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Things you don't understand even when they're explained to you. Options · View
DanielleX
Posted: Sunday, May 12, 2013 1:14:27 PM

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Feedback. As in the loud whining noise you hear when someone's on the radio and they go too near their radio with their telephone, or whatever.

So last week I was at my folk's house and it happened on a phone in on Radio Five Live. My Dad explained to me what did it, but even when he'd told me, I was none the wiser! dontknow

Anyone got any personal examples? And if anyone can explain what feedback is in laymen's terms...


kylie_kained
Posted: Sunday, May 12, 2013 2:05:17 PM

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DanielleX
Posted: Sunday, May 12, 2013 10:55:11 PM

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That's still gobbledygook


CleverFox
Posted: Monday, May 13, 2013 12:20:55 AM

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Feedback is like a driven and under dampened oscillator.

What this means is imagine you have a microphone that is hooked to an amplifying speaker. Any little sound that is picked up by the microphone is the amplified by the speaker. If that microphone is placed in front of the speaker the noise is picked up by the microphone and amplified and then picked up by the microphone and amplified....... Ad infinitum. So the sound keeps getting louder and louder, this is positive feed back.

This is what happens when somebody on a telephone talking to a radio station with that station playing in the background does. The noise is looped and amplified.

I hope that helps.
overmykneenow
Posted: Monday, May 13, 2013 12:47:41 AM

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DanielleX wrote:
So last week I was at my folk's house and it happened on a phone in on Radio Five Live.


First off, stop listening to Radio Five Live phone-ins - 606 will rot your brain!

The phenomenon you're referring to is like standing between two mirrors - you see the reflections bounce off each other forever. The man calling the radio station voice is first then a tiny fraction of a second later you hear his voice again from the radio giving a rather odd echoey quality. It's similar to "microphone bleed" which you sometimes get on conference calls where two of the people are in the same room on different devices.

I'm not sure there's anything that I don't think I could get my head around - but then I'm a man in my mid-forties and we think we know everything.

Warning: The opinions above are those of an anonymous individual on the internet. They are opinions, unless they're facts. They may be ill-informed, out of touch with reality or just plain stupid. They may contain traces of irony. If reading these opinions causes you to be become outraged or you start displaying the symptoms of outrage, stop reading them immediately. If symptoms persist, consult a psychiatrist.

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Guest
Posted: Monday, May 13, 2013 1:05:03 AM

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Feedback is when you say or do something and other people offer their opinions and/or information about it. Example: You wear your favorite comfy shoes and another person says "You should be wearing heels." That's their feedback. Your feedback will probably be: to kick their butt.
DanielleX
Posted: Monday, May 13, 2013 2:52:17 PM

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CleverFox wrote:
Feedback is like a driven and under dampened oscillator.

What this means is imagine you have a microphone that is hooked to an amplifying speaker. Any little sound that is picked up by the microphone is the amplified by the speaker. If that microphone is placed in front of the speaker the noise is picked up by the microphone and amplified and then picked up by the microphone and amplified....... Ad infinitum. So the sound keeps getting louder and louder, this is positive feed back.

This is what happens when somebody on a telephone talking to a radio station with that station playing in the background does. The noise is looped and amplified.

I hope that helps.


That kind of sounds like how my Dad said it. I guess your explanation is a teensy bit more comprehensible but only just.


DanielleX
Posted: Monday, May 13, 2013 2:58:17 PM

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OK my next question in this category is, 'Why is the Earth a sphere and not a shapeless lump of rock?'

Apparently it's something to do with space and time and Einstein? Can anyone explain this in layman's terms? I asked my friend Ashlie who's the clevererest person I know and it was just gobblydegook. How does space and time make the Earth into a sphere? I've been drinking wine, so now might not be the best time...


overmykneenow
Posted: Monday, May 13, 2013 3:10:30 PM

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Everything exerts a gravitational pull. It's extremely weak unless the thing is massive - like a planet. Everything that makes that planet wants to fall to its centre of gravity. Everything. When everything falls towards the centre of an object, over time the object will become more and more spherical.

The smaller a body is the less likely it will be spherical. Mars' two moons are much much smaller than ours and are irregular misshapen lumps.

Actually Earth isn't a perfect sphere. As it spins around it bulges a bit at the equator and is a bit flat at the poles.

Warning: The opinions above are those of an anonymous individual on the internet. They are opinions, unless they're facts. They may be ill-informed, out of touch with reality or just plain stupid. They may contain traces of irony. If reading these opinions causes you to be become outraged or you start displaying the symptoms of outrage, stop reading them immediately. If symptoms persist, consult a psychiatrist.

Why not read some stories instead

NEW! Want a quick read for your coffee break? Why not try this... Flash Erotica: Scrubber
pegasus2126
Posted: Monday, May 13, 2013 3:16:04 PM

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Why before I was married my now wife wanted sex all the time. Now I am married sex has dried up
Courtneyxoxo
Posted: Monday, May 13, 2013 3:46:26 PM

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"Why is the Earth a sphere and not a shapeless lump of rock?"

