb{R}^2}$$

user218912

@BernardMeurer I feel like it's time to move on, and I don't think people like me here :p

Bernard Meurer

@obe I'd say you're being stupid, but you literally never listen, so do your thing man. Thanks for all the help you gave me back when applying to Waterloo, I truly appreciate it. Let me know if you ever need anything.

Secret

Typo: I timeout in the edit, thus there are couple of bolding I cannot fix, hopefully they are clear enough that you can work out what they should be

Bernard Meurer

@Secret I like you

You wrote a thesis for my dumb question, lol

user116211

5:15 AM

@DanielSank o/

user116211

Hey @obe.

Secret

@SirCumference There's one ending of the universe which might be a happier ending if it is true: A cyclic universe, one which expand and contract forever

Sir Cumference

@Secret Yeah but that violates the second law of thermodynamics

If entropy must always increase, then it would increase between cycles

We'd find a dead universe eventually

That fact has led many astronomers to abandon the oscillating universe hypothesis

@Secret This paper says

> ...one principal obstacle is the second law of thermodynamics which dictates that the entropy increases from cycle to cycle. If the cycles thereby become longer, extrapolation into the past will lead back to an initial singularity again, thus removing the motivation to consider an oscillatory universe in the first place.

The only hope is that future revelations in what we know about dark energy may help us evade the entropy problem

Secret

Agreed

user116211

@SirC, do you know obe's name at Skype?

Sir Cumference

5:26 AM

@MAFIA36790 'Fraid not

But he still hasn't deleted his account

He said he would do so over a day ago

user116211

@SirCumference He already requested.

Sir Cumference

@MAFIA36790 It's been 24.5 hours since he said he requested

user116211

@SirCumference yes.

Sir Cumference

@MAFIA36790 Do you know what country he's from?

DanielSank

@MAFIA36790 \o

user116211

5:28 AM

no; maybe @Bernard knows.

Bernard Meurer

@SirCumference Canada

@MAFIA36790 Hey mate

user116211

@BernardMeurer hey .

Sir Cumference

@BernardMeurer Nope, didn't find anything in skype search

user116211

@SirCumference yes, I didn't find anything either.

Sir Cumference

But perhaps mods can see deleted messages

@ACuriousMind to the rescue?

user116211

5:30 AM

@SirCumference What deleted message?

Bernard Meurer

@SirCumference Who are we talking about?

user116211

@BernardMeurer obe.

Sir Cumference

@MAFIA36790 Obe gave his skype name yesterday, but he deleted it a few seconds later

Bernard Meurer

He's Canadian

I've skyped with him

Sir Cumference

He didn't want it staying here

Bernard Meurer

5:30 AM

He's very much canadian

Sir Cumference

@BernardMeurer So help Mafia out

Bernard Meurer

What's going on?

user116211

@SirCumference I missed that :( Poor connectivity is always a problem of mine.

Sir Cumference

5 mins ago, by MAFIA36790

@SirC, do you know obe's name at Skype?

Bernard Meurer

I'll sell that information for 5 dollars

Sir Cumference

5:31 AM

@MAFIA36790 lol, repeated that

@BernardMeurer ...

Bernard Meurer

Okay

I'll put it real quick and then delete ir

Are you looking @MAFIA36790?

Sir Cumference

@BernardMeurer K

Wait

Make it a riddle

It'll be more interesting that way

Bernard Meurer

No, I'm busy

Sir Cumference

:/

user228700

I...have a fantastic memory, u guys.

Sir Cumference

5:35 AM

@BernardMeurer So?

Bernard Meurer

@SirCumference Waiting for @MAFIA36790 to say he;s looking

user116211

@BernardMeurer wait; leave a comment in any of my post; I'll then reply; you'd delete it then; my connectivity is poor; so I may not catch the comment here before you delete it.

Sir Cumference

Oh boy

Bernard Meurer

@MAFIA36790 LOOK QUICK

Sir Cumference

@MAFIA36790 LOOK QUICK!!!

BEFORE IT'S TOO LATE

user116211

5:36 AM

\o/

user116211

gotcha.

Bernard Meurer

:)

Sir Cumference

high five

Bernard Meurer

You owe me a coffee or something

You better have good coffee in india

user116211

@BernardMeurer :)

Sir Cumference

5:36 AM

@BernardMeurer No such person exists in skype's contact search...

