Hi Everyone,

Could someone explain to me why if atoms are buzzing around inside matter, that we humans do not see the effects of this?

Thanks

You don't see the effects of it? Or FEEL it? Are you trying to tell me that you don't hear, feel and see everything vibrating?
I'm sorry, can you rephrase your question?

When the molecules of water in a lake aren't buzzing around very much you can wallk across it. Take a pan of that water and heat it so the molecules are buzzng around more. Now stick your hand in it. Yow. That hurt. So, we do see. and feel, the effects of those vibrations.

But what about say a block of iron. It has atmos and electrons whizzing around and yet looks perfect still.

You cant see it. Doesnt mean it isnt happening. Heat is one way of transferring energy from one body to another, and our bodies are configured to sense it. There is also radiation.
Why are you asking these questions, they sound a little confusing.

Bear in mind that atoms are so small that roughly 1 x 10 to the power 23 of carbon atoms are in just 12 grams of carbon. Thats a lot of atoms. They are so small that you cannot see them using light.

Thanks. I appreciate your answers. I am reading a book on einstein and just trying to get my head around some of the basic theory. For example, if you shoot a quark at the same block of iron, it would pass right through it right? So does that mean that if we magnified the surface of the iron block enough it would be mostly empty space?

Why can't I walk through walls? :(

- N

Thanks. I appreciate your answers. I am reading a book on einstein and just trying to get my head around some of the basic theory. For example, if you shoot a quark at the same block of iron, it would pass right through it right? So does that mean that if we magnified the surface of the iron block enough it would be mostly empty space?

The gap between the nucleus of an atom and the orbital path of an electron is huge. ( i may be wrong, but i think its something like a basketball as your nucleus, the electron is like a grain of salt orbiting it 100 yards away)A Quark being a number of magnitudes smaller than the components of an atom would have no problem passing thru atoms as the vast majority of the volume they occupy is essentialy nothing.So yes, the iron block would be mostly appear to be empty space. Freaky stuff Quantum eh? :eek:

RE: Iron - in solids, the atoms are much closer together, and don't do much "zipping around". they vibrate, but all mostly stay in the same basic structure. Imagine 15 people stuffed into a phonebooth. They can all move, but not very much ;)

Photons shot at a peice of matter (iron, gold, whatever), will not always pass through. Most of the time they will, because 95% of the atom's spacial volume is empty (just like 95% of our solar systems' space is empty, and most ateroids pass througb w/o hitting anything).
Sometimes, though, the photons will hit something, and be deflected or bounced back toward the photon source.


Most likely, though, they are not talking about shooting quarks, but photons, which are much easier to handle in a lab.
Quarks are even smaller than photons (three quarks per photon, IIRC one up, two down?), so shooting a quark would be even more likely to pass through the matter uneffected.




BTW:, guthrie just taught us all what a Mole is, when talking about chemestry. who caught it? hands? :D

Why can't I walk through walls? :(

- N
you can, you just have to learn how to line up all of your atoms with the empty spaces in the wall's atoms ;)

Awesome, thanks everyone. I think I am getting it.

But why, if a block of iron is mostly empty space, look so solid?

Perspective: namely, the small, small size of the atoms.

Think of impressionism. Paintings made up not of brush strokes, but lots of little dots which up close, look like...well...a bunch of little dots.

When you step back and take in the whole image from a distance, though, it looks like a single cohesive something.

Its nice ot know my chemistry degree is good for something :)

The trickier thing about radiation and quarks and stuff passing through a block of iron is that only certain wavelengths of electro magnetic radiation will interact with things. For example, glass coated with I think its titanium or something, or on the SHuttle, gold. visible wavelengths of light can pass through, their energies are such that they do not "fit" in with the atoms in the glass. Infra red wavelengths though do, such that they are reflected.

On the other hand, neutrons, as elementary particles, dont react in quite such a manner. They will pass through material, since there is such a huge amount of space between atoms, but will also rebound off the ones they hit, or be deflected, because they are repelled by the nuclei of the atoms.

And you cant walk through walls because you are too large to fit between the atoms. In order to do so you would have to be rendered down to your component atoms and fired through one at a time.

Plus the block of iron looks so solid because of the pointilism, as river-wind says, but its also simply because its too small. When you see something your eyes are reacting to a blizzard of photons from the object, however there are so many photons that it all looks like one big object, since although the photons each originate with an iron atom, there are too many of them. Your eye just cannot resolve any meaningful picture.

much appreciated, that really helps me out.

thanks again.

http://xanadu.math.utah.edu/java/brownianmotion/1/

Well, actually you can see the effects of atoms. It's called Brownian motion after Robert Brown, the first person to notice it in 1827. He saw pollen grains jiggling when suspended in water. Pollen grains that had been stored for 100 years had the same motion.

In 1877 Desaulx advanced the hypothesis that the thermal motion of water molecules on particles caused the jitter. If the particle gets bumped more on one side than the other, then it jumps to the side.

In 1889 G. L. Gouy noticed that particles moved faster if they were smaller. Pollen grains moved more than a pet rock. In 1900 F. M. Exner associated higher temperatures with faster motion.

Finally in 1905 Albert Einstein provided the math for the movement, for which he won the Nobel Prize. We all know him for his 1905 special theory of relativity, but it was his work on Brownian motion that originally won him fame.

Finally in 1905 Albert Einstein provided the math for the movement, for which he won the Nobel Prize Not quite correct - Einstein published three papers in 1905 - Brownian motion, GR and the photoelectric effect. The paper which won the Nobel prize was the photoelectric effect.
http://nobelprize.org/physics/laureates/1921/index.html

three quarks per photon Actually, there are no quarks in a photon, only hadrons are composed of quarks (by definition), while the photon is an elementary particle.

DAmmit, I forgot about Brownian motion. Now cant you also see the effects of atoms in Cloud chambers?