# Massless "particle?"

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Please explain a bit (those experiments, so I can grasp what's happening). Spectacular sounds interesting.

I just converted the mass to different units (kg to eV/c^2). But the article cited https://en.wikipedia.org/wiki/Photon#Experimental_checks_on_photon_mass

says that

"If a photon did have non-zero mass, there would be other effects as well. Coulomb's law would be modified and the electromagnetic field would have an extra physical degree of freedom. These effects yield more sensitive experimental probes of the photon mass than the frequency dependence of the speed of light. If Coulomb's law is not exactly valid, then that would allow the presence of an ]electric field to exist within a hollow conductor when it is subjected to an external electric field. This thus allows one to test Coulomb's law to very high precision.[/size] A null result of such an experiment has set a limit of m ≲ 10[/size]−14 eV/c2."

(It's 14 orders of magnitude, not 13. mea culpa)[/size]

I think that counts as being spectacularly wrong.

But that's nothing

"Sharper upper limits on the speed of light have been obtained in experiments designed to detect effects caused by the galactic vector potential.

...

The fact that no such effects are seen implies an upper bound on the photon mass of m < 3×10−27 eV/c2."

So you're actually off by 27 orders of magnitude. That's impressive.

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Free fall is not acceleration. (Free fall means you are experiencing no force so if you had an accelerometer with you, it would read zero.)

If you measure (a freely) fall(ing object)

in a vacuum

(=no air resistance)

you will measure acceleration,

whether light

or an object

is falling.

Thus I can't follow

(Maybe you mean weightlessness?)

I just converted the mass to different units (kg to eV/c^2). But the article cited https://en.wikipedia.org/wiki/Photon#Experimental_checks_on_photon_mass

says that "If a photon did have non-zero mass, there would be other effects as well. Coulomb's law would be modified and the electromagnetic field would have an extra physical degree of freedom. These effects yield more sensitive experimental probes of the photon mass than the frequency dependence of the speed of light. If Coulomb's law is not exactly valid, then that would allow the presence of an ]electric field to exist within a hollow conductor when it is subjected to an external electric field. This thus allows one to test Coulomb's law to very high precision.[/size] A null result of such an experiment has set a limit of m ≲ 10[/size]−14 eV/c2."

(It's 14 orders of magnitude, not 13. mea culpa)[/size]

I think that counts as being spectacularly wrong.

How do you explain coax (TV) cable?

The outer sheath (conductor)

would be your hollow conductor mentioned.

Theoretically, no electric field should be possible

within that (sheath conductor).

Or do you mean something else?

But that's nothing

"Sharper upper limits on the speed of light have been obtained in experiments designed to detect effects caused by the galactic vector potential.

...

The fact that no such effects are seen implies an upper bound on the photon mass of m < 3×10−27 eV/c2."

So you're actually off by 27 orders of magnitude. That's impressive.

I'm still not clear how you are "measuring" there (so far away).

(=I'm a bit foggy.)

Could you clarify, a bit?

etc. = Latin Et ceterahttps://en.wikipedia.org/wiki/Et_cetera

but I meant:

what other things are possible?

A particle can be accelerated or decelerated,

but what else can happen? (=your "etc", what other examples?).

Edited by Capiert
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Thus I can't follow

(Maybe you mean weightlessness?)

How do you explain coax (TV) cable?

The outer sheath (conductor)

would be your hollow conductor mentioned.

Theoretically, no electric field should be possible

within that (sheath conductor).

Or do you mean something else?

You could go to the citation in the article for details. I don't see why I have to explain a coax cable — the shielding effect (no external field penetrating) is a reason you use them.

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I just converted the mass to different units (kg to eV/c^2). But the article cited https://en.wikipedia.org/wiki/Photon#Experimental_checks_on_photon_mass

says that "If a photon did have non-zero mass, there would be other effects as well. Coulomb's law would be modified and the electromagnetic field would have an extra physical degree of freedom. These effects yield more sensitive experimental probes of the photon mass than the frequency dependence of the speed of light. If Coulomb's law is not exactly valid, then that would allow the presence of an ]electric field to exist within a hollow conductor when it is subjected to an external electric field. This thus allows one to test Coulomb's law to very high precision.[/size] A null result of such an experiment has set a limit of m ≲ 10[/size]−14 eV/c2."

