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19 September 2012

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Babak Makkinejad

There are too many issues involved.

The original paper required the creation of regions with negative energy density - an impossibility. This condition, also plagues the Worm-Holes etc.

Secondarily, the warped region is semi-classically unstable. See http://arxiv.org/abs/0904.0141

Also see:

http://www.fqxi.org/data/essay-contest-files/Finazzi_warpdrive_essay.pdf

Thirdly, the statement: "size of 300 Earths into something that weighs only 1,600 pounds" does not compute. The first is reference to mass (units of Kg in SI units) and the second one to weight (Newton, in SI units).

That does not mean that super-luminal space travel is an impossibility. Signals have to able to travel faster than the speed of light else different regions of the Universe will become "dis-connected" from another; their signals will not reach one another.

Jose

I read about Dr. Miguel Alcubierre's paper in 1996, but at the time it was impossible due to the energy requirements. As technology and our understanding of physics improve, the energy requirements have dropped. Too bad we cannot afford something like the following:

http://en.wikipedia.org/wiki/Project_Daedalus

Alpha Centauri would be a better target:

http://www.centauri-dreams.org/?p=22603

The Moar You Know

Not soon enough. If I'm lucky I've got about forty more years and I want to see interstellar space with my own two eyes before I die.

Get on it, NASA.

Charles

Yeah,
I am 64 and mad that I won't be around to go. Shame to waste all of those Engineering degrees. Drat!
Regards,

DH

Make it so, Number One.

mongo

Hello, Sir:

It is abundantly clear that the article is written by someone with no comprehension of what he is reporting on. The "football-shaped" spacecraft in the accompanying video actually has *laces*. A slightly better explanation can be found here:

http://www.space.com/17628-warp-drive-possible-interstellar-spaceflight.html

It, unfortunately, includes more detail on just how speculative the concept is, and it also fails to explain exactly what is meant by the "1600 pounds required" for the engine. If they are talking about mass-energy equivalence, then here are some fun facts to consider:

1. This amount of energy is equivalent to about the same as what's released from a 15,000 megaton explosion, or

2. If you assume that the average home consumes 30kWh a day, and NYC has 11 million homes, this is enough energy to power those homes for about 150 years.

These aren't "off the scale" numbers, but they're still very large and present some interesting engineering challenges. They may well figure this one out in 100 years. :-)

mongo

Grimgrin

Well reading over the Wiki the proposed drive requires exotic matter having negative mass, and it's not clear that this actually exists, or can possibly be created.

My idea (although it may not be my original idea, but I'm not aware of having read anything about it before I thought of it) is to see if it's possible to lower electrical and magnetic permittivity of a particular region of vacuum.

Essentially the speed of light through that region would be higher, so you could sidestep the relativistic effects that make it so energy prohibitive to travel close to the speed of light.

My uneducated guess is that macro-scale FTL travel isn't possible, and the workaround isn't going to involve physics but biology. Making humans or post-humans who can live forever (or at least long enough that a 100 year trip isn't a big deal) seems to me to be the simpler problem than getting the energy together to fling a standard human across interstellar space in a reasonable fraction of a standard human lifetime.

Walrus

Babak, not necessarily impossible. If you read Alexander Franklin Mayers book.

Cosmology was hijacked in 1929 by Hubble. Once we dispense with the Big Bang theory, a lot of other currently unexplainable things get explained and new prospects open up.

For example, it appears black holes, white holes and worm holes exist to redistribute energy across the event horizon. The Alderson drive is a definite maybe.

Lars

You probably have to start with getting Congress to do anything other than naming post offices within a year or so. Compared to that, the physics are probably easier.

I got to see the last shuttle depart KSC for retirement duties this morning. They accomplished quite a bit with that program but now we have entered a more experimental era. Hopefully they will do fine but I suspect traveling faster than light may be somewhat delayed in the meantime.

mongo

Hi, Grimgrin:

That's an intriguing idea, but I don't think that it would significantly reduce the energy cost for propulsion, just shift it to creating the physical conditions around a spacecraft to make it work. If it's even possible -- I have no idea.

I'm still hopeful that some clever person will finally figure out a Grand Unified Theory linking gravity to the (formerly) other three forces, which are now understood as a single force that manifests itself differently on different scales. In which case your idea may well turn out to be the same thing as Alcubierre's concept.

On the subject of longevity, you also need to perfect the engineering for a closed ecosystem like a "slow boat" type of craft. In addition to the biology, there's also sociology -- how would a group of humans change over a 100 year trip? That would make for an interesting sci-fi novel...

Regards,

mongo

Rocketrepreneur

Pat,

Not sure what to think--I just work on tractor beams.

~Jon

mongo

Hi, Walrus:

As a former astrophysics geek, I have to offer a clarification: Edwin Hubble did observational astronomy, not cosmology for the most part. The Big Bang theory traces its roots to Einstein and de Sitter, and was first formalized by Friedman, Robertson and Walker. So you're cheesed at the wrong guy.

Hubble's observations and measurements happen to fit the FRW cosmological model, and they've been repeated by just about everybody. He was just the messenger and doesn't deserve the bad rap for that. :-)

Regards,

mongo

mike

Can't happen fast enough for me. But I believe 200+ years is a better estimate.

@ Lars:

"...naming post offices..." ???? Don't you mean shutting down post offices. Us small townies now need to drive 30+ miles to the county seat to get to a post office.

Jose

Folks, this has more potential to explain reality if we can understand the basic principles:

http://scienceblog.com/56488/mathematician-offers-unified-theory-of-dark-matter-dark-energy-altering-einstein-field-equations/

Babak Makkinejad

I was unable to find a mathematical statement of his ideas; I was looking for his version of "Field Equations of General Relativity". My sense of it is that he is not postulating new equations altering their interpretations. But am not sure.

