If we could build an Alcubierre Drive what would we see?

[Speakpigeon]

You could also clean up a corridor in front of the ship up to Alpha by sweeping all the photons there on either side.

With tachyon broom no doubt.

Ha-ha-ha don't be silly! No, just using the same trick as when you move the ship. If you could do one you definitely could do the other.
EB

 

[barbos]

You could also clean up a corridor in front of the ship up to Alpha by sweeping all the photons there on either side.

With tachyon broom no doubt.

Ha-ha-ha don't be silly! No, just using the same trick as when you move the ship. If you could do one you definitely could do the other.
EB

Tachyon broom is a standard equipment on United Federation ships.

 

[Speakpigeon]

Ha-ha-ha don't be silly! No, just using the same trick as when you move the ship. If you could do one you definitely could do the other.
EB

Tachyon broom is a standard equipment on United Federation ships.

Sorry, I wouldn't know, I'm not a Sci-Fi fan.
EB

 

[Speakpigeon]

Come to think of it, it would also be possible to marshal the photons in front of the ship to get them to light up interstellar dust on the wayside all along the way to Alpha, for the enjoyment of the passengers on the ship.
You could obviously arrange to have advertisements and infomercials from Alpha firms to pay for the trip. Electioneering slogans? Health advice? Jokes? Tweets of the President? Who knows. I don't.
EB

 

[bilby]

That may save the travelers on board the ship, but it won't save the observer at the destination.

Piece of cake -- don't aim for the destination. Aim your ship to come out of warp drive a light hour or so to the side of Alpha Centauri. All those piled up photons shoot off harmlessly into deep space, and then you fly your ship to the target planet at a nice safe speed like .1 c.

How many photons are there going to be? The ship (or warp bubble or whatever) is only collecting photons from distant stars; Effectively it's surrounded by a black body at ~3K. How much energy is it going to collect in 4ly of travel?

I would guess that the vast majority of these photons would come from the destination star, 'cos it's the only one you get close to; with the rest of the universe adding a trivial fraction. So you are looking at what, same amount of energy as the solar (? centaurar) energy incident on the ship if it was at the destination for some fraction of the 4 year output? It's going to be a small fraction too, with the inverse square law - most of the trip is spent a long way away from any stars, including the target system.

 

[Jokodo]

That may save the travelers on board the ship, but it won't save the observer at the destination.

Piece of cake -- don't aim for the destination. Aim your ship to come out of warp drive a light hour or so to the side of Alpha Centauri. All those piled up photons shoot off harmlessly into deep space, and then you fly your ship to the target planet at a nice safe speed like .1 c.

How many photons are there going to be? The ship (or warp bubble or whatever) is only collecting photons from distant stars; Effectively it's surrounded by a black body at ~3K. How much energy is it going to collect in 4ly of travel?

I would guess that the vast majority of these photons would come from the destination star, 'cos it's the only one you get close to; with the rest of the universe adding a trivial fraction. So you are looking at what, same amount of energy as the solar (? centaurar) energy incident on the ship if it was at the destination for some fraction of the 4 year output? It's going to be a small fraction too, with the inverse square law - most of the trip is spent a long way away from any stars, including the target system.

Oh, but it's not joules that worry me, but the watts. If the ship scoops up the photons along the way it'll bring four years worth* of irradiation with it - and emit it in a literal instant the moment it drops out of warp speed.

 

[bilby]

How many photons are there going to be? The ship (or warp bubble or whatever) is only collecting photons from distant stars; Effectively it's surrounded by a black body at ~3K. How much energy is it going to collect in 4ly of travel?

I would guess that the vast majority of these photons would come from the destination star, 'cos it's the only one you get close to; with the rest of the universe adding a trivial fraction. So you are looking at what, same amount of energy as the solar (? centaurar) energy incident on the ship if it was at the destination for some fraction of the 4 year output? It's going to be a small fraction too, with the inverse square law - most of the trip is spent a long way away from any stars, including the target system.

