/sqt/ /qtddtot/ - stupid questions thread

[Anonymous No.11552971]

"kinda weird you ghosted me desu"
Previously >>11540602

>what is /sqt/ for
Questions relating to math and science, plus appropriate advice requests.
>where do I go for other SFW questions and requests?
>>>/wsr/ , >>>/g/sqt , >>>/diy/sqt , >>>/diy/ohm , >>>/adv/ , etc.
>pdfs?
libgen.is (Warn me if the link breaks.)
>book recs?
https://sites.google.com/site/scienceandmathguide/
https://4chan-science.fandom.com/wiki//sci/_Wiki
>how do I post math symbols?
https://i.imgur.com/vPAp2YD.png
>a google search didn't return anything, is there anything else I should try before asking the question here?
https://scholar.google.com/
>where do I look up if the question has already been asked here?
>>/sci/
https://boards.fireden.net/sci/
>how do I optimize an image losslessly?
https://trimage.org/
https://pnggauntlet.com/

Question asking tips and tricks:
>attach an image
>look up the Tex guide beforehand
>if you've made a mistake that doesn't actually affect the question, don't reply to yourself correcting it. Anons looking for people to help usually assume that questions with replies have already been answered, more so if it has two or three replies
>ask anonymously
>check the Latex with the Tex button on the posting box
>if someone replies to your question with a shitpost, ignore it

Resources:
Good charts: https://mega.nz/#F!40U0zAja!cmRxsIoiLFZ_Mvu2QCWaZg
Shitty charts: https://mega.nz/#F!NoEHnIyT!rE8nWyhqGGO7cSOdad6fRQ (Post any that I've missed.)
Verbitsky: https://mega.nz/#F!80cWBKxC!ml8ll_vD2Gbw4I1hSLylCw
Graphing: https://www.desmos.com/
Answer engine:
https://www.wolframalpha.com/
Tables, properties, material selection:
https://www.engineeringtoolbox.com/
http://www.matweb.com/

[Anonymous No.11553025]

~UNANSWERED~

Math
>>11541589
>>11541591
>>11543513
>>11545615
>>11549098

Physics
>>11547809 (Another anon and myself both seem to think there is not enough information given. I think the best you can do is find dV/V, but I could be wrong. Help this anon.)
>>11549774
>>11551032
>>11551832
>>11552272

Bio+Medicine
>>11551023

Stupid
>>11542479
>>11542483
>>11542657
>>11542664
>>11543405 (Did you have a question?)
>>11550225 :3
>>11551710
>>11551968
>>11552940

[Anonymous No.11553031]

Is furyanon and 2huanon the same person?

[Anonymous No.11553110]

I'm trying to wrap my brainlet head around certain properties of black holes. From my understanding if something falls into a black hole an observer some distance away will view it asymptotically approach the event horizon but never reach it (in practice they will be red-shifted away until they are invisible but that isn't relevant to this question).

Since black holes gradually evaporate and have finite lifetimes, it would follow that the outside observer could continue to observe the object until the black hole disappears completely and the object is released, never having "reached" the event horizon. This seems to imply that the perspective of an observer who is falling into the black hole would view outside time progressively moving faster as it approached the event horizon, eventually viewing the event horizon falling away from it as the black hole evaporated, and being released.

Is this correct or is am I misunderstanding the relativistic effects? If it is correct it would seem that there is no issue of information loss as no particle ever truly "crosses" the event horizon so why is the issue of information loss brought up so often with black holes?

In addition, what exactly is going on with Hawking radiation in this context, how can one of a virtual particle pair be on the "other side" of the event horizon when it seems like that is not a well founded location in any reference frame?

Last question, as an observer approaches a black hole it would apparently being evaporating much quicker, why does this happen from the perspective of this observer? Is it due to spacial dilation, i.e. the black hole's surface area appears to grow proportionally to the time dilation the observer is undergoing?

[Anonymous No.11553130]

>>11553031
>

[Anonymous No.11553133]

>>11552940
probably a few years of middle school

[Anonymous No.11553168]

>>11552971
>>11553025
kill yourself you furry piece of shit

[Anonymous No.11553194]

>>11553110
Recall that blacholes are punctures/singularities in spacetime, hence as it disappears we would observe "object's clock" slowly begin to tick again, at least classically speaking. This then begs the question "is this object the same as the one falling in?"
However, blackhole evaporation is a quantum effect, hence in your scenario there is really no sense to talk about classical "objects". The above question, when phrased in terms of quantum states, is related to the blackhole information paradox: the mechanism of blackhole evaporation, i.e. Hawking radiation, seems to disentangle pair-created quantum states and "absorb" entropy/information. If it does, then it will not conserve quantum states falling into it, by which point there would be no sense for us to discuss "what happens to [math]the[/math] quantum state after blackhole evaporates" unless we know how the disentanglement occurs (namely find the source of the information loss and effectively solve the blackhole information paradox), since it gets scrambled beyond recognition as soon as it enters the event horizon.
Now there are proposed resolutions to this, a personal favourite of which is the "fuzzball" (https://arxiv.org/abs/1812.11641)), which details how the initial quantum state couples to the "stringy" mess around the event horizon, effectively siphoning information out to elsewhere. If this were actually true, then objects near the event horizon would be disintegrated qubit by qubit into other parts of the universe. It may or may not be sensible [math]then[/math] to pose your questions.

[Anonymous No.11553208]

Tourist on this board, sorry for the stupid question.
Can an organism live after being frozen for an extremely long period of time (possibly thousands of years) and then thawed?

[Anonymous No.11553224]

>>11553208
Yes, there are already some ancient bacteria that have survived being thawed by festering in damp, dark, deoxygenated soil. But nothing multicellular (especially not anything as complex as The Thing) could survive isolated and cold for that long.

[Anonymous No.11553255]

>>11553224
Thanks.

[Anonymous No.11553479]

Just finished marathoning this. What's next?

[Anonymous No.11553614]

graduated in december, starting grad school in the fall for amo physics. should i brush up on general physics and math during the long wait, or maybe just look ahead to courses i will take and research papers in the field?

[Anonymous No.11553652]

>>11553479
Michael Artin, Algebra

[Anonymous No.11553669]

Go to the better thread:
>>11553666
>>11553666
>>11553666
(it has trips)

[Anonymous No.11553811]

>>11553031
>2huanon
Not well defined. There are at least two posters repeatedly posting 2hou images, one is the incredibly obnoxious yukari fag, the other seems to be quite nice and informative.

[Anonymous No.11553934]

>>11552272
Have you ever been outside during a full moon? It casts a shadow. If it casts a shadow, then surfaces can reflect. The moon trivially reflects off the earth.

[DoctorGreen !DRgReeNusk No.11553940]

>>11552971
kill yourself, furry

[Anonymous No.11554070]

>>11552971
kill yourself, furry

[Anonymous No.11554578]

>>11553940
>tripfag speaks