Interstellar Travel Challenge

[CraigS]

So what does space look like at 0.99c ?

Ya got aberration firstly .. so all stars appear to be in the direction you're travelling, yeah ? (All scrunched up together .. little/no separation between them). The whole universe looks like its coming from one point ahead of you, eh ?

Then you have doppler shifting, so red stars appear closer to blue, blue go to X or gamma ray wavelengths. So some stars would get closer to human eye sensitive wavelengths .. some would disappear as they move beyond visible wavelengths .. (Need radiation shielding/screens !)

So, it looks like we also need a nifty wideband (variable sensitivity) telescope with us with really high resolving power (to separate those scrunched together stars) …

And all that's even before we've started thinking about relativistic effects !

Cheers

[renormalised (Carl)]

I'm not feeling so good today, so I won't ramble on too much here with a really long reply...only to say this, you lot are barking up the wrong tree. You have little imagination. You're assuming that we will never be able to break the speed of light barrier and you're talking about the same old boring ways of getting around that have been gone over again and again. All this talk about sending generations ships, DNA carriers etc etc. Won't work and for many of the reasons that you've stated here. Won't work unless you can come up with a way to basically make the information that is being carried immortal. Either totally incorruptible digital or quantum storage systems (for DNA code storage), or you have immortal (or close to immortal) passengers on the generation ships. You also have to have perfect replication of the DNA at the end of the trip if you use the first method. If you use actual DNA, you then have the problems of the storage, plus the degradation of the DNA over time as well as protection from mutation, damage etc etc. If you send people, to make it viable, you're going to have to enormously extend the lifespans of the people onboard, unless you want all sorts of problems occurring with people of normal lifespans living in a confined space for many millenia. The consequences of fooling around with their genetics and their medical condition to create occupants that live for, say, 1000-10000 years are an even greater unknown than sending just DNA in any form. The technology to be able to do this is even further beyond our present understanding than actually designing a workable FTL drive.

If you're going to restrict yourselves that this level, you might as well send robots and forget about it. You'll never explore the galaxy yourselves and will have to do it by proxy. Even there, you'll have problems with the longevity of your equipment...whether they're macroscale robotic craft or nanobots. If they're nanobots, you may have the chance of self-replication built into the design, but then you have the problems of data storage, redundancy, swarm cohesion etc, and even the replication itself.

Ultimately, if your going down the paths you're traveling for ways to get about, you might as well just sit put where we are and forget about interstellar travel. Unless you develop methods of circumventing the light speed barrier (spacetime warp fields, wormholes etc etc), you will not be able to travel to the stars. Unless, of course, you can come up with some "paranormal" way of projecting your consciousness to anywhere at any time.

As for navigation....think!!!. Yes, the stars do move about the galaxy. But you workout how far they move in any one given moment and then you'll have your answer to your navigational problems. It's not traveling at c, or faster, that is the problem. It's creating the starmaps in the first place. The changes in position are easy to map, once you have the template maps drawn up. It's just a matter of accounting for the stars true space velocities and their vectors of travel. Simple 4D mathematics.

[CraigS]

Ahhh ya see Carl … this is the engineering phase ! I think you missed the brainstorming party !

We've only got a few weeks to come up with something that sounds reasonable …

...can you tell us how we do FTL in like, say, the next 5 minutes …we have dealines here y'know … the project schedule just can't wait !!

C'mon get a move on … no excuses !! .. Drop and give me twenty !!


Cheers

[mswhin63 (Malcolm)]

Originally Posted by renormalised

As for navigation....think!!!. Yes, the stars do move about the galaxy. But you workout how far they move in any one given moment and then you'll have your answer to your navigational problems. It's not traveling at c, or faster, that is the problem. It's creating the starmaps in the first place. The changes in position are easy to map, once you have the template maps drawn up. It's just a matter of accounting for the stars true space velocities and their vectors of travel. Simple 4D mathematics.

I agree this is not a problem, scientist already know where most of the star a going and you you never travel far that it would take a 100 years to get there.

We need to manage the environment on Earth 1 first before trying to live on an artificial environment for longer than we have technologically live on this planet.

[CraigS]

Originally Posted by mswhin63

I agree this is not a problem, scientist already know where most of the star a going and you you never travel far that it would take a 100 years to get there.