Oh, but it's not joules that worry me, but the watts. If the ship scoops up the photons along the way it'll bring four years worth* of irradiation with it - and emit it in a literal instant the moment it drops out of warp speed.

OK; But you need both for there to be a problem. A brief exposure to high power isn't a problem - like flicking your finger through a candle flame, as long as the energy source is only present for a very short time, the damage is negligible.

Also, frequency matters - if the photons have very high energies, then they will form a burst of gamma rays, much of which will pass right through whatever it hits. Even if this hits a planet, the effects will be 'spread out' through the planet's mass.

 

[Speakpigeon]

That may save the travelers on board the ship, but it won't save the observer at the destination.

Piece of cake -- don't aim for the destination. Aim your ship to come out of warp drive a light hour or so to the side of Alpha Centauri. All those piled up photons shoot off harmlessly into deep space, and then you fly your ship to the target planet at a nice safe speed like .1 c.

How many photons are there going to be? The ship (or warp bubble or whatever) is only collecting photons from distant stars; Effectively it's surrounded by a black body at ~3K. How much energy is it going to collect in 4ly of travel?

I would guess that the vast majority of these photons would come from the destination star, 'cos it's the only one you get close to; with the rest of the universe adding a trivial fraction. So you are looking at what, same amount of energy as the solar (? centaurar) energy incident on the ship if it was at the destination for some fraction of the 4 year output? It's going to be a small fraction too, with the inverse square law - most of the trip is spent a long way away from any stars, including the target system.

Maybe not.

As I see it, in the case of the Alcubierre Drive, if you're not careful the drive would sweep nearly all photons in front of the ship between the Earth and Alpha. These photons would include the photons from the Sun and from the three stars in Alpha Centauri, and then some, and that's photons emitted by those stars during 4.4 years. If you're subjected to that amount of photons, I'm sure you're burnt to a crisp, like being exposed to the equivalent of 4.4 years of sunlight, unscreened by any atmosphere, within potentially one small fraction of one second. Crisp.
EB

 

[bilby]

How many photons are there going to be? The ship (or warp bubble or whatever) is only collecting photons from distant stars; Effectively it's surrounded by a black body at ~3K. How much energy is it going to collect in 4ly of travel?

I would guess that the vast majority of these photons would come from the destination star, 'cos it's the only one you get close to; with the rest of the universe adding a trivial fraction. So you are looking at what, same amount of energy as the solar (? centaurar) energy incident on the ship if it was at the destination for some fraction of the 4 year output? It's going to be a small fraction too, with the inverse square law - most of the trip is spent a long way away from any stars, including the target system.

Maybe not.

As I see it, in the case of the Alcubierre Drive, if you're not careful the drive would sweep nearly all photons in front of the ship between the Earth and Alpha. These photons would include the photons from the Sun and from the three stars in Alpha Centauri, and then some, and that's photons emitted by those stars during 4.4 years. If you're subjected to that amount of photons, I'm sure you're burnt to a crisp, like being exposed to the equivalent of 4.4 years of sunlight, unscreened by any atmosphere, within potentially one small fraction of one second. Crisp.
EB

Well the ship is presumably a lot smaller than a star, so the energy involved is proportionally smaller.

4 years is about 130 million seconds; a ship big enough to sweep up a 130 millionth of a star's output would still be a decent size - bearing in mind that the crew only need to be onboard for less than a day. The sun's radius is about 700,000km; a ship with an 8 metre radius would pick up at most about a second's worth of photons in four lightyears at superluminal velocity.

And who's unprotected? If someone is floating in space unprotected, being burned to a crisp is the least of their problems.

 

[Speakpigeon]

How many photons are there going to be? The ship (or warp bubble or whatever) is only collecting photons from distant stars; Effectively it's surrounded by a black body at ~3K. How much energy is it going to collect in 4ly of travel?