Bernard Meurer

@SirCumference O.o

Sir Cumference

I copied and pasted

Bernard Meurer

He's here for me

Me too

user116211

wait, let me check.

Sir Cumference

oh nvm

It's because I only looked for people in canada

Secret

6:14 AM

1. I can float myself to the skies by kicking as if I am swimming
2. Space based on familar locations are usually at least twice as big
4. I usually have the power to rewind time or a dream scene

Despite all of this (except 3, which seemed to carry a very powerful emotion or some other reason that will almost always destablise the dream) my dreams have learnt how to handle them to the point that it is mostly in control even when I have powers.

That is, it is possible for me to be aware I am dreaming without becoming lucid

My dream and I are like two different people, and we together fabricate the dream world that we experienced. We sometimes compete for dominance, other times we worked together

Secret

6:26 AM

physics.stackexchange.com/questions/293700/…

I don't like his attitude. However...

arxiv.org/abs/0807.3286

I don't know enough of quantum mechanics to say anything about this

Anonymous

@Secret That was a troll :-P

Anonymous

I think it will be closed soon

Secret

Digging his profile: If something is off topic in philoSE, then it is very very bad

2

John Rennie

@ACuriousMind Accurate though :-)

Secret

6:50 AM

@SirCumference I know that feel. This is one reason why we cannot have an endothermic fire (a fire that lowers the temperature of things), because $T\Delta S$ will eventually drop to a point that the reaction will stop

Anonymous

@JohnRennie I have a regarding about one of your answers physics.stackexchange.com/a/152695/135977. I recently read that increasing or decreasing magnetic fields through a certain area produce clockwise or anticlockwise electric fields in circular pattern by Faraday's law. But how is "charge" involved here in the generation of the electric fields (having a circular pattern) ?

John Rennie

@S007 you'd have to provide a reference. As far as I know a changing magnetic field doesn't produce an electric field. But electrodynamics isn't my favourite subject, so it's entirely possible I'm wrong about this.

Anonymous

@JohnRennie Okay, one minute please

Secret

If we want to make an explosively self sustaining endothermic reaction, then given

$$\Delta G = \Delta H - T\Delta S$$

for each second of the reaction the increase in $\Delta S$ has to outpace the reduction in the temperature $T$ in order to make $T\Delta S$ to grow without bound. however it is not very clear on how this can be achieved, or whether any reaction can acheive that

One possibility is that entropy can be increased by an expansion in volume, and the expansion accelerates as the temperature lowers

Suppose we can achieve this (even for a sufficiently long finite amount of time), then these endothermic explosives might be potentially more powerful than their exothermic counterparts without much change in heat

This is because their volume has to be expanded in an accelerated fashion in order to be able to sustain itself for long enough

Anonymous

7:00 AM

Induced Electric Field in Time Varying Magnetic Field (GA_EMI12)

►

Anonymous

@JohnRennie Could you check these out ^

John Rennie

OK I'll have a look at the video, though that won't be until a bit later today.

Anonymous

@JohnRennie No problem. Take your time :). It is not very long though.

Secret

7:15 AM

@JohnRennie Suppose I want to follow a combustion reaction (e.g. burning coal). While the Gibbs free energy will tell me that at constant pressure and a given temperature $T$ the reaction is spontaneous, as the reaction continues with time the temperature will increase.
It is correct to to say that the rate of change of the Gibbs free energy is just differentiating the $\Delta G$ equation by time, or something more complicated need to be done to incoporate the change in temperature (assuming pressure is relatively constant and stay at ambient pessure)

Sir Cumference

I'm ashamed to admit that only a few days ago I realized that electrons get their name from electric.

Anonymous

@SirCumference I think you said this same thing a couple of days back :)

Sir Cumference

@S007 Yeah, but now I realized the same thing about photons

Photo = light

Mew

here's a new one for you, neutron is a neutral particle

Anonymous

Well that thing about photons happened with me as well

Sir Cumference

7:18 AM

@Mew That I realized a while ago

@S007 Hence, photograph, photosynthesis, etc.

Mew

and tachy means fast , tachyon = fast particle

Sir Cumference

@Mew Whoa, that I didn't know

Anonymous

@SirCumference Well, most particle names in physics have some reference to their behaviour

Anonymous

Or are named after scientists

Sir Cumference

@S007 Like bosons

Fermions too

Anonymous

7:20 AM

Yep

Sir Cumference

Bohrons?

