More on Light's Mass, Energy, Frequency - Science Forum

Addict Joined: Aug 04, 2005 Posts: 69

Hence you obviously missed the beginning of this discussion.

Novice Joined: Sep 09, 2005 Posts: 6

O.k. it's like that: You are looking at it but you don't see it.

Please don't think that I'm trying to make fun of your questions. The understanding of relativity is like learning to ride and balance a two wheel bike. You can use auxiliary wheels and train with them as much as you like but it will never prepare you for the feeling of the two wheel drive.

When you read about relativity you found stunning facts like:
1. If you drive at speeds near to [c] than
-> your length decreases
-> your mass increases
-> your time slows down
-> . . .
So this facts are the "auxiliary wheels" of the relativity. They amaze but they don't help you feel the ideas. I'll try another approach to make you feel the relativeness.

Let us look at the example with the rocket man Rock that starts from the Earth on his rocker R1. Let Rock weights 80kg and is 180 cm tall. Let he takes with him 1) his personal scale; 2) his ruler; 3) some space buoys;
Rock is about to break the speed limit for a rockets so his instructors gave him some wornings Smile

1) On high speeds you'll be shorter so put your things on the lowest shelf !
2) On high speeds you'll be heavier so don't overeat space food !
2) On high speeds you'll be slower so get up earlier to catch up with your day schedule !

So Rock lifted off on R1 and headed up. He recorded:
1) I spent 10% of the fuel to reach 1/2c !!!
--> my scale shows - I am 80 kg; my ruler shows - I am 180 cm; my movements are not slower;
--> I dropped space buoy No1
2) I spent another 10% of the fuel to reach 1/2c respective to space buoy No1 !!!
--> my scale shows - I am 80 kg; my ruler shows - I am 180 cm; my movements are not slower;
--> I dropped space buoy No2
3) I spent another 10% of the fuel to reach 1/2c respective to space buoy No2 !!!
--> my scale shows - I am 80 kg; my ruler shows - I am 180 cm; my movements are not slower;
--> I dropped space buoy No3
4) I spent another 10% of the fuel to reach 1/2c respective to space buoy No3 !!!
--> my scale shows - I am 80 kg; my ruler shows - I am 180 cm; my movements are not slower;
. . .

Here are some lines from the log of the Earths observer
1) He spent 10% of the fuel to reach 1/2c !!!
--> remote scaling shows - he is 90 kg; remote sizing shows - he is 170 cm; his movements are 10% slower;
--> he dropped space buoy No1
2) He spent another 10% of the fuel to reach 3/4c !!!
--> remote scaling shows - he is 120 kg; remote sizing shows - he is 140 cm; his movements are 30% slower;
--> he dropped space buoy No2
3 He spent another 10% of the fuel to reach 7/8c !!!
--> remote scaling shows - he is 500 kg; remote sizing shows - he is 70 cm; his movements are 90% slower;
--> he dropped space buoy No3
4 He spent another 10% of the fuel to reach 15/16c !!!
--> remote scaling shows - he is 9000 kg; remote sizing shows - he is 1 cm; his movements are 99.9% slower;
. . .
We told him so, didn't we ?

This is an example of the two differen view points on one single piece of the universe.

Here is another example with one electron accelerated in a particle accelerator to speeds close to [c].
The way scientists usually explain what happens is that while accelerating the electron gains weight.
For example:
With energy E -> velocity reaches 1/2c; the electron becomes hevier and with another amount of energy E -> velocity reaches 3/4c; the electron becomes more hevier and with another amount of energy E -> velocity reaches 7/8c;
But if we measure things from the view point of the electron then:
First he receives energy E and reaches velocity 1/2c. Then he has the same mass but receives another amount of only 1/2E energy and reaches 3/4c. Then he has the same mass but receives another amount of only 1/4E energy and reaches 7/8c.

