Electric suns, solar flares and coronal mass ejections.

[Loudmouth]

No, you're absolutely and completely wrong. They have both mass and kinetic energy RC. They only thing they lack for is *rest mass*, because they are never "at rest"! You really do not even understand 'classic' particle physics theory apparently.

Nothing with mass can travel at c, and photons do travel at c, and only at c. Photons do not have mass, resting or otherwise.

 

[Michael]

Nothing with mass can travel at c, and photons do travel at c, and only at c. Photons do not have mass, resting or otherwise.

No photon is without kinetic energy and E=MC^2. Every wavelength has a different energy state and every photon has kinetic energy. Why didn't you fix RC's error? Oh ya, I know why.

 

[Michael]

LM....

Read that paper by Dungey and tell me if electrical discharges occur in plasma?

 

[Michael]

My science data book says that the mass of a photon is zero. But how can photon exert radiation pressure, as it occurs in the sun?

 

[Michael]

1958IAUS....6..135D Page 135

FYI, I noticed that RC's link to Dungey's original electrical discharge paper is not freely available, but this is a follow up paper that is freely available that addresses the same topic.

 

[Tiberius]

Michael, care to explain how something with mass can travel at the speed of light? Tell me how it gets around e=mc^2.

 

[Michael]

Michael, care to explain how something with mass can travel at the speed of light? Tell me how it gets around e=mc^2.

A photon simply has no "rest" mass, but it does in fact have mass that is a direct result of the formula you just cited. George Mourstris does a *fantastic* job explaining this issue. Photons do have mass, just not rest mass. They absolutely have kinetic energy.

My science data book says that the mass of a photon is zero. But how can photon exert radiation pressure, as it occurs in the sun?

[SIZE=-1]But relativity also tells us that every particle with mass m is equal to an energy E given by the famous equation:

E=mc^2

where m the mass of the particle, c the speed of light and E the energy that equals to the mass m. This equation also works backwards.An amount of energy E equals to a mass m. Photons however may not have rest mass, but they DO have energy. The energy of a photon is given by the equation:

E=hf

where h is a constant (Planck's constant) and f the frequency of the photon (don't forget that the photon is an electromagnetic WAVE and has a frequency). If we combine these two equations, we come up with the following,which gives us the mass of a photon

mc^2 = hf => m=hf/c^2

which means that though photons don't have rest mass, they do have energy and thus they have mass.[/SIZE]

LM and RC have no idea what they are talking about. All photons have energy. All photons have mass. They simply lack for 'rest mass', not *all* mass. [SIZE=-1]m=hf/c^2[/SIZE]

 

[Tiberius]

So basically, you are saying that photons have mass because they have energy and energy can be converted into mass.

 

[Michael]

So basically, you are saying that photons have mass because they have energy and energy can be converted into mass.

Did I say that, or did George say that?

 

[Michael]

http://www.swpc.noaa.gov/ftpdir/plots/xray/20121023_xray.gif

FYI, the number of active regions on the sun has picked up substantially over the past 6 months. Today we're seeing some x-ray spikes related to electrical discharges from one of the active regions in the southern hemisphere, and a less active region in the northern hemishpere. Fortunately nothing has been aimed our way yet, but the active region in the southern hemisphere remains very active, and its rotating our way.

This is a 38meg video from SDO on the 131A wavelength that shows the electrical discharges that created the x ray spikes we observe in the GOES data. The larger electrical discharge (x-ray) events tend to show up very nicely in the 131A images.

http://sdo.gsfc.nasa.gov/assets/img/latest/mpeg/latest_1024_0131.mpg

 

[Tiberius]

Did I say that, or did George say that?

Well, you're agreeing with him, aren't you?

 

[Michael]

Well, you're agreeing with him, aren't you?

Anyone that understands GR and/or SR would agree with him. Even SR does not claim that photons have *zero* total mass, just zero *rest* mass. Every theory of a photon explains that a photon has and transfers kinetic energy and E=mc^2. m=hf/c^2. This is basic photon physics 101.

 

[Tiberius]

Anyone that understands GR and/or SR would agree with him.