Mike Martin, Yorktown, VA

As a retired Air Force airlift guy, the idea of moving 300 Earths on one pallet is not without appeal. One sortie, engine running offload, recover and go to the club. However, that technology and capability would certainly imperil a number of the critical types of programs that assure retired generals seats on corporate boards and so must be important to national defense.

As a boomer who grew up on Captain Video, science fiction, nuke threats and Neil Armstrong, hell, this is just too cool.

David

"...Signals have to able to travel faster than the speed of light else different regions of the Universe will become "dis-connected" from another; their signals will not reach one another."

Babak,
Are you referring to the Horizon problem here ?
If so, Cosmic inflation solve that problem.

See
http://en.wikipedia.org/wiki/Horizon_problem

UrsaMaior

Well said. Same here. I grew up on sci-fi.

Lars

Naming post offices seems to be the only activity Congress has managed to perform, within a reasonable time frame, for all too long. The dismal state of USPS's balance sheet will require a lot of re-organizing, with loss of service. It is probably a miracle that anything gets delivered.

Grimgrin

Fair points. The other problem with it is that you still need an engine that's capable of accelerating your ship to and (depending on how high you can push the speed of light) beyond the speed of light in a normal vacuum.

I was thinking that what longevity does is make suspended animation/hibernation more practical for people. If you could be frozen right now for 100 years, that would be something akin to your committing suicide for the people who know you. Likewise, odds are you wouldn't see any of them again. If people live indefinitely, barring accidents, then there isn't the same issue with suspended animation, since they'll probably still be around when you wake up on the other side. Communication is an issue, but hopefully you'll be able to haul enough quantum entangled bits or one end of a microscopic wormhole along on the ship by then to make an interstellar telegraph of sorts.

Immortality also gets you into what happens to society if people don't die, not just what happens to people on the ship. As long as we're talking sci-fi novel plotting, I can see that being a major driver for emigration. If the Baby Boomers were never going to die, I'm sure Gens X, Y would be hard at work on their own star-ships by now.

SAC Brat

What happened to my flying car and the beach house at the Salton Sea I was promised would exist when I got older?

Will

actually the alderson drive according to the wiki article was a wormhole to wormhole concept. warp drive is a different concept. here is a third concept altogether: Hauser & Droscher extended Heim 8 dimensional theory for space propulsion.
http://www.hpcc-space.de/publications/documents/AIP2010Hauser.pdf

walrus

Hubble plagiarized the earlier work of George Lemaitre, a Catholic priest and astrophysicist who published a paper in French in an obscure Belgian publication at least a year before Hubble announced his "discovery". Hubbles paper did not reference lemaitre who had visited Hubble at Mt Wilson about a year earlier. We know this because a photo exists of them together at Mt Wilson and Mayer found it.

LeMaitre set out in about 1923 to reconcile genesis with current cosmology, in particular Gods first command - "let their be light" a primordial explosion leading to a cosmos with a constant radial expansion - which is what he published and what Hubble then announced he had found from Vesto Sliphers measurement of the red shift of galaxies. All this is documented in excruciating detail with references in Mayers book.

Hubble had "form" and was a known fantasist with questionable stories about his own exploits. To put it another way, the big bang theory is scientific creationism. The Cosmic background radiation of course was announced as "proof" of its correctness. Since then the theory has been unable to explain a lot of observations, leading to the need to postulate first "dark matter" (aka Faerie dust) and now "dark energy" to try and save it. This is exactly the same tactic as Koestler describes in his book "the sleepwalkers" - just add more crystal spheres to try and make observation fit theory.

De Sitter speculated that the red shift was an artifact of curved space time but couldn't take it further.

The person who could and did take it further was Herman Minkowski, Einsteins math teacher, however Einstein described his formulation (using complex numbers) as "superfluous erudition", and Minkowski tragically died from peritonitis at age 47 before he could explain the implications of his work.

What Mayer has picked up is that the Minkowski formulation isn't superfluous at all. Mayer realised that the Minkowski metric implies that time is orthogonal to all space dimensions. It is analogous to "Altitude" on earth - the realisation of which is the reason the flat earth could be dispensed with. We don't fall off the earth down here in the Antipodes because gravity is radial. De sitter missed the implicaions of Minkowski as well.

To put that another way there is no single "arrow of time". What we see when we look out towards distant galaxies is that their timeline is slightly skewed from our timeline and this results in an apparent red shift in their light as measured from here, and according to Mayers ideas and calculations this theory offers a better explanation of observations than the Big Bang idea and with no dark energy or dark matter required.

There are a host of implications that follow from this as you would expect. Mayer believes he has the evidence for this effect in multiple forms.

Mayer has been struggling with this idea for a few years, I don't know if he will succeed in writing his book, although I have several of his earlier drafts (now removed from the web)


http://www.sensibleuniverse.com/index.html

walrus

Re my post above, this paper is just one more attempt to reconcile observation with the spurious constructs of dark energy and dark matter to try and save the big bang theory.

Babak Makkinejad

I think Steady-State Theory is more plausible. Big Bang suffers many problems; one being the short life-time of the Universe.

Another is the distance measurements based on redshifts; some of the redshifts could actually be caused by intereference of electromagnetic radiative sources (stars) that are distributed over large distances.

Both models suffer from the viloation of Conservation of Mass-Energy; Big Band requires that at the start of Cosmic Expansion - through Inflation - and the Steady State require steady matter creation all the time and everywhere.

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