Deep shower thoughts: Light transporting information

Something occurred to me. When we see something, we are witnessing the reflection of light off an object. That light is transmitted through the air into our eyes which is converted into an image. That image is a reconstruction of the object you are looking at but not the actual object. With me so far? The old saying "if a tree falls in the forest with no one around, does it still make a sound?" falls in line with the following question. If an object is in space-time with no one to witness it, does it still reflect light? Like the tree, light requires an interface/receiver to 'decode' information, the same as an ear acts like a speaker. The tree falls, but without an ear to hear it, it only produces inaudible sound waves. However, those sound waves still contain "information" about the particular sound ie: branches breaking, leaves rustling, ground thumping. These are all attributes of the sound of a falling tree. Still with me?

Light contains similar attributes. A chair for instance. We can see it's height, it's dimensions, details in upholstery, composite and color. We can determine it's position in space-time and we can visibly see it at rest. But that's just the front of the chair. What about the back? Say, a chair in the middle of the room with a light shining above it. We 'know' light is reflecting off the chair into our eyes. But light is also reflecting off the chair away from us. Does it still contain information about the chair? I would venture to surmise, yes, why not? IF someone else was suddenly standing behind the chair, they too would see the information, therefore it exists.

So where am I going with this? Perhaps by now you may know what my next question is. Can unseen light be captured and decoded? A reflection of light where no one ever saw it. More simply, the past because essentially this is what the question proposes. If no one was there to witness the object then to retrieve any light from the object would be past-tense. But there's a problem. Do photons decay rapidly or are they infinite?

The notion of the speed of light as the cosmic speed limit is based on the assumption that particles of light, called photons, have no mass. But astrophysical observations cannot rule out the slim chance that photons do have a tiny bit of mass — a prospect with wide ramifications in physics. For instance, if photons weigh nothing at all, they would be completely stable and could theoretically last forever. But if they do have a little mass, they could eventually decay into lighter particles. Now, by studying ancient light radiated shortly after the Big Bang, a physicist has calculated the minimum lifetime of photons, showing that they must live for at least one billion billion years, if not forever.

www.nature.com...

If we can see the rings of Saturn, the sun or even distant galaxies, then light must have an incredible lifespan.

But according to COBE's measurements, the cosmic microwave background appears to behave like a perfect blackbody. No low-energy light seems to be missing, indicating that very few photons, if any, have decayed since the Big Bang some 13.7 billion years ago. This analysis enabled Heeck to calculate that the minimum lifetime of a photon is 1018, or one billion billion, years.

So, in conclusion. We know light carries information. We know photons exist for a very long time. We know information is carried regardless if anyone is there to see it. My next logical question would be...can we look into the past without the need of time travel? The universe is full of information about every single visible object that has ever existed.

I believe you just described what a camera does- it records light information, which can later be used to recreate a replay of what once was.

Light is photons- they live indefinitely as far as I know, and they move pretty darn fast. Problem is, the moment they hit an electron (which surround every atom) they're converted into heat energy.

When we look to the stars, we often see... well, stars. But they're far away- and that light is very old. We've witnessed the death of distant stars we've estimated to have exploded millions of years ago- so in that sense, yes we can witness the past.

However, we can't witness the back of the chair from last week, that light was absorbed by the nearby walls almost the instant it bounced off the chair.

Great reflection! I think the universe is SO more amazing that we already know, that there are things we won't belive until we see with our own eyes. (and probably we will still wonder "am I crazy or this $%!# real???)

We have already seen the past. Light moves at a constant speed relative to an observer. Therefore, if we observe the light from a star say, 200 light-years distant, we are seeing that star as it existed 200 years ago.

