Question

How can you know that every atom is round?

Answer 1

from special equipment like microscopes

Answer 2

Huh.. I didn't actually know that people had seen atoms, cool

Answer 3

You can sort of see atoms, but not exactly. There are very powerful microscopes that can detect the basic shape of an atom, but it's not really seeing it.
Atoms are not perfectly round for many reasons. If you want a better feel for the shape of an atom I suggest you start taking chemistry. Focus on learning what is called 'orbital geometry'. You will see that the electrons make interesting paths around the atom, not just loops.
use this site and click on 'orbitals' to get an idea what I mean.
http://www.ptable.com/

Answer 4

I'll make sure to look into that when i understand quantum mechanics. At least when i have basic knowledge of it.

Answer 5

Chemistry is a good first step to QM, but at least notice the different shapes that the electrons make. This is a result of their wave nature. Good stuff.

Answer 6

I'm pretty sure that electron orbitals and electron placement is totaly theortical, meaning that we cant observe those. You can however with a electron scaning microscope find the neuchlus of an atom. It's been a while since i read on the subject.

Answer 7

It's not as theoretical as you make it sound zbay. If you think that orbital function theory is just a bunch of smoke and mirrors that's rather drastic. It is at least well known that the Bohr atomic model (where the electrons orbit like planets) is very false.

Answer 8

Oh, i actually meant electrons, protons and neutrons separately, not the atom core.

Answer 9

All motion of electrons must take their wave nature into account, and the wave functions of electrons are mathematically understood very well.
If your question is about particles like electrons, protons, and neutrons Inopeki, then they are not round at all! they have no shape, and are represented by points mathematically.

Answer 10

you developed quite an interest in physics

Answer 11

Right?

Answer 12

How can matter have no shape? Who developed interest?

Answer 13

Good question, and very difficult to answer. I think someone more qualified should try to explain that.

Answer 14

Is it even matter? How can we be sure that it is when we haven't seen them? This is when it starts getting interesting!

Answer 15

"How can matter have no shape?" or at least no definite shape. That's a topic of quantum mechanics. The question becomes meaningless if you understand the Heisenberg uncertainty relationship you wrote down earlier.

Answer 16

Is there a chart where i can learn the meanings of all the signs in physics, because to be honest i think i dont understand the equations because of that.

Answer 17

signs?

Answer 18

I'm pretty sure there are too many signs in physics to memorize, but if that is your only obstacle to understanding all the equations... well good for you!

Answer 19

you learn it piece by piece. Just get some good books and begin to work through it.

Answer 20

learn classical physics first

Answer 21

Imranmeah, i meant like that triangle in the uncertanty relationship.

Answer 22

that's basic mathematical notation and means "uncertainty in". E.g.,
\[ \Delta x \]
is uncertainty in position.

Answer 23

..and it's the capital Greek letter 'Delta' by the way

Answer 24

Is the uncertanty relationship the one that states that a comparison is useless without knowing how much the comparison can be off by? like if i measure something i need to have +/- 0.1 centimeters if it could be off by so much?

Answer 25

Oh! I see!

Answer 26

Hi. I see you really like physics, so I would recommend "The Feynman Lectures on Physics". Check them out, they are really interesting... :D

Answer 27

I might do that depending on what they are about, im currently watching lewins videos.

Answer 28

Another good Feynman book for you would be '6 Easy Pieces'.
When you know all that stuff inside out you can check out the sequel '6 Not So Easy Pieces'

Answer 29

that's honest title

Answer 30

well, "The Feynman Lectures on Physics" are actually 3 books.
1st is "Mainly mechanics, radiation, and heat"
2nd is "Mainly electromagnetism and matter"
3rd "Quantum mechanics"

Answer 31

What are they about, i mean the 12 pieces?

Answer 32

The first one is about mechanics and classical physics. The next delves into relativity and quantum physics a bit. They are very short books and use no calculus, only algebra.

Answer 33

Im sorry, my countrys educational system is pretty much retarded compared to yours, so i must ask, what is calculus?

Answer 34

Well it's ok for an 8th grader not to know.
Calculus is a higher mathematics. It's hard to describe quickly, but it has to do with analyzing functions. Rates of change, and the distance covered by an accelerating object, all best found through calculus. It is basically the language of much of physics, but you need to be very comfortable with algebra and trigonometry first.

Answer 35

And what is trigonometry?

Answer 36

basically the mathematics of triangles

Answer 37

And thats an actual subject? What is complicated with triangles?

