Reply
 
Thread Tools Display Modes
  #51  
Old 05-03-2013, 02:18 PM
WordMan is offline
Charter Member
 
Join Date: Apr 2001
Posts: 22,458
Quote:
Originally Posted by Leaper View Post
Devil's advocate: it's a little harder in this case because we are fighting basic, universal laws of physics, not just an arbitrary technological barrier.
What is a tool but a way for a Human to outwit or exploit a physical law for the time period needed?

ETA: that sounds way too simplistic on a second read. My point is that we have developed tools along the way - and the tools shape how we look at the world, like microscopes and industrial robots and radar and computers, cell phones, etc. Who's to say what tools we'll create in the future and how they will enable us to change how we look at currently-insurmountable problems?

Last edited by WordMan; 05-03-2013 at 02:21 PM.
  #52  
Old 05-03-2013, 02:43 PM
Lumpy's Avatar
Lumpy is offline
Charter Member
 
Join Date: Aug 1999
Location: Minneapolis, Minnesota US
Posts: 16,666
Quote:
Originally Posted by Askthepizzaguy View Post
It's overly pessimistic because we don't even know if we can create a warp effect yet?
You weren't arguing it's impossible, you were arguing it's impractical. I agree warp drive is too tentative to count on yet, but I don't think it's a priori ruled out.

Quote:
I like the drones idea. The drone smashes into things and creates another debris field to fly through.
No, it turns a dust grain which was heading towards your ship into a cloud of plasma, most of which is moving away from your ship.

Quote:
The laser idea seems plausible. So I give you much kudos for that. The issue being that something traveling laterally may not hit the laser beam, just collide with the ship.
Assuming most of the relative velocity is due to the forward velocity of the ship, debris isn't going to be moving laterally fast enough to evade the shielding and still hit the ship.

Quote:
If you're going to be moving at 1% of the speed of light, that's 6 million miles per hour. There's not much difference in terms of danger if you went faster than that. There's nothing that I've described which is any more or less dangerous at 6 million miles per hour and 600 million. You might as well approach light speed if you can move that even 1% that fast safely.
1-5% of the speed of light is doable with foreseeable nuclear propulsion systems, without an unworkable mass ratio and without needing fancy tricks like antimatter or ramscooping. Again, engineers have been well aware of the interstellar debris problem from the beginning and they don't seem to think it's insurmountable.

Quote:
I agree that building the new colony isn't as difficult a task as moving near light speed. However, we still need to build it, because the entire point of populating a new star system is so that we don't need to live inside the interstellar ship forever.

So it's not as simple as handwaving away the difficulty in making the new colony. We still have to make it, or we've traveled several light years to float outside of a planet we never intended to colonize, which is ridiculous in the extreme.
Even a purely space-based society might want to move out of the solar system just to get away from everyone else. And a potentially terraformable planet would still offer some advantages from the beginning. Just having an atmosphere of approximately Terran temperature and pressure would mean radiation protection, liquid water at its surface and needing only respiration gear to go outside- a garden spot by space standards.
  #53  
Old 05-03-2013, 03:30 PM
Diceman is offline
Guest
 
Join Date: Mar 1999
Location: Suburbs of Detroit, MI
Posts: 9,859
I hate to be a wet blanket, but I've got to agree with the OP. Speculation about warp drives and wormholes and whatnot is fantasy, and given our current understanding of physics they're pretty much on par with the teleportation spells in a Harry Potter book.

Even sending an unmanned probe to the closest star (4 LY away) would be a daunting task. Using any remotely-feasible propulsion system, our probe would take many decades, perhaps centuries, to get there. Just sending back data would take 4 years. Any kind of real-time control is absolutely impossible. It would take 4 years to become aware of any situation, and another 4 years to send a command back to the probe, and yet another 4 years to see if your command was executed properly. The upshot is, your probe would need to be completely autonomous, able to act without human contact. So, you'd better hope you were able to forsee all possible contingencies when you programmed it. And lets hope the probe doesn't malfunction, and wind up wasting the time and money of generations of people who were hoping to learn from it.
  #54  
Old 05-03-2013, 03:49 PM
Rachellelogram is offline
Guest
 
Join Date: Oct 2010
Posts: 10,110
Not with current technology, no. Not logically. But we're babies at quantum mechanics, which is capable of doing and explaining all kinds of shit that absolutely defies logical thought. Never say never. The only limit we have is "sometime before the sun goes dwarf." Even if our current level of civilization ends up getting nuked and extinguishing 99% of humanity, that still leaves an unimaginably long time to rebuild and discover new technology.
  #55  
Old 05-03-2013, 08:59 PM
Der Trihs's Avatar
Der Trihs is offline
Guest
 
Join Date: Aug 2005
Location: California
Posts: 38,890
Quote:
Originally Posted by Askthepizzaguy View Post
Wouldn't need to cover it, because it's more absurd than just sending the human bodies to begin with.

The machines required to synthesize and gestate human cells and grow them into adult hood will take up more space and be a lot harder to create than just sending human women.
Nonsense. It's much more likely we'd be talking about something far smaller and lighter than a human, probably some sort of nanotechnology based universal assembler combined with a computer library which will build everything else. And for a human colony you'd be talking about thousands of humans and all the necessary life support/stasis equipment; you aren't going to be strapping some naked woman to a rocket and sending her off. And even that hypothetical naked woman would weigh more than something you can probably hold in your hand.

Quote:
Originally Posted by Askthepizzaguy View Post
If we're going the redundancy route and we have mind beams and synthetic human bodies (clones), just send the human bodies. Assuming your mind beam technology existed, to "beam mind states" into a human body, that means it's possible to clone human beings and also clone your thoughts as well. So you just do that, and put them aboard several redundant vessels. They're clones, so who gives a damn.
The clones.

Quote:
Originally Posted by Askthepizzaguy View Post
And then you're talking about building a laser beam and using it to hit a target in your other star system, which is moving. That's one heck of a bulls-eye.
Not hard at all. It's not dodging after all.

Quote:
Originally Posted by Askthepizzaguy View Post
But I'll assume for the moment that we can do this. It's one thing to have any light whatsoever be received via a laser pulse, it's quite another to send the amount of data contained within a human brain via a series of laser pulses. Nothing can interrupt this laser beam, or parts of your "mind" will be missing upon arrival. So we can't have, for example, one of those trans-neptunian objects moving across your beam. You can't have your clones forgetting how read or comprehend language.
So you send redundant copies, and don't use any defective copies.

Quote:
Originally Posted by Askthepizzaguy View Post
But again, this doesn't solve any problem that we already know how to get around.
Only if your implausible assumptions are taken as a given.

Quote:
Originally Posted by Askthepizzaguy View Post
The issue isn't that I'm afraid we will lose some people on the way there, the issue is that it will take too long at safe speeds. Unsafe speeds will destroy every single one of your spermatozooan seed craft due to the interstellar medium, so you must travel slow enough to move through the medium.
As said, that's just not true.

Quote:
Originally Posted by Askthepizzaguy View Post
Well, that will certainly make the trip even longer.
So what? If it takes a million years it doesn't matter; for a slow moving "city ship" the ship is home, not wherever they happen to be headed. Assuming they are even headed any particular direction. Such a replicating fleet would eventually reach other stars because eventually they'll reach everywhere in the galaxy.

Quote:
Originally Posted by Jman View Post
Quote:
Originally Posted by Der Trihs
Personally, I predict that in a few centuries at most there won't be a significant amount of what we would call humans anywhere, in or out of this system.
In what way of speaking? Are you talking about a nuclear annihilation? If so, then, well, it's certainly possible we'll wipe out a very large chunk of humanity...though I'd imagine there would still be a fair few left. Maybe we'll cause our own extinction in a few centuries. Definitely a possibility. However, excepting that.....

