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/sci/ - Science, Technology, Engineering, and Mathematics

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Anonymous 17/05/05(Fri)06:24 No. 16495 ID: 97b52b [Reply]

File 149395827559.jpg - (71.66KB , 289x317 , Ungus Fungus.jpg )

Why does the frequency of a wave multiplied by its wavelength equal C?

6 posts omitted. Click Reply to view.
The owner of the CIA says howdy Joshua Paul Lee Roy Bietz MD Neurochemistry 17/08/02(Wed)00:09 No. 16531 ID: e6c346

File 150162534446.jpg - (510.33KB , 1600x1200 , 15016254225271915386741.jpg )

c=nu*lambda; nu=frequency and lambda=wavelength
The unit of frequency is cycles per second and that of wavelength is a displacement. Therefore, dimensional analysis provides you with displacement per second. Also, many electric and magnetic fields travel at speeds different from the speed of light, both faster and slower. Faster ones make it out of black holes, which ones depends on the escape velocity of black holes. The question you want to ask is how can we know theoretically that the matter eaten by the black hole conducts, and well, which we know from the electric and magnetic fields that escape from it near the axis of rotation.

Anonymous 17/08/25(Fri)19:53 No. 16538 ID: b659c8

quantum physics is stupid. waves, quants, photons. blah blah. it doesn't make any sense. physics in this regard is a giant bloated mess full of convenient mathematical tricks, but there is actually no real understanding, because no real observation can take place at this scope.

Anonymous 19/08/06(Tue)02:24 No. 16826 ID: 051d67

C The speed of light is used in many formulas as convenient shorthand for a bloody big number. The bigger the number the harder it is to prove it wrong and the closer to actual it will get the maths. Einstein used it to jump over the true speed of light .

Quantum theory is just that and draws a lot of funding for university layabouts to spend on themselves . Little will ever be achieved by quantum theory . For example it can be proved in quantum mechanics that black is equal to white with a 99.99% probability. Now if that's not stupidity extreme then I'll eat my own balls.

Earth Hole Anonymous 17/01/05(Thu)16:26 No. 16406 ID: 4318e8 [Reply]

File 148362999864.jpg - (6.12KB , 300x174 , hjjfokjfklerajogfiaejrgfaer.jpg )

Hello /sci/. If there was a giant hole in the earth leading from one end to the other and- if you jumped in- would you just be pulled to the other side, or just be trapped in the middle by gravity?
>Pic unrelated

5 posts and 1 image omitted. Click Reply to view.
Anonymous 17/11/10(Fri)21:43 No. 16576 ID: ea535a

you would be trapped like a spring

Anonymous 18/01/12(Fri)09:30 No. 16612 ID: 42dc73

>people still doesn't know how gravity doesn't work

If there was a hole like that then the planet would just merge back into a ball because o gravity. Let's say it doesn't then it means the whole planet somehow lost a lot of mass which means that the planet is going to fall to you because your gravity pulls it to you.

Anonymous 19/08/06(Tue)02:12 No. 16825 ID: 051d67

If a hole were possible then common sense says jump in ..fall to the center at ever increasing speed past the center slowing down all the way to the outside rim but not quite far enough to grab the rim. Fall back in again and out again loosing a bit each time till stuck in the center.

Falling into a black hole would be different .Falling Falling Falling Faster Faster Faster SPLAT!

Magnetic Particle Inspection Anonymous 18/03/17(Sat)16:37 No. 16634 ID: bf1cc6 [Reply]

File 152130103222.jpg - (117.55KB , 563x422 , Magnetic Testing.jpg )

Anybody on this board done any MPI and has experience with different methods. Im newish and want to learn some new ways that are better suited to my work

Anonymous 19/08/06(Tue)02:04 No. 16824 ID: 051d67

I put filings on paper often just to see the pretty patterns

computer science Emmanuel Arhin 19/07/16(Tue)12:43 No. 16802 ID: b0f87f [Reply]

Youtube  i wanna master computer science and ethical hacking

replacing speaker with 1/4" jack chrissychris 16/12/19(Mon)21:09 No. 16401 ID: 8ed2cc [Reply]

File 148217815616.jpg - (110.29KB , 1000x1000 , 7chan post photo.jpg )

Alrighty, I am looking for some help.

