Why do we think light travels the same as sound? Some questions for astrophysics folks out there

[Space Lynx]

Wavelength is easy to explain in light. Let me ask you a simple question...what is the color observed?

Question ? Do Light Photons have Mass

Answer of Course they Do...............

or the working principal of Light Sail's is general proof of this.
Light Photons push Light Sail's ................To Push something physical you need mass
"Newtons law"

Depends what color you are talking about, there are some colors humans can't see, and some other colors that only 0.1% of all humans can see called tetrachromat people and make up 0.1% of the population. we know there are colors we can not see and others that we can see but in limited shades, so maybe the universe is literally... so you tell me where is the color humans can not see observed on the wavelength?

does denser gravity bend light differently than lighter gravity? i would need to understand this as well to see if its similar to sound and air. I'm not convinced that sound travels differently on other planets with different chemical makeups, I agree with you if we are talking about sound on Earth, but sound on other planets may be an entire different beast.



I forgot about light sails, hmm, interesting to think about.

 

[A Computer Guy]

I'm not convinced that sound travels differently on other planets with different chemical makeups, I agree with you if we are talking about sound on Earth, but sound on other planets may be an entire different beast.

I'm confused by your statement. (if we assume this statement from wikipedia is correct) In physics, sound is a vibration that propagates as an acoustic wave, through a transmission medium such as a gas, liquid or solid. Why would sound work any differently here vs. out there on other planets?

If light (not in a vacuum) has mass does it make a sound when it hits a surface? Does it sound differently depending on how much is absorbed or reflected from that surface?
And as a bonus question: If it does sound differently could one transmit (non-digital) music across space time with the right pattern of light?

 

[dorsetknob]

I forgot about light sails, hmm, interesting to think about.

Knew a Retailer of Marching Powder ( in my Youth)
He Was a tight complaing sod and i Sold him
A Set of Pharmacutical Balance Scales inc very large bell Dome ( made whole scales Airtight )
Chuffed to wuck with their accuracy ............and to prove how sensitive they were i shone a mirror reflecting the sun on to one of the perfectly balance pans.
guess what the illuminated pan Dipped

 

[A Computer Guy]

Knew a Retailer of Marching Powder ( in my Youth)
He Was a tight complaing sod and i Sold him
A Set of Pharmacutical Balance Scales inc very large bell Dome ( made whole scales Airtight )
Chuffed to wuck with their accuracy ............and to prove how sensitive they were i shone a mirror reflecting the sun on to one of the perfectly balance pans.
guess what the illuminated pan Dipped

AH ha! Did it dip because of the light or because the light was heating the surface causing the air to move the illuminated pan downward?

 

[Count von Schwalbe]

If it does sound differently could one transmit music across space time with the right pattern of light?

The Pentagon Mimicking Human Speech With Lasers Is the Creepiest Thing You’ll Hear All Week

In the future, that disembodied voice you hear could be nothing more than two lasers interacting with one another.

www.popularmechanics.com

so you tell me where is the color humans can not see observed on the wavelength?

Visible light is only one small part of the electromagnetic spectrum. Everything from radio waves, gamma waves, microwaves, light, radiated heat, et cetera are all part of the electromagnetic spectrum.

 

[AusWolf]

Depends what color you are talking about, there are some colors humans can't see, and some other colors that only 0.1% of all humans can see called tetrachromat people and make up 0.1% of the population. we know there are colors we can not see and others that we can see but in limited shades, so maybe the universe is literally... so you tell me where is the color humans can not see observed on the wavelength?

Here.

 

[lexluthermiester]

Question ? Do Light Photons have Mass

Answer of Course they Do...............

or the working principal of Light Sail's is general proof of this.
Light Photons push Light Sail's ................To Push something physical you need mass
"Newtons law"

Very good example.

