Let's discuss science.

[Morganator]

Interesting little fact I'd like to share with you all.

The universe is expanding at a rate that is faster than the speed of light. Right now, there are galaxies that are moving so fast, we'll never see them unless we break the light barrier. The universe's rate of expansion directly contradicts the theory being espoused that nothing can travel faster than the speed of light.

[Rapture]

Interesting little fact I'd like to share with you all.

The universe is expanding at a rate that is faster than the speed of light. Right now, there are galaxies that are moving so fast, we'll never see them unless we break the light barrier. The universe's rate of expansion directly contradicts the theory being espoused that nothing can travel faster than the speed of light.

Well it's not so such that we won't see them as it is they still emit light that will one day reach the Earth. Also, these galaxies are and aren't moving faster than the speed of light. The universe (spacetime) is simply expanding in every direction at once, but the matter itself is not accelerating to and past c. The reason this happens is because each point in the universe functions as its own reference frame for a center. To us, that distant galaxy may seemingly be traveling at faster than light speed because of the universal expansion away from us, but really it may be moving only at 60kms. So it's actually not a contradiction.

[itachi73378]

Well it's not so such that we won't see them as it is they still emit light that will one day reach the Earth. Also, these galaxies are and aren't moving faster than the speed of light. The universe (spacetime) is simply expanding in every direction at once, but the matter itself is not accelerating to and past c. The reason this happens is because each point in the universe functions as its own reference frame for a center. To us, that distant galaxy may seemingly be traveling at faster than light speed because of the universal expansion away from us, but really it may be moving only at 60kms. So it's actually not a contradiction.

Okay so lets say we live in galaxy A and we see galaxy B travelling away from us faster than light. From Galaxy B's frame of reference, Galaxy A is moving away from it faster than light. So any light coming from galaxy B won't reach galaxy A. Its like saying a car going 40km/h can catch up to a car going 60km/h

That's just what I think. May be completely wrong (most probably)

[the_jim]

Interesting little fact I'd like to share with you all.

The universe is expanding at a rate that is faster than the speed of light. Right now, there are galaxies that are moving so fast, we'll never see them unless we break the light barrier. The universe's rate of expansion directly contradicts the theory being espoused that nothing can travel faster than the speed of light.

But it's the SPACE between the galaxies that is expanding and space doesn't carry information. It's a bit like saying shadows are FTL when they aren't really.

EDIT: I see Rapture beat me to it

Although, within the "observable universe" we would never see any galaxies moving away from us FTL because the light would be trying to go through an ever expanding space and would never reach us. Itachi's comparison to the two cars is exactly right.

it was my understanding that our understanding on gravitons was less than that of the higgs?

i certainly know a fair bit about the higgs but damn near nothing on gravitons o.O other then its omission from the standard model

given how little is known about black holes though it would be best to look at the next best thing, and something we know to be part of the standard model, electromagnetism. they're near enough the same thing...

photons are energy that have no mass. its my understanding that the 'energy' present in a photon is not constant, it varies, kinda like a beacon. this energy cannot vanish or travel so it must be carried by something when it[photon] has no energy. if the photon has no energy then the energy is held outside the packet....i believe this is where the 'virtual particle' comes from

Yes, it would seem the graviton is still in the teritory of a "theoretical" particle. Considering the size of the LHC just to find the Higgs, you would think something similar could be made to find the graviton...

But it's very near impossible in practice- I read that a detector the size of Jupiter would need to be in operation for 1000's of years, just to see one graviton

Thanks for shedding some light on the virtual particles though (excuse the pun )- I guess the energy has to be somewhere if E=mc^2 and there is no mass!

[Super_Lilith]

Why do we have seasons?

[RaY_210]

Why do we have seasons?

I believe it has to do with the angle of the Earth to the sun. Don't know where you're from, but when you're tilted closest to the sun, it's summer. When you're tilted furthest, it's winter. I'm sure someone else can elaborate better

[LC77]

What went BANG!?