Mew

and gluons, "glue" quarks together

Sir Cumference

Boron

@Mew Yeah, realized that too

Quarkons

Anonymous

Neutrino :-P

Sir Cumference

Jeez, every neutral particle creatively has "neutral" in it. Neutron, neutrino, neutralino...

Anonymous

7:23 AM

Anonymous

I don't have any justification for charm and strange though :-P

Sir Cumference

@S007 Why'd ya post the table of elementary particles?

Anonymous

@SirCumference What does "charm" and "strange" mean?

Anonymous

Charming particles ? :-D

Anonymous

Strange particles ? :-D

Anonymous

7:25 AM

LOL XD

Sir Cumference

@S007 Well the concept of strangeness predates strange quarks

Anonymous

Good to know

Anonymous

and charm ?

Sir Cumference

@S007 No clue

Anonymous

:-P

Sir Cumference

7:26 AM

@S007 But I can say that topness is often called "truth", and bottomness is often called "beauty"

So we got truth, beauty, charm and strangeness

Anonymous

Ok. So physicists become romantic sometimes. Like poets :-P

3

Ramanujan

7:47 AM

How to make profile like this?

Anonymous

@Ramanujan What ?

Anonymous

Which part of the profile are you talking about?

Ramanujan

Keeping a low profile

Anonymous

You can't. That user hasn't made any posts that is why they are displaying a custom message

Anonymous

You have already made so many posts

Anonymous

7:49 AM

@Ramanujan

Ramanujan

OK,sorry

Anonymous

no probs

user228700

8:01 AM

Morning :-) (Erm, afternoon here :-P)

Ramanujan

@Kaumudi good afternoon

Anonymous

@Kaumudi Good 1:32 pm IST :)

user228700

Lol :-P

Anonymous

@Ramanujan @Kaumudi you guys use quora ?

user228700

I don't ask questions, no.

Anonymous

8:15 AM

Even i don't ask questions there, but I found it recently and feel it is a great website and better than stack exchange in some aspects :-)

Anonymous

Especially the technology and science section is too good :)

user228700

Hmm, you discovered the website now?!

Anonymous

Well, a couple of months back

user228700

(Also, Quora addiction is a genuine thing, I'm not even kidding. Many of my friends suffer from this :-P)

Anonymous

I would love to get addicted to it (especially to the science and tech section) :-P

user228700

8:20 AM

But the academia sections contain some great questions and answers, yes. Although, I dunno if I would go so far as to say that it's better than SE in some aspects.

Anonymous

BTW I think i am addicted to stack exchange also :-P

John Rennie

@S007 all sites have their strengths and weaknesses. The strong point of the SE sites is they quickly identify which members know what they're talking about and which are the nutcases.

2

Secret

1 hour ago, by Secret

@JohnRennie Suppose I want to follow a combustion reaction (e.g. burning coal). While the Gibbs free energy will tell me that at constant pressure and a given temperature $T$ the reaction is spontaneous, as the reaction continues with time the temperature will increase.
It is correct to to say that the rate of change of the Gibbs free energy is just differentiating the $\Delta G$ equation by time, or something more complicated need to be done to incoporate the change in temperature (assuming pressure is relatively constant and stay at ambient pessure)

Anonymous

@JohnRennie I know. SE is great when you have some technical queries. But i feel Quora is a great place to learn new facts (even about topics on which you have no mastery) :) I agree with the fact that every site has its strengths and weaknesses. Like quora doesn't have good moderation :-P

user228700

8:46 AM

@JohnRennie:

John Rennie

Morning ...

user228700

> "William Willet, the grandfather of the great grandgather of the frontman of Coldplay, is credited as the pioneer of daylight saving."

user228700

:-D Just a piece of trivia I thought u may be interested to learn.

John Rennie

Things I never knew about Coldplay :-)

Anonymous

@Kaumudi "grandfather of the great grandfather" XD...by that logic I am related to every person that ever existed on the planet :-P

John Rennie

9:01 AM

@Kaumudi I'm feeling a little guilty that I might have dissed Coldplay, but i didn't mean to. We all have bands that are special to us - in my case Hawkwind, in your case Coldplay. Trying to explain these attachments logically is a futile endeavour :-)

Bernard Meurer

@JohnRennie You're clearly an unidentified nutcase :P

(plz don't ban me)

Larry Harson

9:18 AM

Has anyone here come across the zero-component lemma in vector analysis?

user228700

@JohnRennie Oh, that's OK sir :-) Indeed. It certainly proved to be futile when I attempted to explain it to my mother whilst watching the program last night.

user228700

Hawkwind? Will look it up, sometime...

