Archived threads in /sci/ - Science & Math - 1041. page

>>8567177
Friendly reminder that nothing in that book will ever help prove interesting mathematics

>>8567180
HoTT/UF is objectively the best foundation for modern mathematics.
Prove me wrong without assuming AC or excluded middle.
Protip: You can't.

>>8567177
explain further

>>8567048

bump

>>8567048

*22/36

>>8567063
Got 29 and I'm not even a native speaker. How autistic are you, senpai?

at least i can tie my shoes

>>8567041
wat

>>8567038
>Medical physics.
Such a meme. *pat* /thread

>>8566711
Here is what I got so far.

Suppose we have a field [math]\phi :\Sigma \to M[/math] from some n-dim manifold to our target space. Governed by a simple action [math]S\left[ \phi \right] = \int\limits_\Sigma {{{\left| {\operatorname{d} \phi } \right|}^2}} [/math].


We get a functional measure [math]\left[ {D\phi } \right][/math] on the space of maps [math]\left\{ {\phi :\Sigma \to M} \right\}[/math] via some generalization of the Wiener measure.


If sigma is bounded we define measures [math]\mu \left[ \phi \right][/math] on the space of maps [math]\left\{ {\phi :\partial \Sigma \to M} \right\}[/math].
There give a "conditional path integral measure" obeying the rule [math]\int {\left[ {D\phi |\mu } \right] \cdot } F\left( {{{\left. \phi \right|}_{\partial \Sigma }}} \right) = \int {\operatorname{d} \mu \left[ \phi \right]} \cdot F\left( \phi \right)[/math].


Using this we define numbers [math]{U_\Sigma }\left[ \mu \right] \equiv \int {\left[ {D\phi |\mu } \right] \cdot } \exp \left( { - S\left[ \phi \right]} \right)[/math]. These can be manipulated to obey a variant of gluing axioms.

View sigma as cobordism [math]\Sigma :\partial \Sigma \to \emptyset [/math].

So functorialy we have a map [math]Z\left( \Sigma \right):Z\left( {\partial \Sigma } \right) \to Z\left( \emptyset \right)[/math] where [math]Z\left( \emptyset \right) = \mathbb{C}[/math] by definition.

Let [math]{\left\{ {{\mu _i}} \right\}_{i \in I}}[/math] be a basis for the space measures [math]\mu \left[ \phi \right][/math].

Then we get our equivalence by letting [math]Z\left( {\partial \Sigma } \right) \cong \operatorname{span} {\left\{ {{\mu _i}} \right\}_{i \in I}}[/math] and [math]Z\left( \Sigma \right)\left( \mu \right) = {U_\Sigma }\left[ \mu \right][/math].


How do I show this is symmetric and monoidal?

can you put this in the form of a frog meme?

>>8566711
https://ncatlab.org/nlab/show/FQFT

Suppose there exists a program halt(program x, input y) that returns a boolean indicating if x halts on y.

Define the following program:
bool fuckery(program x):
| if (halt(x, x)):
| | while(true);
| return true;

What does fuckery(fuckery) do?

>>8566642
Being recursive here implies fuckery needs input: fuckery(fuckery(fuckery(...) so this can't be said because there is never a complete program x to be analysed. The fact that programs either halt or don't halt implies there is halt(code, input), that is what I think. The fact to compute it is besides the point, even with an easy general algorithm computation would still be required to apply such algorithm. Those are my thoughts, I hope there is a tautologically better proof or even that I am wrong and the world is not this stupid.

>>8566654
It's not recursive.

>>8566604
I imagine its harder to do the process correctly if you're on meth

>>8566614
GAAAAAAHAHAAAAA GREAT JOKE FELLOW 10/10 REALLY IRONIC NICE MEME 10/10

>>8566604
Explosions are causes when the fumes build up too much and are not properly vented. Too many flammable things are used to make that shit. Any one of them can cause an explosion.

Bump really interested in this
any source on this kind of stuff?

>>8566531
please do not bumb on /sci/. fairly slow board and no one will take your post seriously.

As for your question, if you want to learn the physics of what is happening in your pic read up on mechanical pressure waves. Usually a second quarter course in intro college physics.

If you want to know how your audio filters work, you will need to read about signal processing theory. That is pretty complicated stuff, normally a 2nd or 3rd year course in electrical engineering. The pre requisite math behind it is Complex Analysis, Differential Equations, Linear Algebra, and Functional Analysis.

You will never get a good grasp of how these things work intuitively without such reading, but if you are interested in it in some lighter sense, try reading the "plain english wikipedia" articles on those topics.