(It's 14 orders of magnitude, not 13. mea culpa)[/size]

I think that counts as being spectacularly wrong.

But that's nothing

I agree.

I don't see,

how you can have an electric field

in a hollow conductor

because the (volume) charge density

of the metal

should be (significantly) the same

overall.

That means

NO potential difference

in the volume within (=inside).

If however we consider

the conductor has a DC resistance

then it may be possible

to consider a (very) slight

voltage drop

between the source's 2 poles (or plates)

far(ther) away

from the hollow conductor.

(I think)

here we have a hypothesis

expected (to be used) as truth

to (try to) disprove

a photon's mass.

That is absurd.

Why isn't an (known) observed effect used instead,

to prove or disprove (photon mass);

rather than inventing

(an (new) effect that has never been found (at all)

to deny a(n existing) calculated mass.

That's not spectacular,

that's a scandal.

I.e. 1st propose (=predict) something that does NOT exist;

& then use that assumption

to disclaim a(n existing) (photon's) mass.

I call that false prophecy.

Or have I missed something?

Edited by Capiert
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I think your problem (there) is

gravity's free fall g=-9.8 m/(s^2)

It's 9.81 m/s^2 only on Earth, and only at the surface (sea level) of Earth.

At 200m a.s.l. it'll be different,

At 2000m a.s.l. it'll be different,

At 20 km a.s.l. it'll be different.

It's variable, gradient depending on various things (even what is below ground f.e. iron mine), not constant.

I think your problem (there) is

gravity's free fall g=-9.8 m/(s^2)

is an acceleration

(when you say that);

light falls (like any other moving object, (ruffly) without air resistance);

sound does NOT.

That means light accelerates.

Please explain a bit (those experiments, so I can grasp what's happening). Spectacular sounds interesting.

Are you familiar with Gravitational Redshift equation?

https://en.wikipedia.org/wiki/Gravitational_redshift

If you're making conjecture that photon is accelerating (and decelerating in reverse direction):

- is photon accelerating differently depending on its energy/frequency/wavelength, or is it uniform regardless of their properties.. ?

- you should make equations which will predict how much they accelerate/decelerate which will match (or not?) gravitational redshift..

- you should learn how gravitational redshift is tested in lab experiments (f.e. elevator/tower experiment), and provide alternative explanations (including math calculations) which will match result of experiment.

Edited by Sensei
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It's 9.81 m/s^2 only on Earth, and only at the surface (sea level) of Earth.

At 200m a.s.l. it'll be different,

At 2000m a.s.l. it'll be different,

At 20 km a.s.l. it'll be different.

It's variable, gradient depending on various things (even what is below ground f.e. iron mine), not constant.

Yes, the gravitational acceleration is compensated by Newton's centrifugal acceleration,

wrt height,

depending on radius, & orbit speed.

Are you familiar with Gravitational Redshift equation?https://en.wikipedia.org/wiki/Gravitational_redshift

Yes, another fascinating task from you.

"In 2011 the group of Radek Wojtak of the Niels Bohr Institute at the University of Copenhagen collected data from 8000 galaxy clusters and found that the light coming from the cluster centers tended to be red-shifted compared to the cluster edges, confirming the energy loss due to gravity.[6]"

Cluster center versus back:

A question of light source distance:

edge's (average), versus center's (front, middle & rear=back mixture).

Explaining the back of a cluster

with more red shift.

(Considering the red shift is proportional

to the distance away

(from the earth)

in this expanding universe,

& thus the amount of acceleration

duration (time).)

Is it not possible,

the center (spectral) samples

also have "distances" (from earth to light source)

beyond the (cluster's) center

to the (cluster's) "furthest end"

thus (also have) larger distance

& (more light) amount (e.g. densest population, = most number of stars)

than the edges (e.g. perimeter)

which could be seen (=interpretted)

as (ruffly=aproximately) the average distance

(from earth)

to the (cluster's) middle (or center)

when viewing the cluster as ruffly a sphere?

Those edges do NOT extend (from earth) to the cluster's back "half".

The (observed cluster) center would have all sorts of distances

to the cluster: front, middle, & "back";

explaining the extra red shift.

