79 réponses à ce sujet

[jamesp81]

Bearcut wrote...

Photons do have mass.

Edit: As evidenced by the fact that they can be "Trapped" in black holes, and tend to "bend" spectrally around large celestial objects.

I was wondering about this myself.  I read some stuff about it, and the idea I got was that photons don't have mass.

The reason they can't escape black holes, apparently, isn't because of gravity pulling light in.  It's because a black hole warps spacetime so much that, inside the black hole's event horizon, there is no path back out of the event horizon.  From an observer inside the event horizon, no matter which direction you went or how far you went, you wouldn't find a path outside the event horizon.

That's how I understood what I found.  My understanding could very well be flawed.  Astrophysics is interesting to me, but I'm no expert.  I know just enough to be dangerous.

The spectral bending effect is caused by gravitational lensing.  Again, it's because a large body alters the shape of space time, not because it can drag massless photons off their present path.

Modifié par jamesp81, 19 mai 2011 - 08:23 .

[Black Raptor]

Lady Olivia wrote...
Just think, flying at the speed of light, you'd need around 30000 years to reach the center of the galaxy, let alone the other side.

30000 years relative to Earth. Once you start travelling at the speed of light, you no longer move forward in time so the journey would be instant relative to those onboard this hypothetical spaceship. 

Time moves slower for objects moving fast. CERN has been able to greatly increase the lifespans of quickly decaying particles by having them move as close to the speed of light as they can get. 

Photons don't age. 
This also means that travelling faster than light would also involve travelling backwards in time. 

Modifié par Black Raptor, 19 mai 2011 - 08:23 .

[Phaedon]

Doesn't QM say that some particles can reach FTL velocities?

What about: Tachyons? etc.

But anyway, the intro text seems to imply that "mass effect" alters spacetime.

[Black Raptor]

jamesp81 wrote...

Bearcut wrote...

Photons do have mass.

Edit: As evidenced by the fact that they can be "Trapped" in black holes, and tend to "bend" spectrally around large celestial objects.

I was wondering about this myself.  I read some stuff about it, and the idea I got was that photons don't have mass.

The reason they can't escape black holes, apparently, isn't because of gravity pulling light in.  It's because a black hole warps spacetime so much that, inside the black hole's event horizon, there is no path back out of the event horizon.  From an observer inside the event horizon, no matter which direction you went or how far you went, you wouldn't find a path outside the event horizon.

That's how I understood what I found.  My understanding could very well be flawed.  Astrophysics is interesting to me, but I'm no expert.  I know just enough to be dangerous.

The spectral bending effect is caused by gravitational lensing.  Again, it's because a large body alters the shape of space time, not because it can drag massless photons off their present path.

This^

You are right. 

[Lady Olivia]

Black Raptor wrote...

Lady Olivia wrote...
Just think, flying at the speed of light, you'd need around 30000 years to reach the center of the galaxy, let alone the other side.

30000 years relative to Earth. Once you start travelling at the speed of light, you no longer move forward in time so the journey would be instant relative to those onboard this hypothetical spaceship. 

Time moves slower for objects moving fast. CERN has been able to greatly increase the lifespans of quickly decaying particles by having them move as close to the speed of light as they can get. 

Photons don't age. 
This also means that travelling faster than light would also involve travelling backwards in time. 

Ok, ok, I should have put the /end-RL-physics tag after the first paragraph in that post.

[Fiery Phoenix]

Phaedon wrote...

Doesn't QM say that some particles can reach FTL velocities?

What about: Tachyons? etc.

But anyway, the intro text seems to imply that "mass effect" alters spacetime.

Tachyons are a purely mathematical concept. And for a particle to reach FTL velocities, it would have to have some sort of "infinite mass"; as mass breaks down with increased speed and the only way to overcome that would be to have an infinite supply of mass, which, of course, is impossible according to our current understanding. It's also the reason we will never be able to create a wormhole.

[Black Raptor]

Fiery Phoenix wrote...

Phaedon wrote...

Doesn't QM say that some particles can reach FTL velocities?

What about: Tachyons? etc.

But anyway, the intro text seems to imply that "mass effect" alters spacetime.

Tachyons are a purely mathematical concept. And for a particle to reach FTL velocities, it would have to have some sort of "infinite mass"; as mass breaks down with increased speed and the only way to overcome that would be to have an infinite supply of mass, which, of course, is impossible according to our current understanding. It's also the reason we will never be able to create a wormhole.

