Community > Forum > Technology & Science > Consequences of travelling by c ...

Consequences of travelling by c ...

Posted by: Ekkehard Augustin - Tue Dec 04, 2007 12:22 pm
Post new topic Reply to topic
 [ 11 posts ] 
Consequences of travelling by c ... 
Author Message
Moderator
Moderator
avatar
Joined: Thu Jun 03, 2004 11:23 am
Posts: 3745
Location: Hamburg, Germany
Post Consequences of travelling by c ...   Posted on: Tue Dec 04, 2007 12:22 pm
Would it be reasonable to be able to travel by c?

Because of the dilation of time time would be constant at c - meaning that a vehicle travelling by c would be at the same time at several locations in parallel from it's own point of view. It simply and only would have to imtend to go to an additional location and would be there in the same moment while being at other locations in parallel.

What problems might the vehicle get?


...


Does this involve paradoxa? Am I getting trapped in such paradoxa here?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


Back to top
Profile
Space Station Commander
Space Station Commander
User avatar
Joined: Wed Dec 08, 2004 12:55 pm
Posts: 506
Location: Germany
Post    Posted on: Tue Dec 04, 2007 12:52 pm
Following conventional physics you would need infinite energy to reach c, so not possible.

_________________
"The hardest hurdle to space isn't the technicalities and money. But rather, the courage and the will to do it." - Burt Rutan.


Back to top
Profile WWW
Moderator
Moderator
avatar
Joined: Thu Jun 03, 2004 11:23 am
Posts: 3745
Location: Hamburg, Germany
Post    Posted on: Fri Mar 06, 2009 7:09 pm
To continue this academic topic - it in principle doesn't matter if it is possible because I wonder(ed) if something useful might be found this way.

The physics of the universe might prevent us from achieving c because we would get into extreme troubles then.

So what might be the list of troubles possible? Was I right to supose the vehicle would be at very much places in parallel from its own point of view? Are there additional paradoxa? And what are they? Would one or the other occur at slower velocities as well?

If so - what is the critical maximum velocity?



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


Back to top
Profile
Space Station Commander
Space Station Commander
avatar
Joined: Thu Oct 27, 2005 7:44 am
Posts: 707
Location: Haarlem, The Netherlands
Post    Posted on: Fri Mar 06, 2009 10:07 pm
There's no paradox, there's a singularity. It's not just not physically possible, it's mathematically impossible. That is way worse, because it means that we can not even talk about it.

If you put v = c into the equations of special relativity, you'll get a division by zero. And that doesn't exist. The operation can't be done. It's undefined. We can get arbitrarily close (mathematically, physically you'll run out of energy at some point), but to actually get there we have to go beyond the mathematics, and without the maths we can't say anything about anything. And so literally anything could happen...


Back to top
Profile
Space Station Commander
Space Station Commander
User avatar
Joined: Mon Oct 06, 2003 9:22 pm
Posts: 843
Location: New York, NY
Post    Posted on: Fri Mar 06, 2009 10:14 pm
there's nothing to say that if you started out going c or greater you couldn't stay that fast forever, but you can't accelerate to c, just to inifnitely close to it. the only thing that we know of that goes c is a photon (maybe neutrinos too? i don't remember..). there might be other stuff that we can't see though. maybe that other stuff would be useful, but this is not stuff to be seriously discussed, this is the kind of stuff you use to explain warp drives in star trek.

_________________
Cornell 2010- Applied and Engineering Physics

Software Developer

Also, check out my fractals


Back to top
Profile
Moderator
Moderator
avatar
Joined: Thu Jun 03, 2004 11:23 am
Posts: 3745
Location: Hamburg, Germany
Post    Posted on: Sat Mar 07, 2009 6:56 am
Hello, Lourens,

the Mathematics just confirms that it is impossible. But that's not the point I am out on.

Your issue is that there is a singularity - a mathematical one.

My issue was, that from the dilation of time it follows - I've read that in a popular science article or book written by a scientist - that for a photon time stands still, which would mean that that photon is at all places in parallel from its own point of view.

Now a singularity might mean that all those places are not away from each other...

Black Holes are viewed as singularities - so matter going by c might result in a Black Hole. If that would be right then it could mean a criterion which velocities below c should be avoided since velocities very close to c would mean very high masses caused that could have further impacts.

If so then even velocities achievable by available technologies should have to be avoided.

This to a limites degree describes what I am out on.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


Back to top
Profile
Space Station Commander
Space Station Commander
User avatar
Joined: Mon Oct 06, 2003 9:22 pm
Posts: 843
Location: New York, NY
Post    Posted on: Sat Mar 07, 2009 5:17 pm
ekkehard i'm not sure you understand what a singularity is. black holes are not singularities. they are called singularities, but the laws of physics still apply in them, just in very strange ways. one way to look at it is this- if you could go to c, you would acquire infinite mass. having infinite mass, you would then proceed to violate just about every known conservation principle and probably destroy the universe. so basically, you can't accelerate to c. that's not to say you can't go faster, it just would involve changing the nature of space rather than actually making yourself go faster.