 

[Space Lynx]

Visible light is only one small part of the electromagnetic spectrum. Everything from radio waves, gamma waves, microwaves, light, radiated heat, et cetera are all part of the electromagnetic spectrum.

this is precisely my point, maybe there are things on the end of that that we still don't understand, the spectrum I always see in science lecture with the visible medium, then it expands outward as you point out, what if it expands outward even more than we realize? maybe this is why we don't understand or mislabel Dark Matter/Energy? we observe things but can't explain it.

the human eye color thingy was just an example in this direction

 

[TumbleGeorge]

It takes an incredible amount of gravity to affect light

No. Any amount of force affect. Just you may problem to see that with your eyes when gravity isn't an "incredible amount"

 

[Count von Schwalbe]

Dark Matter/Energy

If you really want to break your brain, there is a theory of the universe (the electrical theory I believe) that thinks those are constructs to support the gravitational theory, and that they don't exist. Which, considering that quantum mechanics and general relativity are fundamentally at odds with each other, seems at least plausible.

 

[1freedude]

What is your favorite radio station?

 

[JoeTheDestroyer]

Sound involves transfer of kinetic energy through matter and so requires a medium to propagate. (Think of it as billiards/pool balls bouncing of each other. There can't be any bounce without the balls.)

Light is a self-propagating packet of electric and magnetic fields. Simple physics, a changing electric field induces a magnetic field, but that changing magnetic field itself induces an electric field. Repeat ad infinitum. It travels via energy transfer between the two field types, thus needs no medium to propagate. Or to put it a different way, light is its own medium.

Wave-particle duality is often misunderstood to mean a photon can switch between the two types, that's not the case. A photon is a wavefront, but due to its self-reinforcing nature it forms a packet of traveling energy with position and size, thus has particle-like properties. In other words, it has both wave-like and particle-like properties simultaneously.

Final bit...the speed of light and the speed of sound are dependent upon their medium. ... Light travels at light speed only in a vacuum...and science has effectively demonstrated a near stop of light in a medium.

False. You're confusing effective speed with true speed. To vastly oversimplify, light gets bounced around inside matter so the actual travel path is much longer than the observed distance.

The speed of light as a physical constant (for example as used in relativistic applications as the "ultimate speed limit of the universe") does not change inside matter.

Question ? Do Light Photons have Mass

Answer of Course they Do...............

or the working principal of Light Sail's is general proof of this.
Light Photons push Light Sail's ................To Push something physical you need mass
"Newtons law"

This is debatable. First off, quoting Newton here is pretty sketchy because Newtonian physics are only a sub-relativistic approximation to "true" physics (whatever that turns out to be).

However, even taking Newton at face value, your argument is flawed because strictly speaking Newton only requires a transfer of momentum. And although Newton is usually described in terms of mass-with-momentum, there's no requirement that mass and momentum need be inextricably tied. In fact, photons having been proven to have momentum, but thought to be without mass, were long held up as the poster child of this concept.

On the other hand, it is now known that photons do induce a gravitational field when it was long held that mass was required for this. So either photons do have mass, or gravity does not require mass, only energy.

Honestly, I don't find it a terribly fruitful debate. In any way that matters to physics, there is no difference between energy and mass. In a way, it gets into circular definition territory, because energy vs. mass is really only a human distinction, so we can talk about the difference between taking a spotlight or a bowling ball to the face.

 

[backwoods]

Sound vs the speed of Light becomes apparent with lightning. You’ll always see lightning before you hear the sound of thunder, because at great enough distance the speed difference becomes apparent to your brain.

 

[JoeTheDestroyer]

Depends what color you are talking about, there are some colors humans can't see, and some other colors that only 0.1% of all humans can see called tetrachromat people and make up 0.1% of the population. we know there are colors we can not see and others that we can see but in limited shades, so maybe the universe is literally... so you tell me where is the color humans can not see observed on the wavelength?

Color and the wavelength of light are not equivalent. The wavelength/frequency of light is a physical measurable property of individual photons.