We need to manage the environment on Earth 1 first before trying to live on an artificial environment for longer than we have technologically live on this planet.

… We'll have to give this guy the sack !!

... He's not a team playa !!

… We're trying to design a spaceship that'll allow us to cover 4 lightyears and that can be built within 100 years !

.. Now where's my Human Resources rep when I need 'em ??

Cheers
PS: I'm just havin' fun here Malcolm… don't take me seriously ..

[mswhin63 (Malcolm)]

Originally Posted by CraigS

PS: I'm just havin' fun here Malcolm… don't take me seriously ..

None taken enjoy some banter sometime

[renormalised (Carl)]

Originally Posted by CraigS

Ahhh ya see Carl … this is the engineering phase ! I think you missed the brainstorming party !

We've only got a few weeks to come up with something that sounds reasonable …

...can you tell us how we do FTL in like, say, the next 5 minutes …we have dealines here y'know … the project schedule just can't wait !!

C'mon get a move on … no excuses !! .. Drop and give me twenty !!


Cheers

The way I feel at present, if I drop, I'll be flat out getting back up again

Are you going to submit a proposal to DARPA??

Sounds like you guys are

[CraigS]

Originally Posted by renormalised

The way I feel at present, if I drop, I'll be flat out getting back up again

Are you going to submit a proposal to DARPA??

Sounds like you guys are

Yep .. we're going to use your name because of your heavy input into it all ..
I mean, FTL is the core of our proposal … and it requires heavy 'renormalisation' !!!

Now … drop and give me another twenty .. this time remove ya clothing, swim that frozen lake and prepare to drink you own urine !! (It very medicinal y'know).

[renormalised (Carl)]

Originally Posted by CraigS

...can you tell us how we do FTL in like, say, the next 5 minutes …we have dealines here y'know … the project schedule just can't wait !!

I'll have to go spec the rubber bands I need for the propulsion units. Might have to wait a week or two

[renormalised (Carl)]

Originally Posted by CraigS

Yep .. we're going to use your name because of your heavy input into it all ..
I mean, FTL is the core of our proposal … and it requires heavy 'renormalisation' !!!

Now … drop and give me another twenty .. this time remove ya clothing, swim that frozen lake and prepare to drink you own urine !! (It very medicinal y'know).

I'll categorically deny any involvement in this, since it's doomed to failure right form the start

I don't do "Bare" Grylls routines (pardon the pun)

[CraigS]

Bringing this back on track again (apologies for my outburst .. gotta get Carl when he's down, eh ?) .. what bugs me is that the fastest Ultra-High energy cosmic ray detected was travelling at something like 0.99c and it is believed to most likely be a proton .. to give some feel for it ...

In fact, the proton was traveling so close to the speed of light, [(1 to 5×10−24) × c], that in a year-long race between light and the cosmic ray, the ray would fall behind only 46 nanometers (5×10−24
light-years), or 0.15 femtoseconds (1.5×10−16s).

.. so if a proton can achieve these velocities .. then its currently not impossible for matter to achieve sufficient speed to make the trip feasible.

Cheers

[renormalised (Carl)]

Originally Posted by CraigS

Bringing this back on track again (apologies for my outburst .. gotta get Carl when he's down, eh ?) .. what bugs me is that the fastest Ultra-High energy cosmic ray detected was travelling at something like 0.99c and it is believed to most likely be a proton .. to give some feel for it ...


.. so if a proton can achieve these velocities .. then its currently not impossible for matter to achieve sufficient speed to make the trip feasible.

Cheers

Hardly

Yes, possible, but not feasible using present technology or any extrapolation of it. To propel a craft weighing one ton to the same speed would require more energy than the entire US uses in several thousand years. Well, at least that's the theory and what the maths tells you.

[mswhin63 (Malcolm)]

Originally Posted by renormalised

Hardly

Yes, possible, but not feasible using present technology or any extrapolation of it. To propel a craft weighing one ton to the same speed would require more energy than the entire US uses in several thousand years. Well, at least that's the theory and what the maths tells you.

I think once a speed can be attain how much energy does it require to stay at the same speed. From what I understand not a lot.