Isn't it the other way around? The faster you go the heavier you get, so only things with no mass to start with could reach 3000000m/s

[Phaedon]

I definitely need to start rechecking those stuff again.

Aren't there some sort of photons who transfer data to each other at FTL velocities though?

Anyway, we are still discussing science completely different than the one ME claims to be based on.

Modifié par Phaedon, 19 mai 2011 - 08:33 .

[Fiery Phoenix]

Black Raptor wrote...

Fiery Phoenix wrote...

Phaedon wrote...

Doesn't QM say that some particles can reach FTL velocities?

What about: Tachyons? etc.

But anyway, the intro text seems to imply that "mass effect" alters spacetime.

Tachyons are a purely mathematical concept. And for a particle to reach FTL velocities, it would have to have some sort of "infinite mass"; as mass breaks down with increased speed and the only way to overcome that would be to have an infinite supply of mass, which, of course, is impossible according to our current understanding. It's also the reason we will never be able to create a wormhole.

Isn't it the other way around? The faster you go the heavier you get, so only things with no mass to start with could reach 3000000m/s

Actually, yes, that's correct. I must have mixed things up. Sorry.

Also, in regards to James' post above, that's how I understand it as well. After all, the reason black holes are black is because not even light can escape from them. So they're literally dim and don't reflect ANY kind of light.

[jamesp81]

Lady Olivia wrote...

Phaedon wrote...

Anyway, FTL Travel =/= FTL velocities

Really? What then?

Some FTL theories rely on methods whereby breaking the lightspeed barrier isn't necessary.

For a Mass Effect example, the FTL drives of space ships create a bubble of spacetime around themselves where the speed of light is much higher than normal.  The ship inside the spacetime bubble doesn't exceed lightspeed, it just changes the rules where light can go much faster than normal.

Star Trek's warp drive and the Albucierre drive work on a somewhat different concept.  These drive systems fold space so that two points are close together.  Imagine a piece of spaghetti noodle.  If you needed to travel from one end of it to the other, you'd normally go in a straight line from one end to the other.  A warp drive, in effect, brings the two ends together by bending the noodle, then you merely step across what small gap remains.  This is also similar to wormhole travel.

The Albucierre drive, in particular, is built on sound mathematics.  It's chief problems are 1) the energy requirements are massive and 2) the drive relies on the use of exotic matter, none of which has been discovered yet.  However, if exotic matter does exist and we find it, an Albucierre drive becomes a very real possibility.

[jamesp81]

Phaedon wrote...

Doesn't QM say that some particles can reach FTL velocities?

What about: Tachyons? etc.

But anyway, the intro text seems to imply that "mass effect" alters spacetime.

Tachyons are theoretical, and described by mathematics.  They've never actually been detected, last I heard.

If they are real, I wonder if current instrumentation even could detect them?

[Spartanburger]

Here's an idea: They're searching for the 'god' particle, right? The particle that explains gravity?


EEZO = god particle.

Cave johnson, were done here.

[jamesp81]

Fiery Phoenix wrote...

Phaedon wrote...

Doesn't QM say that some particles can reach FTL velocities?

What about: Tachyons? etc.

But anyway, the intro text seems to imply that "mass effect" alters spacetime.

Tachyons are a purely mathematical concept. And for a particle to reach FTL velocities, it would have to have some sort of "infinite mass"; as mass breaks down with increased speed and the only way to overcome that would be to have an infinite supply of mass, which, of course, is impossible according to our current understanding. It's also the reason we will never be able to create a wormhole.

What if it had negative mass?  That's what the concept of exotic matter is.

[Phaedon]

Last I heard, FTL travel was about spacetime shortcuts, not FTL velocities.

[Black Raptor]

Phaedon wrote...

I definitely need to start rechecking those stuff again.

Aren't there some sort of photons who transfer data to each other at FTL velocities though?

Anyway, we are still discussing science completely different than the one ME claims to be based on.

I believe the Illusive man had a link with the Normandy SR2 via quantum entanglement. On paper it looks like it could be used to communicate instantly however, in reality it wouldn't work due to the Heisenburg uncertainty principle. 

[jamesp81]

Spartanburger wrote...

Here's an idea: They're searching for the 'god' particle, right? The particle that explains gravity?


EEZO = god particle.

