Physics history documentary.

[William Gaatjes]

Physics history from another view by Professor Jim Al-Khalili.
It is old perhaps but fun to watch if you like history.

You can see some of the old equipment they used. A page of the notebook of Marie Curie that is still radioactive after a century. The competition between Team Einstein and Team Bohr (While both had good points that later turned out to be fitting theories of each group).

After the discovery of radioactivity :
Facial cream with radium processed into it to give you that energetic look.
Soap with radium in it for that extra effect. ^_^

Experiments where nitrogen turns slowly into oxygen and hydrogen when exposed to the radiation of radium. And a whole lot more.
Sigh, I sure hope that one day i can visit these labs when shown as exhibitions.



Part 1 = ~60 minutes.
http://video.google.com/videoplay?docid=-4974977412862654856#

Part 2 = ~60 minutes.
http://video.google.com/videoplay?docid=-4974977412862654856#docid=-5003968210604570515

Part 3 = ~60 minutes.

http://video.google.com/videoplay?docid=-5003968210604570515#docid=-8533827560077385330

 

[DrPizza]

Thanks for that find. The Part 1 covers 90% of one particular lecture I do on the discovery of the atom & different models of the atom. If I can edit it down to 42 minutes, and provide supplementary reading, diagrams, equations, etc., it could be more enjoyable.

Thanks!

 

[William Gaatjes]

Glad to be of help.

There are 2 questions that i would like to ask :

When virtual particles are created, they then again must annihilate. But since this happens so often, this energy must be measurable. I mean a matter anti-matter explosion is the most energetic reaction right ? Yet this is only measurable with electrons.

Another question i have with the Casimir effect. This effect has been measured with 2 plates of metal in a vacuum. The distance between these plates seems to decrease over time and this is accounted to quantum fluctuations. What happens when 3 plates are used or 4 plates or 20 plates ? Are these plates still pushed to each other ? Because that makes me think of gravity and quantum fluctuations being the same phenomenon. And does the casimir effect also work for 5 wires or 7 spheres ? I use these random shapes in my question to determine what the effect would be. Meaning the shape should be of no importance.

 

[William Gaatjes]

I thought some more about the casimir effect. This is what i think is going on :
And quantum fluctuations are not similar to gravity. But i can predict that when 3 plates or 20 plates are placed close towards each other the same contraction between all 3 plates or 20 plates will happen if the effect is independent of the element the plates are comprised of. It seems to me to be similar as diffraction. Because it only works at very small distances.
It is similar where an object small enough when compared to the wavelength of a wave cannot be detected by that wave. Hence it is not influenced by it. Some hidden connection with the expanding universe and quantum fluctuations i would think. But this can only be the case if the element the plates are made of is generally speaking of no importance. The result must be the same no matter if the plates are metallic or not. Some special cases are bound to exist just like iron ... ^_^

 

[DrPizza]

re: as far as the energy, see Einstein. E=1/2 mv^2. Since there are two particles that are turned into energy, simply mv^2. The mass is TINY. I'm no expert on quantum mechanics, but unless I'm mistaken, the energy is "borrowed" from the vacuum & returned to the vacuum; t< planck time, etc. Hopefully someone could straighten me out on this.

 

[William Gaatjes]

re: as far as the energy, see Einstein. E=1/2 mv^2. Since there are two particles that are turned into energy, simply mv^2. The mass is TINY.

True, very tiny. But it happens all the time on a large scale. Some sort of background noise should be present.

I'm no expert on quantum mechanics, but unless I'm mistaken, the energy is "borrowed" from the vacuum & returned to the vacuum; t< planck time, etc. Hopefully someone could straighten me out on this.

This last part, is why i am so interested in de Broglie and the wave nature of matter. And why i lean more towards a wave nature instead of a particle nature. Because IMHO it reads to me exactly as wanting to see something with a much smaller wavelength with a wavelength that is to large. What you get is not what is there. If you see anything, you will see interference only. You can imagine that at higher energy where energy again is related to wavelength, you get different forms of interference.

I wish i could explain it better. But at the moment i cannot. Two centuries of science by dozens of people working in different disciplines is not something that is easily gathered , ordered, analyzed , calculated and explained. Even with modern technology, that will take years. And i am also not an expert.

 

[zebrax2]

Anyone could recommend documentaries similar to this one?

 

[William Gaatjes]

Anyone could recommend documentaries similar to this one?

These are great fun to watch :

Call tech, the mechanical universe. About 50 episodes on different subject, complete with history.

http://video.google.com/videoplay?d...5jt-Qbm4tmCDw&q=electromagnetic+waves&view=2#

For the starters who want to know more about physics :

http://www.colorado.edu/physics/2000/index.pl?Type=TOC


A more detailed history about the relation between Bohr and Heisenberg :

http://video.google.com/videoplay?docid=-3325831859220140461#

 

[TechAZ]

Great videos!

What I don't understand yet, is how the 1st and 2nd element were formed? I can't remember which ones they said were the first 2 that ended up forming the rest of the 92 elements.

This ties into 1 of the other concepts I can't grasp. Although I think the Big Bang theory is the most accurate, how does density, atoms, and temperature even exist in the beginning? I'm not even a religious person, but I can't understand how something comes out of nothing. Same can be said about a "god"....but I personally subscribe to the Big Bang as far as my personal questions go.

It really is amazing at how much we have learned, and how much is still unknown.

 

[CycloWizard]

This last part, is why i am so interested in de Broglie and the wave nature of matter. And why i lean more towards a wave nature instead of a particle nature. Because IMHO it reads to me exactly as wanting to see something with a much smaller wavelength with a wavelength that is to large. What you get is not what is there. If you see anything, you will see interference only. You can imagine that at higher energy where energy again is related to wavelength, you get different forms of interference.

I wish i could explain it better. But at the moment i cannot. Two centuries of science by dozens of people working in different disciplines is not something that is easily gathered , ordered, analyzed , calculated and explained. Even with modern technology, that will take years. And i am also not an expert.

It has been shown (by de Broglie and others, all Nobel laureates for this work) that the quantum "particles" may be described as particles or waves. The different physicists started from the assumption that the electron, photon, or whichever quanta you want was a wave or a particle and developed theories from that basic assumption which are exactly mathematically equivalent. The most commonly employed explanation which I read for this is that the particle or the wave depiction of quanta is simply an abstraction which makes their behavior accessible to us as particles and waves are everyday phenomena that we can visualize. In reality, quanta are neither particles nor waves, but may be described mathematically as both particles and waves.

 

[William Gaatjes]

It has been shown (by de Broglie and others, all Nobel laureates for this work) that the quantum "particles" may be described as particles or waves. The different physicists started from the assumption that the electron, photon, or whichever quanta you want was a wave or a particle and developed theories from that basic assumption which are exactly mathematically equivalent. The most commonly employed explanation which I read for this is that the particle or the wave depiction of quanta is simply an abstraction which makes their behavior accessible to us as particles and waves are everyday phenomena that we can visualize. In reality, quanta are neither particles nor waves, but may be described mathematically as both particles and waves.

I agree. But for some reason i find particles limiting as visualization method and waves not. Do not ask me to give proof why this is, because i really do not know. It is more that i feel at ease with waves and particles give me the same feeling as a John Hagee does. Even though particles are more easy to visualize than waves it seems that it points me in the wrong direction. I know it is abstract, but still even translated to an abstraction it should make sense. My view is more of this :
The best way i can explain it is that nature does not have if-then-else statements. And the particle model is for my feeling an collection of if-then-else statements. Nature just flows without abrupt sideways but with jumps.