Answer 38

it's a bit more complicated than triangles. TT was trying to explain it in simple terms for you.

Answer 39

Oh ok, ill have to loom into that too...

Answer 40

turing did u get the answers?

Answer 41

No dude, where are all the other questions? only one I saw was unanswered and I didn't know it.

Answer 42

?it was ther in the doc

Answer 43

:(

Answer 44

What are you talking about?

Answer 45

arvind wanted me to do his homework for him...

Answer 46

Aravind.. That is not cool!

Answer 47

lol

Answer 48

So you didnt do it?

Answer 49

No, didn't find it. Don't want to get caught up in that conversation though. Sorry to get distracted.

Answer 50

Its ok, you couldnt just ignore him. I have a question, why do you write time^2?

Answer 51

what are the units of velocity?

Answer 52

What do you mean? time and speed?

Answer 53

Units of speed or velocity are distance over time.
m/s for instance.
what about acceleration\[a=\frac{\Delta v}{\Delta t}\] So the units of acceleration should be\[\frac{\frac{m}{s}}{s}=\frac{m}{s}*\frac{1}{s}=\frac{m}{s^2}\]

Answer 54

Delta was uncertainty right? So what do you mean with the uncertainty in velocity and time? As for the second equation, you mean that it just simplifies it?

Answer 55

here Delta means something a little different than we discussed earlier.

Answer 56

Ah

Answer 57

this time its 'difference in'\[a=\frac{\Delta v}{\Delta t}=\frac{v_f-v_0}{t_f-t_0}\] so if I change my velocity from 0 to 20m/s in a time of 4s, then my acceleration is\[a=\frac{\Delta v}{\Delta t}=\frac{v_f-v_0}{t_f-t_0}=\frac{20-0}{4-0}=5m/s^2\] That's a change in velocity of 5 meters per second per second - or meters per second squared.

Answer 58

Im confused. How do i know when it means uncertainty? I first heard that it was change.

Answer 59

Ill take that back for now, ill read your comment first

Answer 60

For you it almost always means difference in - final minus initial of something. Later you will use JamesJ's definition.

Answer 61

I see,but what does that f mean?

Answer 62

final
o is initial

Answer 63

oh ok

Answer 64

Now i see! so you only use time^2 in acceleration?

Answer 65

well you'll see its in the units of force as well\[F=ma=\frac{kgm}{s^2}\]So Newtons (the SI unit of force) has units of kilogram-meters-per-second-squared.

Answer 66

that should be written a little differently above, those expressions are not really equal. The thing on the right is just the units.

Answer 67

Newtons i am familiar with, what is a kilogrammeter?

Answer 68

a kilogram times a meter...

Answer 69

Why would that be necessary?

Answer 70

I get it if its times a meter^2 or meter^3 i get it.

Answer 71

Right, that's the process, it's rather abstract if you think about it too much.
It is necessary to establish some base units. If the SI units of force were 'gram-feet-per-hour-squared, we would have to convert our answers. It helps scientists stay on the same page.

Answer 72

Yeah, i have another question that may sound stupid but why do americans use feet, ounces, gallons and that unit system instead of the metric system, its so cluttered and unorganised..

Answer 73

Because we are stupid, that is the only answer I have, sorry.

Answer 74

An while were on units, why do scientists use kelvin and rankine?

Answer 75

I see no point in it...

Answer 76

Oh.. I didnt mean to call you stupid..

Answer 77

No, it's very stupid, I'm the one saying it.
Kelvin is just like Celsius, but is better to get a feel for what the number means in terms of physics because it is based on Absolute Zero, the temperature at which all atomic motion stops. Never heard of the other thing you mentioned, lol.
I gotta go eat now, but it's fun talking about this. Maybe I'll be back later.
See ya!

Answer 78

Can someone help me?

Answer 79

as you can see by my post I'm leaving

Answer 80

Thanks for all the help you've given me! rankine is like kelvin but it uses farenheits way of counting.

Answer 81

stupidscience, what do you need help with?

Answer 82

Ànd by the way, medal for the appropriate name for our conversation

Answer 83

i posted a question from my physics homework and nobody is responding and i'm very confused!

Answer 84

I'll look at it and see if i can help.

Answer 85

The momentum of a system before a collision is 2.4 × 103 kilogram meters/second in the x-direction and 3.5 × 103 kilogram meters/second in the y-direction. What is the magnitude of the resultant momentum after the collision if the collision is inelastic?

Answer 86

okay thanks!

Answer 87

Im sorry, i dont think i can help you with that.