Cave johnson, were done here.

Might be the Higgs-Boson particle they're looking for too.

Messing with Higgs-Boson particles is all fun and games until some jackwagon opens a portal and Dreen invaders start pouring out of it

Cookie for whoever gets the reference.

[Black Raptor]

Spartanburger wrote...

Here's an idea: They're searching for the 'god' particle, right? The particle that explains gravity?


EEZO = god particle.

Cave johnson, were done here.

Isn't the whole element 0 thing called that because it comes before hydrogen on the periodic table?
You wouldn't be able to mine and use Higgs bosons. 

[jamesp81]

Phaedon wrote...

Last I heard, FTL travel was about spacetime shortcuts, not FTL velocities.

Pretty much.

[Fiery Phoenix]

jamesp81 wrote...

Fiery Phoenix wrote...

Phaedon wrote...

Doesn't QM say that some particles can reach FTL velocities?

What about: Tachyons? etc.

But anyway, the intro text seems to imply that "mass effect" alters spacetime.

Tachyons are a purely mathematical concept. And for a particle to reach FTL velocities, it would have to have some sort of "infinite mass"; as mass breaks down with increased speed and the only way to overcome that would be to have an infinite supply of mass, which, of course, is impossible according to our current understanding. It's also the reason we will never be able to create a wormhole.

What if it had negative mass?  That's what the concept of exotic matter is.

Sure, but given how little we know of negative mass, it's kind of hard to think about. I can't even imagine what kind of properties an object with negative mass would have. It would be completely exotic, and apparently that's exactly why negative mass would mean the perfect space travel.

[jamesp81]

Black Raptor wrote...

Spartanburger wrote...

Here's an idea: They're searching for the 'god' particle, right? The particle that explains gravity?


EEZO = god particle.

Cave johnson, were done here.

Isn't the whole element 0 thing called that because it comes before hydrogen on the periodic table?
You wouldn't be able to mine and use Higgs bosons. 

That's what the little symbol suggests (atomic number 0 when you pick eezo in the game).

Does make you wonder what eezo is, though.  It can't just be a cloud of free electrons, as the electrons have mass too.  It has to be some kind of hypothetical exotic matter particle.

[Black Raptor]

jamesp81 wrote...

Spartanburger wrote...

Here's an idea: They're searching for the 'god' particle, right? The particle that explains gravity?


EEZO = god particle.

Cave johnson, were done here.

Might be the Higgs-Boson particle they're looking for too.

Messing with Higgs-Boson particles is all fun and games until some jackwagon opens a portal and Dreen invaders start pouring out of it

Cookie for whoever gets the reference.

Into the looking glass?

[Spartanburger]

true, you wouldn't be able to mine the Higgs, but nonetheless, it may be possible that they have similar effects to each other. Assuming you could collect enough of them.
I'm no expert on the subject though.

[Black Raptor]

Fiery Phoenix wrote...

Sure, but given how little we know of negative mass, it's kind of hard to think about. I can't even imagine what kind of properties an object with negative mass would have. It would be completely exotic, and apparently that's exactly why negative mass would mean the perfect space travel.

Antigravity and the ability to go faster than light and travel through time. 

[Phaedon]

Black Raptor wrote...

Spartanburger wrote...

Here's an idea: They're searching for the 'god' particle, right? The particle that explains gravity?


EEZO = god particle.

Cave johnson, were done here.

Isn't the whole element 0 thing called that because it comes before hydrogen on the periodic table?
You wouldn't be able to mine and use Higgs bosons. 

I think that element 0 refers to neutronium.

Tetraneutron: A tetraneutron is a hypothetical particle consisting of four bound neutrons. Reports of its existence have not been replicated. If confirmed, it would require revision of current nuclear models

This sounds promising.

Modifié par Phaedon, 19 mai 2011 - 08:47 .

[Fiery Phoenix]

Black Raptor wrote...

Fiery Phoenix wrote...

Sure, but given how little we know of negative mass, it's kind of hard to think about. I can't even imagine what kind of properties an object with negative mass would have. It would be completely exotic, and apparently that's exactly why negative mass would mean the perfect space travel.

Antigravity and the ability to go faster than light and travel through time.

Which are still completely exotic, yet so fascinating.

I recall reading somewhere that negative mass is mathematically possible; we just haven't figured out how it would work in the real world, let alone know if it even exists.