The Physics of Starship Battles: Lasers and Kinetic Energy

[Starfox1701]

http://www.youtube.com/watch?v=0AV5aY7HYAk

I liked and wanted to share

 

[Hellkite]

true and quite enjoyable

 

[Majestic]

I'll have to wait till I get new speakers before I can fully enjoy any video. My old ones start to cause issues with my PC, making it unable to start and zapping too much power.

 

[Atlantis]

I'm not sure I agree with the bit about "blue and purple lasers are better than red and orange ones". Well, I sort of agree with it, but not the reasoning given.

The way I see it, the frequency of a Laser determines the colour (Duh!), and the... hmm, how to put it... "sliceyness" of the laser. The higher frequency means that instead of broad "punching" damage, it can more easily penetrate the molecular structure. Note that this is NOT simply the amount of damage it can do, but HOW it damages the target.

Example: Babylon 5. The Earth Alliance and the Narn Regime's Red Lasers tend to "punch" more. There's a bit of slicing, but (with exceptions, I'm sure) that's more of a "sword" kind of slice than "surgical scalpel". For that, we look further along the spectrum. The Minbari's yellow/green lasers are more slicey, but even that's nothing compared to... the SHADOWS, with their purple lasers (as shown in that video), and the Drakh with their blue lasers.

Real reason for damage: The damage itself is caused by the energy transferred within the wave, not the shape of the wavelength itself. If you look at the graph of a wave, the energy is the amount of area contained between the wave line and the 0 line. So, whether you have a red frequency or a purple frequency, if you have a big amplitude, you can still kick it.

*wanders off to watch the rest of the video*

 

[Hellkite]

The thing is this is real physics that were taking about here what we see on show is irrelevant given that they are fantasy based

 

[Starfox1701]

Real reason for damage: The damage itself is caused by the energy transferred within the wave, not the shape of the wavelength itself. If you look at the graph of a wave, the energy is the amount of area contained between the wave line and the 0 line. So, whether you have a red frequency or a purple frequency, if you have a big amplitude, you can still kick it.

Since is the measurment of the wavelength from peak to trough, not the number of waves in a pulse it doesn't show total energey expended. Merely the energy of a single wave. Therfore how is it the mechanisum for showing damage potential?

 

[Atlantis]

That's exactly my point. It's NOT the wavelength/frequency, but the amplitude which defines energy (therefore damage), surely.

 

[Starfox1701]

Actuall its the Hz; the number of cycles over a given timeframe. 2 lassers can have the same amplitude but different Hz and the 1 with the highest Hz will be the most damaging.

 

[Atlantis]

But a purple light does not deliver more light than a red one. The colour is different, but it's just as bright either way.

 

[Hellkite]

wavelength has everything to do with the color

Our eyes are sensitive to light which lies in a very small region of the electromagnetic spectrum labeled "visible light". This "visible light" corresponds to a wavelength range of 400 - 700 nanometers (nm) and a color range of violet through red. The human eye is not capable of "seeing" radiation with wavelengths outside the visible spectrum. The visible colors from shortest to longest wavelength are: violet, blue, green, yellow, orange, and red. Ultraviolet radiation has a shorter wavelength than the visible violet light. Infrared radiation has a longer wavelength than visible red light. The white light is a mixture of the colors of the visible spectrum. Black is a total absence of light.

Violet Light
The visible violet light has a wavelength of about 400 nm. Within the visible wavelength spectrum, violet and blue wavelengths are scattered more efficiently than other wavelengths. The sky looks blue, not violet, because our eyes are more sensitive to blue light (the sun also emits more energy as blue light than as violet).
Indigo Light
The visible indigo light has a wavelength of about 445 nm.
Blue Light
The visible blue light has a wavelength of about 475 nm. Because the blue wavelengths are shorter in the visible spectrum, they are scattered more efficiently by the molecules in the atmosphere. This causes the sky to appear blue. blue spectrum.
Green Light
The visible green light has a wavelength of about 510 nm. Grass, for example, appears green because all of the colors in the visible part of the spectrum are absorbed into the leaves of the grass except green. Green is reflected, therefore grass appears green. green spectrum.
Yellow Light
The visible yellow light has a wavelength of about 570 nm. Low-pressure sodium lamps, like those used in some parking lots, emit a yellow (wavelength 589 nm) light. yellow spectrum.
Orange Light
The visible orange light has a wavelength of about 590 nm.
Red Light
The visible red light has a wavelength of about 650 nm. At sunrise and sunset, red or orange colors are present because the wavelengths associated with these colors are less efficiently scattered by the atmosphere than the shorter wavelength colors (e.g., blue and purple). A large amount of blue and violet light has been removed as a result of scattering and the longwave colors, such as red and orange, are more readily seen.