If you aren't talking about nuclear annihilation, how do you figure? Evolution doesn't happen that fast.
Natural evolution, no, not usually. But if our civilization doesn't collapse there's no way we won't modify ourselves far faster than natural evolution works; and there's the possibility of us being replaced by our own creations as well.
  #56  
Old 05-03-2013, 09:18 PM
smiling bandit is offline
Guest
 
Join Date: Nov 2001
Posts: 16,955
Quote:
Originally Posted by WordMan View Post
What is a tool but a way for a Human to outwit or exploit a physical law for the time period needed?

ETA: that sounds way too simplistic on a second read. My point is that we have developed tools along the way - and the tools shape how we look at the world, like microscopes and industrial robots and radar and computers, cell phones, etc. Who's to say what tools we'll create in the future and how they will enable us to change how we look at currently-insurmountable problems?
Perhaps. But up till now we've mostly been dealing with relatively small and trivial problems in comparisons. Swift travel between stars does not require new tools; it requires entire new sciences. They may exist, but there is no guarantee.

It's also possible that a sufficiently enormous material culture - one able to capture massive quantities of solar energy and can do pretty much whatever it wants with the materials in this system, could eventually build something practical by sheer time and near-unlimited wealth and resources. Neither seems very likely within even the remotest limits of our science or engineering as it now stands. We are in a much different position even than explorers a few centuries ago. They didn't have the resources to do what they might want. After all, it took very little time to develop early locomotives, and then cars and planes, once good enough materials and energy sources became available - these concepts were hypothetically known eons ago. It was a (not-so-) simple matter of applying the new resources to the known problem. An engineering challenge.

But now we're running into limits of the universe themselves, and we have no known ways of working around them. I can see some possibilities, but nothing in any kind of reasonably-foreseeable timeframe. But one never knows what idea may occur, or what new space a developing technology might uncover.
  #57  
Old 05-03-2013, 09:50 PM
bup is offline
Guest
 
Join Date: Sep 1999
Location: glenview,il,usa
Posts: 11,905
All this discussion - both pro and con - has assumed we'd travel vast distances across space by going through space (except for the wormhole thing, which has been dismissed).

Right. We're never going to get 100,000 light years away from here by traveling in a ship that traverses 100,000 light years. We need shortcuts

But there are more physical dimensions than the three we observe. Variations on the double-slit experiment imply effects that temporally precede causes. Somehow information travels faster than light.
  #58  
Old 05-03-2013, 09:56 PM
aceplace57 is offline
Guest
 
Join Date: Oct 2009
Location: CentralArkansas
Posts: 26,305
Even Shatner said years ago that interstellar travel was a pipe dream. The massive distances makes it impossible. Even a Mars mission is being presented as a one way trip.

I'm a big science fiction fan but there's no getting around reality.

I do think the odds are good that there is life out there somewhere. Simply because of the number of galaxies and planets. It's hard to imagine there isn't life. But we're safely separated by the expanse of space. A good thing because we'd probably start a war with them.

Last edited by aceplace57; 05-03-2013 at 09:59 PM.
  #59  
Old 05-05-2013, 02:43 PM
BigT's Avatar
BigT is offline
Guest
 
Join Date: Aug 2008
Location: "Hicksville", Ark.
Posts: 36,596
Dude, we'll be past the singularity at that point. (And I don't mean the woo version). We (or our creations who take over) will be so smart we can't even predict what we'd be thinking, let alone what we would discover. We're talking exponential growths in intelligence here. There's just no way you can predict that far in advance. Yeah, it's not going to happen any time soon, but it is definitely pessimistic to say it won't happen in 100,000 years.

Even if you think FTL travel will never happen, the sleeper ship scenario you gave is entirely based on current or near-future tech. Despite what you were taught on Star Trek, there's no inherent that reason all devices need regular maintenance. And there's no reason you couldn't have maintenance anyways in a generational ship. There's no reason to think we won't develop longer lasting materials in a timespan that is longer than recorded history itself.

So, yeah, you're a pessimist, and, what's worse, the worst kind of pessimist. You are both unknowingly ignorant about the subject, and, worse, actually get off on trying to dash the hopes of optimists (and even realists). You're trying to preemptively rub people's noses in their supposed mistakes. That'd be bad even if you turned out to be right.
  #60  
Old 05-05-2013, 03:07 PM
colander is offline
BANNED
 
Join Date: Nov 2012
Location: Home of the golden bear
Posts: 1,468
Quote:
Originally Posted by BigT View Post
Despite what you were taught on Star Trek, there's no inherent that reason all devices need regular maintenance.
Is this a joke? Any device that performs useful work will eventually need maintenance to continue functioning. Perhaps you envision a system with very low maintenance requirements, but to eliminate the need for maintenance in a system as complex as a functioning spacecraft on the timescale necessary to perform interstellar travel? I mean, you might as well just say that wizards will take care of it.
  #61  
Old 05-05-2013, 03:11 PM
billfish678 is offline
BANNED
 
Join Date: Jun 2006
Posts: 16,681
Quote:
Originally Posted by aceplace57 View Post
Even Shatner said years ago that interstellar travel was a pipe dream.
Unless you are talking about some Shatner other than the one I think you are that may be the funniest statement I have ever read on the internet.

And, OP, I take it travel to other galaxies is straight out?
  #62  
Old 05-05-2013, 03:25 PM
panaccione is offline
Member
 
Join Date: May 2009
Posts: 2,022
Quote:
Originally Posted by Anne Neville View Post
So... no pizza delivery to Alpha Centauri, then?
That's cause it's a bad neighborhood and they don't tip!
  #63  
Old 05-05-2013, 03:39 PM
Der Trihs's Avatar
Der Trihs is offline
Guest
 
Join Date: Aug 2005
Location: California
Posts: 38,890
Quote:
Originally Posted by colander View Post
Any device that performs useful work will eventually need maintenance to continue functioning.
Unless it's capable of self repair, which a really advanced spacecraft would almost certainly be.
  #64  
Old 05-05-2013, 06:35 PM
colander is offline
BANNED
 
Join Date: Nov 2012
Location: Home of the golden bear
Posts: 1,468
Quote:
Originally Posted by Der Trihs View Post
Unless it's capable of self repair, which a really advanced spacecraft would almost certainly be.
non-engineers are funny
  #65  
Old 05-05-2013, 06:38 PM
colander is offline
BANNED
 
Join Date: Nov 2012
Location: Home of the golden bear
Posts: 1,468
PS: Let me guess: nanobots will do it, right?

Last edited by colander; 05-05-2013 at 06:40 PM.
  #66  
Old 05-05-2013, 07:10 PM
Der Trihs's Avatar
Der Trihs is offline
Guest
 
Join Date: Aug 2005
Location: California
Posts: 38,890
Quote:
Originally Posted by colander View Post
non-engineers are funny
People who think that entropy is some magical force and only humans have some mystical ability to oppose it are funny.

Quote:
Originally Posted by colander View Post
PS: Let me guess: nanobots will do it, right?
How would I know? However, the world is full of self repairing organisms. And the fact that maintainance is possible at all shows that self repair is possible, you just have to make the machine sophisticated enough to do it itself rather than needing a human to do it.

Last edited by Der Trihs; 05-05-2013 at 07:11 PM.
  #67  
Old 05-05-2013, 08:11 PM
Dr. Strangelove's Avatar
Dr. Strangelove is online now
Guest
 
Join Date: Dec 2010
Posts: 7,967
As others have said, you write off colony ships too quickly. We already have the technology to reach 1% of the speed of light, and at that rate it's <500 years to Alpha Centauri, and only a few thousand years to get to quite a few more interesting places.

