B Can a Wave Exist Without a Medium?

[Gary Smith]

The molecules of the air around us (most of them are oxygen and nitrogen molecules) have speeds around 500 m/s (average). This is higher than the speed of sound in the air. The atoms in a solid vibrate about their equilibrium positions. Some of them may do this billions of time per second. It is very difficult indeed to find an atom that does not move (in respect to other surrounding atoms).

Thank you. I see that my understanding of physics will never be fully informed. But gaining this piece of understanding helps me grow closer to the actual picture. Finding specific information like this with a general search would be like looking for a needle in a haystack. I appreciate the time of all who respond.

 

[sophiecentaur]

Thank you. I see that my understanding of physics will never be fully informed.

That is true for all of us. But I can say that most PF members would not aspire ever to 'know it all'. We can all learn as we go and most of us do a fair amount of reading round on a regular basis.

 

[nasu]

Thank you. I see that my understanding of physics will never be fully informed. But gaining this piece of understanding helps me grow closer to the actual picture. Finding specific information like this with a general search would be like looking for a needle in a haystack. I appreciate the time of all who respond.

Actually is not so hard to find information nowadays.
"Speed air molecules" in Google provides the answer right on top, in bold characters.

 

[Gary Smith]

Actually is not so hard to find information nowadays.
"Speed air molecules" in Google provides the answer right on top, in bold characters.

Okay, I can drop my mental barrier then to finding such answers with a Google search. Normally I am quite adept at searching in this way, but for some reason had the pre-conceived idea such specific information would not be found. My solution to the frustration of having posts blocked is to make inquiries first of Mentors, to have an okay before posting new questions.

 

[nasu]

I am not advocating Google as the main source of learning. I still think that books are the best source for systematic learning. But for finding quickly a specific fact, the web is a great advance over the times when you had to go through several books just to find a simple fact.

 

[Gary Smith]

I am not advocating Google as the main source of learning. I still think that books are the best source for systematic learning. But for finding quickly a specific fact, the web is a great advance over the times when you had to go through several books just to find a simple fact.

Yes, the problem of only doing Google searching, or even reading from what seems to be reputable sources, is that someone like me has some difficulty piecing it together without getting lost in a maze of wishful thinking. That is why I come to PF. I have just posted a bio on my profile in case anyone is interested in knowing 'where I am coming from.'

 

[zbikraw]

Atom of oxygen was used as non-bonded idea, I suppose. In reality oxygen exists mainly in diatomic molecules, sometimes triatomic (ozone). Monotomic one exist in high temperatures and "dimerizes" spontaneously and strongly exothermally. Tchnically this is used in a Langmuir torch.

 

[Gary Smith]

Atom of oxygen was used as non-bonded idea, I suppose. In reality oxygen exists mainly in diatomic molecules, sometimes triatomic (ozone). Monotomic one exist in high temperatures and "dimerizes" spontaneously and strongly exothermally. Tchnically this is used in a Langmuir torch.

Does 'diatomic molecule' mean a pair of bonded atoms of oxygen?

 

[nasu]

Yes, this is how oxygen is found in the air. The single atom of oxygen is not stable in normal conditions. Not in the sense that it decays but that it will find another atom to bind to.

 

[Gary Smith]

Yes, this is how oxygen is found in the air. The single atom of oxygen is not stable in normal conditions. Not in the sense that it decays but that it will find another atom to bind to.

That type of answer makes it worthwhile to ask. Thank you.

 

[Gary Smith]

Please see my post #18 above .

That is correct. But also note that when talking about particles on this level (e.g. elementary particles), "particle" does not mean a classical object with a specified size (like let's say a small ball, a grain of sand or a dust particle), it means an object behaving according to the Rules of Quantum Mechanics.

EDIT: Here is an overview of the elementary particles:
http://hyperphysics.phy-astr.gsu.edu/hbase/Particles/parcon.html

What a great diagram! Clearly I am a visual person.

May I ask, when is it right to say Quantum Physics and when Quantum Mechanics?

