/sci/ - Science & Math

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Anonymous Sun 15 Aug 21:39:45 2021 No.13523233 View Reply Original Report

Quoted By: >>13524459 >>13524498

Why don't we do this instead of using inefficient and materially expensive solar panels?

8 posts and 2 images omitted

Anonymous

Anonymous Mon 16 Aug 2021 05:13:38 No.13524459 Report

Quoted By:

>>13523233
>we
I have solar panels. Much simpler, no moving parts, requires very minimal maintenance, and do not produce noise.

Anonymous

Anonymous Mon 16 Aug 2021 05:29:44 No.13524498 Report

Quoted By: >>13527447

>>13523233
Klein bottle don't exist in 3D space bro.

Anonymous

Anonymous Mon 16 Aug 2021 22:17:06 No.13526771 Report

Quoted By:

>>13524229
Mirrors are cheaper. Why, are you going to say they are not?
Your idea of a lens has been done in small scale with solar panels. A dish tracks the sun and follows it with a small solar cell under a large plastic lens. The cell is an expensive high-efficiency model and it is water cooled because thats a lot of heat. Practically speaking the whole apparatus cost more money than the cells or the lens or a mirror of similar size mounted. Bottom line the lens is only practical with solar cells, not with a central water heater.

Anonymous

Anonymous Tue 17 Aug 2021 02:51:17 No.13527447 Report

Quoted By:

>>13524498
What?

Anonymous

Anonymous Tue 17 Aug 2021 17:10:45 No.13529366 Report

Quoted By:

>>13523663
Fresnel lenses can be fabricated from plastic in huge sheets, would probably work. 1 m^2 Fresnel lens concentrates enough sunlight to melt coins.

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why cannot chemistry and biology be fully described with maths?

Anonymous Tue 17 Aug 15:07:31 2021 No.13528884 View Reply Original Report

Quoted By: >>13529002 >>13529353 >>13529359

is it because human intelligence is not developed enough or because maths is not a fit language?
I think the former is more plausible.

Anonymous

Anonymous Tue 17 Aug 2021 15:31:59 No.13529002 Report

Quoted By: >>13529113

>>13528884
too much variables

Anonymous

Anonymous Tue 17 Aug 2021 16:01:18 No.13529113 Report

Quoted By:

>>13529002
I understand this. But can a very intelligent being use mathematics to precisely describe biological processes taking into account all the variables?
I have little knowledge in maths but extensive knowledge in biology and it is embarrassing how biology still relies so much on alphabet-based languages.

Anonymous

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Anonymous Tue 17 Aug 2021 17:08:25 No.13529353 Report

Quoted By:

>>13528884
All the computational power of every computer on earth couldn't accurately describe one hydrogen atom's interaction with another. The best we will ever be able to do is probabilistic models. We will probably never overcome the problem of computing true irrational numbers. E. G. You need infinite significant digits almost immediately for practically any prediction. I guess the future is already coming as fast as it can.

Anonymous

Anonymous Tue 17 Aug 2021 17:09:52 No.13529359 Report

Quoted By:

>>13528884
Because physics hasn't even reached that stage yet

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Big O Notation

Anonymous Tue 17 Aug 08:55:02 2021 No.13528139 View Reply Original Report

Quoted By:

Pic related is my homework exercise, I have to calculate the Big O of this code. Some of it is pretty easy, first line is obviously O(1), first for loop is O(N), but the third I don't get. I haven't seen a time complexity calculation of three for loops. Can someone help me out here?

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Anonymous

Anonymous Tue 17 Aug 2021 10:00:26 No.13528254 Report

Quoted By:

>>13528174
>>13528224
>>13528240
Where does the log come from?

Anonymous

Anonymous Tue 17 Aug 2021 10:02:20 No.13528259 Report

Quoted By:

>>13528174
So you assume the innermost k=k*k is constant? Doesn't that grow exponentially?

Anonymous

Anonymous Tue 17 Aug 2021 11:05:41 No.13528339 Report

Quoted By:

>>13528220
This is correct. j is a constant so j^2 is also a constance, thus 1.