Solving the societal issues will be interesting. We'll have to breed or genetically engineer people that are resistant to living in a confined space. Though it won't have to be all that confined--the techniques used for getting up to that speed (Orion project) actually work better the bigger the ship. A million tons is probably doable.

There's no worry about germs. If there's life where we land, we won't even interact with the native life, except mechanically. We can't even digest left-handed sugar; more complex interactions like bacterial/viral infections (if that even makes sense for alien life) are implausible.

There is more than enough matter and energy in the solar system to send out lots and lots of ships, so each one doesn't have to be all that reliable.

It's extremely implausible that we won't figure out how to build a self sufficient local colony in 100k years time. Personally, I'd put it at 1k years on the outside. It's just not that hard, and it gets dramatically easier every year.
  #68  
Old 05-05-2013, 09:18 PM
jz78817 is online now
Member
 
Join Date: Aug 2010
Location: Under Oveur & over Unger
Posts: 12,338
look, shit like "warp drive" and "transporters" only exist because they were used in old TV shows and movies to move their plots forward. some people have hypothesized how such devices might work, but we're nowhere close to making them work. The elephant in the room of interstellar travel is fuel. The faster you want to go, the more fuel you need, but the more fuel you need, the more massive your craft is, which means you need more fuel, and more powerful engines, and more fuel, which means your craft is even more massive, and can I introduce you to thermodynamics to tell you you're playing a losing game? And yeah, I know, solar blah-blah; we're practically bathed in solar energy on this planet but we're not all that good at exploiting it. In fact the only solar energy we're good at exploiting is that which has been way underground for millions of years.

sorry, folks. ain't gonna happen.
  #69  
Old 05-05-2013, 10:45 PM
colander is offline
BANNED
 
Join Date: Nov 2012
Location: Home of the golden bear
Posts: 1,468
Quote:
Originally Posted by Der Trihs View Post
How would I know?
I am not sure, but damned if you don't keep talking anyway. It's like listening to a drunk five-year-old trying to explain how babies get made.

Last edited by colander; 05-05-2013 at 10:47 PM.
  #70  
Old 05-05-2013, 11:00 PM
Der Trihs's Avatar
Der Trihs is offline
Guest
 
Join Date: Aug 2005
Location: California
Posts: 38,890
Quote:
Originally Posted by colander View Post
I am not sure, but damned if you don't keep talking anyway. It's like listening to a drunk five-year-old trying to explain how babies get made.
An insult post that avoids actually answering anything I said.
  #71  
Old 05-05-2013, 11:46 PM
Mosier is offline
Guest
 
Join Date: Oct 2003
Location: Vegas
Posts: 7,612
Quote:
Originally Posted by colander View Post
non-engineers are funny
What exactly is the theoretical problem with machines that can repair themselves, or each other?
  #72  
Old 05-06-2013, 02:11 AM
Idle Thoughts is offline
 
Join Date: Aug 2003
Location: Arizona
Posts: 12,266

Moderator Note


Quote:
Originally Posted by colander View Post
I am not sure, but damned if you don't keep talking anyway. It's like listening to a drunk five-year-old trying to explain how babies get made.
This is stepping over the line for this forum, from now on, use the Pit. The next time won't be a note for you as you should know this by now.
  #73  
Old 05-06-2013, 02:19 AM
Askthepizzaguy is offline
Guest
 
Join Date: Oct 2009
Location: Norway
Posts: 2,910
Quote:
Originally Posted by BigT View Post
Dude, we'll be past the singularity at that point. (And I don't mean the woo version). We (or our creations who take over) will be so smart we can't even predict what we'd be thinking, let alone what we would discover. We're talking exponential growths in intelligence here. There's just no way you can predict that far in advance. Yeah, it's not going to happen any time soon, but it is definitely pessimistic to say it won't happen in 100,000 years.

Even if you think FTL travel will never happen, the sleeper ship scenario you gave is entirely based on current or near-future tech. Despite what you were taught on Star Trek, there's no inherent that reason all devices need regular maintenance. And there's no reason you couldn't have maintenance anyways in a generational ship. There's no reason to think we won't develop longer lasting materials in a timespan that is longer than recorded history itself.

So, yeah, you're a pessimist, and, what's worse, the worst kind of pessimist. You are both unknowingly ignorant about the subject, and, worse, actually get off on trying to dash the hopes of optimists (and even realists). You're trying to preemptively rub people's noses in their supposed mistakes. That'd be bad even if you turned out to be right.
Hilarious post. Thanks for the laugh.
  #74  
Old 05-06-2013, 02:20 AM
Askthepizzaguy is offline
Guest
 
Join Date: Oct 2009
Location: Norway
Posts: 2,910
Quote:
Originally Posted by billfish678 View Post
Unless you are talking about some Shatner other than the one I think you are that may be the funniest statement I have ever read on the internet.

And, OP, I take it travel to other galaxies is straight out?
Actually- if you can solve the interstellar travel problems, it is no longer that much of a leap to go to another galaxy, since there's at least one galaxy HEADIN RIGHT FOR US

*shoots gun*
  #75  
Old 05-06-2013, 02:36 AM
Askthepizzaguy is offline
Guest
 
Join Date: Oct 2009
Location: Norway
Posts: 2,910
Quote:
Originally Posted by Dr. Strangelove View Post
As others have said, you write off colony ships too quickly. We already have the technology to reach 1% of the speed of light, and at that rate it's <500 years to Alpha Centauri, and only a few thousand years to get to quite a few more interesting places.
That same technology can theoretically push you further than 1% of light speed.

The issue is that, at nearly 7 million miles per hour, anything you come into contact with including gas and dust will either obliterate your spacecraft or wear it down to nothing.

The front of the craft will be experiencing atomic nucleus smashing against atomic nucleus at very high speeds, resulting in a much higher release of energy than, say, heat from friction would cause, on orders of magnitude difference. This isn't flying through the air at mach 2, this is flying through something less dense than air, but at speeds that are thousands of times greater.

That's tough even if it is just thinly dispersed gas. Micro-asteroids and dust would be like an atomic bomb exploding on the nose of your spacecraft. This is how we destroy atoms, not just molecules, or structures. All structure breaks down at those kinds of high-energy collisions. We bust quarks apart that way. I mean seriously, expecting our craft to survive those kinds of speeds is ludicrous.

You obviously have to move slower, as there is no *kind of matter* let alone element, let alone alloy, let alone construction method, which will survive such speeds moving through a non-vacuum, and space is not a vacuum. Particularly when you play the odds and end up running into a 500-foot wide random asteroid which is going to happen somewhere along your 41,500,000,000,000 kilometer journey.

But as I said, your craft never made it halfway that far because the gas tore the atoms of your spaceship apart at those speeds.

I have more than just pessimism, by the way. See my next post.

Last edited by Askthepizzaguy; 05-06-2013 at 02:37 AM.
  #76  
Old 05-06-2013, 03:11 AM
Askthepizzaguy is offline
Guest
 
Join Date: Oct 2009
Location: Norway
Posts: 2,910
Now that I've laid out what I consider to be all the limits, my solution involves much of what was proposed in this thread and I haven't yet rejected.

What is possible: Moving pretty darn fast by our standards, but not on the order of 1% of light speed.

What else is possible: "Generational" starships. Human stasis. We haven't perfected it, but the key seems to be dehydrating beforehand, so that your cells do not rupture when frozen. You need to survive the dehydrating process (well, not survive it, per se.... but be able to be revived from it) and you need to have the dehydrating/freezing process occur rapidly enough to prevent brain damage.

As long as your cells survive the freezing and thawing, and your brain is not deprived of oxygen for too long, humans could survive stasis.

We can do better than generational ships:

You have one crew capable of maintaining the ship and piloting it and being awake and aware during the journey.