John

9:47 AM

Does anyone know anything about the Lorentz force

Anonymous

@John Yep

John

@S007 Ok so I was told that current cannot be induced unless there is a change in flux. But this does not account for why a single wire, looped outside of the field, when moved through a uniform magnetic field will have an emf induced across it - as there is no area for which flux can flow.

@S007 So am I correct in thinking that it is not a flux change which induces an emf in this scenario?

Anonymous

@John In case of a moving wire, the wire "cuts" through the magnetic flux and hence by faraday's law emf is produced

Anonymous

Suppose speed of wire is v and length of wire is l

Anonymous

Then in time dt it cuts through magnetic flux region having area Blvdt

John

9:55 AM

@S007 but we only talk about flux for an area - a single wire has no 'area'

Anonymous

@John We are talking about the area the wire has traversed here

Anonymous

in time dt

Anonymous

$d\phi=Bvldt$ and emf=$\frac{d\phi}{dt}=Bvl$

Anonymous

where B is supposed to be the magnetic field perpendicular to velocity direction

Anonymous

I know that you area feeling confused because a wire cannot contain any area

Anonymous

9:58 AM

But think of the area in this case as the area traversed by a wire

John

@S007 I'm not talking about a wire on two metal rails which moves through the field - there is an area in this case due to the complete circuit being inside the magnetic field, and this area changes. So a change in area results in a change in flux, hence emf is produced.

Anonymous

@John We do not need two metal rails. Even if the wire moves in a magnetic field flux will be cut by the wire. You just need to know the area traversed by the wire

Anonymous

EMF Induced in a Moving Conductor in Uniform Magnetic Field-Motional EMF (GA_EMI06)

►

Anonymous

See the whole video if you still have a doubt

John

Other answers on stack exchange have said one cannot talk about area, hence flux, for a single wire - it's the Lorentz force acting on the changed particles

Anonymous

10:01 AM

@John We can explain the phenomenon in both ways. By lorentz force method or by faraday's law

Anonymous

Anyway see the video. Your doubts will be cleared

John

Ok, I'll go watch the video and get back to you

Anonymous

@John If you are in a hurry then start from 4:52 of the video

Secret

Caption: Ok finished analysis. It seems it is theoretically possible to have an extreme cooling reaction if you can get the entropy change to accelerate as the temperature drop in the reaction, until maximum entropy.

It in unsure how this can be done, other than somehow, you need to generate microstates at a rate faster than the loss of numbr of accessible microstates due to the reduction in temperature

The issue is, however, not only entropy increases until maximise in a closed system, it also slows down in that increase over time due to the natural log dependence

Therefore, this explains why neither exothermic and endothermic reactions can go on forever, as these physical scenarios means the gibbs free energy cannot decrease forever

John Rennie

10:18 AM

@Kaumudi You wouldn't like Hawkwind. Trust me on this one :-)

How dare you? That's not true - I'm not an unidentified nutcase!!
I'm an identified nutcase :-)

John

@S007 ok so emf is induced when flux changes or when it is cut

Anonymous

@John Exactly :-)..any other doubts ?

John

@S007 so what about if we have a rectangular coil of wire and pass it through a uniform magnetic field. There is no change of flux, but the flux is still cut, yet no emf is induced

Anonymous

Yes, emf will be generated but you need to keep in mind the direction of emf generated also. In one side of the rectangle the emf may be in one direction and in the opposite side the emf may be in the opposite direction..hence making the net emf zero

Anonymous

@John

John

10:27 AM

@S007 ah ok that's what I was thinking

Anonymous

You need to calculate net emf in such cases

Anonymous

i hope it is clear now @John

John

@S007 so, back to the single wire, we can talk about this as motional emf (Lorentz force) or induced emf(Faradays' law)

Anonymous

yes..both are correct!

Anonymous

@John

John

10:29 AM

@S007 ahh ok. Well thanks, you've been a massive help!