As I understand it, the earth started of as a shapless lump of rock and over time the force of gravity forces it to compact, and as it does so it shifts around to make thew force equal on all of it, and the only way to do that is by becoming a sphere.
CleverFox
Posted: Monday, May 13, 2013 4:30:03 PM

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DanielleX wrote:
OK my next question in this category is, 'Why is the Earth a sphere and not a shapeless lump of rock?'

Apparently it's something to do with space and time and Einstein? Can anyone explain this in layman's terms? I asked my friend Ashlie who's the clevererest person I know and it was just gobblydegook. How does space and time make the Earth into a sphere? I've been drinking wine, so now might not be the best time...


The Earth is a sphere because a sphere is the shape that has the lowest surface area to volume ratio of any shape. Fluids(this means liquids and gasses)always assume the shape of the lowest possible surface area to volume ratio possible in zero gravity. Think of water droplets in the a international Space Station. They are always round. Rain drops would be round but they are deformed by air resistance as they fall.

Now when the Earth was molten, the gravitational pull of the Earth tried to pull the Earth into the smallest point possible. This would make the Earth form a sphere. Anytime a part of the Earth slipped out of the spherical shape then the Earth's own gravity would pull that part back into place even after the Earth cooled.

This has nothing to do with space/time or any of Einsteins theory's of Relativity.
psychiee
Posted: Monday, May 13, 2013 5:23:07 PM

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Courtneyxoxo wrote:
"Why is the Earth a sphere and not a shapeless lump of rock?"

As I understand it, the earth started of as a shapless lump of rock and over time the force of gravity forces it to compact, and as it does so it shifts around to make thew force equal on all of it, and the only way to do that is by becoming a sphere.



sorry Courney.. earth and ALL other objects in space started off as gas... collection of matter in the form of gas which then cooled.. over billions of years... and so the sperical shape... the main driving force of course being the gravitational pull..
DanielleX
Posted: Tuesday, May 14, 2013 1:35:26 PM

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Hmmm... Ashlie said something about gravity making the space-time curve and that's what makes it a sphere. But what does that mean? I don't know any physicists and I accept this question might not have a layman's version type answer, but it really fascinates me.




CleverFox
Posted: Tuesday, May 14, 2013 2:08:09 PM

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I am a physicist. I have a bachelor degree in Physics from Kent State University.(Yes, that Kent State.)

Gravity does bend space/time but it takes a very strong gravitational field before we will notice anything. The strongest gravitational field in our solar system(the Sun) barely bends space/time enough so that experimental physicists were able to confirm Einstien's General Theory of Relativity.

Gravity bending space/time has nothing to do with why the Earth is a sphere.

If I had a chalkboard I could graphically explain Special Reletivity and General Reletivity to you and you would understand it. You might need me to explain it to you again but you would see the basic concepts.
DanielleX
Posted: Friday, May 17, 2013 3:32:45 PM

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I still don't get how gravity makes the Earth a sphere, yet an asteroid is a lump of rock. I get that's something to do with mass and that the Earth is big. So what's the smallest thing in the universe that's a sphere?


ByronLord
Posted: Friday, May 17, 2013 3:50:15 PM

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DanielleX wrote:
I still don't get how gravity makes the Earth a sphere, yet an asteroid is a lump of rock. I get that's something to do with mass and that the Earth is big. So what's the smallest thing in the universe that's a sphere?


There is a limit to how big you can build in brick before the force of gravity causes collapse, its about 12 stories which is why New York city skyscrapers have steel framed. Solid rock allows you to build higher but there is a limit there as well. A few miles depending on how steep the sides slope. Hence Mt Everest is the highest spot.

There are other factors involved. The majority of the earth is actually molten due to the decay of uranium isotopes in the core and mantle. So most of the earth is actually liquid.

Pluto is only just big enough for gravity to squash it into a rough sphere.

The earth is also a squashy sphere because the rotation on its axis causes a bulge at the equator.

The cores of Jupiter and Saturn are smoother spheres because the force of gravity is much stronger.

Asteroids are by definition not large enough to squash themselves into a sphere. What the astronomers are now calling dwarf planets are things that are midway between the two.

Pluto is still a planet though.

ByronLord
Posted: Friday, May 17, 2013 4:02:13 PM

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DanielleX wrote:
Feedback. As in the loud whining noise you hear when someone's on the radio and they go too near their radio with their telephone, or whatever.

So last week I was at my folk's house and it happened on a phone in on Radio Five Live. My Dad explained to me what did it, but even when he'd told me, I was none the wiser! dontknow

Anyone got any personal examples? And if anyone can explain what feedback is in laymen's terms...


Feedback simply means that a part of the output is going back into the input.