Now, you have 500 more crews, capable of doing the same thing.

One crew not in stasis, per year. The other 500 crews in stasis, waiting for their shift where they watch over the ship.

How it would go: Thaw, and run the ship for a year. Then, return to stasis, after crew number 2 thaws and is prepared to return to duty.

500 years pass outside of the stasis, but for you, you've only aged one year.

One year versus 500 years. That means for every year you age on this interstellar journey, you have traveled 500 years toward your destination.

No need for generational ships. One generation. Everyone makes the journey to the nearest star system, even if the trip takes 3,000 years, it would only require six years of your active life. Go 3,000 years into the future in six years.

And, of course, if the trip takes twice that long, 6,000 years, then you take 1,000 crews. All trained to do the task. All available in case of emergency. And in case you have deaths or accidents, you have backup crews.

And when you arrive at your destination, you have an entire viable colony, not just a struggling crew of six or twenty to try to build a civilization.

You have construction crews build living quarters and as they become available, the colony emerges from stasis in a staggered form.

Using this method, you could "shorten" even a much larger trip. It just requires large numbers of people.

A crew of 100, let's say, times as many crews as you need.

It would be easy to scare up 100,000 people for this voyage. I mean, we have 7 billion people on Earth.

So, say the journey took an astounding 10,000 years.

You would need two thousand crews, each working for 5 years during the voyage. All perfectly feasible.

Assuming perfect stasis technology, assuming you can survive several revival and hibernation attempts, and assuming you have enough people willing to volunteer and train... and assuming you can store 200,000 people in individual stasis chambers, well then. You have two thousand crews of 100 people, serving aboard the ship for 5 years each, resulting in a fully staffed crew for 100,000 years.

In a single generation. It would make volunteering for the journey much more meaningful to the folks doing it- it means you leave Earth today, and arrive in the next star system 5 years later. You get to see the end of the journey.

And that means you can travel at slow enough speeds to survive the journey, and maneuver out of the way of larger objects or dust clouds, and gas won't hurt your ship.

Safe, interstellar travel. Within 5 years of your "lifetime".

Just remember it is a long journey, and it is pretty much a one-way event. You won't be traveling back to Earth ever. Which is fine, this is what you'd expect.

Then you just plan ahead- make sure you have enough fuel to make the journey many times over, so that way if you get to the next star system and it turns out to be less attractive than we thought, you can go to the next one, and keep going if that one doesn't seem like the best place to settle.

And if you happened to want to return home, keeping in mind the travel time would make "home" a very different place, you technically could.

Those are the extremely conservative numbers. Add in the proposals for a fleet of ships scanning for debris or danger ahead of your main craft, and some kind of shielding system, and perhaps you can up the speed, and make the journey even more reasonable.

Then go as fast as is actually safe, get there ahead of schedule with reserve power, reserve crew, reserve fuel. Then, you could even make this a twofer.

Settle half your crew in that star system, and the other half keep going to the next one. Makes sense to not waste such an opportunity given the prohibitive costs of building even one interstellar craft.

Building it:

Futuristic magnetic mass ejection system on Earth shoots material and so forth into space more cost efficiently than rocket fuel, using stored solar energy as the source. The energy is limitless, assuming you have time to wait for the energy to be collected and stored. Then you release material into orbit.

This is then assembled into a shipyard/processing center which uses asteroids and so forth as raw materials, which can then be turned into the hull of the spacecraft.

You mine the asteroid belt until you have enough raw materials. You eject people and food and other materials that are easier to assemble on Earth, into orbit, when absolutely necessary. You keep standard chemical rocketships on standby in case they are needed to do an emergency rescue operation that wouldn't be feasible using the magnetic launching system.

You wouldn't construct the ship on Earth, and 95% of the matter used for the ship should be found in space to keep the costs economical. You phase out rocket fuels as the main method of getting us up there, use solar power and magnets instead. Or a superior technology if there is one available, but we could build something like this using today's technology. It would require a dedicated NASA project, but we could do it.

Difficulties:

Become manageable. Economics of rocket fuel go out the window.

Time ceases to be an issue. Speed becomes manageable and no longer dangerous.

You simply have to train the crews, complete research on human stasis technology (there is no law of physics stopping us here, this is entirely realistic) and dedicate time, energy, and funding to the projects of a launching system, an orbital processing facility/construction yard for the interstellar craft, and get decent at mining asteroids.

Once you have time, speed, chemical fuel constraints, and technological requirements all solved as problems, you can then presume that an interstellar journey would be not just possible, but feasible, and an intelligent exercise.

The thing is, the process will still take many thousands of years. If you can handle this, then our fate may not be to be stuck in this star system until we expire.

But it does require looking at things like time and speed realistically. We won't be traveling at near light speed. And we won't get there very soon at all.

Now, I'm ready to hear your criticisms. I've just spent the whole thread saying this project is ridiculous, in almost every way. However, like most of you, I would like to be able to say it's possible, realistic, feasible.

This is my proposed solution- it involves not unrealistic technology, not unrealistic logistical requirements, not unrealistic travel time and travel speed.

Hit me with your reasons why it doesn't work, doesn't solve enough (or any) problems associated with this voyage, or why your solution was better.

I'm a big boy and I can handle the internet hating on my idea children. Ideas are meant to be criticized, so the bad ones get tossed and the good ones remain.

Kill my bad ideas, and do it heartlessly. Show me why they're bad.

GO!
  #77  
Old 05-06-2013, 04:37 AM
Askthepizzaguy is offline
Guest
 
Join Date: Oct 2009
Location: Norway
Posts: 2,910
Note/ETA: when I refer to dehydration, I don't mean removal of all water, just a lessening of the amount of water, such that the frozen cell membrane does not rupture.
  #78  
Old 05-06-2013, 04:52 AM
Dr. Strangelove's Avatar
Dr. Strangelove is online now
Guest
 
Join Date: Dec 2010
Posts: 7,967
Quote:
Originally Posted by Askthepizzaguy View Post
Particularly when you play the odds and end up running into a 500-foot wide random asteroid which is going to happen somewhere along your 41,500,000,000,000 kilometer journey.
I'll have to get to your other stuff later, but already it's clear that you haven't actually run the numbers.

Suppose all matter in the Milky Way consisted of randomly distributed 500-foot asteroids.

Mmw = 1.5e12 stars * 2e30 kg/star = 3e42 kg
Mast = 1.85e6 m^3/ast * 3.5e3 kg/m^3 = 6.5e9 kg/ast
Nast = 3e42 kg / 6.5e9 kg/ast = 4.6e32 ast

Volume of the Milky Way is approximately:
Vmw = 5e62 m^3

And the volume a 1 km diameter conical ship intersects over a 4.15e16 m path is:
Vpath = 4.15e16 * 7.85e5 m^2= 3.26e22 m^3

So the volume ratio is:
Vpath / Vmw = 6.52e-41

And therefore the likelihood of intersecting an asteroid is:
P = 4.6e32 * 6.52e-41 = 3e-8, or 3 millionths of a percent.

Of course, this is an absurdly conservative estimate, since an infinitesimal fraction of the Milky Way's matter is in the form of asteroid-sized bodies, and what amount there is is mostly near stars. But even with that, the chances are nil. Space is big.

Now, there is some worry about smaller objects. A 1 cm object would do some damage, though I suspect the odds of hitting even one of those in deep space is close to zero.

Dust won't cause atomic bomb scale energy releases. Cosmic dust is something like 1e-7 m in diameter, and therefore ~2e-18 kg in mass.
KE = 0.5*mv^2 = 0.5 * 2e-18 kg * (3e6 m/s)^2 = 9e-6 J.

So at 1% of the SoL, a dust particle impacting delivers 9 millionths of a joule of energy. There's probably a fair amount of dust along the way, and so your shield will experience erosion, but a single impact is still minuscule.