 

[nasu]

Why not ask? Others did before you. :)
https://physics.stackexchange.com/q...-mechanics-and-quantum-physics-the-same-field

 

[Gary Smith]

This could be word salad, I think.
You would probably benefit from reading a few Popular Science books. They would at least direct your path through the subject in an ordered way and show the way thinking has progressed over the centuries. You could try "Forces of Nature" by Brian Cox. It has a lot of good reader revues.
Q and A is all good fun but it tends to lead you along a 'random walk', which will not take you very far very fast. Questions are only of use if they can give you answers that you can understand - hence my idea of 'structured learning'.

I understand your idea of 'structured learning' but in my case it works far better to ask specific questions. Briefly, I am 64 and though semi-retired have daily responsibilities and a lifestyle which make prolonged periods of reading next to impossible. Also, I have little interest in physics outside my specific questions. Though once an avid reader, that was before 2000. Since then, I have rarely made it through even a book which started out to be quite compelling. It just is not my way of learning. I have enough of whatever it takes to sort things out eventually, with some solid pieces of information which answer my specific questions. There have been some real gems in this thread for me.

 

[Gary Smith]

Why not ask? Others did before you. :)
https://physics.stackexchange.com/q...-mechanics-and-quantum-physics-the-same-field

From that article,

'So one could say that all the three terms are synonyma. Physicists would almost always pick "quantum mechanics" as the preferred label for any theory that follows the postulates of quantum mechanics or for the postulates themselves. On the other hand, "quantum physics" and "quantum theory" is more likely to be used by the outsiders or in the non-expert context.'

If it won't offend anyone, I will continue to use 'quantum physics,' as mine is in the non-expert context. Thanks.

 

[sophiecentaur]

but in my case it works far better to ask specific questions.

It may be less trouble but are you really in a position to judge that it is better? And you have not been asking a specific question, which is why this thread has had so many facets and so few answers for you. A grumpy response, perhaps but you are actually undervaluing the subject by imagining that there is much mileage in the scattergun approach that you advocate. If you have found it hard to make it to the end of the books you have been reading you could perhaps start with less advanced texts. I know how turgid a book can be when you find something new and difficult on each new page. I have launched out on several books and been relieved to put them down, unfinished.

 

[Gary Smith]

sophiecentaur, I really appreciate your input. Yes, I would say that with a lifetime of experience -- of observing and measuring what works and what doesn't for me -- I am in a position of saying what works better -- more effectively, efficiently and productively. I am quite happy with the answers in this thread, which I inadvertently confused by mentioning atoms as an example, when the question was about waves. Everyone who responds does so voluntarily, and I appreciate each response, even grumpy ones.

 

[rootone]

An atom of oxygen can be suspended in air, yes? Can a wave be suspended independently? Or does it need to be generated?

Oxygen in air is largely O2 molecules, and it exists in the air with other gases, mostly N2, but there are significant other components of air, water vapor being one.
The atmosphere does have waves in it, like the sea does, we call it weather systems,
The air on Earth is for now though a fairly predictable mix.
H20 content being of most interest for practical stuff like agriculture.

 

[Gary Smith]

Oxygen in air is largely O2 molecules, and it exists in the air with other gases, mostly N2, but there are significant other components of air, water vapor being one.
The atmosphere does have waves in it, like the sea does, we call it weather systems,
The air on Earth is for now though a fairly predictable mix.
H20 content being of most interest for practical stuff like agriculture.

Thank you.

 

[Khashishi]

G. - I had to look up the definition of EM waves. Of course, ElectroMagnetic. Would you say that all waves of quantum physics are EM waves?

No. EM waves are one type of wave. Water waves, sound waves, and matter waves are different kinds of waves.

G. - Photons, it seems, are in a class by themselves. A physicist told me a few years ago that super-string theory had been replaced by 'wavicles.' Is it true that photons behave sometimes like waves and sometimes like particles? I also read that photons are particles without mass. Oi. So many new questions come to mind...

No. It's possible something got lost in translation. According to https://en.wikipedia.org/wiki/Wave–particle_duality, Eddington coined the term wavicle for a particle that has wavelike characteristics in 1928. It has not entered standard parlance, and today we don't ever use the term. We just call particles "particles", where our modern definition of particle includes all of the wavelike behavior. So, it doesn't make sense to say a particle "sometimes acts like a wave and sometimes like a particle" since a particle always acts like a particle by definition. But yes, it has wavelike properties.

