Thread: a question about light

now i learned about light last week in school i am in the ninth grade and i am wandering because my teacher said that photons have no mass they are energy or something and he also talked about lots of other properties of light like the electromagnetic spectrum just basics but i was wondering if i could shine a light on something and end up moving it.

every action has an equal and oppisite reaction newtons 3rd law i think so if i shine a light on u the light has so little mass that it hits u and than bounces off without moving u but if i had a powerful enough light could i shoot it and maybe move like the head of a pin if it were like a few thousand atoms thick???

i asked my dad something about this and he said it is like throwing paper balls at a lead bowling ball on a string so i am realy just asking 2 questions DO PHOTONS HAVE MASS AND CAN I MOVE SOMETHING WITH LIGHT no practical use just the satisfaction of my curiosity and preservation of my sanity.


thx

There are a couple of proposed propulsion concepts for space travel that deals with light:

1. A light-weight craft is struck with a pulsating laser. This craft has a concave bottom. When laser strikes the air combusts and thus give thrust. This happens on a certain cycle depending on how much thrust is needed.

2. Solar Sails. ever heard of this?

From Wiki:

Solar sails (also called light sails or photon sails, especially when they use light sources other than the Sun) are a proposed form of spacecraft propulsion using large membrane mirrors. Radiation pressure is about 10-5 Pa at Earth's distance from the Sun[1] and decreases by the square of the distance from the light source (e.g. sun), but unlike rockets, solar sails require no reaction mass. Although the thrust is small, it continues as long as the light source shines and the sail is deployed.

There is a pressure mentioned above. So if you want to push something, you can do the ratio. And then try to obtain that intense light.

Light has no mass but it does have momentum.

Very observant. The short answer is, yes, light can push stuff. Every time light bounces off a mirror, the energy it takes to change the direction of the light (a tiny, but non-zero amount) is transfered to the mirror by Newton's 3rd law. Light still has no mass, but as Janus said, it still has momentum.

Originally Posted by MagiMaster

Very observant. The short answer is, yes, light can push stuff. Every time light bounces off a mirror, the energy it takes to change the direction of the light (a tiny, but non-zero amount) is transfered to the mirror by Newton's 3rd law. Light still has no mass, but as Janus said, it still has momentum.

That does not make sense.

Light is electrons. They do not have mass. They do not bounce off a mirror.

Because bouncing would create another breach in the rules of multi subatomic particle science, light speed.
To stop and bounce would require a change in speed. What useful information could they bring you? None. Because the mountainous surface of the mirror would cause the electrons, even if they could bounce, to go off in totally useless directions.

However if light works as I say and I was taught. Then light hits a surface, creates a charge of electrons upon the surface.
As ambient radiation, comes from behind the mirror and passes through the mirror it is slowed at the lit surface. And that is what carries the information to you.

http://www.Rockwelder.com/Flash/mrbill/mrbill.html

Sincerely,


William McCormick

Someone correct me if I get this wrong, but yes, light does not, at a small enough scale, exactly bounce. However, the details aren't something I know how to explain. Can someone else fill in here?

Anyway, William, even if what you say is true, the idea that a ray of light reflects off the surface of a mirror would still be a useful fiction since it's much easier to deal with in day to day life (and it's quite accurate).

Originally Posted by maddog67

now i learned about light last week in school i am in the ninth grade and i am wandering because my teacher said that photons have no mass they are energy or something and he also talked about lots of other properties of light like the electromagnetic spectrum just basics but i was wondering if i could shine a light on something and end up moving it.

every action has an equal and oppisite reaction newtons 3rd law i think so if i shine a light on u the light has so little mass that it hits u and than bounces off without moving u but if i had a powerful enough light could i shoot it and maybe move like the head of a pin if it were like a few thousand atoms thick???

i asked my dad something about this and he said it is like throwing paper balls at a lead bowling ball on a string so i am realy just asking 2 questions DO PHOTONS HAVE MASS AND CAN I MOVE SOMETHING WITH LIGHT no practical use just the satisfaction of my curiosity and preservation of my sanity.


thx

This is a radiometer, it moves by light rays.

http://www.Rockwelder.com/WMV/Radiom...adiometer.html


Sincerely,


William McCormick

Originally Posted by MagiMaster

Someone correct me if I get this wrong, but yes, light does not, at a small enough scale, exactly bounce. However, the details aren't something I know how to explain. Can someone else fill in here?

Anyway, William, even if what you say is true, the idea that a ray of light reflects off the surface of a mirror would still be a useful fiction since it's much easier to deal with in day to day life (and it's quite accurate).

The world is flat is a useful fiction too I suppose. Next thing you know you wake up and they are teaching it as something real in school.