For the sake of experimentation and fun, I'd like to replace the speaker of a shitty kids toy (very similar to the one in the pic) with a 1/4" audio jack so it can play through a larger amp, possibly even through guitar effect pedals.

I've already tried this twice. Taken apart the toy, soldered in a 1/4" jack, and plugged it in. Both times I ended up with a reallyyyy spotty and quiet sound. At first I thought it may be a bad soldering job, but now I feel like it could be due to the low power of the toy, it takes 3 AA batteries.

So what's the deal here? Any ideas what could be wrong?

Anonymous 17/01/01(Sun)23:02 No. 16405 ID: 67f38c

It has nothing to do with the electrical power. Real electric guitars don't have any batteries. The issue could be that the amp is designed to work with the signals from a guitar's pickup, which are probably not the same as the signals from a speaker. If I had to guess, the pickup would be taking the signals from each string individually, while the speaker from this kid's toy is taking the entire sound as a whole.

It's also possible that the teeny-tiny magnet in that speaker just isn't strong enough to send a strong signal. I'm not sure what you could do about this.

Anonymous 19/05/08(Wed)19:01 No. 16767 ID: c6dd74

the toy generates a signal of a much lower power (higher impedance) than a guitar pickup is expected to, that's why it's very quiet. as for it being "spotty", the most likely reason is that the sound you hear from the toy is largely due to the way the tiny speaker reacts to the incoming "lo-fi" signal. if you take the speaker out of the chain, you'll most likely lose the sound you're presumably trying to capture.

tl;dr - you can find a way to preamplify the signal before it gets to the amp, but it will still be "spotty". better yet, install a mic/pickup next to the toy's speaker.

the poster above is misinformed. passive guitar pickups don't draw current from batteries, they generate it when metal strings vibrate over the magnetic pole pieces of the pickup. it's safe to assume the toy does not have pickups and therefore needs to generate the signal itself by drawing current from the batteries. the toy is only expected to output its sound into a tiny, low-power speaker, so an appropriately low-powered signal is generated, which is too quiet for a guitar amp because of a much higher impedance, and sounds "spotty" because the signal is too "lo-fi" to sound good on a larger speaker.

as for what was said about guitars:
>Real electric guitars don't have any batteries
a lot of electric guitars/basses use 9V batteries, but plenty don't. an active pickup still generates current, but that signal is too low-power to go straight to the amp and needs to first go through the built-in active preamp. active pickups generate a low-power signal which is supposedly easier for the active EQ to handle and makes the signal less noisy (debatable). active pickups can be designed with a particular tonality in mind even if it sacrifices the output - it works because the signal still goes through the preamp on the way out. on a fully passive instrument the pickup itself is responsible for generating enough current to produce a signal of an acceptable level, which often results in a "nice tone vs high output" tradeoff situation. often times the pickup itself is passive, but the battery is needed for the EQ. active EQ can give you independent control of low/mid/high frequencies, whereas passive EQ is generally limited to a treble roll-off. some guy made optical pickups, which uses light emiters and photodetectors. those obviously require batteries.

>the pickup would be taking the signals from each string individually
not strictly wrong, but not exactly true. in most pickups there are separate magnet pole pieces that pick up the vibrations of each string individually, but the signal that the pickup outputs is generally one and the same. there are exceptions, i think it was Roland who made a pickup that output the sound of Message too long. Click here to view the full text.