 

[Gary Smith]

No. EM waves are one type of wave. Water waves, sound waves, and matter waves are different kinds of waves.No. It's possible something got lost in translation. According to https://en.wikipedia.org/wiki/Wave–particle_duality, Eddington coined the term wavicle for a particle that has wavelike characteristics in 1928. It has not entered standard parlance, and today we don't ever use the term. We just call particles "particles", where our modern definition of particle includes all of the wavelike behavior. So, it doesn't make sense to say a particle "sometimes acts like a wave and sometimes like a particle" since a particle always acts like a particle by definition. But yes, it has wavelike properties.

Thank you.

 

[QI]

Thank you.

hi Gary, in describing waves / particles etc it may be of help to create a drill down from Space to the atmosphere on Earth ----- to the nucleus etc, defining and redefining as needed for each addition / change in definition. This it quit old fashioned but I have always found it an invaluable tool for focusing the mind and you pick up things that most people miss. :)

 

[Gary Smith]

hi Gary, in describing waves / particles etc it may be of help to create a drill down from Space to the atmosphere on Earth ----- to the nucleus etc, defining and redefining as needed for each addition / change in definition. This it quit old fashioned but I have always found it an invaluable tool for focusing the mind and you pick up things that most people miss. :)

Thank you. I probably have to look in another direction to find my answers.

 

[sophiecentaur]

Thank you. I probably have to look in another direction to find my answers.

You also need to be looking for a way to connect all these answers together in a coherent way. It's the relationship between things that makes Science what it is. It's not just a set of interesting instances. That's why I have been batting on about structured learning. it can't be done without it.

 

[Gary Smith]

You also need to be looking for a way to connect all these answers together in a coherent way. It's the relationship between things that makes Science what it is. It's not just a set of interesting instances. That's why I have been batting on about structured learning. it can't be done without it.

I grew up in a household dominated by academic and scientific thinking. I understand structured learning. It sounds like being force-fed another person's ideas. Even if it is peer reviewed and meets the highest standards of science, it is from an incomplete perspective. Not for me, thank you.

 

[sophiecentaur]

I grew up in a household dominated by academic and scientific thinking. I understand structured learning. It sounds like being force-fed another person's ideas. Not for me, thank you.

OK. That's your choice but don't expect to get much real understanding with your method. It's a shame that you use the word "dominated". Scientific thinking liberates one because it give you the tools with which to learn. 'Dabbling' doesn't achieve very much except that it can be enjoyable.

 

[Gary Smith]

All I meant by dominated is that my dad was a university professor. His academic choices and scientific mind influenced my family life growing up. We never fully understood each other, but our mutual love and respect was enough. I just made other choices in life.

sophiecentaur, if you have interest to know why I choose my method, a visit to my PF profile might help. I don't expect you to read it, but if you do you may realize that structured learning will not give me the tools I need. What physics class will provide anything I want to know about the consciousness of matter?

 

[davenn]

What physics class will provide anything I want to know about the consciousness of matter?

nothing ... because again you are straying into the non-science realm which won't do any good in the long run as far as gaining knowledge about the world around you and how it works

If you want to learn real science, we are all willing to help you.
But if you want to talk about stuff that cannot be grounded in reality, then you are on your ownDave

 

[sophiecentaur]

a visit to my PF profile might help

There is nothing on your page except your age and location. They 'explain' nothing to me.

What physics class will provide anything I want to know about the consciousness of matter

This is just more word salad. If you want to discuss such airy fairy stuff then you need a very different forum. Read the PF mission statement and it will tell you what we discuss. It suits us fine.

 

[UsableThought]

There is nothing on your page except your age and location. They 'explain' nothing to me.

@sophiecentaur - you must click the "Info" tab for someone's profile to see if they have written anything about themselves. If you right-click on the tab you will also find it has a direct link - in this case, https://www.physicsforums.com/members/gary-smith.626067/#info

 

[sophiecentaur]

@UsableThought: thanks. I can't think how I didn't know that already. Perhaps the format has changed over the years.