Sincerely,


William McCormick

What is a radiomenter?

From Answeres.com:
A device that measures the intensity of radiant energy, consisting of a partially evacuated glass bulb containing lightweight vertical vanes, each blackened on one side, suspended radially about a central vertical axis to permit their revolution about the axis as a result of incident radiation.

Here are some properties of light when it strikes something:
1. Reflection
2. Refraction
3. Scaterring

Radiometer uses reflection/refraction as the term 'incident' implies. The light bounces off the vanes. That gives pressure to the vanes.
The blackened vanes are used to capture all of the spectrum of light. Using other colors will allow other colors to escape. Like if you use red, red will bounce off but the other light passes through. (Proof? Your eyes detects it. That is why you see colors. Light does bounce.)

If William says that light passes through the mirror, then it defeats the principle of radiometer which he used as an example.

With that said, he just negated what he said.

Useful fictions are used all the time in school. You don't tell an elementary school student all the details of how calculus works. As long as you get around to the whole truth eventually, it can make the process go a lot smoother. Of course, that leaves the drop-outs at the "knows just enough to be dangerous" stage sometimes.

Originally Posted by William McCormick

Light is electrons. They do not have mass. They do not bounce off a mirror.

First off, light is not electrons. Light is packets of energy referred to as photons. Second off, electrons have mass. Their mass when they are at rest is 9.11 × 10^31 kg. Third off, of course light bounces off of mirrors. It bounces off of every object actually and that is how we see.

Originally Posted by CoolEJ

What is a radiomenter?

From Answeres.com:
A device that measures the intensity of radiant energy, consisting of a partially evacuated glass bulb containing lightweight vertical vanes, each blackened on one side, suspended radially about a central vertical axis to permit their revolution about the axis as a result of incident radiation.

Here are some properties of light when it strikes something:
1. Reflection
2. Refraction
3. Scaterring

Radiometer uses reflection/refraction as the term 'incident' implies. The light bounces off the vanes. That gives pressure to the vanes.
The blackened vanes are used to capture all of the spectrum of light. Using other colors will allow other colors to escape. Like if you use red, red will bounce off but the other light passes through. (Proof? Your eyes detects it. That is why you see colors. Light does bounce.)

If William says that light passes through the mirror, then it defeats the principle of radiometer which he used as an example.

With that said, he just negated what he said.

No you just assumed that mass education is correct.

You guys are not good scientists at all. There are obvious scientific flaws that you can view in colleges themselves. Flaws that their arrogance cannot even reach down low enough to see.

All the colleges tote that their college is number one. That there college offers the finest education. Or the better facilities. And mostly their efforts are to try to maintain that, so they can win the award next year.
When if they were actually educators they would instantly volunteer their time to actually educate the other schools and bring them up to equal or better status.

However it is obvious that education is not what colleges stand for. They stand for money. Where is vice president Arron Burr when you need him?

I have noted that radiant heat, can make that radiometer take off like crazy. But not without a barely visible white light source. If the radiant heat is not combined on the same side as the barely visible white light source the radiometer will not turn.

This does not make sense yet to me. However it is very interesting. It shows that the radiometer does appear to need white light. However weak light that is no where near turning the radiometer, in conjunction with radiant heat, radiant heat, that does not turn the radiometer alone, can turn the radiometer in conjunction with white light.

I can also turn the radiometer with a magnetic field. Even a very weak silent magnetic field. This device needs some more experiments done on it. Before I would even consider what is turning it.




Sincerely,


William McCormick

Originally Posted by HarryPotter

Originally Posted by William McCormick

Light is electrons. They do not have mass. They do not bounce off a mirror.

First off, light is not electrons. Light is packets of energy referred to as photons. Second off, electrons have mass. Their mass when they are at rest is 9.11 × 10^31 kg. Third off, of course light bounces off of mirrors. It bounces off of every object actually and that is how we see.

Again that is what you were taught. You have no proof, or even ideas of how to prove that. You will just quote conflicting information that would require the definitions of words of the last 100 years to be thrown out.

I was there for the change. I saw what they were planing for you guys. It is sick.

Electrons have no mass. Matter has no mass or weight actually. Time to a near collision, created by space, between electrons that make up matter, create the illusion of mass and weight. You can demonstrate this principle easily. The demonstration was part of real American's training from their fathers in a pool hall as small kids.

If you were around for the battles you would know that, with electricity you can show that it is not effected by gravity. Meaning it has no mass or weight.

You can pick up fragile objects and hurl them unharmed, from zero to the speed of a bullet. Using electrical forces, similar to gravity, but more powerful.

But all this would also be proof we need a revolution in America.

Sincerely,


William McCormick

Do you have proof of your ideas as well? Actual words or computations and not mere pure words.