Jump to content

Recommended Posts

Posted
13 hours ago, Mordred said:

For example if you pass the photon beam through a polarizer lens you can split the original photon wavelength into two seperate beams.

The two waveforms will be half the wavelength of the original beam.

Half the wavelength? This would double the energy and frequency... It is not the case..

Polarization filter passes one (i.e. it is transparent to) photon with "appropriate" polarization, and reflects another photon with "inappropriate" polarization. What is "appropriate"/"inappropriate" depends on angle of polarization filter.

Energy is conserved prior and after the event. If the original light beam was not polarized at all, half of all photons pass through and other half of the photons are reflected. Wavelength/frequency/energy of the photon is unchanged (or not significantly changed to be detectable by human).

The simplest example is to place a polarizing filter on the front of an LCD/LED computer screen, and rotate, as shown in this thread:

 

 

Posted
17 minutes ago, Sensei said:

Half the wavelength? This would double the energy and frequency... It is not the case..

Polarization filter passes one (i.e. it is transparent to) photon with "appropriate" polarization, and reflects another photon with "inappropriate" polarization. What is "appropriate"/"inappropriate" depends on angle of polarization filter.

Energy is conserved prior and after the event. If the original light beam was not polarized at all, half of all photons pass through and other half of the photons are reflected. Wavelength/frequency/energy of the photon is unchanged (or not significantly changed to be detectable by human).

Note that Mordred did not say polarising "filter".

I assumed he was referring to parametric down conversion. This produces two photons with half the frequency (not wavelength).

Posted
5 minutes ago, Strange said:

Note that Mordred did not say polarising "filter".

I assumed he was referring to parametric down conversion. This produces two photons with half the frequency (not wavelength).

Thanks that is the correct process must have been overtired yesterday. Long day at work lol.

Posted
2 hours ago, swansont said:

I don’t understand. Something takes part in the interaction. You’ve had two of us state that.

 

That was my assumption. Something had to take part, and the photon had to have the sufficient energy you mentioned with respect to the frame of that "something".

I expect you might find that obvious or trivial, but not everyone would.

22 hours ago, swansont said:

If you have a photon of sufficient energy you can create a particle/antiparticle pair. 

That is why I questioned it.

Posted
1 hour ago, J.C.MacSwell said:

That was my assumption. Something had to take part, and the photon had to have the sufficient energy you mentioned with respect to the frame of that "something".

I expect you might find that obvious or trivial, but not everyone would.

That is why I questioned it.

Yes. If it has enough energy in the rest frame of the other particle, it has enough energy in any frame. 

Posted
On 11/27/2019 at 7:28 PM, MigL said:

Again, this is not 'energy' becoming matter.

This was my comprehension of the “beginning”. Extremely dense energy too hot to be converted to matter yet, then when it spread out and cooled enough, it began converting to matter....... Just like they are attempting to do here. https://phys.org/news/2018-03-underway.html

 

10^-43 seconds 

Known as the Planck Era, this is the closest that current physics can get to the absolute beginning of time. At this moment, the universe is thought to be incredibly hot, dense and turbulent, with the very fabric of space and time turned into a roiling morass. All the fundamental forces currently at work in the universe - gravity, electromagnetism and the so-called strong and weak nuclear forces - are thought to have been unified during this stage into a single "superforce".

10^-35 seconds 

The so-called Grand Unification Era, at the end of which the superforce begins to break apart into the constituent forces we see today. Around this time so-called inflationary energy triggers a dramatic burst of expansion, expanding the universe from far smaller than a subatomic particle to far larger than the cosmic volume we can see today. In the process, the primordial wrinkles in space-time are smoothed out. 

The energy dumped into the universe by the end of inflation leads to the appearance of particles of matter via Einstein's celebrated equation E=mc^2. 
 

Screwed up the multi quote, still learning this forum.


MigL said:

“Energy does gravitate, and in that way it is certainly equivalent to mass.

In the earliest moments of the universe, everything would have consisted of fields.
Fields which have an energy density, and therefore an equivalent 'mass'.”

 

How can energy  have an equivalence to mass because energy “gravitates” when it was unknown how strong gravity was going to be yet? I’ve heard of computer models simulating gravity being to strong and the universe ending up as nothing but black holes and on the flip side, gravity being too weak and the universe ending up with no Stars, galaxies, etc. 

Posted
53 minutes ago, Short timer said:

 MigL said:

“Energy does gravitate, and in that way it is certainly equivalent to mass.

In the earliest moments of the universe, everything would have consisted of fields.
Fields which have an energy density, and therefore an equivalent 'mass'.”

 

How can energy  have an equivalence to mass because energy “gravitates” when it was unknown how strong gravity was going to be yet? I’ve heard of computer models simulating gravity being to strong and the universe ending up as nothing but black holes and on the flip side, gravity being too weak and the universe ending up with no Stars, galaxies, etc. 

