When we say light (A.K.A. photons) have zero mass, what we really mean is that they have zero "rest" mass.
In E=mc^2, E is the energy of unmoving particles.
For a moving particle, the eqn is~
E^2= (P^2 c^2) + (m^2 c^4)
Now, put m=0 for light in the above eqn, and you get~
E=Pc
So yeah, simply put the photons have zero mass, but they have energy. Just Google you'll get loads of stuff to read about it, or ask your science teacher.
The weight of a box = x
Place some light into the same box and it now weighs x+1
When we say light (A.K.A. photons) have zero mass, what we really mean is that they have zero "rest" mass.
In E=mc^2, E is the energy of unmoving particles.
For a moving particle, the eqn is~
E^2= (P^2 c^2) + (m^2 c^4)
Now, put m=0 for light in the above eqn, and you get~
E=Pc
So yeah, simply put the photons have zero mass, but they have energy. Just Google you'll get loads of stuff to read about it, or ask your science teacher.
Wow, I have got to research what "rest" mass is. Other than that, thanks for the info.
The weight of a box = x
Place some light into the same box and it now weighs x+1
Light has no weight.
It absolutely does - and so does everything else.
Light does have weight, meaning that it is a source of gravitational fields. A box of light weighs more than an empty box. The reason is that ALL forms of energy have weight.
Everything is energy in one form or another or it would not exist.
The sticking point is when mass becomes described as a “wave”. This is only convenience.
Nothing exists at absolute rest.
Hence - it must have weight.
I'm a fifth grader sooo i don't no anything about this
Nothing exists at absolute rest.
Hence - it must have weight.
Yes, but going back to what Abinhav said, light has zero "rest" mass. If something has no mass, it can not have weight. However, I am only in 7th grade, so I don't know quantum physics. If I am wrong, it is because I am just using my own common sense.
Common sense is best.
Think again.
If something has no mass... does it exist ?
Definitions .. definitions ....
Nothing is at rest to begin with !
It’s hypothetical.
If anything we’re to be truly at rest - it would have zero mass and infinite mass. Unmeasurable.
But since everything is in motion -
everything as weight - even a massless (by definition) wave.
Try this line of thinking...
if something exists - it can be measured. If it can be measured - it must have weight.
*note: weight and mass are not synonymous. By conventional definition a wave has no mass at rest - but it never is at rest and hence in motion it has weight.
A single photon has weight.
It’s even theorized that our thoughts have weight - as it is possible to measure them.
Try this line of thinking...
if something exists - it can be measured. If it can be measured - it must have weight.
*note: weight and mass are not synonymous. By conventional definition a wave has no mass at rest - but it never is at rest and hence in motion it has weight.
A single photon has weight.
It’s even theorized that our thoughts have weight - as it is possible to measure them.
Yeah, good point. Just seems strange that something with no mass could have weight.
Well ... everything does have mass. Just not in the traditional sense that the term invokes.. Terms get tricky. Mass gets defined differently - even in scientific reference according to which discipline is being discussed. “Mass” invokes a mental image. Quite a few things are not a match. I suggest - if it exists it has “something that can be measured/observed”. May as well call it all the same thing. Similar to energy/matter being one in the same.
Theories state “if at rest” such and such would posses zero mass. From this comes an extrapolation- helping us to understand it’s properties (which are never at rest). It’s a starting point. Some things move very slowly- others very fast as measured. Einstein helped us understand the relationship - it’s relative nature.
Nothing is at absolute rest. The earth is moving, our galaxy, all others. It’s impossible for anything to be at total rest. I think it’s the same idea regarding mass- nothing can exist if it does not posses substance, whether described as mass or a wave - as in light.
Remove a single photon from the universe and it’s nature has diminished. If it were possible to measure the difference it would be observed as being lighter. Weight is directly related to Gravity - a phenomenon that is barely understood regarding “why”? The how is measured with extreme accuracy. But as to why it happens remains the biggest scientific mystery. It’s postulated an elementary particle must exist making influence- the graviton. The search is long standing - but just might prove a dead end. The field is daunting- so much so many simply give up and pursue practical research.
The short answer is "no", but it is a qualified "no" because there are odd ways of interpreting the question which could justify the answer "yes".
Please don't give me those "odd ways". My mind will explode if you explain them.
Electromagnetic radiation does have mass, because it is pure energy, and energy can be converted into mass. I heard somebody weighed the Internet. It was the weight of a chicken's egg.
Electromagnetic radiation does have mass, because it is pure energy, and energy can be converted into mass. I heard somebody weighed the Internet. It was the weight of a chicken's egg.
???
Now, I am just a Middle Schooler, so I do not know much (okay, anything) about quantum physics and/or mechanics, but I do know Einstein's famous theory: E = mc^2 (^ means to the power of). For those of you who don't know what this means, it means "Energy equals mass multiplied by the square of the speed of light". That got me thinking; what is the equivalent energy of light? Since light has no mass, how can we use it to make energy via the use of solar panels? Wouldn't the energy equivalent of light be zero? Please post comments below.