As seen in the Following Formula

In other to have get lambda IE wavelength, divide frequency by : speed of light

The shorter the wave wavelength the Higher the frequency they are dependent variables


to the point

Spoiler: Laser

A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The emitted laser light is notable for its high degree of spatial and temporal coherence, unattainable using other technologies. Spatial coherence typically is expressed through the output being a narrow beam which is diffraction-limited, often a so-called "pencil beam."

Temporal (or longitudinal) coherence implies a polarized wave at a single frequency whose phase is correlated over a relatively large distance (the coherence length) along the beam. This is in contrast to thermal or incoherent light emitted by ordinary sources of light whose instantaneous amplitude and phase vary randomly with respect to time and position. Although temporal coherence implies monochromatic emission, there are lasers that emit a broad spectrum of light, or emit different wavelengths of light simultaneously.

Most so-called "single wavelength" lasers actually produce radiation in several modes having slightly different frequencies (wavelengths), often not in a single polarization. There are some lasers which are not single spatial mode and consequently their light beams diverge more than required by the diffraction limit. However all such devices are classified as "lasers" based on their method of producing that light and are generally employed in applications where light of similar characteristics could not be produced using simpler technologies.

In laser the lower the wavelength the deeper the color shift to Violet side of the spectrum and the higher the photon temporal coherence

or in layman the more power it has because it is delving more photons per unit of time so more powerful


[Takes off Spock ears and put back on his flight jacket ]

 

[Starfox1701]

[Takes off Spock ears and put back on his flight jacket ]

Gee I thought you'ed by wiping of the data makup Thanks thats whar I was tring to say

 

[Hellkite]

Gee I thought you'ed by wiping of the data makup Thanks thats whar I was tring to say

They are easier to keep in a pocket than a jar of gold paint and a lot easier to take off and put on in a pinch

 

[Atlantis]

Yes... I understand that shorter wavelength means MORE waves, but if the amplitude is the same, then those waves are actually SMALLER in AREA. (height x width)

The energy transferred is equal to the area contained within the wave.
Let's say purple has a frequency double that of red.

So if you have a red light, you have a wave 1 "unit" high and 2 "units" wide.
If you have a purple light, you have TWO waves, each 1 "unit" high (no change in amplitude) and ONE "unit" wide.

My point is, what is the area contained within the waves? Do two "narrower" waves contain more area than one "wider" one?

I know the proportions aren't 1:2, but that doesn't matter. If n=1 and 2n=2, then any proportion also matches.

 

[Starfox1701]

I think this comes down to how photon are different then conventional matter. With normal matter you need space to get more in and therefore carry more energy. Since photons behave like waves as well as particals the oposite is true the less space the higher the amount of energy.

 

[Adm_Z]

Its funny that they use C for the speed of light, implying its a constant when its not. I could be wrong, but I remember reading that the speed of light is no longer considered a constant because it does change under certain circumstances.

 

[Atlantis]

Hmm, also I suppose it's important to remember conservation of energy. Energy in = Energy out.

Unless red is less "efficient" than purple, it should be the same energy transference anyway...

 

[Dominus_Noctis]

I'd prefer using gamma or x-ray over any of those visible light beams of limited death in any case

Its funny that they use C for the speed of light, implying its a constant when its not. I could be wrong, but I remember reading that the speed of light is no longer considered a constant because it does change under certain circumstances.