I would guess that the vast majority of these photons would come from the destination star, 'cos it's the only one you get close to; with the rest of the universe adding a trivial fraction. So you are looking at what, same amount of energy as the solar (? centaurar) energy incident on the ship if it was at the destination for some fraction of the 4 year output? It's going to be a small fraction too, with the inverse square law - most of the trip is spent a long way away from any stars, including the target system.

Maybe not.

As I see it, in the case of the Alcubierre Drive, if you're not careful the drive would sweep nearly all photons in front of the ship between the Earth and Alpha. These photons would include the photons from the Sun and from the three stars in Alpha Centauri, and then some, and that's photons emitted by those stars during 4.4 years. If you're subjected to that amount of photons, I'm sure you're burnt to a crisp, like being exposed to the equivalent of 4.4 years of sunlight, unscreened by any atmosphere, within potentially one small fraction of one second. Crisp.
EB

Well the ship is presumably a lot smaller than a star, so the energy involved is proportionally smaller.

4 years is about 130 million seconds; a ship big enough to sweep up a 130 millionth of a star's output would still be a decent size - bearing in mind that the crew only need to be onboard for less than a day. The sun's radius is about 700,000km; a ship with an 8 metre radius would pick up at most about a second's worth of photons in four lightyears at superluminal velocity.

And who's unprotected? If someone is floating in space unprotected, being burned to a crisp is the least of their problems.

I'm not talking about people inside the ship. They would be safe in any case.

The people who would have to worry would be any "observer" at the destination point, on the planet or whatever. It's not the ship that's sweeping the photons, it's the drive, i.e. all the space in front of the ship. The effect would be at least that of the sunburn you would get from being exposed in the blink of an eye to 4.4 years of unscreened sunlight and light from the three Alpha stars, and that would be much, much more than just being exposed to unscreened sunlight continuously during 4.4 years.

That being said, I suspect a shield at destination would be enough to protect the personnel there.
EB

 

[Speakpigeon]

The effect would be at least that of the sunburn you would get from being exposed in the blink of an eye to 4.4 years of unscreened sunlight and light from the three Alpha stars, and that would be much, much more than just being exposed to unscreened sunlight continuously during 4.4 years.

That being said, I suspect a shield at destination would be enough to protect the personnel there.
EB

Oops, sorry, the bit "and light from the three Alpha stars" is wrong. If the ship docks on its destination port after travelling in a straight line from Earth, most of the photons from the Alpha stars would still be heading broadly in the opposite direction of that of the ship, and so would resume their journey broadly towards the Earth, safely away from the supposed observer at the destination point.

Some Alpha photons would still be reflected towards the docking bay by the ship's hull when coming out of the Drive, but as already suggested by Bomb#20 I think, the ship could come out of the Drive some distance away from the dock and that would be enough to reduce the impact of that.

Unless it's the USS Enterprise NX-01 and then all bets are off.
EB

 

[steve_bank]

There are FTL theories. but they all have problems. One creats a ST like bubble around the vehicle so all is normal om the ship. Theoretically it does not violate causality.Problem is it requires energy to jave a negative polarity, impossible in this universe.

"Not yet observed" is NOT the same as "impossible".

'Impossible' is a dangerous word to use without VERY good evidence to support it.

You are a real trip. In SI and in all variables energy is proportional to a magnitude squared. kinetic energy 0.5mv^2, energy in an inductive magnetic field 0.5LI^2, atomic energy o0.5mc^2...and so on. I did not say never, I said all FTL theories have fundamental problems not always related to C and causality. In the ST universe, all is possible. I can write the differential equation for amd electrical parallel inductor and capacitor circuit without resistance, convolve it with an impulse to inject energy, and it will oscillate with a sine wave forever. I can put the circuit into the SPICE circuit simulator and it will oscillate forever. It can never be built in reality, there is no such thing as a lossless electric circuit. Can such a thing occur in the future? I leaned from experience to never say never, but the probability is very low. Same with something called negative energy/. I expect negative energy would violate conservation in some form.