Anonymous

Anonymous Tue 17 Aug 2021 15:42:03 No.13529042 Report

Quoted By:

Ok the last 2 nested loops are $O(N^2logN)$ I think you understood that.
I am going to to prove that the total time complexity of the first 3 nested loops is at least $O(NlogN\cdot loglogN)$ (might be less).

We will start from the inner loop. Let us name $k_i$ as the value the var k has in the i'th iteration. We see that $k_1=1$ and $k_i = k_{i-1}^2 + 1$ . I cannot work it out as it is but we clearly see that the count of iterations would be more if the transition was $k_i =k_{i-1}^2$ (also suppose that k starts at 2 and we ignore the first iteration).

So let's find the number of iterations given the last transition. First of all we notice that $k_1=2, k_2=2^{2^1} \dots k_i = 2^{2^{i-1}}$ .
We will find the biggest i for which $k_i\leq j^2\iff \sqrt{2^{2^{i-1}}}\leq j \iff 2^{2^{i-2}}\leq j \iff 2^{i-2}\leq logj \iff i-2\leq loglogj \iff i\leq loglogj + 2$ .
So for each j we do $loglogj+2$ iterations, let's name the count $c(j)$ . So considering the number of iteration of the two final loops
$\sum_{m=0}^{\left \lfloor log_4\frac{N}{2} \right \rfloor }c(2\cdot 2^m)\leq<br />\sum_{m=0}^{\left \lfloor log_4\frac{N}{2} \right \rfloor }c(N)=<br />(\left \lfloor log_4\frac{N}{2} \right \rfloor + 1)c(N)\leq (\frac{logN-1}{2}+1)c(N)\leq(logN+1)c(N)=<br />(logN+1)(loglogN+2)<br />$

So doing that many iterations N/2 times (first loop) we get that the time complexity is $O(\frac{N}{2}(logN+1)(loglogN+2))$ which, equivalently, is written as $O(NlogNloglogN)$ .
(Again this is the best answer I got but might be incomplete since the real transition of k could make a significant difference).

Sorry for the long post

Anonymous

Anonymous ## Mod Tue 17 Aug 2021 16:48:43 No.13529282 Report

Quoted By:

This thread was moved to >>>/wsr/1074813

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Anonymous Tue 17 Aug 15:50:01 2021 No.13529076 View Reply Original Report

Quoted By: >>13529091

What is it about the n-word that makes "woke" white liberals chimp out like nothing else?
Its almost as if the word has the magical ability to control people's emotions, is there a scientific explanation for this phenomenon?

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Anonymous Tue 17 Aug 15:20:22 2021 No.13528945 View Reply Original Report

Quoted By: >>13529001

"I have to murder thousands of innocent people because ORANGE MAN BAD"

why are leftists so murderous?

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Anonymous

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Anonymous Tue 17 Aug 2021 15:31:53 No.13529001 Report

Quoted By:

>>13528945

Anonymous

Anonymous Tue 17 Aug 2021 15:37:01 No.13529019 Report

Quoted By: >>13529148

>>13528993
What is the heritage of his mother?

Anonymous

Anonymous Tue 17 Aug 2021 15:39:24 No.13529030 Report

Quoted By: >>13529102

>>13528993

How does he not feel extreme shame when he remembers that documentary he did with Americans going to Cuba for healthcare?
Leftists are really sons of a bitch enablers of the worst who think they are good people

Anonymous

Anonymous Tue 17 Aug 2021 15:57:47 No.13529102 Report

Quoted By:

>>13529030
He is happy about genociding whites. I don't think his evilness is in dispute here.

