Forum Home Forum Home > Topics not related to music > General discussions
  New Posts New Posts RSS Feed - Sci Fi TV science or fiction?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Topic ClosedSci Fi TV science or fiction?

 Post Reply Post Reply Page  <1 34567 23>
Author
Message
Gerinski View Drop Down
Prog Reviewer
Prog Reviewer
Avatar

Joined: February 10 2010
Location: Barcelona Spain
Status: Offline
Points: 5154
Direct Link To This Post Posted: July 26 2013 at 18:44
Originally posted by Dean Dean wrote:

[/QU
Thanks, that was really constructive. I would just perhaps argue that, travelling at precisely the speed of light and looking back at where you come from, you would still see a still picture rather than just black nothingness. You would see black nothingness if you exceeded the speed of light by any fraction. But you are welcome to argue that, I'm not 100% sure.
Regarding what we might "see" ahead of us, I get your points and yet I'm not sure of what a practical interpretation might be (regardless of the fact that we know that we can never achieve the speed of light in practice). I understand that we can not receive a photon before it has been emitted, in the hypothetical case of travelling at c towards the light source we would receive the photon just at the same time it was emitted.

But if we agree that as we travel faster and faster we will see the events in front of us unfolding quicker and quicker, what is the limit when we approach light speed? what does it mean "watching the events happening in front you extremely fast but still not before they happened"? I assume it means seeing events simply as they truly happen, without any time delay due to the distance they are being observed from, so actually they would end up not looking fast-forward at all but at the same speed we perceive them now, just without any delay. But since we said that events would appear to happen quicker and quicker the faster we travel, I still have some doubts as to what might that mean in practice. Things would just appear to happen without any delay at all. Would that have any practically appearance effect? How would events shift from appearing to happen fast-forward (with increasingly smaller delay) to appearing 
to happen at normal speed (without any delay)?


Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 26 2013 at 19:31
Originally posted by Gerinski Gerinski wrote:

Originally posted by Dean Dean wrote:

Thanks, that was really constructive. I would just perhaps argue that, travelling at precisely the speed of light and looking back at where you come from, you would still see a still picture rather than just black nothingness. You would see black nothingness if you exceeded the speed of light by any fraction. But you are welcome to argue that, I'm not 100% sure.
No, you would see nothing. The photons of EM radiation would be travelling at exactly the same speed as you are so they would never reach your eyes.
 
/edit: You can never see a still image - that is impossible. Once the photons hit your retina to form an image they are "spent" - our persistence of vision will maintain that image for 1/25th of a second and then it to will be gone. There will be no more photons arriving because they cannot travel faster than light.
 
Originally posted by Gerinski Gerinski wrote:

Regarding what we might "see" ahead of us, I get your points and yet I'm not sure of what a practical interpretation might be (regardless of the fact that we know that we can never achieve the speed of light in practice). I understand that we can not receive a photon before it has been emitted, in the hypothetical case of travelling at c towards the light source we would receive the photon just at the same time it was emitted.
There is no practical interpretation over what I have stated -
So no. You will see it after it has been emitted even if that "after" is septillionth of a second after, it will still be after, it can never be just at the same time.
 
 
Originally posted by Gerinski Gerinski wrote:


But if we agree that as we travel faster and faster we will see the events in front of us unfolding quicker and quicker, what is the limit when we approach light speed? what does it mean "watching the events happening in front you extremely fast but still not before they happened"? I assume it means seeing events simply as they truly happen, without any time delay due to the distance they are being observed from, so actually they would end up not looking fast-forward at all but at the same speed we perceive them now, just without any delay. But since we said that events would appear to happen quicker and quicker the faster we travel, I still have some doubts as to what might that mean in practice. Things would just appear to happen without any delay at all. Would that have any practically appearance effect? How would events shift from appearing to happen fast-forward (with increasingly smaller delay) to appearing to happen at normal speed (without any delay)?
You are making the mistake of speeding up the light relative to the source not the observer - it is the observer that is moving relative to the emitted light from the source, relative to the source the light is unchanged.
 
So, there is always a distance between event and observer even if the observer is moving so the light still has to cross that distance. That takes a finite time so you will never see the event as it truly happened. At faster than light speeds you will be travelling that fast but the light coming towards you will still be travelling at the speed of light. If you are 1 light year from Sirius and travelling at 2c \; the light from Sirius will have taken a year to reach you, if you are travelling at a septillion times faster than light and are 1 light year from Sirius the light from Sirius will still have taken a year to reach you.
 