The extreme edge

(away from the center,

not front nor back sides)

would only be approximately middle (=average)

distance, e.g. similar to

from earth to the cluster's center.

(E.g. Think of the cluster in 2D,

as a circle (e.g. flat

like an equator)

with a near & far end

wrt the earth.)

Edited by Capiert
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I agree.

I don't see,

how you can have an electric field

in a hollow conductor

because the (volume) charge density

of the metal

should be (significantly) the same

overall.

That means

NO potential difference

in the volume within (=inside).

You can't apply standard physics to the problem when you are trying to assess if you are trying to see if new physics applies. IOW the same physics that tells you that there is no electric field inside a hollow conductor tells you that the photon has no mass.

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You can't apply standard physics to the problem when you are trying to assess if you are trying to see if new physics applies. IOW the same physics that tells you that there is no electric field inside a hollow conductor tells you that the photon has no mass.

Sorry, I can't follow, I'm too conservative there.

You're proposing what I normally do;

but I'm not allowed to do it;

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Sorry, I can't follow, I'm too conservative there.

You're proposing what I normally do;

but I'm not allowed to do it;

You make little sense

as usual

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=That's a break in physics,

no longer the same topic,

(a quantum leap if you will, e.g. (absurd like) a lepton.)

("You can't apply standard physics

(to the problem when you are trying to assess

if you are trying to see if new physics applies.)"

=If you can not apply physics,

then it (=the so_called "new" physics) is NOT physics (at all).

Science confirms (=experimentally reproduceable, independently;

(there is more than 1 way to skin a cat;

I doubt your method of elimination

is done correctly.)

I remodel.

You make little sense

as usual

You oppose "my (so_called) new" physics;

but it is only a remodeling

seeing things from a different perspective

(using common sense physics).

You then say I make little sense

when trying to make sense of your mess.

e.g. trying to make your puzzle pieces fit.

If you don't understand

what I say,

you can tell me what you understand (from me)

& then ask (what you did not (understand),

if you want).

Obviously I must have left something out,

if not in error.

Edited by Capiert
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Free fall is not acceleration. (Free fall means you are experiencing no force so if you had an accelerometer with you, it would read zero.)

Well ../ If one drops a ball from an helicopter standing still , and the person on earth know the time of start from the helicopter and record the time of the touch down an makes the difference in time of the duration of the fall at 32 F.. S.....square, !~ what will we learn from that experiment../ Acceleration ? perhaps../ .

Edited by Roger Dynamic Motion
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" an helicopter standing still "

This is wrong on so many levels, it would be funny if it wasn't so sad.

If in water waves the wave travels, but the water molecules don't move much,

and in air the sound wave travels, but the air molecules don't move much,

then by the ( wrong ) analogy, the light wave travels, but the photons don't move much.

So why do you need an aether ?

Seems to me it's rather superfluous.

Incidentally, any object with mass ( yes even as little as a neutrino ) requires an infinite amount of energy to accelerate to the speed of light in a vacuum.

That would suggest that light has no rest mass, can never be at rest, and cannot accelerate.

But don't let facts stop you from throwing sh#t against the wall and seeing what sticks.

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!

Moderator Note

Frank Jacobs hijack split off to its own thread. Keep to the OP please.

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" an helicopter standing still "

This is wrong on so many levels, it would be funny if it wasn't so sad.

If in water waves the wave travels, but the water molecules don't move much,

and in air the sound wave travels, but the air molecules don't move much,

then by the ( wrong ) analogy, the light wave travels, but the photons don't move much.

So why do you need an aether ?

Seems to me it's rather superfluos.

I think what he means is

Einstein's Ether (concept)

(which he (=Einstein) believed physics absolutely needed)

was a frozen sea of photons. -Leiden University lecture 1922.

Edited by Capiert
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I think what he means is

Einstein's Ether (concept)

(which he (=Einstein) believed physics absolutely needed)

was (something) like a sea of frozen photons. -Leiden University lecture 1922.

I can only assume you haven't read his lecture. He said no such thing.

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That's what I got out of it, my words.

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Then the problem must be with your comprehension skills. He said no such thing.

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I think what he means is

Einstein's Ether (concept)

(which he (=Einstein) believed physics absolutely needed)

was a frozen sea of photons. -Leiden University lecture 1922.

(I don't see "frozen" or "photons" there.)