The particle-accelerator-type energies you bring up are irrelevant here. Particle accelerators work at 99.lots-of-nines% of SoL. We're at 1%. It's not even close to relativistic.
  #79  
Old 05-06-2013, 05:26 AM
Askthepizzaguy is offline
Guest
 
Join Date: Oct 2009
Location: Norway
Posts: 2,910
Quote:
Originally Posted by Dr. Strangelove View Post
I'll have to get to your other stuff later, but already it's clear that you haven't actually run the numbers.
Yes, this is very clear. My OP stated that I am not a scientist or expert.

I will not attempt to suggest that your math is wrong as I can't double check it myself. It could be entirely correct arithmetic and it probably is. But it also deals with assumptions and the problem of on average.

Space is big, odds are you won't hit anything. The solar system is big, odds are you won't hit anything. On average, the solar system contains no planets. What I mean by that, is that in any planet-sized region of the solar system, odds are extremely, extremely good that there's no planet there, and that you won't hit one. That's all well and good until you do. If you want to make this journey, you should be prepared to do it safely.

There are planets in the solar system, and there are asteroids, and there are comets and dust. If you try to travel through the star system at near light speed, you might hit nothing. The odds might even be very good. I still wouldn't recommend navigating the star system blindly, because all it takes is one.

One statistical improbability can ruin your entire day. And you're gambling that your luck will be good, and the odds in your favor, for many many years of moving too fast to avoid colliding with things, through unexplored deep space. That's making some assumptions. We don't yet fully understand the nature of dark matter, just as one example. Did we factor that into your math?

I didn't see anywhere where you included it. Given that it is such a large percentage of the total mass of the universe, according to our estimates, that should be included. And we don't know exactly where it is, or what it does. We could run straight into a filament of dark matter without even knowing we're about to do so.

And even then, we're only talking estimates and educated guesses. This is not precise science. This is guessing, plus math.

That's the problem with the unknown. It's difficult to precisely calculate your odds since we're not including all the variables, and all the variables are unknown.

Quote:
Of course, this is an absurdly conservative estimate, since an infinitesimal fraction of the Milky Way's matter is in the form of asteroid-sized bodies, and what amount there is is mostly near stars. But even with that, the chances are nil. Space is big.
Yes, and smaller objects are small and hard to detect.

Quote:
So at 1% of the SoL, a dust particle impacting delivers 9 millionths of a joule of energy. There's probably a fair amount of dust along the way, and so your shield will experience erosion, but a single impact is still minuscule.
Where is your calculation which describes how many dust particles per second you'll be hitting? There's obviously a big difference between hitting one dust particle and a dust cloud, just like there's a difference between traveling through air and traveling through the ocean.

Quote:
The particle-accelerator-type energies you bring up are irrelevant here. Particle accelerators work at 99.lots-of-nines% of SoL. We're at 1%. It's not even close to relativistic.
Particle accelerators also deal with trying to force sub-atomic particles to collide with one another. We're talking about not just atoms or molecules but city-sized spacecraft colliding with objects much larger than single atoms.

The energy involved in such collisions is still orders of magnitude greater than anything we've ever experienced here on earth in any other craft, and much greater than anything any of our spacecraft have ever had to endure.

I can't fault you on your math or grasp of the subject matter, obviously much better than my own, and in truth I'm the wrong person to debate you because I cannot bring the best argument to the table, as I'm an amateur. But math is not all we are dealing with.

I thank you for dealing with it in mathematical terms, however.

What kind of turbulence could you expect from plowing through an interstellar dust cloud or molecular cloud? What about the forces exerted on such a craft when attempting to steer? How do you factor in the unknown, such as matter we can't detect so well at a distance?

And my main criticism still remains:

Quote:
Now, there is some worry about smaller objects. A 1 cm object would do some damage, though I suspect the odds of hitting even one of those in deep space is close to zero.
The odds of hitting the lottery are long, but people still do it every day.

You travel for light years through unexplored deep space at speeds approaching light speed, and expect to be able to accurately calculate the odds of reaching your destination without knowing all of the dangers, and using the odds alone as the ONLY means of survival, since we cannot avoid colliding with things, and I get a weak stomach about it.

I don't trust in probabilities to win the day, especially when we cannot be very certain of our accuracy when we can't describe exactly the reason why the universe seems to be much heavier than it looks like it should be.

I want to be able to pilot the craft out of the path of danger, even if we didn't calculate probability of such a thing existing. I want to play it safe, and be able to navigate through something like the Oort cloud instead of hitting the ion drive and crossing my fingers.

We have yet to detect and identify and path all the objects in the solar system, and it's difficult to think we could detect and identify and path all the objects between here and Centauri en route. And I don't want to be playing Russian roulette with a city full of people with an unknown number of bullets in an unknown number of chambers, which is what trying to calculate the odds of surviving such a journey would be, if you don't know all the variables.

I'll grant that if I'm just talking out of my ass, and the odds are so stacked against there being a danger, then I'm a worry wart. And then, I'll say "my bad."

But when you use terms like "I suspect the odds are close to zero" I don't feel like trusting your predictions. Your arithmetic could be flawless, but your assumptions could be quite flawed.

Last edited by Askthepizzaguy; 05-06-2013 at 05:29 AM.
  #80  
Old 05-06-2013, 07:35 AM
Lumpy's Avatar
Lumpy is offline
Charter Member
 
Join Date: Aug 1999
Location: Minneapolis, Minnesota US
Posts: 16,666
PizzaGuy, your premise just doesn't hold up. We know exactly how much energy interstellar dust grains have at 1-5% SoL, and it just isn't as dangerous as you insist. You don't need a magically invulnerable ship, you just need something cheap and expendable to clear a path. It's been proposed that simply having a cloud of dust precede your ship would do it.
  #81  
Old 05-06-2013, 07:48 AM
iiandyiiii's Avatar
iiandyiiii is online now
Member
 
Join Date: Aug 2010
Location: Arlington, VA
Posts: 35,575
Quote:
Originally Posted by Askthepizzaguy View Post
Hit me with your reasons why it doesn't work, doesn't solve enough (or any) problems associated with this voyage, or why your solution was better.
I think my solution is better because it's far less expensive (far less mass needed to maintain frozen genetic material vs thousands of frozen/sleeping people)... for every one of your ships that could be sent out, hundreds (or perhaps thousands) of mine could be- so even if the success rate is just 1% or even less, my idea would have a greater chance of successfully spreading humanity than yours.

The only disadvantage of my idea is the psychoses that would inevitably develop from having babies and children raised by robots and computers- even if these robots and computers were soft, huggable, human-like, and used lots of media that displayed plenty of (long-dead) real humans.
  #82  
Old 05-06-2013, 08:31 AM
Xema is offline
Guest
 
Join Date: Mar 2002
Posts: 12,259
Quote:
Originally Posted by Askthepizzaguy View Post
... make sure you have enough fuel to make the journey many times over ...
This is a very tough one, given what we currently know about physics. Making wildly optimistic assumptions about energy sources (antimatter?) and rocket engines (advanced ion drive?) you still end up having to consume a troublesome percentage of the ship's total mass as reaction mass to make the journey even once (accelerate to an acceptable velocity, then slow down at the destination).

The (very sensible) provision to allow for multiple journeys (because the originally chosen destination proves useless) will increase the mass, cost, and complexity of the ship exponentially.

Conclusion: we'll need some new physics (e.g. a way to produce thrust without reaction mass - IOW a violation of conservation of momentum) for this to be doable.
  #83  
Old 05-06-2013, 09:26 AM
Peremensoe is offline
Guest
 
Join Date: Apr 2010
Posts: 11,928
Or, you need a propulsion system that can potentially be refueled in each mission's target area.

