Archived threads in /sci/ - Science & Math - 141. page
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Basic science has failed me. I've tried to make a basic astable multivibrator circuit with the exact same components on the left and right side but one side lasts way longer than the other.
I'm using the following components:
2×1k resistors
2×1M resistors
2×10 uF 63V capacitors
2×NPN transistors (C337 W6d)
2×Red 5mm LED's
It's on 5V all in a breadboard.
Pic related, it's the circuit diagram of what I've made.
Any way to debug this or tell what's wrong etc? How come the theory fails me?
>>8078911
did you use matched transistors? with a time constant of 1s it's likely to be significant
>>8078950
I'm not entirely sure what you mean by matched transistors? They are the exact same type, everything about them is the same as far as I can tell.
For the time constant thing, I need something that oscillates at 225 seconds and another thing that oscillates at 128 seconds.
I thought of using raspberry pi's, arduino's, 555 timer chips but in the end I figured that all I really need is an astable multivibrator as pictured.
>>8078964
your circuit looks fine which means either you mixed up some components or there's a problem with the components themselves.
matched means they're made from the same silicon substrate so they have the same saturation current and thermal voltage.
Lastly, I would recommend just using a 555. it's going to cost the same and they jest werk.
Hypothetically, what would be the best way for a guerrilla anarchist to ignite a gas station while making it look like an accident and walking away unharmed? Is it possible to do it with static electricity somehow?
>>8078903
there's not much point if it looks like an accident moron.
>>8078903
Not gonna happen bud. They'll investigate the fuck out of it
Your best bet is a hit and run, or doing it while the place is closed. Much more freedom in your methods that way too
>>8078913
This.
White people can't into guerilla tactics.
Do you:
Work in science-related fields for fun?
Research interesting science topics?
Listen to science podcasts?
Watch/read science fiction/hard science fiction?
Teach others about science?
Fuck off and do things completely unrelated to science?
>>8078866
i study male human anatomy with the aid of bars and grindr
>>8078866
>Work in science-related fields for fun?
Science is boring as fuck. However, it's fun to do math.
>Research interesting science topics?
Science is boring.
>Listen to science podcasts?
Science is boring.
>Watch/read science fiction/hard science fiction?
I watch anime. Some of them are sci fi.
>Teach others about science?
When...
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>>8078866
Watch movies/anime/twitch
Read manga
Going into physics w/calc 2
Little nervous
Wish me luck
You'll be fine, it's all just unit conversion.
>>8078864
Why luck? You're doing a physics course, not playing roulette.
Good skill, OP.
I've got 2 groups of 5 people. The groups differ in regard to some characteristic which I'm studying.
Data is collected in a state of rest, then both groups are subjected to a condition, after which data is collected again. Data I care about is mean pitch, standard deviation of pitch and pitch range, all in Hz.
I would like to be able to see if data is significant on the individual level, if there is a significant increase in Hz from rest to condition. Earlier studies have accomplished this through one-factor ANOVA, but I can't as I don't have...
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>>8078816
Bamp. I need your help, you're my only hope.
Look up student's t-distribution. It was devised for working with very small sample sizes and unknown population SD.
>>8079024
doesn't let me do what I wanna tho, right?
Does the human brain generate a quantifiable electric field?
Also what is current neuroscience work, in terms of reading the noise in our brains? It's not a lot and I imagine that you'd have to be very precise to be able to take advantage of that for whaever reason, perhaps in prosthetics.
Prefer this thread stay close to reality if possible. Speculation is fine, but I just don't want another thread to derail into the paranormal.
Yes but society will lose productivity if we could do things like think awake
It's playing God and toying with our very beings. We are our brains.
>>8078777
>Does the human brain generate a quantifiable electric field?
By separating oppositely charged ionic particles via the use of molecular pumps and then opening the channels between these two groups so that a current is produced
Is biopunk plausible?
>>8078735
Why not?
>>8078740
Because you didn't specify what you meant,so I won't specify an answer.
Maybe give some actual examples and we can work through them
A janitor mistakenly deleted a thread that was about explaining physics to laymen in an informal context. Good job, janitor, we're all very proud of you. So here's essentially the same thread.
ITT: we explain physics to laypeople.
>>8078646
Wasn't here for that thread, how does this work? Do laypeople come in and ask questions?