So what was the point of " Did I say that, or did George say that? "

 

[Michael]

So what was the point of " Did I say that, or did George say that? "

The intent was to get you to note that there are plenty of *external* resources to resolve this issue.

 

[RealityCheck01]

My science data book says that the mass of a photon is zero. But how can photon exert radiation pressure, as it occurs in the sun?

Explained in Radiation pressure.

From the perspective of quantum theory, light is made of photons: particles with zero mass but which carry energy and —importantly in this argument— momentum . According to special relativity, because photons are massless their energy (E) and momentum (p) are related by E=pc.[8]

This cites Pressure (p=F/A) and a force is a change in momentum. A photon that reflects off a surface, changes its momentum, and so exerts a force.

 

[RealityCheck01]

...electrical discharges from one of the active regions in the southern hemisphere,

FYI, Michael: The Sun is a ball of plasma and Electrical discharges are impossible in plasma!

 

[RealityCheck01]

Anyone that understands GR and/or SR would agree with him. Even SR does not claim that photons have *zero* total mass, just zero *rest* mass. Every theory of a photon explains that a photon has and transfers kinetic energy and E=mc^2. m=hf/c^2. This is basic photon physics 101.

Not quite right, Michael.
Basic photon physics 101 states that photons have energy that is not related to E=mc^2 (photons always have zero mass) but is derived from the definition of energy in SR:

and then setting mass = 0.

If you just state "kinetic energy" then a photon always has zero kinetic energy because basic photon physics 101 states that photons have a mass of zero.
But there is the equivalance of energy and mass (E=mc^2). So you can treat photon energy as a "mass". This is not often used in physics since it hides stuff, e.g. radiation pressure is due to a change in photon momentum exerting a force.
ETA: Photons always travel at the speed of light in a vacuum. That gives them a gamma factor of infinity. Infintity multiplied by anything except zero is infinity. Thus even SR claims that photons have *zero* total mass and zero *rest* mass.

 

[Tiberius]

The intent was to get you to note that there are plenty of *external* resources to resolve this issue.

Let's start with the intent to speak clearly, mkay?

 

[Michael]

Explained in Radiation pressure.

This cites Pressure (p=F/A) and a force is a change in momentum. A photon that reflects off a surface, changes its momentum, and so exerts a force.

Ya, and the explanation right before it explained the same exact process in terms of kinetic energy and mass. You're still full of hot air RC. Do you think I did not notice that you never dealt with that link I handed you from Kong? Did he not discuss photon kinetic energy RC?

http://www.greatians.com/physics/wave/energy%20of%20photon.htm#WD.1.0

What exactly *is* your point in engaging in this thread anyway RC? You've already demonstrated that you are A) not an astronomer, B) have no knowledge of photon kinetic energy, and C) you are blissfully ignorant of the fact that electrical discharges occur in plasma. What possible use are your posts here RC? You don't have a EU/PC hater posse here to protect you RC. You've already destroyed your own credibility in this thread in terms of the actual physics. You lost all scientific credibility on this forum about two weeks ago about here:

http://www.christianforums.com/t7688433-45/

 

[Michael]

Gamma Rays and Kinetic Energy

[FONT=Arial, Helvetica, sans-serif]

Question: Does gamma radiation have kinetic energy?

Replies: Yes, it does. In fact, since photons have zero rest mass, all their energy is kinetic. In fact, if you could slow them every so little from the speed of light, they would cease to exist, since they would have zero energy. Relativity is very strange, isn't it? A photon is a quantum (a little piece) of light.

Best, Dick Plano, Professor of Physics emeritus, Rutgers University

[/FONT]
http://www.christianforums.com/t7688433-41/#post61575350

Photon "kinetic energy" cannot change (is always zero) and so has nothing to do with frequencey shifts.

And there is that "kinetic" again. A photon always has a kineteic energy of zero .

Are you still going to claim that photon kinetic energy is always zero? I mean really RC, what's the point of demonstrating the fact that you're incapable of using Google, and incapable of admitting your scientific mistakes when they are pointed out to you?