Or a program plan that accepts some dead-end destinations in its target list.
  #84  
Old 05-06-2013, 01:43 PM
aceplace57 is offline
Guest
 
Join Date: Oct 2009
Location: CentralArkansas
Posts: 26,305
The pink elephant in this discussion is space radiation. Imagine a long Mars mission. The crew would be DOA before reaching Mars.

NASA article
http://radbelts.gsfc.nasa.gov/outreach/effects.html
Quote:
Anytime that satellite technology or astronauts are being affected by forms of radiation in space such as fast-moving particles and X-rays, this usually causes some changes to occur. Most of the time these changes are so minor that they have no real consequences either to the way that the satellite operates, or the health of the astronaut. But sometimes, and especially during a severe solar storm or 'space weather event', the conditions in space can change drastically. The term 'space radiation effects' has to do with all of the different ways that these severe conditions can significantly change the way a satellite operates, or the health of an astronaut working and living in space.

Last edited by aceplace57; 05-06-2013 at 01:45 PM.
  #85  
Old 05-06-2013, 02:17 PM
Left Hand of Dorkness's Avatar
Left Hand of Dorkness is online now
Charter Member
 
Join Date: May 1999
Location: at the right hand of cool
Posts: 41,583
I remember an argument I had with a roommate back in 1995. He thought science had pretty much discovered everything important, and now we're just filling in the details.

I naturally have some problems with this view .

When I think about what life will be like in 500 years, I imagine explaining World of Warcraft to someone from 1513. I don't have the technical knowhow to convince someone from that time that the game is possible, and they could likely give me very good reasons why my description ("I can sit down in front of a piece of glass and move an object that looks like a mouse carved from ivory, while pressing buttons on what looks like a drastically modified printing press typeset box, and the glass will glow with internal light, creating a painting that moves in response to my movements of the ivory mouse and the typeset, telling a narrative about fantasy creatures, some of whom are manipulated by other people sitting at similar glasses in other parts of the world, but really what I'm doing is causing tiny manmade sparks to flow through certain invisibly-tiny pieces of metal and silicon, and we do it because--oh, forget it") was impossible.

To say what our generations-distant descendants will be capable of strikes me as a wee bit hubristic. We're only a few centuries away from the beginning of the enlightenment, and already look what we've done. We don't even know what the next cognitive shift in our species will be--or if there is another one coming. Will it revolutionize technology as much as the Enlightenment did?

So your reasons look good, AtPG, but I'm not buying .

Last edited by Left Hand of Dorkness; 05-06-2013 at 02:18 PM.
  #86  
Old 05-06-2013, 02:22 PM
Lumpy's Avatar
Lumpy is offline
Charter Member
 
Join Date: Aug 1999
Location: Minneapolis, Minnesota US
Posts: 16,666
On an interstellar trip the radiation is going to be cosmic rays, which are more or less a known constant. Unlike in system when solar flares or radiation belts are a problem.

Also: if you're in hibernation/suspension you body's self-repair mechanisms are as slowed down as everything else, so you need much more radiation protection. Still, enough shielding is probably a trivial problem if you can mount an interstellar journey in the first place.
  #87  
Old 05-06-2013, 03:57 PM
smiling bandit is offline
Guest
 
Join Date: Nov 2001
Posts: 16,955
Quote:
Originally Posted by Left Hand of Dorkness View Post
When I think about what life will be like in 500 years, I imagine explaining World of Warcraft to someone from 1513. I don't have the technical knowhow to convince someone from that time that the game is possible, and they could likely give me very good reasons why my description [snip] was impossible.
That may be, but all that implies is that we are likely to get *something* we didn't know was possible. But what far too many people keep believeing is not that we are likely to get some things we didn't know were possible, but that we will get one specific thing we know to be *impossible* - or at least a lot of technologies we can use to do an end-run.

Aside from which, your roommate may have been closer to correct than you think. The era of big physics discoveries may well be over. The era of big scientific discoveries itself may be over.

Last edited by smiling bandit; 05-06-2013 at 03:57 PM. Reason: spelling
  #88  
Old 05-06-2013, 04:45 PM
Dr. Strangelove's Avatar
Dr. Strangelove is online now
Guest
 
Join Date: Dec 2010
Posts: 7,967
Quote:
Originally Posted by Askthepizzaguy View Post
Yes, this is very clear. My OP stated that I am not a scientist or expert.
Neither am I, but the math is high-school physics and probability and the data is stuff I've looked up on the web. You can do this stuff too.

Quote:
Originally Posted by Askthepizzaguy View Post
That's all well and good until you do. If you want to make this journey, you should be prepared to do it safely.
Nothing is safe. Every activity has some risk associated with it. Interstellar journeys are going to be dangerous; no doubt about it. But there's a big difference between a 1% chance of failure and a 99.9% chance.

Quote:
Originally Posted by Askthepizzaguy View Post
One statistical improbability can ruin your entire day.
There are some finite odds that tomorrow, a large asteroid will hit the Earth and kill all life bigger than an ant. At some point, you simply have to say that the odds of some event are negligible and ignore it.

Quote:
Originally Posted by Askthepizzaguy View Post
We don't yet fully understand the nature of dark matter, just as one example. Did we factor that into your math?
Dark matter is not neutrinos, but it's something like neutrinos. As such, it barely interacts with normal matter. There is at the moment a large flux of neutrinos (and probably a smaller flux of dark matter) passing through you right now. The colony ship probably won't even have a dark matter detector since it would have to be massive (though maybe you could double-purpose the water/ice tanks). It certainly couldn't "hit" the ship.

Quote:
Originally Posted by Askthepizzaguy View Post
That's the problem with the unknown. It's difficult to precisely calculate your odds since we're not including all the variables, and all the variables are unknown.
We actually do have a good idea of most of the variables. There are multiple very good reasons to believe that the interstellar medium has very little matter of any kind, and what matter there is is mostly hydrogen and helium gas or plasma.

Quote:
Originally Posted by Askthepizzaguy View Post
Where is your calculation which describes how many dust particles per second you'll be hitting? There's obviously a big difference between hitting one dust particle and a dust cloud, just like there's a difference between traveling through air and traveling through the ocean.
As I said, there will probably be a fair amount of dust. I don't know yet if it's significant. I'll see if I can find figures.

Quote:
Originally Posted by Askthepizzaguy View Post
Particle accelerators also deal with trying to force sub-atomic particles to collide with one another. We're talking about not just atoms or molecules but city-sized spacecraft colliding with objects much larger than single atoms.
The size of the craft doesn't matter here since it's much bigger than the objects it might hit. The only two inputs we really need are the mass of the particle and the speed of the ship.

Quote:
Originally Posted by Askthepizzaguy View Post
The energy involved in such collisions is still orders of magnitude greater than anything we've ever experienced here on earth in any other craft, and much greater than anything any of our spacecraft have ever had to endure.
Not for the dust grains, as I already showed.

Let me take your side for a while. What do we need to actually have an atomic-scale energy release? A modest atomic bomb is 10 kilotons, which is 4.2e13 J. Running this through the KE equation, we get a 9.3 kilogram object.

So, clearly it would be bad news if that hit you. I can't use my math above to show that the odds are still nil, because close to a billion 9.3 kg objects fit in the original asteroid you proposed.

But as I said, I made an absurdly conservative estimate--probably by a factor of a million or more. But showing that will require data I don't have right now, so I can't exclude it completely.

That said, shielding is an option. One proposal is to have your shields far ahead of the ship; perhaps held in place by laser pressure. You build them out of very thin foil, and there are many layers. When an object hits the first layer, it starts breaking apart, though without losing much energy/velocity. As it progresses through the layers, it breaks apart more and more until it forms a cone of dispersing particles. By the time the cone gets to the ship itself, it is spread apart quite widely, and the conventional shields on the ship can deal with the debris.