Yeah, wikipedia is your best bet. There is such a thing as active noise cancellation that is very common. The way this works is to generate an audio signal which is completely out of phase with the noise you wish to cancel. Amplitudes add. Videos would also be helpful. A picture is worth a thousand words and nobody is going to sit down and type thousands of words to explain something to you that you can easily google and learn about yourself.

>>8566275
No, you basically need to go to HPMSCB for pure math to have a chance at a tenure track job at a decent place and a 3.8 will not cut it unless you have something else that signals ability like publications or being a Putnam fellow.

False. Some of my most successful instructors and professors had sub-3.5's during undergrad. I go to a prestigious research university.

3.8 is good, OP; you could obviously do better, but a 3.8 isn't going to limit you.

>>8566302
It was easier to get in to top grad schools and get tenure track jobs when your professors were undergrads.

Does the bulb actually work? Have you set the zero point properly?

>>8566235
>or maybe the cuvette thing I have isn't even compatible since I can't even close the cap (but I thought the meter wobble a bit or something when it's open and closed).
oh i missed this bit. No spec is going to work properly if the lid doesn't close. You'll get readings but they won't be as accurate as they could be.

But you should be seeing the needle move around as you go from closed to open, and the fact that yo don't is why I was curious about >>8566255

>>8566255
>bulb
I guess it's because of that then. I'm really rusty on my analytical instruments but I should at least see some light somewhere inside the slot itself, right? It's totally dark.

Apparently some (unlucky) students still had to use this ancient spectrometers relatively recently, but I guess this was not one of the working specimens unless it's my fault with the bumpy ride. I didn't have any cushioning handy for that ride so I might have broken more than that.

>>8566183
https://www.youtube.com/watch?v=t4e7PjRygt0
this thread might be moved to /v/

>>8566183
Command blocks are cheating. Use redstone.

>>8566183
Wow, a shitty plotter, just what I need to waste my time on as a real scientist.

>>8565981
>but by our very definition that room should be full as well.
it is
that's why you have to move that guy to the room over too

>>8565985
then somebody will always be out of a room and that's precisely how we can add the new guest, by removing another

>>8565981
>>8565997
>Meaning we shouldn't be able to move a guest to a room above theirs
Not true because infinity

Our species as a whole will be A okay. Humanity is in no way in danger. Most of the people on earth though are in fora rough time. After a mass extinction the rich will exist in perfect automatied cities.

whom are you quoting?

>>8564894
You mean like vaccines and flu shots?

>>8564028
https://m.youtube.com/watch?v=GHC8z6ULs18

Apparently at least one researcher thinks it's possible.

Of course its possible, we're traveling into the future right now. Time travel into the past is possible, but you'd need more energy than the entire universe to reverse the chemical reactions.

The age old time travel question...
Even the best, and smartest don't fully understand it
Look at just some of the things you would need to move a copper penny on foot across a table top
1 a place for it to happen (the universe)
2 the matter in question (the penny)
3 a direction (can only move in one direction, away from it's starting position)
4 a speed
5 energy to set it in motion
6 this is a big one! The time to move a given distance!
How many things have I forgot to mention?
The past is still here, just in another form, the tree that was in your back yard 10,000 years ago has just broke down and moved to a new location.
The space it occupied has not changed. The energy it gave in transition was spent, how do you put that Jennie back in the bottle? Let's just say you found a way to cheat time and go back just one minute, you would find yourself where you were completely unaware. The distant past happened without you there, so if you did step out of some magical doorway, it would not be the same past. Or you would be there in the form that you were when that moment happened, particles in some rock.
Time is some kind of law to prevent this from happening, it prevents matter from being in two places at the same time, there is a reason for the light speed limit, go faster and you cheat time , it is impossible! Now the future, who knows....

>>8563533
>Biologist

Dropped.

>It is far easier for scientists to acquire needed collaboration from mathematicians and statisticians than it is for mathematicians and statisticians to find scientists able to make use of their equations.

SUICIDE WATCH
UICIDE WATCHS
ICIDE WATCHSU
CIDE WATCHSUI
IDE WATCHSUIC
DE WATCHSUICI
E WATCHSUICID

>>8563533
He's an ecologist, so it's not surprising that he makes these embarrassing claims.

How Can The Sum Of Natural Numbers Be Real If The Riemann-Zeta Function Isn't Real?

>>8562379
Is this some kind of complex joke?

>>8562378
Numberphile said it was legit. Proof enough for me.