The Plasma rocket which I believe should be ready for testing soon can already predict a trip to Mars lowered to approx 39 days. A leap forward in technology. http://www.voanews.com/english/news/...123960664.html
These kind of leaps could make near Light Speed possible in the 100years or so.

[CraigS]

Here's a snippet .. the EU folk are working towards a presentation/bid to DARPA on this.
.. Interstellar Birkeland current propulsion, Energetic Neutral Atoms as craft propulsion, ion thrust from double layers … the list goes on …!
(So much for my thoughts about science-based speculation).

[renormalised (Carl)]

Originally Posted by mswhin63

I think once a speed can be attain how much energy does it require to stay at the same speed. From what I understand not a lot.

The Plasma rocket which I believe should be ready for testing soon can already predict a trip to Mars lowered to approx 39 days. A leap forward in technology. http://www.voanews.com/english/news/...123960664.html
These kind of leaps could make near Light Speed possible in the 100years or so.

No, not a lot to keep it at a certain speed, but it's the acceleration to that speed which takes up the energy. Accelerate at 1g for a year and you'll get upto that speed (even faster), but to sustain 1g acceleration for a whole year takes a lot of fuel, no matter what rocket type you use.

But that's the stupidity of it all....they're still thinking inside their limited little boxes. Using rockets. They can't seem to get themselves out of their box, almost like they have some mental block to leap beyond the boundaries of their confined and limited ideas.

Yes, the new ion thrusters that ANU and the US group have come up with are very good and they should be space tested asap. 39 days to Mars is much better than what they've been talking about. However, the idiots at NASA and such are still holding onto the old technologies like they're sacred relics and can't be replaced. It's like having an F35 to go into battle against a SU37, but you can't use it because we must use Spitfires as we used them in WW2 and they worked.

[renormalised (Carl)]

Originally Posted by CraigS

Here's a snippet .. the EU folk are working towards a presentation/bid to DARPA on this.
.. Interstellar Birkeland current propulsion, Energetic Neutral Atoms as craft propulsion, ion thrust from double layers … the list goes on …!
(So much for my thoughts about science-based speculation).

ANU and Ad Astra Rocket Co have beaten them to it

Idiots.

[renormalised (Carl)]

Apart from that, are they proposing we ride the equivalent of their "interstellar lightening bolt" to get around the stars??. The only thing that's going to happen here is that lightening bolts will strike them on their behinds

[Rob_K]

Originally Posted by avandonk

A last thought. Even if time travel were possible how would you navigate spatially. The Earth rotates goes around the Sun goes around the Galaxy is moving etc. Where were you even ten minutes ago relative to the 'fixed' Quasars.


Bert

Go Time Team! You wouldn't have to navigate. Just a limitation on how far you could go back so you're still within the Milky Way, as it rotates and is moved by local gravitational forces. Breadth of the MW might be accommodating but the thickness is a worry - but I refuse to let that get in the way of a fight of fancy!

In effect, wind time back till a suitable planet/system occupies the space in the vicinity of where Earth is now. Parsec or two'll do! Ignore the expansion of the Universe as all parts are expanding equally (is your starship smaller when it materialises?). If at the end you still need to travel a fair way, stop off a few times for the odd gravitational slingshot from serendipitously passing bodies to build up the speed. You'd hit the ground running and be there by dinner time. Provided you didn't materialise next to an outbursting nova, or in the line of a GRB or have a sputtering comet sitting on the starship bridge, or....

Anyway, rubbish aside, an interesting discussion guys, lots of good points! But I don't see a lot of discussion about the social aspects of maintaining a seed colony in some sort of order and purpose in close confines for perhaps millenia (other than freezing everyone for the duration, or taking the bits). Do you think it would it be possible?

Cheers -

[CraigS]

The Alcubierre drive !!

[sjastro]

Originally Posted by CraigS

Here's a snippet .. the EU folk are working towards a presentation/bid to DARPA on this.
.. Interstellar Birkeland current propulsion, Energetic Neutral Atoms as craft propulsion, ion thrust from double layers … the list goes on …!
(So much for my thoughts about science-based speculation).

Idiots

How may Space Arks (or is that Space Arcs) are we going to have to build.

Regards

Steven