And now we return to the emitter moving toward the receiver of a photon. How to look at this event:
1) between the emittion and reception of the photon no force interacts with it and nothing changes for it
2) measured from the emmiter the photon is emmited with energy E and is received with energy E
2) measured from the receiver the photon is emmited with energy E + dE and is received with energy E + dE

That's all. It may look silly or it may work out, but I did my best Cool

Addict Joined: Aug 04, 2005 Posts: 69

Thus you finally catch up.

Both answers can't be right. The light cannot leave with energy E and E+dE. We know they are both emitted by a scientific law with energy E, so what accounts for the increased energy measured here on earth. If you say the shortened frequency, it is like answering the question to why is the sky blue with the answer because blue is the color of the sky.

Is it length contraction?

Ok, having come to that, I have further questions about light traveling with the momentum of the source, the whole light clock experiment where a light clock in on a train traveling at 0.8c. Why is it believed that the light will travel at an angle from the direction it is emitted, thus hitting the mirror that has moved on from where it was at the time that the light was emitted from the source. I believe that light has momentum in the direction it travels, but I was under the belief that our relative motion with respect to the sun does not increase it's momentum. Apparently this is where my problems lie. E=h*(nu)=pc or h/c=p/(nu). The equations here suggest that there is more momentum in higher frequency light. If light is blue shifted then it's energy is increased and thus momentum has been added to it, or rather it is our momentum traveling toward it.

I wish Einstein were around to talk about this.

Moderator Joined: Jun 21, 2005 Posts: 264

I can prove light has mass. By Einstein's definition matter's mass is concentrated energy. Light is quantized. The photon is light's concentrated energy. It is mass. And it is relative.

The party line is light is massless. I no longer subscribe to its unprovable hypothesis. There are no exceptions to E=mc^2. Light's energy is no exception to the rule.

Moderator Joined: Jun 21, 2005 Posts: 264

Cwes says: Why is it believed that the light will travel at an angle from the direction it is emitted, thus hitting the mirror that has moved on from where it was at the time that the light was emitted from the source.

I understand your point cwes. The other way of looking at it is the light beam should travel straight with the mirror moving ahead.

All I can say is Einstein thought that in a space ship light would only be left behind if it accelerated. That the steady movement through space didn't effect light but that acceleration did. Light would follow a curved path only in an accelerating spaceship.

But you make a good point. How would light know to be emitted with this additional momentum? How does light know to go crooked?

Moderator Joined: Jun 21, 2005 Posts: 264

How does light know to go crooked?

Novice Joined: Sep 09, 2005 Posts: 6

Addict Joined: Aug 04, 2005 Posts: 69

And yet, thousands of astrophysicists are trying to explain the large discrepency between calculated and measured energy in the cosmos, thus getting to dark matter/energy.

Moderator Joined: Jun 21, 2005 Posts: 264

I know the answer to this Cwes: Relatives owe their existence to the absolutes.

Einstein said: When the station comes to the train. But what he didn't take into account is that only one(the train) is moving through space toward the other. So the relative motion of the station comes into existence as a result of the absolute motion of the train.

Relatives only exist because of absolutes!

Another example: a ship takes off from Mars accelerating toward the Earth - can we say the earth is moving through space to get closer to this space ship?(ignoring its natural orbit around the sun of course)

The answer is no. Only the space ship that has acccelerated toward the earth is moving closer to the earth; not the other way around.

Relatives are tricky! Relatives are relative. They arn't absolutes in themselves as arogant science would have you believe.

The earth rotates. The sky doesn't turn!

Addict Joined: Aug 04, 2005 Posts: 69

I think having read this, everyone who reads this will see why I get frustrated by Nick.

Relative - of or compared to something else (in this case, one's own inertia)

The earth rotates from the point of view of someone sitting far enough out in space, while a person on earth would be equally accurate in saying that the sky is moving because I am standing still. Thus is the idea behind the word relative. As you said there are no absolutes, just relatives (Aunt Betty for example :lol:

Moderator Joined: Jun 21, 2005 Posts: 264

If light has no mass why does it convert to mass when it is absorbed?

MITCH RAEMSCH

· Encyclopaedia · Wikipedia

· Encyclopaedia
· Wikipedia