_________________
Cornell 2010- Applied and Engineering Physics

Software Developer

Also, check out my fractals


Back to top
Profile
Space Station Commander
Space Station Commander
avatar
Joined: Thu Oct 27, 2005 7:44 am
Posts: 707
Location: Haarlem, The Netherlands
Post    Posted on: Sat Mar 07, 2009 5:29 pm
If I get on a spaceship and fly away from Earth at a large enough velocity, you will notice that I seem to be speaking more slowly than normal when you contact me. From your point of view, my clocks are moving more slowly. However, speed is relative (even in Newtonian mechanics this is the case!), and the whole situation is symmetrical. By the same reasoning, I will find that you appear to be speaking rather slowly. Neither of us will notice anything strange about ourselves.

One way to actually observe this is to look at cosmic rays. Cosmic rays are high-energy particles raining down on us from space. Many of these have a half-life so short that they shouldn't reach the earth at all. However, because they are travelling so fast, time appears to move slower for them from our point of view, and the particles survive long enough to hit our detectors. Of course, from the point of view of the particle everything proceeds normally, except that on this planet that is rushing up at relativistic speeds, everything appears to be going a little slower than usual.

So, extending this concept into the singularity, the photon's clock would appear to be stopped to us who are standing still, and our clock would be standing still from the point of view of the photon. So, from our point of view, the photon appears to be in different places at the same point of its time. Our time is still running however, so from our point of view, it is not in different places at the same time. From the point of view of the photon, it's clock is running normally and it is in only one place in each instant.

And that is why people say special relativity is counterintuitive :-).

Black holes are a part of general relativity. I'm not familiar enough with that to be able to say anything about them, but saying that two things must be related because they both cause singularities in the mathematics is invalid reasoning. The equation 1/x has a singularity near x = 0, but that doesn't mean that you risk creating a black hole every time you try to plot its graph!


Back to top
Profile
Space Station Commander
Space Station Commander
User avatar
Joined: Mon Oct 06, 2003 9:22 pm
Posts: 843
Location: New York, NY
Post    Posted on: Sun Mar 08, 2009 5:11 pm
that's a pretty good description.

i haven't done general relativity at all but im guessing there are far fewer elegant descriptions of it around.

_________________
Cornell 2010- Applied and Engineering Physics

Software Developer

Also, check out my fractals


Back to top
Profile
Moderator
Moderator
avatar
Joined: Thu Jun 03, 2004 11:23 am
Posts: 3745
Location: Hamburg, Germany
Post    Posted on: Wed Mar 11, 2009 7:09 pm
Hello, TerraMrs,

I am very familiar with what you say.

I don't assume that Physics don't apply within Black Holes. I also know well that by changing the nature of space distant locations can be got to in less time than possible at going by c.

I don't want to invove changes of the nature of space nor do I need any assumption about Physics.

The point still is to alter the direction of thinking and view - not from slow to fast but from fast to slow. The circumstance that nothing having a mass can go by c might point to useful insights.



Hello, Lourens,

I don't say that the two things must be related because they cause mathematical singularitues.

What I do is to apply something I read in a journal like the german version of Scientific American or in a book comparable to such a journal.

According to what I read for a photon time stands still because a photon can go by c since it has no mass and hence experiences infinte dilation of time. But a photon passes a lot of locations and places.

So either the photon is at several places at the same time or those places are all the same as seen by the photon.

Both alternatives would mean that it makes sense that things having mass can't go by c. Either the mass of them would be ubiquitous or their mas would be concentrated in one point. This would mean that the density is that high that a Black Hole would be formed...

This also might correspond to the infinite energies required to achieve c.

If it really is so then even velocities below but close to c might involve dangers that must be avoided and thus would put another upper limit of velocity that is less than c.



Dipl.-Volkswirt (bdvb) Augustin (Political Economist)


Back to top
Profile
Space Station Commander
Space Station Commander
User avatar
Joined: Mon Oct 06, 2003 9:22 pm
Posts: 843
Location: New York, NY
Post    Posted on: Thu Mar 12, 2009 12:52 am
yea not really, black holes require finite energy to form. there's no reason to believe that it's at all dangerous to go close to c from a fundamental physics standpoint (though obviously you will have to have crazy radiation shielding if you are doing that). as far as i'm aware, the mass increase due to going really fast doesn't actually change your own gravitational field, and is instead just a consequence of E=mc^2=m0*c^2+T (assuming no potential field). besides, we've never had any indication from particle accelerators that it's dangerous, and we can accelerate electrons to like .9999c at least in a big one. that's way faster than we could possibly consider sending a spaceship.

maybe i don't understand what you're trying to say?

_________________
Cornell 2010- Applied and Engineering Physics

Software Developer

Also, check out my fractals


Back to top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 11 posts ] 
 

Who is online 

Users browsing this forum: No registered users and 30 guests


© 2014 The International Space Fellowship, developed by Gabitasoft Interactive. All Rights Reserved.  Privacy Policy | Terms of Use