[Morganator]

Well it's not so such that we won't see them as it is they still emit light that will one day reach the Earth. Also, these galaxies are and aren't moving faster than the speed of light. The universe (spacetime) is simply expanding in every direction at once, but the matter itself is not accelerating to and past c. The reason this happens is because each point in the universe functions as its own reference frame for a center. To us, that distant galaxy may seemingly be traveling at faster than light speed because of the universal expansion away from us, but really it may be moving only at 60kms. So it's actually not a contradiction.

Actually, these points will never be seen by each other since the rate of expansion between the two points is faster than light. But you are right about one thing. the matter is not accelerating, however, the matter was already moving at faster than light.

[Rapture]

Actually, these points will never be seen by each other since the rate of expansion between the two points is faster than light.

Actually, we can already observe galaxies exceeding the speed of light as we can detect galaxies with a redshift greater than 1.4. The moment we can no longer see the light is when the expansion of spacetime exceeds a theorized threshold and approaches a sort of cosmological event horizon.

But you are right about one thing. the matter is not accelerating, however, the matter was already moving at faster than light.

But it's not. From our perspective it's moving at or faster than c, but again the matter itself is not. It's impossible for particles with mass to move faster than light. This is the basics of relativity: Driving a car backwards while turning your headlights on means you're moving away from the photons at faster-than-light speeds, but you're really only at a a small speed general speed. Spacetime is not bound by energy requirements in its expansion, whereas mass is in its acceleration.

To prove my point, consider that we are moving away from these galaxies at FTL speeds. Light propagates at c within our relative space perfectly fine, so we can conclude that we and they (the other galaxies) are not traveling faster than light. Also, if your statement was true, it contradicts itself as the matter would always be accelerating, and at one point is did accelerate to c.

Unless this is what you already meant? Because I got the impression that you were disagreeing with me.

[keefy]

Lets make science interesting

[Morganator]

Actually, we can already observe galaxies exceeding the speed of light as we can detect galaxies with a redshift greater than 1.4. The moment we can no longer see the light is when the expansion of spacetime exceeds a theorized threshold and approaches a sort of cosmological event horizon.



But it's not. From our perspective it's moving at or faster than c, but again the matter itself is not. It's impossible for particles with mass to move faster than light. This is the basics of relativity: Driving a car backwards while turning your headlights on means you're moving away from the photons at faster-than-light speeds, but you're really only at a a small speed general speed. Spacetime is not bound by energy requirements in its expansion, whereas mass is in its acceleration.

To prove my point, consider that we are moving away from these galaxies at FTL speeds. Light propagates at c within our relative space perfectly fine, so we can conclude that we and they (the other galaxies) are not traveling faster than light. Also, if your statement was true, it contradicts itself as the matter would always be accelerating, and at one point is did accelerate to c.

Unless this is what you already meant? Because I got the impression that you were disagreeing with me.

Actually, what I'm saying is that the universe has been expanding at a rate faster than light since the beginning.

[Fijiandoce]

Lets make science interesting

professor cox is GOD!!

his BBC series 'Wonders of the Universe' is just epic! if you have a HD screen and love the universe you need to buy and watch this show.

[Super_Lilith]

I believe it has to do with the angle of the Earth to the sun. Don't know where you're from, but when you're tilted closest to the sun, it's summer. When you're tilted furthest, it's winter. I'm sure someone else can elaborate better

So are you saying that the seasons are because of the distance a place on the Earth is from the Sun?

[MacP]

Additionally, anyone with basic understanding of special relativity would know that this would allow one to construct a scenario where you can send information back in time, which to the cries of many science fiction writers and dreamers is simply impossible

This well could be happening right now, have you ever heard Einstein's theory time dialiation? Well if we are able to bridge that gap between other planets. http://en.wikipedia.org/wiki/Time_dilation then who knows what is possible.

[keefy]

So are you saying that the seasons are because of the distance a place on the Earth is from the Sun?

Not exactly.
Depends on the hemisphere.
Southern hemisphere Summer occurs closest to the sun.
Northern hemisphere summer occurs furthest from the sun.

The main thing that effects the seasons is as Ray says the tilt of the earth as it spins around the sun which is 23.5 degrees.
IT seems as though its more about focusing of light than the distance itself. Kind of like using a magnifying glass to burn leaves or ants. If you hold it too close it will not burn anything same for too far but if you get it right it will burn and set things on fire.