There is nothing in first MigL's statement that would let you apply it to the first fraction of a second of the universe and think that the conclusion is derived from that. It's a conclusion from what we observe now.

Posted (edited)
2 hours ago, swansont said:

There is nothing in first MigL's statement that would let you apply it to the first fraction of a second of the universe and think that the conclusion is derived from that. It's a conclusion from what we observe now.

Sorry for the confusion, I thought it was clear in the first post of this thread, that’s what I was talking about. Here’s the question again from the original post. Edit: and he did state “in the earliest moments of the universe”.

On 11/26/2019 at 12:44 PM, Short timer said:

I need to clear up some confusion. In the beginning of the universe, before inflation ended, there were no “objects” just energy. Is it proper to refer to that energy as “mass” before it cooled enough to be converted to matter? 

 

 

Edited by Short timer
Posted
26 minutes ago, Short timer said:

Sorry for the confusion, I thought it was clear in the first post of this thread, that’s what I was talking about. Here’s the question again from the original post.

By that point we had established that the premise of your OP was incorrect; energy is not mass, and mass being proportional to the energy content is not the definition of mass

 

26 minutes ago, Short timer said:

Edit: and he did state “in the earliest moments of the universe”.

 

In a separate (and later) part of the post. 

Posted
14 minutes ago, swansont said:

energy is not mass

So without the “object” aka matter, there is no mass.

Energy associated with a field would gravitate as an equivalent amount of mass would.

To refer to the singularity as infinitely dense energy would be correct. 
 

To refer to the singularity as infinite mass would be incorrect? 

Posted (edited)

If I may clarify my statements...

In the earliest moments of the universe, the universe consisted of fields.
Fields which have an energy density ( at the time, very high ), and the concept of 'mass'was non-existant at this time..
Any particles 'bubbling' up from these fields, which exceeded the threshold energy to become real ( as opposed to virtual ) would have been massless.
It is only after the separation of the electroweak force into EM and Weak, and subsequent inflation ( brought about by the false vacuum state ) that some of the particles, now called fermions, were able to interact with the scalar Higgs field, and gain the property we now call mass.
We NOW recognize that these two properties, mass and energy, are like two sides of the same coin, and intimately related

Edited by MigL
Posted
1 hour ago, Short timer said:

So without the “object” aka matter, there is no mass.

No, that’s not what I said.

I said energy is not mass. They are not the same thing.

1 hour ago, Short timer said:

Energy associated with a field would gravitate as an equivalent amount of mass would.

Yes. That’s why GR includes energy, and not just mass.

 

 

Posted

Is kinetic energy a special case, when it comes to bending space time etc? 

Since it's different in every inertial frame, I can't see how it translates into an equivalent of matter.

Posted
1 hour ago, mistermack said:

Is kinetic energy a special case, when it comes to bending space time etc? 

Since it's different in every inertial frame, I can't see how it translates into an equivalent of matter.

Just a follow up question; is the mass that I observe of an object (when at rest near each other they all have the same mass), going with 90% the speed of light towards me or with 20% the speed of light away from me, different?

Posted
2 hours ago, mistermack said:

Is kinetic energy a special case, when it comes to bending space time etc? 

Since it's different in every inertial frame, I can't see how it translates into an equivalent of matter.

Using the inertial frame of the system:

Kinetic energy (of a system's components) with respect to the centre of mass of a system contributes to the rest mass of the system.

 

Posted
10 hours ago, Short timer said:

Does your definition of mass require an “object”?

Depends how you define "object". Part of the definition of "matter" (which I assume an "object" would be made of) is that it has mass.

So we end up with a circular definition. If it has mass, it is (probably) matter and therefore(?) an object. 

The trouble is that there are bosons with mass, and bosons are generally considered force carriers and not matter. But would you count them as "objects" anyway (because they have mass)?

And then fermions such as muons have mass so would they count as "objects" in your definition?

So unless you can define your terms better, I don't think it is possible to give a definitive answer.

Posted (edited)
5 hours ago, Strange said:

Depends how you define "object". Part of the definition of "matter" (which I assume an "object" would be made of) is that it has mass.

So we end up with a circular definition. If it has mass, it is (probably) matter and therefore(?) an object. 

Yes, that’s where I’m looking for clarification. Since mass is a “property” of an object, without the object, there would be nothing for mass to be a property of. No muon, no mass. No baseball, no mass. No sun, no mass. The “object” has to exist before mass can be a property of it. 

5 hours ago, Strange said:

The trouble is that there are bosons with mass, and bosons are generally considered force carriers and not matter. But would you count them as "objects" anyway (because they have mass)?

And then fermions such as muons have mass so would they count as "objects" in your definition?

My answer is yes, I would consider them objects if they have mass, how could they not be? To me, it’s completely nonsensical to think of something having mass as not an object. This is more of a question than a statement, hence  the title of the thread. I’m looking for clarification. I want to make sure my thoughts are matching the science and not vise versa. I’ve received lots of great information so far from everyone, but I don’t see where my question is answered yet. Can mass be called mass without the object? My thoughts tell me most definitely, no. I’m pretty sure @MigL agrees with my thoughts, no objects, no such thing as “mass”, yet. 