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Yes.

(I don't see "frozen" or "photons" there.)

I agree. He used

Quasi_rigid

(reading between the lines, solid, if)

it was NOT liquid,

& did NOT disagree with SR.

A solid is a (rigid) frozen liquid.

"When in the first half of the nineteenth century the far-reaching similarity was revealed which subsists between the properties of light and those of elastic waves in ponderable bodies, the ether hypothesis found fresh support. It appeared beyond question that light must be interpreted as a vibratory process in an elastic, inert medium filling up universal space. It also seemed to be a necessary consequence of the fact that light is capable of polarisation that this medium, the ether, must be of the nature of a solid body, because transverse waves are not possible in a fluid, but only in a solid. Thus the physicists were bound to arrive at the theory of the "quasi-rigid" luminiferous ether, the parts of which can carry out no movements relatively to one another except the small movements of deformation which correspond to light-waves.

This theory - also called the theory of the stationary luminiferous ether - moreover found a strong support in an experiment which is also of fundamental importance in the special theory of relativity, the experiment of Fizeau, from which one was obliged to infer that the luminiferous ether does not take part in the movements of bodies. The phenomenon of aberration also favoured the theory of the quasi-rigid ether."

He (=Einstein) did NOT say photons, I did.

If we have a solid (=something rigid)

& it is NOT matter,

then (with what is left)

I can assume we are dealing with

something electromagnetic

(like photons).

Einstein describes matter as

"condensations of the electromagnetic field".

I suppose photons could also be seen so

but move (=travel, away).

Einstein denies that the ether particles move around,

but that does NOT deny the particles themself.

"Special relativity forbids us to assume

the ether is made of (matter) particles observable through time,

but the ether itself does NOT conflict with special relativity."

---

1920

https://wikilivres.ca/wiki/Äther_und_Relativitätstheorie

Although the ether is irrelevant for SR

(seeming as an empty hypothesis);

"Allerdings erscheint die Ätherhypothese vom Standpunkte der speziellen Relativitätstheorie zunächst als eine leere Hypothese."

it's NOT for GR.

(Last paragraph:)

"Zusammenfassend können wir sagen:

Summarizing we can say:

Nach der allgemeinen Relativitätstheorie

According to GR

ist der Raum mit physikalischen Qualitäten ausgestattet;

space has physical qualities;

es existiert also in diesem Sinne ein Äther.

meaning an ether exists.

Gemäß der allgemeinen Relativitätstheorie

According to GR

ist ein Raum ohne Äther undenkbar;

a space without ether is unthinkable;

denn in einem solchen gäbe es nicht nur keine Lichtfortpflanzung,

because in such not only would light NOT travel,

sondern auch keine Existenzmöglichkeit von Maßstäben und Uhren,

but also no possibility of length & clocks,

also auch keine räumlich-zeitlichen Entfernungen im Sinne der Physik.

also meaning no space_time distances of physics.

Dieser Äther darf aber nicht

But this ether is not allowed

mit der für ponderable Medien charakteristischen Eigenschaft ausgestattet gedacht werden,

to be thought of as having ponderable medium's characterictics,

aus durch die Zeit verfolgbaren Teilen zu bestehen;

made of particles followable using time;

der Bewegungsbegriff darf auf ihn nicht angewendet werden."

the word motion is not allowed on it (=the ether).

--

Ruffly Einstein is saying:

Space has physical properties, so an ether exists (according to relativity).

No ether is unthinkable (wrt GR),

because without it (=ether) light would NOT travel;

also length & clocks for space_time distances would NOT be possible in physics.

This ether is not

the same as a ponderable medium's properties,

of particles that can be followed with time

because the ether does not move.

("The word motion (=travelling) is not allowed

to be used on the ether.")

But as a solid of photons, vibration would be possible instead.

The particles would not move away, for good (=ever).

If you translate german word for word

you can miss the meaning

because a 1:1 corelation to english does not always exist.

They (=the Germans, also) have cliches (=figures of speach).

E.g.

aus "durch" die Zeit verfolgbaren Teilen zu bestehen;

made of particles followable "thru" (=by using) time;

E.g.

der "Bewegungsbegriff" darf auf ihn nicht angewendet werden."

the "word motion" is not allowed on it (=the ether).