It's a constant as defined by by EM traveling in a vacuum. Of course wavelengths of light can be slowed down - aka, refractive index - but that has absolutely zilch to do with the fact that c is independent of the inertial frame of reference, or the source that emitted the signal . If this were not the case, you'd know immediately. Say goodbye to your computer!

 

[Starfox1701]

Unless red is less "efficient" than purple, it should be the same energy transference anyway...

Exactly the larger the wave the less efficient it is as it takes longer to impart the power becaause it takes longer to cycle.

 

[Atlantis]

Exactly, but it has twice as much power to give! Twice the wavelength = twice the area contained within. 2x1=1x2. Energy in = energy out.

 

[Starfox1701]

Remember Light speed is constant. The only way to get more power in is to shortn thecycle time and that means shortening the wavelength.

 

[Hellkite]

[Puts Spock ears back on]

Nope Atlantis


The longer the wavelength weaker the Lower the frequency weaker the laser

and the counter-positive is true

The shorter the wave wavelength the Higher the frequency stronger the laser


You need to look at in Quantum mechanics and see that light has Wave–particle duality

Spoiler: Wave–particle duality

Wave–particle duality is the concept that all matter exhibits both wave and particle properties. Being a central concept of quantum mechanics, this duality addresses the inadequacy of classical concepts like "particle" and "wave" in fully describing the behavior of quantum-scale objects. Standard interpretations of quantum mechanics explain this ostensible paradox as a fundamental property of the Universe, while alternative interpretations explain the duality as an emergent, second-order consequence of various limitations of the observer. This treatment focuses on explaining the behavior from the perspective of the widely used Copenhagen interpretation, in which wave–particle duality is one aspect of the concept of complementarity, that a phenomenon can be viewed in one way or in another, but not both simultaneously.

to put it in to layman and ms paint graphing

The red and blue are the paths of photons for a red and blue laser as they hit a target every time they crosses the white time line a photon hits the target

As you can see The Blue crosses the line significant more time over the same amount of time than the Red


So more photon have hit the target in the blue laser


In physics, power is the rate at which work is performed or energy is converted

If ΔW is the amount of work performed during a period of time of duration Δt, the average power Pavg over that period is given by the formula

It is the average amount of work done or energy converted per unit of time. The average power is often simply called "power" when the context makes it clear.

In our cast (W) Work is the number of photons hinting the target

 

[Atlantis]

So can you please explain the following:

1) What is the area contained within the wave graph then, if not energy?

It's the same as water. Waves closer together (but the same height) might make the water more "choppy", but the same amount of water is moving as in one bigger wave.

2) How can power out NOT = power in? How can power out be variable when power in is constant?

POWER OUT = POWER IN

If purple gives more energy out than red, where does the excess energy in red go?
If we're talking dissipation, then it's still power out, meaning DAMAGE doesn't change, but RANGE does.

Apologies for doublepost; too late to edit.

I'll just go ahead and answer them questions myself.

1) The area contained in the wave IS the amount of energy transferred.

2) To GET purple lasers takes more energy than red lasers to begin with. That's why purple stars are hotter than red ones.

So, energy IS conserved, and each unit of energy that goes in does come out, so pound for pound (or kW for kW, if you like) they DO give out the same damage potential. The difference is that to get purple lasers generally take more energy input to begin with, so you do end up with a higher output.

 

[Hellkite]

first off

Power is the rate at which work is performed or energy is converted

Energy is a quantity that is often understood as the ability to perform work.


Quantity: is a kind of property which exists as magnitude or multitude.


Rate: is a ratio between two measurements

It's the same as water. Waves closer together (but the same height) might make the water more "choppy", but the same amount of water is moving as in one bigger wave.

No Wrong

"The longer the wavelength weaker the Lower the frequency weaker "

Look if the Waves closer together you have reduced the the wavelength and increased the frequency in order for this to happen requires more energy

Simple put the wave are more energetic "have more energy in them "


back to the lasers

but remember that were dealing with a photon and the wave is just the resident frequency of the photon

 

[Starfox1701]

Yes rememeber photons don't act like normal mater and they have a fixed speed. The speed of a water wave or sound wave can change as the energy passes through the medium of transmission. Photons propagate in a vaccum and act like waves WITHOUT a transmission medium. They are nothing like kenetic waves like sound or water.