>>8078659
The OP had an image of girls sitting at a dinner table, and the post read something like "you're into physics right, anon? Tell us something about physics".
>>8078675
That was a pure shitposting thread.
Is biology a hard science?
You could say it's applied chemistry and physics and you do need a certain basic understanding of those disciplines, especially chemistry.
But is it a "hard" science? I don't know. Biology at the cellular level you might consider hard, since it's reproducible and the mechanisms are better understood.
I guess it depends on your field. Cell biologist, yeah sure, why not. Ecologist, probably no.
>>8078567
"Science"
Depends on the field.
Rate my purchase pls bought them all 3 second hand for 10 euro
Texas Instrument TI-82 everything works perfectly (graphics are just not optimized)
TI-Nspire CAS everything works perfectly
Voyage 200 (was most interested in this one) couldn't sadly start him yet because I don't have a small CR-1616 battery here
autism/10
>>8078406
10 EUROS?
AMAZING
11/10
> calculator enthusiasts
currently planning on making a small scale space programme
my aim is to send some stuff to the stratosphere and return it but im hung on what type of propellant to use.
should i use multi stage solid or use a larger liquid stage using asparagus staging with solid boosters to supplement it?
>>8078368
A sugar based propellant, super easy to make if you're not into spending a lit of $ on other chemical compounds.
there are also a lot of guides and things that can point you in the right direction for your project.
A common sugar based propellant is
64% KNO3
35% Regular table sugar
and 1% Iron(III)oxide (Fe2O3)
The iron oxide will act as a catalyst to increase burn rate.
>>8078368
sending stuff the stratosphere is not a space program
>>8078397
fuck this guy, just use mentos and cocacola
Facts:
1: There is no "technological singularity" in the sense as you may know it. Humanity has discovered nearly all relevant science that can be used by humanity to advance technologies that will be useful to humanity. It is now up to engineers to figure out ways to use these discoveries to the advantage of humanity to advance our technology.
2: Humanity is too large and too politically fragmented for everyone to have consensus on preventing the destruction of the environment of Earth. Even if the West gets its shit together and stops polluting and...
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>>8078357
6: Technological development of on-Earth habitats and off-world habitats will be necessary for humanity to survive this coming problem with the environment. This will mean micro environments under domes on Earth and O'Neill Cylinders in space. Expansion into deep space will need to be done using Interstellar Arks these will most likely be Generation Ships (not likely to survive) or merely Seed Ships that will bombard viable planets with extremophile lifeforms and/or embryonic humans.
https://en.wikipedia.org/wiki/O'Neill_cylinder
https://en.wikipedia.org/wiki/Biosphere_2
https://en.wikipedia.org/wiki/Interstellar_ark
https://en.wikipedia.org/wiki/Generation_ship
https://en.wikipedia.org/wiki/Embryo_space_colonization
Technologies,...
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>>8078357
1. This is a bad way to start. There are numerous unsolved problems in physics and science. The unknown in the smallest scale and the largest scale have the potential to be just as relevant as past advances. And we have barely scratched the surface of genetics and human behavior.
>>8078357
wait for it, wait for it, I know this one fag is gonna post that 'muh singularity' pic with the colored lines and say all this is impossible.
>> Humanity has discovered nearly all relevant science
them's fightin' words
What scientsts and biographies influenced you to study science?
My hs teacher. That guy had a war story for us every fucking physics class. Even when we were black holes the fucker connected it to war somehow. (he was in a war tho)
Probably Einstein, feynmann, Planck, Dirac, Fermi and the rest.
I still don't know much about what I study (self taught) but I try.
No one, I just like it
How do i proof
[math]\lim_n a_n = a \Rightarrow \lim_n \sqrt[m]{a_n} = \sqrt[m]{a}[/math]
Ps.: Do i have brain damage for not being able to do that?
>>8078298
Can you answer my question? I seriously can't find a proof. I thought this is the math related board.
>>8078265
The root function is continuous.
For the proof of that you should look at exp(1/m * ln(a)) which is the m-th root of a. It's obviously a composition of continuous functions and by that also continuous.
What are some interesting and/or exotic astronomy words? Or something having to do with planets, galaxies or stars? I'm trying to find a good name for a gamertag somewhere around those lines.
>>8078041
aphelion
>>8078041
Selene
Oort
It might be more well known but it looks neat