Edited by Short timer
Posted
39 minutes ago, Short timer said:

Yes, that’s where I’m looking for clarification. Since mass is a “property” of an object, without the object, there would be nothing for mass to be a property of. No muon, no mass. No baseball, no mass. No sun, no mass. The “object” has to exist before mass can be a property of it. 

I really don't see the issue here.

One of the characteristics of 'properties' as defined in pure logic and in mathematics is that the can characterised as including one or more of

1) Reflexive A ~ A

2) Symmetric If A ~ B then B ~ A

3) Transitive if A ~ B and B ~ C then A ~ C

The equality property obeys all three of these

There are other properties (often called relations) as well

https://www.varsitytutors.com/hotmath/hotmath_help/topics/reflexive-symmetric-transitive-properties

 

So how do you think this applies to 'mass' considered as a property?

, bearing in mind that there are two entirely different and unconnected definitions of mass in Physics that some accident of the Universe brings into coincidence.

Posted (edited)
12 minutes ago, studiot said:

I really don't see the issue here.

One of the characteristics of 'properties' as defined in pure logic and in mathematics is that the can characterised as including one or more of

1) Reflexive A ~ A

2) Symmetric If A ~ B then B ~ A

3) Transitive if A ~ B and B ~ C then A ~ C

The equality property obeys all three of these

There are other properties (often called relations) as well

https://www.varsitytutors.com/hotmath/hotmath_help/topics/reflexive-symmetric-transitive-properties

 

So how do you think this applies to 'mass' considered as a property?

, bearing in mind that there are two entirely different and unconnected definitions of mass in Physics that some accident of the Universe brings into coincidence.

It doesn’t, because in the “beginning”, what this thread is about,  there were no “A” “B” “C”.

Edited by Short timer
Posted
57 minutes ago, Short timer said:

Yes, that’s where I’m looking for clarification. Since mass is a “property” of an object, without the object, there would be nothing for mass to be a property of. No muon, no mass. No baseball, no mass. No sun, no mass. The “object” has to exist before mass can be a property of it. 

My answer is yes, I would consider them objects if they have mass, how could they not be? To me, it’s completely nonsensical to think of something having mass as not an object. This is more of a question than a statement, hence  the title of the thread. I’m looking for clarification. I want to make sure my thoughts are matching the science and not vise versa. I’ve received lots of great information so far from everyone, but I don’t see where my question is answered yet. Can mass be called mass without the object? My thoughts tell me most definitely, no. I’m pretty sure @MigL agrees with my thoughts, no objects, no such thing as “mass”, yet. 

So it sounds as if your definition of "object" is anything that has mass. With that definition, the answer to your question is (by definition): you can't have mass without an object. (In these sort of philosophical questions, the answers often come down to "how do you define X".)

The only bit that sounds a little dubious (on a metaphysical level) is: 'the “object” has to exist before mass can be a property of it'. Which suggests that object have to exist without mass before they can gain mass. One could ask how for long they have to exist without mass, and various other related questions.  But I don't think that is a very useful line of thought. 

An interesting question: do you consider that things which don't have mass can be objects too? For example is a photon (or a lightwave) an object?

Also, there is a difference between your definition of object and the usual definition of matter (which is something that has mass and some physical extent; ie it takes up space). Just food for thought...

Posted
12 minutes ago, Short timer said:

It doesn’t, because in the “beginning”, what this thread is about,  there were no “A” “B” “C”.

 

Didn't take you long to dismiss thousands of years of human thinking by the best in the business.

Strange has already observed both that it depends how you define property and how you define mass, which situations both mitigate against a clear unequivocal answer.

Momentum = mass times velocity, (since you don't like my relational symbolism I have used the equals sign)

So does everything that has momentum have mass?

And what about the two different definitions of mass as defined in Physics, which one are you using ?

You didn't answer my question before, why not?

Posted
11 minutes ago, Strange said:

An interesting question: do you consider that things which don't have mass can be objects too? For example is a photon (or a lightwave) an object?

No, I would consider them a massless particle. 

3 minutes ago, studiot said:

And what about the two different definitions of mass as defined in Physics, which one are you using ?

Invariant.

15 minutes ago, Strange said:

Also, there is a difference between your definition of object and the usual definition of matter (which is something that has mass and some physical extent; ie it takes up space). Just food for thought...

Are you saying the elementary particles that have mass don’t take up space? 

Posted
5 minutes ago, Short timer said:

No, I would consider them a massless particle. 

So being a particle does not necessarily mean it’s an object?

You appear to have a circular definition: To be an object it must have mass, and to have mass it must be an object.

one issue here is that we have come up with definitions based on physics we observe, and you are inquiring about the first moments of the universe, as if looking for some loophole in the definitions. Why does this matter? 

 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.