When you place a microphone close to a loudspeaker that is being fed by that microphone, the microphone is going to pick up a very slightly delayed version of its own signal. The amplifier is then going to take that signal, amplify it and feed it into the speakers.

If the microphone is far enough away from the speaker, the feedback sound reaching the microphone will have spread out far enough that it is quieter than the original and there will be a dampening effect.

If the microphone is too close then the oposite will happen and each time the signal is fed back into the amplifier it is going to get louder. After a few thousand cycles (a second or two) the volume will max out whatever the amplifier can produce and you will have a feedback 'howl'. The pitch of the howl will be determined by the delay in the feedback loop and the characteristics of the amp.

WellMadeMale
Posted: Friday, May 17, 2013 11:24:28 PM

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Courtneyxoxo wrote:
"Why is the Earth a sphere and not a shapeless lump of rock?"

As I understand it, the earth started of as a shapless lump of rock and over time the force of gravity forces it to compact, and as it does so it shifts around to make thew force equal on all of it, and the only way to do that is by becoming a sphere.


Nice pair of spheres you're sporting there, Courtney.

If ya can't beat 'em... pay someone to do it for you.
BlueEyedBelle
Posted: Saturday, May 18, 2013 7:30:02 AM

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Something I think I'll never wrap my head around - the ending of Lost
madbadpenguin
Posted: Sunday, May 19, 2013 9:47:42 AM

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The simplest way I can think to explain feedback is two annoying people.

One is a microphone, the other a speaker, imagine them in jumpers with their names on.

Now this pair being idiots of the type in dumb and dumber, they got into an argument, what ever the microphone says the speaker says back a little louder. The microphone can hear the speaker so repeats this again a little louder, the speaker then shouts the same a little louder. At some point the word that was said is lost and the important thing is these two idiots are making noise (hence the tone you hear not the original noise repeated), as they can shout as loud as each other, and are stupid enough to not get bored, the only way to stop it is to move the away from each other.

I hope that helps, just remember any idea can be explained, as long as its done right.
DanielleX
Posted: Sunday, May 26, 2013 11:38:35 AM

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madbadpenguin wrote:
The simplest way I can think to explain feedback is two annoying people.

One is a microphone, the other a speaker, imagine them in jumpers with their names on.

Now this pair being idiots of the type in dumb and dumber, they got into an argument, what ever the microphone says the speaker says back a little louder. The microphone can hear the speaker so repeats this again a little louder, the speaker then shouts the same a little louder. At some point the word that was said is lost and the important thing is these two idiots are making noise (hence the tone you hear not the original noise repeated), as they can shout as loud as each other, and are stupid enough to not get bored, the only way to stop it is to move the away from each other.

I hope that helps, just remember any idea can be explained, as long as its done right.


Thank you. Yes, I like that explanation.


madbadpenguin
Posted: Tuesday, May 28, 2013 4:34:54 PM

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Glad I could be of assistance
castlequeen
Posted: Wednesday, May 29, 2013 5:06:28 PM

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Curling. Seriously, I have no idea what the hell it's about. I know every single rule and regulation in both American football and ice hockey, (yes, the "tuck rule" was pure bullshit) but despite several Canadian friends attempting to explain the great sport of Curling to me, I'm lost.

"A black cat crossing your path signifies that the animal is going somewhere." - Groucho Marx
Emerys
Posted: Wednesday, May 29, 2013 6:33:56 PM

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Most of the things I learned in chemistry, geometry, and calculus, basically. I really hate numbers and dense scientific stuff. Combining the two? My absolute worst nightmare.

Also, pretty much half the things I learned in advanced economics. How I passed with A- I have absolutely no idea. Oh, right, it's because I worked my ass off to remember everything. I rarely understood the concepts behind a lot of what we learned (and sucked at applying them), and pretty much forgot everything I learned a week after I got back my results.

ETA: Half of what went on in s6 of Doctor Who.

Guest
Posted: Wednesday, May 29, 2013 6:36:08 PM

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I've always thought curling is like darts on ice. The skip holding the broom at the other end is giving impossible to follow directions. You throw the rock and with weird science/geometry angles you can get it to go where you want, by bouncing it off other rocks. The two schleps sweeping are actually melting the ice to help speed up, slow down and steer the rock.
Guest
Posted: Wednesday, May 29, 2013 6:38:24 PM

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I forgot the darts part, trying to get closest to the bullseye! You get points for your rocks being closest. This is a very simplistic explantion, but viable
LauraLee_sugah
Posted: Wednesday, May 29, 2013 7:27:36 PM

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the math behind radio frequency technology... like the kind in your passport or a hotel key card.

Guest
Posted: Wednesday, May 29, 2013 7:58:35 PM

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Women. No matter how much you try and work them out they still surprise you with something weird and not always wonderful.
jessicahahn
Posted: Wednesday, May 29, 2013 8:14:37 PM

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The calculus behind String Theory.
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