[Rapture]

Actually, what I'm saying is that the universe has been expanding at a rate faster than light since the beginning.

That certainly doesn't seem like what you were saying. Explain.

This well could be happening right now, have you ever heard Einstein's theory time dialiation? Well if we are able to bridge that gap between other planets. http://en.wikipedia.org/wiki/Time_dilation then who knows what is possible.

I'll read into it.

Edit: OK, this is exactly what I knew it to be. Time dilation allows, at best, time-travel into the future, but that's a hard and hopeful theoretical. As of present there is zero support to show that time travel into the past is even remotely possible -- again, this would commit causality. Everything we know suggests that it's simply impossible.

[itachi73378]

Watched the first episode of "Wonders of the Universe"

Simply amazing

[Morganator]

That certainly doesn't seem like what you were saying. Explain.

What I mean is that the rate the universe is expanding - since the big bang - has been faster than light. Scientists have done the calculations and what they're saying is that because the universe is expanding at a rate that is faster than light, there are galaxies' light source which you nor I will never be able to see conventionally. Perhaps I may be wrong though. Afterall, I got this information from this show and I'm basing my argument on that.

[Super_Lilith]

Not exactly.
Depends on the hemisphere.
Southern hemisphere Summer occurs closest to the sun.
Northern hemisphere summer occurs furthest from the sun.

The main thing that effects the seasons is as Ray says the tilt of the earth as it spins around the sun which is 23.5 degrees.
IT seems as though its more about focusing of light than the distance itself. Kind of like using a magnifying glass to burn leaves or ants. If you hold it too close it will not burn anything same for too far but if you get it right it will burn and set things on fire.

I'm still a little confused, what has the tilt of the Earth got to do with the focusing of light?

Thank you very much.

[smiggy]

Watched the first episode of "Wonders of the Universe"

Simply amazing

Ah this is a great series, also check out Wonders of the Solar System if you haven't already. Also by Brian Cox and the BBC.

I'm still a little confused, what has the tilt of the Earth got to do with the focusing of light?

Thank you very much.

This should help

[Super_Lilith]

LOL so during summer the sunlight hits the Earth at a more head on angle and during winter at a more extreme angle: so the energy per unit area from sunlight is greater during summer and less during winter.

All this talk about CERN and boson and faster than speed of light stuff to stretch your epenises and no one could explain Seasons properly except this vid...

[keefy]

what I posted I learnt at school 15-20 years ago so forgive my epenis for being rusty next time I wont bother.


Physics isn't the only science.

[Rapture]

Or, more realistically, no one chose to. The cause for Earth's season's is fairly basic; sun spots, the elliptical orbit, and the tilt of the Earth. Besides, Keefy gave a general enough explanation to you.

What I mean is that the rate the universe is expanding - since the big bang - has been faster than light. Scientists have done the calculations and what they're saying is that because the universe is expanding at a rate that is faster than light, there are galaxies' light source which you nor I will never be able to see conventionally. Perhaps I may be wrong though. Afterall, I got this information from this show and I'm basing my argument on that.

I see. Then I misunderstood your point. It should take about 16 billion years of space expansion before a galaxy passes the 'sight threshold', and the universe is only 14 billion years old. I've read that there are galaxies beyond our sight, but I don't see how given the math. I'll be sure to look more into it, but I think it relates to comoving distance.

[Morganator]

I see. Then I misunderstood your point. It should take about 16 billion years of space expansion before a galaxy passes the 'sight threshold', and the universe is only 14 billion years old. I've read that there are galaxies beyond our sight, but I don't see how given the math. I'll be sure to look more into it, but I think it relates to comoving distance.

It's cool man. If I'm wrong, I'm wrong and will learn from it.

[MacP]

That certainly doesn't seem like what you were saying. Explain.



I'll read into it.

Edit: OK, this is exactly what I knew it to be. Time dilation allows, at best, time-travel into the future, but that's a hard and hopeful theoretical. As of present there is zero support to show that time travel into the past is even remotely possible -- again, this would commit causality. Everything we know suggests that it's simply impossible.

Basically when time elapses with planet B from planet A you get time dilation, I believe when that happpens that's how we see ghosts.