Of course, the forward shield is destroyed. But because it's made of such thin foil, you can just replace it immediately, and you can keep hundreds of replacements on board. You can also recycle the remains of the shield.

Quote:
Originally Posted by Askthepizzaguy View Post
What kind of turbulence could you expect from plowing through an interstellar dust cloud or molecular cloud? What about the forces exerted on such a craft when attempting to steer? How do you factor in the unknown, such as matter we can't detect so well at a distance?
The short answer is that we won't know until we try it. But we already know a lot, and our instruments will be fantastically better in just 100 years, let alone 100k.

Quote:
Originally Posted by Askthepizzaguy View Post
I don't trust in probabilities to win the day
Well, you should. Every time you step out the door you risk your life (actually, every time you don't step out the door, you also risk your life). The chances of it happening on any given instance is low, though, so you don't think about it.

More importantly, the people who build this ship will be aware of probabilities. The engineers who sent men to the Moon were aware, and built in a certain degree of redundancy: for instance, the Saturn V could handle a single first stage engine loss. And they needed it on Apollo 13, because the system wasn't 100% reliable. It couldn't have coped with losing two engines, though, even though that was clearly a possibility. You define a level of acceptable risk and build the system to meet that.

Quote:
Originally Posted by Askthepizzaguy View Post
I want to be able to pilot the craft out of the path of danger, even if we didn't calculate probability of such a thing existing. I want to play it safe, and be able to navigate through something like the Oort cloud instead of hitting the ion drive and crossing my fingers.
Might not be possible. It depends on how good your sensors are. The longer the range, the more time you have, and the less fuel you have to use to maneuver. But it may not matter.

Quote:
Originally Posted by Askthepizzaguy View Post
I'll grant that if I'm just talking out of my ass, and the odds are so stacked against there being a danger, then I'm a worry wart. And then, I'll say "my bad."
It's not impossible that there's a danger, and it's something to think about. It just doesn't look insurmountable, because there just isn't that much matter out there, and what stuff there is isn't that dangerous. I think I can safely say that we'll know for sure in under 100 years.
  #89  
Old 05-06-2013, 06:26 PM
Xema is offline
Guest
 
Join Date: Mar 2002
Posts: 12,259
Quote:
Originally Posted by smiling bandit View Post
The era of big scientific discoveries itself may be over.
This seems dubious, coming shortly after convincing evidence for dark matter and dark energy has surfaced.
  #90  
Old 05-06-2013, 08:25 PM
Left Hand of Dorkness's Avatar
Left Hand of Dorkness is online now
Charter Member
 
Join Date: May 1999
Location: at the right hand of cool
Posts: 41,583
Quote:
Originally Posted by smiling bandit View Post
That may be, but all that implies is that we are likely to get *something* we didn't know was possible. But what far too many people keep believeing is not that we are likely to get some things we didn't know were possible, but that we will get one specific thing we know to be *impossible* - or at least a lot of technologies we can use to do an end-run.
I am not arguing in favor of the proposition "We are going to be doing any interstellar space travel." I am arguing against the proposition "We are not going to be doing any interstellar space travel." In other words, I certainly don't think it's likely we'll do interstellar space travel, but I also think it's awfully premature to predict that our 10,000 years from now descendants won't figure out how to do it.
Quote:
Aside from which, your roommate may have been closer to correct than you think. The era of big physics discoveries may well be over. The era of big scientific discoveries itself may be over.
Since he said that, a fifth state of matter has been discovered, the acceleration of the universe's expansion has been observed, the human genome has been mapped (to take a non-physics example), and the Higgs boson has been found. We've had less than half a century to apply the computing power of a single iPad to the study of our universe. I'll continue taking the bet against my roommate .

Last edited by Left Hand of Dorkness; 05-06-2013 at 08:25 PM.
  #91  
Old 05-07-2013, 02:10 PM
snowthx's Avatar
snowthx is offline
Guest
 
Join Date: Feb 2012
Location: Sacratomato area
Posts: 3,493
Quote:
Originally Posted by Left Hand of Dorkness View Post
I am not arguing in favor of the proposition "We are going to be doing any interstellar space travel." I am arguing against the proposition "We are not going to be doing any interstellar space travel." In other words, I certainly don't think it's likely we'll do interstellar space travel, but I also think it's awfully premature to predict that our 10,000 years from now descendants won't figure out how to do it.
Since he said that, a fifth state of matter has been discovered, the acceleration of the universe's expansion has been observed, the human genome has been mapped (to take a non-physics example), and the Higgs boson has been found. We've had less than half a century to apply the computing power of a single iPad to the study of our universe. I'll continue taking the bet against my roommate .
I am in a pessimistic mood today. While I agree there are going to be discoveries made that we cannot fathom today, keep in mind that all the good things you mention in your last paragraph were accompanied by developments in faster and more efficient methods for us to butcher and slaughter ourselves. All our great discoveries to come may be for naught if we cannot get a handle on our inbred savagery, purposeful ignorance, and greed.
  #92  
Old 05-07-2013, 08:15 PM
Measure for Measure's Avatar
Measure for Measure is offline
Charter Member
 
Join Date: Oct 2000
Posts: 14,165
Quote:
Originally Posted by Askthepizzaguy View Post
We can do better than generational ships:

You have one crew capable of maintaining the ship and piloting it and being awake and aware during the journey.

Now, you have 500 more crews, capable of doing the same thing. ...
Vinor Vinge had a similar idea in A deepness in the sky (1999) except he tacked on humans biologically adapted for space and added human longevity. Wiki: "The book discusses some of the problems of trying to maintain an interstellar trading culture without access to superluminal travel or to superluminal communication."
  #93  
Old 05-07-2013, 08:32 PM
Measure for Measure's Avatar
Measure for Measure is offline
Charter Member
 
Join Date: Oct 2000
Posts: 14,165
Quote:
Originally Posted by smiling bandit View Post
Aside from which, your roommate may have been closer to correct than you think. The era of big physics discoveries may well be over. The era of big scientific discoveries itself may be over.
The last paradigm shift was plate tectonics, during the 1960s. So accepting this premise, we have about 50 years of fully mature science to extrapolate on. How far out would you want to project forward based on that, 200 years maybe?

The Fermi paradox (1950) is based upon the ease of intra-galactic travel over 5 - 50 million year time spans. 200 << 5,000,000. Admittedly, the Fermi paradox cuts both ways: if space travel is so easy, where are the aliens?
  #94  
Old 05-13-2013, 09:41 PM
Askthepizzaguy is offline
Guest
 
Join Date: Oct 2009
Location: Norway
Posts: 2,910
Quote:
Originally Posted by Dr. Strangelove View Post
Let me take your side for a while. What do we need to actually have an atomic-scale energy release? A modest atomic bomb is 10 kilotons, which is 4.2e13 J. Running this through the KE equation, we get a 9.3 kilogram object.
I'm probably not able to be convinced, so I'll certainly forgive you if you give up on trying.

I'll respond to the above in a moment.

Folks say I've got hubris when I suggest that science is not the same as magic and there are actual limits on what we can do, even considering technological progress. If it simply isn't possible to fold space then science can't fix that. It's not magic. If it requires more energy than is contained within a star system, then it becomes useless to us long after we master a different method of interstellar travel, and may never be useful.

This isn't Futurama, not everything is possible if you imagine it.

To me, it takes a fair amount of hubris to suggest that we know the odds that somewhere on a several trillion kilometer journey that we will encounter an object of less than ten kilograms.

Yes, I believe it's possible to suggest an average density of space. That's easy math.