Motion, travelling.

Depends on how narrowly

you want to look at it.

It could be any motion at all,

or else leaving.

That's why he describes

with several sentences,

to build a picture

so you can figure out

what he is saying.

E.g. Till it makes sense.

SR doesn't allow

of time followable particles;

but that doesn't prevent an ether.

That only prevents (assuming) that the ether' particles move (around).

(=We can have an ether

but it does not move.)

Thus we can not say the ether is moving (e.g. away).

"Das spezielle Relativitätsprinzip verbietet uns,

SR prevents us

den Äther als aus zeitlich verfolgbaren Teilchen bestehend anzunehmen,

from assuming the ether is made of moving particles (e.g. like a gas)

aber die Ätherhypothese an sich widerstreitet der speziellen Relativitätstheorie nicht.

but the ether hypothesis does NOT contradict SR.

Nur muß man sich davor hüten,

We must only prevent

dem Äther einen Bewegungszustand zuzusprechen."

saying the ether is moving (around).

Bewegungszustand=state of motion, e.g. translatory linear.

(I agree that doesn't exclude vibration now adays;

but back then(?)

would he go so deep

into all details

(for an intro lecture),

that we will ever know?)

He also said (=estimated)

our universe is finite;

NOT infinite.

---

Edited by Capiert
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Sigh.

The first part you quote is about what people used to think. He then explains why that cannot be.

He then goes on to equate space-time with "ether". This has nothing to do with photons or the luminiferous ether. All he is saying is that space-time has measurable properties.

Photons are quanta of the electromagnetic field and he explicitly points out how this is different from what he is calling "the ether".

However, none of this is science. It is just creating images to help people understand (or, apparently, misunderstand).

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Sigh.

The first part you quote is about what people used to think. He then explains why that cannot be.

Don't you mean he then continued to explain following theories that do not work?

E.g. The further different (ether) theories which disagree with SR;

SR had no problem with the quasi_rigid ether theory,

SR could deal with that (qret);

but the other following ether theories could NOT (work with SR).

He then goes on to equate space-time with "ether". This has nothing to do with photons or the luminiferous ether. All he is saying is that space-time has measurable properties.

Photons are quanta of the electromagnetic field and he explicitly points out how this is different from what he is calling "the ether".

I thought (we agreed) "photon" was NOT mentioned in that Einstein document.

How then could he have done that?

Btw. Isn't space*time a product

derivable by multiplying the quotient (space/time)

by time squared?-Joke.

However, none of this is science.

Yes, by the look of it now.

It is just creating images to help people understand (or, apparently, misunderstand).

Yes. Edited by Capiert
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The way I understand it (and this is really beyond my comfort zone) is that some parts of physics might work with an absolutely tiny mass (ie within the bounds I posted above) but others just would not. Quantum electrodynamics is incredibly accurate, underlies much of our present ideas, and just does not work if mass is non-zero. The presence of zero mass allows certain things to be also set to zero - but any non-zero amount for the mass of the photon means that these parts of the calculation boom up to infinities. So it is not that some theories loses a tiny bit of accuracy - it is that one of our most accurate and predictive theories cannot work if mass is non-zero . I think the same is true for quantum chromodynamics (as the gluon must also be massless), and clearly any of the unifications between the strong, the electromagnetic and the weak.

No physicist would be categorical that there is no possibility of a non-zero value because empirical data rules everything and you cannot prove a zero in these terms. But claiming a non-zero mass is a positive statement - and it is a huge claim - thus some evidence other than a a feeling of unease at the idea of masslessness and a misunderstanding of high school equations must be given to back that claim up

Of course all things considered I am barely halfway through college and struggling at best having changed my major several times. So of course I am prone to botch things. However isn't the statement: "Something is zero" equally hard to prove as "Something is infinite"? Even so I concede my point and am now firmly convinced photons are massless. It is simply strange. However there are far stranger things in the universe.

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Of course all things considered I am barely halfway through college and struggling at best having changed my major several times. So of course I am prone to botch things. However isn't the statement: "Something is zero" equally hard to prove as "Something is infinite"? Even so I concede my point and am now firmly convinced photons are massless. It is simply strange. However there are far stranger things in the universe.

I can't think of a property that is infinite, such that we'd have an example of difficulty of measurement.

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