Anonymous

Welcome and feel free to ask any physics related doubts on hbar :) @John

John

@S007 I'll probably

@soo

@S007 this keyboard, I'll probably be on here again soon:)

Anonymous

bye :)

koolman

10:47 AM

@S007 is this from physics galaxy

user228700

11:10 AM

@JohnRennie Yeaah, I listened to The silver machine and didn't enjoy the experience very much :-P

Anonymous

11:22 AM

@koolman yes

Secret

Caption: Everything is easier with arrays

John Rennie

11:41 AM

Hawkwind - Quark, Strangeness and Charm (HQ)

►

user228700

Hmm, a song that has the word Quarks in the title. I too know a brilliant song that shares this property:

user228700

Strange Charm: A Song about Quarks

►

user228700

11:56 AM

@JohnRennie I liked that! :-)

John Rennie

@Kaumudi The only Hawkwind track non-fans know is Silver Machine because it was their only chart hit, but it isn't really typical. However I still don't think you'd like them. QS&C is one of their poppier songs.

John

If you pass a current through a wire which is in a magnetic field, this will extert a force on the wire. Does this force then induce another emf across the wire in the opposite direction?

Secret

[Division by zero] Got a new result, to be written into a theorem later:
The amount of control the zero terms have on the + structure depends on the range of the 0 row and/or column of the * cayley table
Therefore, if you found multiplying by 0 to all other elements is equivalent to a permutation of the elements, then you are in deep trouble

user228700

@JohnRennie Ah, I see.

user228700

Yeah, no, as Kyle Kanos puts it, I'd listen to them if they were to come on the radio, but I wouldn't go out of my way to look for their music.

user228700

12:05 PM

Say, Camden is in London, correct? Is that very far from where u live?

John Rennie

Camden is in London, and London is a bit over 200 miles from me - about a four hour drive.

Slereah

1:05 PM

hey

koolman

@S007 do you that teacher on

Physics galaxy teaches us

koolman

1:17 PM

*do you know

heather

1:38 PM

hello

user228700

@JohnRennie Ohh, okay :-)

user228700

@heather: Allo!

heather

@obe, please don't leave us...

@Kaumudi, o/

how was coldplay?

user228700

They were <3 <3 <3

heather

=D

user228700

1:41 PM

How was calculus? :-P

user228700

@koolman Oh, that's awesome!

heather

it was <3 <3 \o/ <3 <3 =( =)

the frowny face: where I made multiple stupid mistakes in a row

=P

user228700

Ah, I see. At least the "<3"s outnumber the frowny face :-P

heather

\o/ was where I finally got something right

user228700

:-)

heather

1:43 PM

yep

it was a good day

user228700

Great :-)

koolman

Yeah @Kaumudi

Mew

Hi Kaumudi

sup heather

yo koolman

anyone good at biology here?

heather

7th grade life science: sure
anything beyond that: nope =P

user228700

@Mew: Ello :-) Again, why are u learning Bio at midnight, sir? :-P

user228700

1:54 PM

Also, try The Periodic Table. There is a person named Aaron Abraham who frequents the room. It appears that he knows a lot of Biology.

Mew

nvm i answered my own question

I have a new question

can the laws of physics be derived from reason alone or do they require observation?

If they require observation, does this mean that the laws of the universe are arbitrary?

heather

well, there are a few points I might make here; this is more relevant to mathematics, but it is worth looking at anyway, because physics is described in the language of math.

1. people tried doing this with math; see the Principia Mathematica, a multiple volume work that attempted to create a consistent system for the laws of mathematics. Took until the second volume to prove that 1+1=2; at which point they stated something like "This result is occasionally useful" =P

2. then Godel came along, with his incompleteness theorems, and others came along, and generally proved that it is impossible to create a self-consistent system for all of mathematics.

Mew

point 2 you mention just seems weird to me

would point 2 apply to physics or just maths?

Ramanujan

@heather do you have that book?I am not getting it's PDF online

heather

@Mew, points 1 and 2 apply to math, but one moment, I'm coming back to physics

@Ramanujan, nope, don't have a copy. I'll look around for it though.

3. going back to physics, the basics of it is observation, but all of physics is really described by math (even if we haven't completely pinned down the math). In fact, even the more abstract areas of math have been brought into physics (in most cases).

ACuriousMind

2:04 PM

@Mew Science requires observation by definition. Otherwise you're just doing math (not that there's anything wrong with that)

heather

4. considering whether the laws of physics can be derived from reason alone, isn't that kind of what Aristotle tried to do? and he failed miserably.