Color is a non-physical term used to describe how mixtures of light (i.e., many wavelengths together) are perceived. And, as such, depend upon who is doing the perceiving. The classic example is the color "pink", which doesn't describe a specific frequency of light, but rather a mixture of white light (i.e., all visible wavelengths) with a strong red component. The trichromat nature of typical human vision lets us distinguish this particular mixture from others. Tetrachromats can distinguish between more types of mixtures, thus see more "colors". Bichromats (and humans with color deficiencies, though not exactly equivalent) can distinguish fewer mixtures and thus less colors.

Another example, from the opposite direction, is to consider the color yellow being show to you on your display. In no part of this process is "yellow" light involved (i.e. photons with a wavelength around 580nm). Red and green photons are emitted from the display and enter your eye. Those photons trigger your eye sensors in a way that matches what pure yellow light would do, and thus we perceive it as "yellow".

If you've ever noticed how pets tend to respond differently to photographs on a display vs. the real object, this is why. Many animals are bichromats and perceive color differently than humans. The mixtures of red, green and blue photons that cause humans to perceive a certain color, trigger those animals' sensors in a very different way causing a different color to be perceived. So while the photograph and real object look the same to you, they can look like very different things to your pet.

 

[agent_x007]

No. Any amount of force affect. Just you may problem to see that with your eyes when gravity isn't an "incredible amount"

Eyes have nothing to do with it. Bending light path using Earth's scale of gravity (~9.8m/s^2) is pretty funny.
You basically can't* observe a bend path of light that passes Earth's level of gravity field.
*As even measuring how big of impact it has, will be REALLY hard to do (side note, speed of light = 300 000km/s, and not 300km/s ). Some scale : A photon from outer space, get's pass a planet size of Earth (2x radius of Earth), in ~0.0000424 seconds, or ~0.0424ms.

As for OP question :
As far I know, if "space" can expressed in 3 dimensions, it's "space" a light can exists in (since it's particle/wave "thing", I'm bypassing "true nature of light" here), and if it you add "time" concept to that three dimension space, light can travel through it.
No need for other thing(s) inside, light is it's own "medium" (ie. photon), which will exists where light is (regardless of other stuff in environment, it simply is "generated" under physics/chemistry laws and send away)

Gravity can bend lights path, Yes.
However just because it does it on big scale (Star scale), doesn't mean it does it in measurable way on small scale (as mentioned in my response to quote at beginning of this post). If it helps, maybe try to think of how gravity works on small scale, more like anti-magnetic force. Where it (gravity), doesn't work on small scale in any meaning full way (opposite to magnetic force, which get's more visible the closer two polarized objects are to each other).
Example : Let's assume you want to shoot a modern pistol/rifle at target 100 yards away.
You will be more concerned about wind forces/air resistance, than how much target's gravity field will impact bullet's trajectory (even Earth's gravity will have very limited effect at this scale).
Example 2 : Making small objects (human size), stick to each other using only gravity they generate naturally "doesn't work" (too many other forces having larger impact in real life).

Lastly, about "bending" space/time fabric stuff with gravity :
Gravity simply pulls objects that have mass closer to each other. Object will be "grabbed" by bigger one that is around it (if there are no other factors). "Bending" is result of having mass, and AFAIK, it doesn't require "a medium" to work either (can be proved wrong someday).

 

[kapone32]

What is insane is that we are only aware of 1% of what we call light. Light is also not a constant but effected by Gravity around black holes and passing through and around Galaxies. I love the qoute from Isaac Newton that says "Man's knowledge is like a pebble of sand on a vast beach with a infinite ocean in front". Too bad we are getting dumber with each generation unless you are gilded.

 

[mechtech]

No. Any amount of force affect. Just you may problem to see that with your eyes when gravity isn't an "incredible amount"

True, but it takes an incredible amount to create an incredible difference. I know, cause I can't cause gravitational lensing with my personal gravity

I've tried..............my wife can still see me....................

 

[TheoneandonlyMrK]

I am very much fascinated by light, we all should be.
I spend my days working on the specific wavelength of sulphur, using it to quantify content.
Bit dull but I do love the mad amount of different science you can do with light,.

Still no lightsAber though, which indicates something, were shit I think not sure.