You're traveling at speeds that make it impossible to steer the ship, and an impact of 10 kilograms will obliterate you. Your math suggests that matter in space is not very dense, on average. That objects such as those are going to be rare.

Except of course, for an object that was ejected from a stellar system, which the math and probabilities says isn't even there. Because yes, it is a rare event. But like I said, it only has to happen once. And we are traveling from one star system to another. That tells me we might encounter other objects which have been ejected from a star system. And if folks are telling me they can know the precise odds of such a thing happening or not happening, I am suggesting they are placing too much trust in their ability to know the unknown.

I believe we can use observation and determine that there isn't much of anything out there. I believe we can determine to a fair degree the mass of the galaxy. I believe we can know a lot of things that are difficult to know.

But never would I believe that, having never traveled to another star system, having never even sent a survey probe, that we could plug in the rather unrelated numbers of average matter density of space and distance traveled and arrive at a safe conclusion. That's hubris. That isn't what we need to calculate. You don't just need to know how much matter there is on average. You also need to know that there's nothing that is not-average in your way. And you can't know that.

You might be able to tell from gravitational lensing that there's no star or planet in your way. Yes, I can buy this. But I can't believe that you can venture into the great unknown and suggest it is known via probability.

I think it is a lesser leap of faith to suggest we are actually bound by some of the physical properties of the world around us, and that science isn't magical. I think it's a great leap to think even our greatest scientists know for certain that there's no rocks between here and the next star system, particularly when we're finding more and more and more rocks in our own backyard all the time, that we never noticed were there.

Some things are just not calculable without some actual data. And I don't think average density of the matter in space is enough data to state what you state with such confidence of the odds.

That's my position. If I just can't grasp this matter then so be it. I'm not the one you'd have to convince anyway. I'm just a random skeptic.
  #95  
Old 05-14-2013, 02:24 AM
Mangetout's Avatar
Mangetout is offline
Member
 
Join Date: May 2001
Location: England
Posts: 57,944
Quote:
Originally Posted by Diceman View Post
I hate to be a wet blanket, but I've got to agree with the OP. Speculation about warp drives and wormholes and whatnot is fantasy, and given our current understanding of physics they're pretty much on par with the teleportation spells in a Harry Potter book.
Worse, for such things to be discovered, it is necessary for the basis of a good deal of our current science to be overturned - not the results or products of that science (of which there are many), just their basis.

So in order for warp drives and FTL travel to come into daily use, we will also need to develop brand new explanations for how we managed to invent things like LEDs, nuclear reactors, radios, etc, whilst all the while fundamentally misunderstanding why they worked.
  #96  
Old 05-14-2013, 05:40 AM
Dr. Strangelove's Avatar
Dr. Strangelove is online now
Guest
 
Join Date: Dec 2010
Posts: 7,967
Quote:
Originally Posted by Askthepizzaguy View Post
I'm probably not able to be convinced, so I'll certainly forgive you if you give up on trying.
The problem is really just that you're making a very strong claim--you're saying we can't do it, even in 100k years. What I'm suggesting is that there are no obvious showstoppers to a generation ship.

Maybe it is the case that there are a bunch of 10 kg objects surrounding our solar system. It would be very unusual since they couldn't surround all the solar systems in the galaxy due to mass considerations, but maybe there's something special about ours. Still, you have to make the further bold claim that we can't possibly shield against such things, even though we already have designs that look like they would work, and even with 100k years of development.

Personally, I see a lot of reasons to think that warp drives and the like will never be possible. Our best physics says they aren't. Generation ships don't have this problem--so far, it's just an engineering problem, and reasons why they can't work are speculation.

Obviously, there is the chance of failure. And such ships will be expensive enough that we won't try very often. But it's not impossible that once we have our entire solar system's resources at our disposal, that we can make an attempt every few centuries. Even if the first few fail, surely we will learn from those mistakes and fix them.

In short, you need better evidence before claiming that generation ships are impossible. Improbable--sure, have at it; economics seems the biggest problem to me. But impossible is a scientific claim and needs something backing it.
  #97  
Old 05-14-2013, 06:01 AM
Left Hand of Dorkness's Avatar
Left Hand of Dorkness is online now
Charter Member
 
Join Date: May 1999
Location: at the right hand of cool
Posts: 41,583
Quote:
Originally Posted by Askthepizzaguy View Post
Folks say I've got hubris when I suggest that science is not the same as magic and there are actual limits on what we can do, even considering technological progress. If it simply isn't possible to fold space then science can't fix that. It's not magic. If it requires more energy than is contained within a star system, then it becomes useless to us long after we master a different method of interstellar travel, and may never be useful.
I don't think anyone says what you claim folks say in that first sentence. The hubris doesn't come from distinguishing science from magic. The hubris doesn't come from saying there are limits on what we can do.

The hubris comes from a 21st-century person claiming to know what the limits will be on a 9,999th century person.

I think you (and I, for that matter) are only slightly better qualified to determine what those limits are than a -10th-century-person would to determine what the limits are on 21st-century people.

You observe the current state of knowledge and project it into the future. I observe the current rate of knowledge change and project it into the future. I think I'm on firmer footing.

Again, I don't suggest that we will be able to engage in interstellar travel. I suggest it's too early to say.

Last edited by Left Hand of Dorkness; 05-14-2013 at 06:01 AM.
  #98  
Old 05-14-2013, 06:18 AM
msmith537 is online now
Guest
 
Join Date: Jan 2001
Posts: 27,649
Quote:
Originally Posted by DrFidelius View Post
I'm going to go total nerd here and state that the utilization of space is the solution to our earth-bound problems.
The problem with that is it's so expensive to send anything into space and the technical challenges are so complex, those resources would be much better used right here on Earth.
  #99  
Old 05-14-2013, 06:39 AM
DrFidelius's Avatar
DrFidelius is online now
Guest
 
Join Date: Mar 1999
Location: Miskatonic University
Posts: 12,532
Quote:
Originally Posted by msmith537 View Post
The problem with that is it's so expensive to send anything into space and the technical challenges are so complex, those resources would be much better used right here on Earth.
So, instead of cutting the Panama Canal we should continue to invest in and design more efficient clipper ships? Short-term thinking will doom us all.
  #100  
Old 05-14-2013, 07:07 AM
Mangetout's Avatar
Mangetout is offline
Member
 
Join Date: May 2001
Location: England
Posts: 57,944
Quote:
Originally Posted by Left Hand of Dorkness View Post
I don't think anyone says what you claim folks say in that first sentence. The hubris doesn't come from distinguishing science from magic. The hubris doesn't come from saying there are limits on what we can do.

The hubris comes from a 21st-century person claiming to know what the limits will be on a 9,999th century person.

I think you (and I, for that matter) are only slightly better qualified to determine what those limits are than a -10th-century-person would to determine what the limits are on 21st-century people.
You're saying that current scientific knowledge is only slightly better than it was 1,000 years ago - I disagree, but if you're right, I wouldn't hold out much hope that your 9,999th century person will have fared any better.

Quote:
You observe the current state of knowledge and project it into the future. I observe the current rate of knowledge change and project it into the future. I think I'm on firmer footing.
Are you mathematically extrapolating though, or falling into the trap of making false analogies - I mean, the fact that people once had quite mistaken and uninformed views about this or that limit doesn't necessarily have any connection at all to whether or not our views are correct or properly-informed.

Last edited by Mangetout; 05-14-2013 at 07:08 AM.
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 04:02 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

Send questions for Cecil Adams to: cecil@straightdope.com

Send comments about this website to: webmaster@straightdope.com

Terms of Use / Privacy Policy

Advertise on the Straight Dope!
(Your direct line to thousands of the smartest, hippest people on the planet, plus a few total dipsticks.)

Copyright 2019 STM Reader, LLC.

 
Copyright © 2017