TheRedneck

ETA: so far as we know, light has an infinite range. It is only destroyed when it strikes matter which can absorb the energy it contains. The problem with seeing it after a certain distance is not that it weakens, but that it covers a larger area and therefore has a lower density. The overall energy content remains constant.

a reply to: TheFlyOnTheWall Nothing visual happens in the absence of visual perception. Nothing lasting happens in the absence of time-observer.
Nothing ever is.
Without your shade or kiss.
It's now, together, we all dwell.
Perfection never do, repeat itself.
The moment brings and kills the realm.
But it is still there...

a reply to: TheFlyOnTheWall

My next logical question would be...can we look into the past without the need of time travel?

Everything we see occurred in the past. The farther away it is, the farther in the past.

When we look at the Moon we see 1.3 seconds into the past. When we look at the Sun we see 8 minutes into the past.

a reply to: TheFlyOnTheWall

There's a term for people like you.

Quantum Nihilist

a reply to: TheFlyOnTheWall

Intuitively, I'd say all the information from the past to the future coexists in the present; it's just that some of that information is incrypted. I actually started another thread on it: The Arrow of Time. I'm wringing the bugs out of the code I'm using for my calculations. Hopefully I'll update it soon.

originally posted by: TheFlyOnTheWall
If an object is in space-time with no one to witness it, does it still reflect light?

Hypothetical objects don't emit or reflect light. They're imaginary. They don't exist.

a reply to: Blue Shift

Hypothetical objects don't emit or reflect light.

They do hypothetically.

originally posted by: PoetryInMotion
They do hypothetically.

If I was hypothetical, then maybe I would see it?

a reply to: Blue Shift

That's the question.....

a reply to: TheFlyOnTheWall

Such a fascinating subject!! We only see what the light shows us. I will contribute more later when I have time.

S&F!!

a reply to: Phage

Yes, of course. But what i'm suggesting is light from here is scattered throughout the universe. When we look at stars,we're looking in the past...of the star over there. But perhaps if we look hard enough, we can see the reflection of light that originated from here. The back of the chair from last week. Theoretically.

a reply to: TheFlyOnTheWall

Reflecting off of what? But there's this thing called the inverse square rule though. Sort of gets in the way. But you're not alone with your thought.
www.abovetopsecret.com...

a reply to: TheFlyOnTheWall

Something occurred to me. When we see something, we are witnessing the reflection of light off an object. ..
....That image is a reconstruction of the object you are looking at but not the actual object

That's right.

originally posted by: TheFlyOnTheWall
The back of the chair from last week. Theoretically.

Theoretically, no.

You're thinking about it wrong.

The "light" doesn't "carry information" in that sense. You can't grab some light that reflected off the face of Jesus, Buddha or whatever 2000 years ago and get a picture out of it by somehow sucking information from some random leftover bit of light.

Images are how light reflects or radiates from an object. It's the pattern of the reflections that carries the data, not the light itself. You have to separate the dancer from the dance here.

Once the light from the back of the chair hits the wall and reflects again, you've pretty much lost any hope of reconstructing the image of the back of the chair. A few more bounces, and the data's so conflated it's hopeless.

originally posted by: TheFlyOnTheWall

If we can see the rings of Saturn, the sun or even distant galaxies, then light must have an incredible lifespan.

The Sun's only about eight minutes away, in terms of a photon's flight. From Saturn to Earth, it varies from about 71 minutes to about 88 minutes. Distant galaxies are very far away, though, so there's that.

a reply to: TheFlyOnTheWall


Very interesting musings, the thing i have been thinking about is very similar in concept.Taking the state of the photon,its in a state where time has stopped for it, as its at the speed lof light, which seems a misnomer, because if its in "No time" it cant have speed,or any other dimension.It cant collapse. Since we interpret its information, the cause and effect of what we conclude is purly its information which is converted into a linear time reality.The same with all our other senses. So in reality all the information gathered,is from an infinite timeless state.So for anything meaningfull to occur, it has to be processed in linear time, where cause and effect can be computed.Thus conciousness is an integral part of reality, because it creates reality as a picture of three dimensions in your mind, its very clever because in reality their is just an infinite store of information. So when you have a really good dream,where are the photons and the sound waves coming from? they are as real as what we see around us..which begs the question again are we actually dreaming this reality.