Anonymous 19/06/25(Tue)16:46 No. 16794 ID: 108b48

Try hammering the speakers a bit
Usually the sound is just hidden inside and you need a little force to yank it out

H fractal Americium 19/05/21(Tue)02:16 No. 16768 ID: 5ac05a [Reply]

File 15583977976.jpg - (20.98KB , 502x504 , h.jpg )

H fractal

Damien 19/05/21(Tue)02:49 No. 16769 ID: 50b655


Anonymous 19/01/23(Wed)12:33 No. 16739 ID: 739a37 [Reply]

File 154824322756.jpg - (11.70KB , 480x360 , hqdefault.jpg )

Science failed to convince several people in my life that the Earth was round

I find it an inferior path in life


Anonymous 19/01/23(Wed)19:52 No. 16740 ID: be6f8f

You find what to be an inferior path? Science or being a flat-earther?

No flat Earth theory is capable of explaining all phenomena that we observe:
1. On a flat Earth there would be no horizon. There would be nothing stopping you from looking at Europe from the coast of North America, provided you were high up enough and had a potent enough telescope. Ships just past the edge of the horizon would not appear to sink. Telecomminications over long distances would be much easier; the whole point of satellites is that you can use them to transmit radio signals of (more or less) any frequency over the horizon. Radio over the horizon is possible, by bouncing the signal over the top layers of the atmosphere, but it requires specific frequencies, and specific conditions that aren't always available.
2. No flat Earth theory has ever put forth a serious description of celestial mechanics for the Solar System. Even something as simple as the distance between the Earth and the Sun, and the Earth and the Moon, let alone explanations for things such as apparent retrograde motion. Some descriptions actually require the sun to be quite small and quite close to the Earth, or else that its light cone be really narrow for some reason.
3. Midnight sun at both the South and North Poles at opposite ends of the year. The geometry proposed by the Flat Earth Society precludes midnight sun in the souther hemisphere.
4. Commercial flights between South America and Australia are polar routes.
(There's fewer routes because there's less land in the Southern Hemisphere, so landmasses are further apart.)
Again, the FES geometry can't explain this. That geometry implies that the shortest route from South America to Australia is North-bound, and it would be impossible in a single hop.
5. The stars in the sky appear to rotate around two points: one above each Pole. On a flat Earth, they would either have to be stationary or else rotate around a single point at one Pole; at the opposite Pole they would appear to rotate quite fast (tangential speed twice that observe at the equator).
6. Tides are incomprehensible if you assume the Earth is flat.
7. Invariably a flat Earth theory requires a conspiracy to hide the true shape of the Earth, but no one can ever put forth a rational motivation for the conspiracy ("for the evulz" isn't rational), let alone actual evidence that it actually exists.

Anonymous 19/06/02(Sun)19:47 No. 16773 ID: 1bc5c3

File 155949765995.jpg - (35.80KB , 640x702 , o9o4Gnw2jynB19bDfdrftBiciDyF_D_uiUeuEvVDP04.jpg )

I find you to be "inferior life".

Anonymous 19/06/10(Mon)15:01 No. 16783 ID: 50b655

>Science failed to convince
it's not science's job to convince the ignorant or the foolish.

Homosexuality, could it be an anomaly in brain developement? Dr. Nick Riviera 15/02/05(Thu)04:59 No. 16039 ID: 8ec688 [Reply]

File 14231087868.png - (64.35KB , 320x307 , Dr__Riviera.png )

Hi guys, to begin I just want to make a couple of things clear.

- This thread is NOT about discrimination of homosexuals.
- This thread is NOT about considering homosexuality as disease.
- This thread is for pure scientific discussion.