 

[Atlantis]

Ok, so I will repeat this question one more time.

How can "energy in" NOT = "energy out"? That's what you guys are saying.

If the "power" of the higher frequency is higher, the resultant amplitude MUST be lower. Because "energy in" DOES EQUAL "energy out".

Look up "conservation of energy".

 

[Starfox1701]

If the "power" of the higher frequency is higher, the resultant amplitude MUST be lower

Not with light. Speed is constant so more power in = higher frequency with the same or bigger amplitude. This is how conservation of energy works with light. This happens because speed is no longer a variable. Newtonian physics don't always hold up here in the world of Quantum Mechanics. Energy in still = energy out but it behaves in a manner inconsistent with other waveforms.

 

[Hellkite]

Ok, so I will repeat this question one more time.

How can "energy in" NOT = "energy out"? That's what you guys are saying.

If the "power" of the higher frequency is higher, the resultant amplitude MUST be lower. Because "energy in" DOES EQUAL "energy out".

Look up "conservation of energy".

The law of conservation of energy is an empirical law of physics. It states that the total amount of energy in an isolated system remains constant over time (is said to be conserved over time). A consequence of this law is that energy can neither be created nor destroyed: it can only be transformed from one state to another. The only thing that can happen to energy in a closed system is that it can change form: for instance chemical energy can become kinetic energy.

""For the record there is only one Closed / isolated system that being the Universe itself""


All Lasers is not are in open systems and interact with fundamental interactions forces

Spoiler: fundamental interactions

In physics, fundamental interactions (sometimes called interactive forces) are the ways that the simplest particles in the universe interact with one another. An interaction is fundamental when it cannot be described in terms of other interactions.

The four known fundamental interactions, all of which are non-contact forces, are electromagnetism, strong interaction, weak interaction (also known as "strong" and "weak nuclear force") and gravitation.

 

[Atlantis]

OK, but using the particle side of the duality:

Total energy = Energy per Photon x Number of photons
(all "per time period)

Total energy stays the same, as you can create any colour with any power, as colour in light is caused by absorption spectra.

A purple colour means a higher wavelength, so given the same power input, this means LESS PHOTONS per time (but at a higher energy for each photon).

For one to go up and one to stay the same, the other must go down. Mathematics.

So you have red light, with more photons at lower energy, or purple light with less photons but higher energy. The same total energy. The only way to increase "energy out" is to increase "energy in".

Otherwise, can you explain where the "extra energy in" comes from to make your purple super-laser? If it's "a bigger power source", then you can still plug that power source into a red laser and get the same "energy out".

This still leads to "same damage AMOUNT, different damage STYLE", I'm afraid.

 

[Hellkite]

Using the particle side of the duality

You do know that the total photon density in the beam is that gives it it color right ??


Photon density and wavelength are inverse

Ie

Photon density goes up wavelength will decrees and Vice versa

 

[Atlantis]

So you are saying that the photons of red light carry more energy each? If higher wavelength = decreased density, then to maintain constant energy total, decreased density = increased energy per particle. When I suggested, that you told me I was wrong. For one to go up, the other MUST go down, to keep the total equal.

This is really overcomplicating it. It's unnecessary, as the answer is simple.

No-one seems willing to answer my question "Where does the "extra" energy come from in these purple lasers?" so I will rephrase it again and hopefully make it clear.

The only way to get more energy (therefore damage) out is to put more energy in.
(If this is wrong, then please explain where the "extra" energy comes from? How can you "create" energy out of nothing?)

The only reason purple lasers are more powerful is because the purple light has more energy put into it by its power source. The wavelength/colour is a SIDE-EFFECT of the INCREASED ENERGY, not the REASON behind it.

So to have a more powerful laser, you just put more power into it. Which, if you care to look back and read it, is what I said in my original post.

My speculation as to the type of damage (sliceyness) is a separate thing entirely, based on an idea of some kind of resonance difference from how the different frequencies might interact with their target, regardless of energy amount