What would we see? From AE's biography he used dreams and creative visualization. He would imagine what light would be traveling at C. As we sense both visually and with instruments the EM spectrum the question is what is a photon. The wave particle duality at the heart of electromagnetics is a piecewise approximation to explain the slit diffraction experiment.Relativistic physics applied to macro scale events is all theoretical, there is no way to demonstrate. As a ship approaches C, does our physics hold up?
C is taken as finite , can a photon catch up with a FTL ship?

To know what we would see visually would require to see how photons interact with the theory.

 

[Speakpigeon]

I can write the differential equation for amd electrical parallel inductor and capacitor circuit without resistance, convolve it with an impulse to inject energy, and it will oscillate with a sine wave forever. I can put the circuit into the SPICE circuit simulator and it will oscillate forever. It can never be built in reality, there is no such thing as a lossless electric circuit.

Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors, when cooled below a characteristic critical temperature.

Supercool.
EB

 

[bilby]

I can write the differential equation for amd electrical parallel inductor and capacitor circuit without resistance, convolve it with an impulse to inject energy, and it will oscillate with a sine wave forever. I can put the circuit into the SPICE circuit simulator and it will oscillate forever. It can never be built in reality, there is no such thing as a lossless electric circuit.

Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials, called superconductors, when cooled below a characteristic critical temperature.

Supercool.
EB

'Never' is a dangerous word to use without VERY good evidence to support it, too.

 

[SLD]

It seems to me that the dilemmas pointed out could be resolved by simply requiring that no photons are allowed to escape from the alcubierre bubble. And nothing can come in the bubble either. Then the ship just disappears at earth and just appears at alpha Centauri five minutes later by the ship'd clock. Then there’s nothing to really observe.

No. Then there’s a dilemma with respect to the return to earth trip. The ship disappears for ten+ minutes and then reappears, and appears again at Alpha Centauri four and a half years later. So then you see two ships. That just seems weird but maybe that’s just how it is.

SLD

 

[SLD]

A somewhat optimistic assessment.

[YOUTUBE]https://youtu.be/Xlmdtf3UbmQ[/YOUTUBE]

 

[skepticalbip]

^ ^
I would say quite a bit beyond "somewhat optimistic".

Although I loved his line, "Lets face it. Space is really big."

 

[steve_bank]

Superconductivity at a few degrees Kelvin requires energy to stay cold, IOW refrifridgeration. There is no violation of LOT in terms of perpetual motion. Don't know if it is still running, there was a superconducting current loop that appeared to have no degradation, but again the system in toto is not lossless. Those pesky LOT. The problem is in measuring. Any ,easement requires a transfer of energy, no way to know if resistance is exactly zero.

I have a cousin who worked on the cooling system for the RHIC collider superconducting magnets.

 

[Speakpigeon]

'Never' is a dangerous word to use without VERY good evidence to support it, too.

I agree. It definitely suggests infinities exist in actual fact without the beginning of a clue and this is needlessly upsetting a few people around here.

On the other hand, not saying the word "never" in this particular case is admission to the possibility of perpetual movement, itself a kind of actual infinity I guess.

So, damn if you do, damn if you don't.

Well, in a nutshell that's just life for you, I guess.
EB

 

[bilby]

It seems to me that the dilemmas pointed out could be resolved by simply requiring that no photons are allowed to escape from the alcubierre bubble. And nothing can come in the bubble either. Then the ship just disappears at earth and just appears at alpha Centauri five minutes later by the ship'd clock. Then there’s nothing to really observe.

No. Then there’s a dilemma with respect to the return to earth trip. The ship disappears for ten+ minutes and then reappears, and appears again at Alpha Centauri four and a half years later. So then you see two ships. That just seems weird but maybe that’s just how it is.

SLD

An arrangement of lenses and/or mirrors can allow you to see two ships with no causality violation; It's simply not a problem.

A sufficiently large mirror placed 2ly away would allow you to see two of everything on Earth, with a 4 year time offset. Gravitational lensing allows us to see two (or more) images of the same star, and it is not required that both images follow a path of equal length, so a time offset is possible there too.