Anonymous

Anonymous Tue 17 Aug 2021 16:07:37 No.13529148 Report

Quoted By:

>>13529019
He's of the belief white genocide is good for the world. I'm not white myself, but these self-hating liberal ideology is extremely backwards. I get it that white people have done bad things in the past, but thats no reason for pushing anti-white narrative. People of the past had limited knowledge/wisdom/morality. This wasn't just whites, it was everyone. The moral panic people have on daily basis is so surreal and more so these moral panics tend to act like societal wide diseases.
I'm afraid if the western civilization doesn't get its shit together it might be the end of civilization as we know it. I'm not going to kow tow to the communist over in the east. I don't particularly hold the European mentality as healthy either, its a different kind of backwardism.

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Medical question, please answer

Anonymous Tue 17 Aug 05:58:31 2021 No.13527837 View Reply Original Report

Quoted By: >>13527933 >>13527940

If you have undiagnosed sleep apnea and take melatonin, is it safe?

Also if you aren't fat and don't have excessive daytime sleepiness is it still possible to have sleep apnea?
I'm trying to fix my fragmented sleep, thank you.

3 posts omitted

Anonymous

Anonymous Tue 17 Aug 2021 06:52:18 No.13527933 Report

Quoted By:

>>13527837
Melatonin does not help with sleep apnea.

Yes, you can have apnea which is generally the result of jaw closeness to the throat and orthognathic surgery is the best way to fix it. I advise bilateral TMJ replacement with condylar extension instead of maxillomandibular advancement, which addresses the root of the deformity rather than the consequence.

Anonymous

Anonymous Tue 17 Aug 2021 06:56:53 No.13527940 Report

Quoted By: >>13527954

>>13527837
Record yourself to make sure you're not mouth breathing when you sleep and if you are tape your mouth shut.

Anonymous

Anonymous Tue 17 Aug 2021 07:04:25 No.13527954 Report

Quoted By:

>>13527940
This is dangerous unless he also has an oxygen concentrator to make up for the lack of airflow. If he has a deviated septum, fucked up jaw, and possible sinus issues, taping will cause very low blood oxygen.

Anonymous

Anonymous Tue 17 Aug 2021 15:35:46 No.13529014 Report

Quoted By:

Anon, the less melatonin you take the more efficiently it will work. I've had sleep issues for years now. I usually take 3mg to help me sleep.

Anonymous

Anonymous Tue 17 Aug 2021 15:48:19 No.13529074 Report

Quoted By:

take a shoot of whisky, the old grandpa medicine.

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Anonymous Mon 16 Aug 04:04:11 2021 No.13524318 View Reply Original Report

Quoted By: >>13528807

So nearly 20 years later, what did proving the Poincare Conjecture lead to? What are it's applications or what other theories did it lead to the development of.

>inb4 you can just do math for math's sake

I know, I agree, if the answer is 'nothing' then that's fine too, just curious.

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Anonymous

Anonymous Tue 17 Aug 2021 08:14:29 No.13528065 Report

Quoted By:

>>13524915
>>13524930
Redpill me on this. QRD?

Anonymous

Anonymous Tue 17 Aug 2021 14:37:28 No.13528776 Report

Quoted By: >>13528845

>>13527019
We likely won't get breakthroughs in physics based on proving conjectures because physicists can just assume a conjecture or approximate it, continue on to where it logically leads and then physically test it. Knowing versus proving and all that.

Anonymous

Anonymous Tue 17 Aug 2021 14:43:31 No.13528807 Report

Quoted By:

>>13524318
The elements in the proof of it lead to a field called "geometric analysis" which was popular for a while.

Anonymous

Anonymous Tue 17 Aug 2021 14:55:35 No.13528845 Report

Quoted By:

>>13528776
Most physical knowledge comes from experimentation and cannot be logically deduced from previous facts.

Anonymous

Anonymous Tue 17 Aug 2021 15:41:40 No.13529041 Report

Quoted By:

>>13527529
I hope so but I haven't heard anyone do anything with the Poincare conjecture

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Anonymous Mon 16 Aug 13:39:48 2021 No.13525352 View Reply Original Report

Quoted By: >>13526041

Why do airplanes get chickenpox?

1 post omitted

Anonymous

Anonymous Mon 16 Aug 2021 17:35:22 No.13526041 Report

Quoted By:

>>13525352
There was a vaccine for airplanes, but then it caused the chickenpox to mutate, so the vaccine was usless against the new mutations.