Mew

@ACuriousMind if science requires observation, then would you agree the laws of physics didn't have to be the way they are?

because if the laws could only be the way they are, then one should be able to work out this one solution without observation

ACuriousMind

That is, even if one could derive all laws of physics logically from a simple axiomatic starting point, we would still require observation to check that those axioms actually hold in reality.

Mew

only if there are multiple possible solutions would observation be required

heather

@Mew, but there you are getting into philosophy, surely. If you believe in a God, then it isn't arbitrary, true? Because God created it. If you believe it is all random chance, or maybe that there are multiple universes, then yeah, it is arbitrary.

Mew

2:06 PM

@heather, mabye Aristotle tried and failed, but that doesn't mean a super genius alien couldn't succeed?

ACuriousMind

@Mew I think that is a meaningless question - the set of universes/laws of physics I have observed has cardinality 1. I don't know what "could have been different" is supposed to mean.

Mew

@heather if there is a God, then God may have "free will" and thus could choose which arbitrary laws to create

heather

@Mew, now this is starting to sound like determinism, which quantum mechanics tossed to the wayside, don't you think.

Mew

IF there isn't a god, one would expect the universe could only be what it is?

heather

@Mew, and as for God, He has free will, surely, but then He also has infinite intelligence, therefore allowing him to pick what is perhaps the best possible option?

Mew

2:08 PM

@heather, do you think quantum mechanics really tossed away determinism though? many world's interpretation doesn't require determinism to be tossed

Determinism only needs to be tossed away under the copehan hagen interpretation which isn't that popular

heather

@Mew, as far as I know, most scientists believe in the Copenhagen interpretation. But either way, I don't think the many worlds interpretation is quite right (and neither do I think the copenhagen interpretation is quite right). But at that point, we are discussing interpretation. Your super-alien now must have access to multiple universes. Does that even make sense?

ACuriousMind

@Mew I think the notion of "could only be the way they are" is ill-defined. What is the ensemble of alternatives here? We know of no universe but ours, no laws of physics but the ones we discover. "Could have been different" implies that there is a repeatable event of "starting a universe" and you're asking whether it is deterministic or not. But it's not clear that that event exists at all, let alone is repeatable.

Mew

@heather, philosophy.stackexchange.com/questions/1210/…

@ACuriousMind do you agree with heather that QM means there is no determinsm?

heather

@Mew, and doesn't that answer basically agree with me?

Mew

@heather the point is there is an interpretation of QM where determinism holds. Also QM doesn't mean the actual "laws" of physics are random, but only the outcome of particular events.

@heather the second answer states that QM doesn't disprove determinism

"Quantum Physics doesn't disprove determinism."

heather

2:14 PM

@Mew, it doesn't explain how it doesn't. It says "it significantly complicates it" but gives no example of how you can squeak by.

Mew

Note I'm not concerned with whether the actual events of the universe can only happen in a particular way, but rather whether the "laws" of th euniverse had to be the way they are

ACuriousMind

@Mew No. Once one adopts a collapse-free viewpoint modelling both system and apparatus quantumly determinism is restored. But this is tangential to the question of the laws you originally raised, imo.

Mew

@ACuriousMind I agree, but heather was of the view that QM was inconsistent with determinism so I thought I'd get your input

heather

@Mew, now remember, in this conversation you have to keep in mind that I haven't studied physics nearly as much as either of you.

but I would still have to say that QM is inconsistent with determinism.

Mew

@heather yes that's why I wanted to convince you that QM is compatible with determinsm

heather

2:18 PM

but see the problem with questions like these, is it all comes down to the interpretation. I mean, it's just that, an interpretation.

Mew

But surely the statement "the laws of physics can be derived without observation" is either true or false

not dependent on interpretation

I agree though that whether the results of the universe are deterministic or not probably does depend on interpretation of QM

ok gtg to sleep now

laterz

heather

have a good night

Anonymous

2:45 PM

@koolman You must be from Allen Jaipur I guess ?

Anonymous

You are lucky to have him as your teacher :)

Secret

3:19 PM

[Division by zero] On 5 element division by zero divisor algera: If $a\neq b$ and $ab=0$, $ac=1$ then the algebra is NOT associative

Proof: I have no idea, other than I literally tried every consistent cases and found the nonassociative entries of the cayley table are actually locked up (i.e. has only one possible choice, which is the nonassociative choice)

koolman

3:56 PM

@Mew sorry not in biology

@S007 absolutely right

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