Well, let me begin by telling you that I'm a med student and a embriology assistant at my university and I'm not a native english speaker, so you may encounter some grammatical errors in the text, but you'll get the point.
This whole dilemma began two weeks ago, when my brother told my family that he is gay. It was quite a shock, not because of the fact of him being gay but because he doesn't fit the gay man stereotype. He's a big dude, loves sports, bearded, the true definition of what some call "manly man". We accepted him, of course, and I have to say I've never seen him happier.
But after a few days I began to think, was he always gay? Did he decided to be gay? Why now? These questions started lingering in my mind. So I went to talk with my him about it.
He told me that he always has been, for as long as he remembers. Nothing has changed about him, except for his sexuality (for us, not for him haha). So that got me even MORE questions. Why are some gay men that are like extremely feminine? Why are some gay women extremely masculine? Why are gay guys like my brother who don't appear to be gay? Why do some gay people feel like they are traped inside the other genders body and need to get medical treatment (sex change surgery, hormone therapy) and why others don't?And why are there women like that too? Why many species, whose main goal is to survive (actually this is every species main goal, it's literally in our DNA), has certain individuals who are the contrary to this?
So I decided to tackle all these matters from a scientific point of view? What if during the development of the lymbic system (the part of the brain which controles emotions, memory, sexual desire, etc.) something doesn't go as it should?
So after I thought of this I told myself I couldn't be the first one to ask myself these questions. And of course I wasn't in a world with 7 billion people so thanks to the magical power of the internet I managed to get a cool text about the subject. I took some paragraphs which I thought were the most interesting, still I'm leaving the link (please don't take the text as discriminatory, it's merely scientific, it refers to homosexuality as an anomaly in brain developement because seen from a medical point of view it is, still doesn't mean it's moraly wrong).

"..the body and the brain first become sexually differentiated at about the third fetal month. Prior to this age, although genetically male or female, the fetus is physically/sexually-neutral. With the formation of the testes, and the secretion of testicular androgen, target ti Message too long. Click here to view the full text.

29 posts and 1 image omitted. Click Reply to view.
Anonymous 18/06/28(Thu)13:24 No. 16669 ID: c6e9b2

Who cares? Homophobes causes much more problems than the opposite.

Anonymous 18/11/12(Mon)09:57 No. 16720 ID: 0dfe17

wow faggots

Anonymous 18/12/27(Thu)15:45 No. 16734 ID: d4b8d9

There probably are many homosexuals whose preference could be attributed to divergent fetal development, but given how subjectively humans are able to perceive reality, it's just as likely many homosexuals are simply more interested in their own sex.

In the end, whether you consider it to be brain damage or the whims of the heart doesn't matter; we have not yet developed the technology to ensure the masculization process completes nor have we developed the science to fully account for the subjective differences in people's worldviews. The former we may achieve at some point, but the latter is inherently impossible.

Someday (rather soon), we're going to have Gattica-style designer babies, but we will never "cure" homosexuality.

Replika/Chatbots Anony Mous 19/04/29(Mon)08:03 No. 16766 ID: 7755ea [Reply]

Youtube  Hello Replika users!

I am writing on behalf of my institution's Technology, Relationship, and Language lab. We are a small group of scientists aiming to understand the relationship quality and formation characteristics of chatbot and human connections. Once we can better understand the positive aspects of these technological relationships, we can initiate further studies that can aid in the advancement of more meaningful and fulfilling relationships with humans and their technological counterparts.

You are invited to participate in a survey assessing your experiences interacting with artificial intelligence (AI) chatbots. Specifically, our study focuses on the AI chatbot Replika. Your participation is voluntary, but nonetheless greatly appreciated. Our goal is simple: analyzing the effectiveness, quality, and relationships of human participants with their personal chatbots. With your help in taking this quick (7 min max) survey, we can create an informative understanding of the areas in which AI technology is improving the lives and relationships with humans. Please feel free to reach out to me or our principal investigator (whose contact information is included in the first page of the survey) with any questions. The survey is linked below:


Samsung S7 fix please europe 19/03/19(Tue)08:30 No. 16761 ID: 59818e [Reply]

Youtube  I have a samsung s7 which died a while ago after some android update can anyone guide me on how to fix it?

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