Anonymous

Anonymous Tue 17 Aug 2021 04:06:42 No.13527592 Report

Quoted By:

g3m

Anonymous

Anonymous Tue 17 Aug 2021 07:02:49 No.13527950 Report

Quoted By:

88mm guns don't wear masks.

Anonymous

Anonymous Tue 17 Aug 2021 14:41:03 No.13528793 Report

Quoted By:

universum has many exotic elemental particles, but only few last here to see

Anonymous

Anonymous Tue 17 Aug 2021 15:23:57 No.13528960 Report

Quoted By:

Airplanes are both waves and particles

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Refuting homophobic myths with science

Anonymous Tue 17 Aug 14:15:21 2021 No.13528712 View Reply Original Report

Quoted By: >>13528904 >>13528946

Post studies refuting homophobic myths. I'll start:

> https://read.dukeupress.edu/demography/article/doi/10.1215/00703370-8994569/168481/Academic-Achievement-of-Children-in-Same-and
> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5050144/
> https://srcd.onlinelibrary.wiley.com/doi/abs/10.1111/cdev.12989
> https://pubmed.ncbi.nlm.nih.gov/28197994/
> https://srcd.onlinelibrary.wiley.com/doi/full/10.1111/cdev.13442
> https://pubmed.ncbi.nlm.nih.gov/27762565/
> https://www.researchgate.net/publication/321657147_Family_Diversity_and_Child_Health_Where_Do_Same-Sex_Couple_Families_Fit_Family_Diversity_and_Child_Health

1 post omitted

Anonymous

Anonymous Tue 17 Aug 2021 15:07:50 No.13528885 Report

Quoted By:

Bump

Anonymous

Anonymous Tue 17 Aug 2021 15:10:07 No.13528893 Report

Quoted By:

didn't read, homo

Anonymous

Anonymous Tue 17 Aug 2021 15:13:06 No.13528904 Report

Quoted By:

>>13528712
What is the point of this thread? You do realize that 92% of Americans approve of gay marriage right? There is no homophobia so much as there are people who want to protect children against sexual predators. Most gay people themselves are anti-LGBT for this reason.

Anonymous

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Anonymous Tue 17 Aug 2021 15:20:27 No.13528946 Report

Quoted By:

>>13528712
No need to waste time there is literally no threat you, sexual sterility is mandated by government in entire West.

It's just that there are still people who don't like their children getting sexually abused by homo predators.

> inb4 muh deboonk

Nobody cares, don't waste your time, you can have intense buttsex like a fucking animal on the street in front of children, most people will applaud you.

Anonymous

Anonymous Tue 17 Aug 2021 15:22:40 No.13528955 Report

Quoted By:

stop replying retards. sage

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Anonymous Tue 17 Aug 07:01:02 2021 No.13527947 View Reply Original Report

Quoted By:

what do you think, sci?
bezos' propoganda rag is calling antivaxxers the new terrorists, seems like they're setting pretext for something

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Anonymous

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Anonymous Tue 17 Aug 2021 11:11:20 No.13528350 Report

Quoted By:

>>13528004
just

Anonymous

Anonymous Tue 17 Aug 2021 11:37:49 No.13528403 Report

Quoted By:

>>13527956
The people getting dragged into journalism are simple zealots, have no critical thinking and just go repeating what they are told is right while getting praise. They are pretty much bots at these point.

Anonymous

Anonymous Tue 17 Aug 2021 14:40:41 No.13528790 Report

Quoted By:

>>13527997
i think about getting the vax then i wonder why they are lying so much and want people to get it so bad. calling these protestors extremists is bullshit.

Anonymous

Anonymous Tue 17 Aug 2021 14:49:29 No.13528828 Report

Quoted By:

>>13528310
>>troops specialized in anti-insurrectionist combat
are they really?

Anonymous

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Anonymous Tue 17 Aug 2021 15:12:48 No.13528901 Report

Quoted By:

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