Secondly the scenario you described (of taking 90 years to cover the 9 lightyears to Sirius at 0.1c \;) was a snapshot at t=0 (99 years compressed into 90). At half the distance you are 45 years away and see the light emitted 4.5 years in the past so you have compressed 49.5 years into 45; at three quaters of the way there you have 22.5 years left to travel and are seeing events on Sirius that happened 2.25 years ago so you will have compressed 74.25 years into 67.5... When you are one day away from Sirius you will be seeing events 2.4 hours in the past. So the closer you get to Sirius the events you are seeing are nearer to the present until the moment you arrive at your destination and you see things in realtime. No matter how fast you get there, you can only arrive at realtime, you can never overtake it.
 
Hope that's clearer.
 


Edited by Dean - July 26 2013 at 21:12
What?
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 05:55
One phenomenon of space travel we've not broached yet is time dilation due to relative velocity, (mainly because it does my head in thinking about it in any detail, perhaps Pat or Pat can explain it better than I). Basically, the faster you go the slower time appears to pass on board ship to an outside observer (or the faster time of the static observer appears to be for the passenges on the ship). Time dilation is described by the Lorentz factor, which is another simple formula:
 
\gamma = \frac{1}{\sqrt{1 - (\frac{v}{c})^2}}
 
at v=0.1c, \gamma (gamma) would be 1/sqrt(1-0.01)=1.005 so the 90 year journey to Sirius (as seen by observers on Earth and Sirius) would take 90 years, but for the passengers on the spaceship only 89½ years would have past. If the spaceship is travelling at 0.9c the dilation factor is 2.3 so the [10 year] journey time for the passengers would be 39¼ [edit] 4.36 years [10/2.3]. Because the speed of light (and their relative velocity) remained constant during the journey but the time taken to cross the distance between Earth and Sirius appeared to be shorter for the passengers the distance was contracted by the same proportion as specified by the Lorentz factor: time dilation shrinks space, so at  0.9c the relative distance between Earth and Sirius for the passengers would not be 9 light-years but 3.923 light years [edit: still true 4.36 x 0.9 = 3.923].
 
Imagine the scenario where Sirius is due to explode in 91 years so a spaceship is sent from Earth to observe the event. Travelling at 0.9c for passengers on the ship the total journey time would have taken 39¼  years, but Sirius would still explode 1 year after they arrive because the elapsed time on Sirius would still have been 90 years. [edit: this is wrong, I made a silly mistake - at 0.9c the journey time is 10 years not 90, so the correct scenario would be the Sirus exploding in 11 years the ship would take 10 years, 4.36 years would have elapsed for the passengers but Sirius would still explode 1 year after they arrived]
 
 
Star Trek does not solve this problem, it simply ignores it, their five year mission to meddle with strange new civilisations takes five years onboard ship and back on Earth. In reality their time spent at warp speeds during those five years would mean that hundreds, maybe thousands, of years would have elapsed back on Earth.
 
Unfortunately, the Lorentz factor also increases relative mass by the same proportion so at  0.9c their relative mass would have increased 2.3 times their actual mass, it does not make them 2.3 times heavier (a 70kg man will still weigh 70kg), their mass increases relative to a stationary mass, so it makes them harder to move. [edit: so since energy=½mv² says that more energy is needed the faster you go proportional to the square of velocity, it also means that because relative m also increases the faster you go even more energy is required]
 
 
[edit: I did say time dilation does my head in LOL]
 


Edited by Dean - July 27 2013 at 07:58
What?
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 06:21
Because the Lorentz factor is an inverse square law it also show why light-speed is an absolute limit. As you approach lightspeed the Lorentz factor increases until at light speed it is infinite, [the 1-(v/c)² term becomes zero], so the relative mass becomes infinite and thus the energy required to accelerate the ship to that speed also becomes infinite. Beyond light-speed the 1-(v/c)² term becomes negative, leading to a square root of a negative number (ie it is an imaginary number).
What?
Back to Top
Gerinski View Drop Down
Prog Reviewer
Prog Reviewer
Avatar

Joined: February 10 2010
Location: Barcelona Spain
Status: Offline
Points: 5154
Direct Link To This Post Posted: July 27 2013 at 07:03
Originally posted by Dean Dean wrote:

One phenomenon of space travel we've not broached yet is time dilation due to relative velocity
Indeed. I should have been more careful and say that the trip would last 90 years, Earth or Sirius time. This would actually add to the fast-forward motion appearance I mentioned, since in my example of travelling a 0.1 c, the ship passengers would see 99 years of visual progress unfold in front of them during 89 ½ years of their time, and in your example travelling at 0.9 c they would see 99 years of progress happening during 39 ¼ years of their ship time.
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 07:22
Originally posted by Gerinski Gerinski wrote:

Originally posted by Dean Dean wrote:

One phenomenon of space travel we've not broached yet is time dilation due to relative velocity
Indeed. I should have been more careful and say that the trip would last 90 years, Earth or Sirius time. This would actually add to the fast-forward motion appearance I mentioned, since in my example of travelling a 0.1 c, the ship passengers would see 99 years of visual progress unfold in front of them during 89 ½ years of their time, and in your example travelling at 0.9 c they would see 99 years of progress happening during 39 ¼ years of their ship time.
Nearly. Wink I made an error in the 0.9c example. Embarrassed
 
At 0.9c the journey time is no longer 90 years relative to a static observer it is only 10 years, so the compressed time would be 19 years and elapsed time for the traveller would be 4.36 years.
What?
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 07:55
I should stress at this point that the 99 year compression (or 19 year compression) is an illusion due to the fact that an observer on Earth sees light from Sirius that was emitted 9 years earlier and as you travel towards Sirius the light you see is emitted sooner, when you are 1 lightyear closer the light is only 8 years old. [Similarily when you arrive at Sirius and look back to Earth, the light you see is 9 years old, it left Earth after you did]. You cannot profit from this compression.

Edited by Dean - July 27 2013 at 08:26
What?
Back to Top
Gerinski View Drop Down
Prog Reviewer
Prog Reviewer
Avatar

Joined: February 10 2010
Location: Barcelona Spain
Status: Offline
Points: 5154
Direct Link To This Post Posted: July 27 2013 at 08:52
Originally posted by Dean Dean wrote:

I should stress at this point that the 99 year compression (or 19 year compression) is an illusion due to the fact that an observer on Earth sees light from Sirius that was emitted 9 years earlier and as you travel towards Sirius the light you see is emitted sooner, when you are 1 lightyear closer the light is only 8 years old. [Similarily when you arrive at Sirius and look back to Earth, the light you see is 9 years old, it left Earth after you did]. You cannot profit from this compression.
Indeed, it's just an optical effect, my original extrapolations of the effect to 'what might you see traveling at c' were wrong. And certainly you can not use this to check the lucky lottery numbers for tomorrow Tongue
Back to Top
Finnforest View Drop Down
Special Collaborator
Special Collaborator
Avatar
Honorary Collaborator

Joined: February 03 2007
Location: The Heartland
Status: Offline
Points: 16913
Direct Link To This Post Posted: July 27 2013 at 09:39
Stargate gate travel.

I understand the idea between gate addresses and stable wormholes between them, even though bringing that to fruition is probably a few decades away yet.  ;)     What I don't fully grasp is the process by which the bodies are transported.  Disassembling and reassembling all of our particles on either side of a gate....how exactly does that work ?  I tried to find video of Carter or Jackson explaining that process but could not.  Is it similar to Star Trek "beaming"? 

I assume neither are remotely possible for many hundreds of years.  If they were, I would travel much more than I do. 

By the way, I really enjoyed your responses to the last query.  Much of it was over my head but I read every word.  Thanks for posting them.
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 11:43
Originally posted by Finnforest Finnforest wrote:

Stargate gate travel.

I understand the idea between gate addresses and stable wormholes between them, even though bringing that to fruition is probably a few decades away yet.  ;)     What I don't fully grasp is the process by which the bodies are transported.  Disassembling and reassembling all of our particles on either side of a gate....how exactly does that work ?  I tried to find video of Carter or Jackson explaining that process but could not.  Is it similar to Star Trek "beaming"? 
In Stargate technology (and for Gerard's benefit, we are only talking about the fictional device from the Stargate SG1 franchise) two stargates are required to create a stable wormhole (agan, this is a fictional wormhole and not related to any hyperthetical astronomical wormhole) between them. Since astronomical wormholes are gravitational (created by a black hole for example) they would destroy any matter that passed through them the writers of SG1 overcame this by sending the energy signature of the traveller through the wormhole. The event horizion of the wormhole (the shimmering vertical puddle) performs the matter-energy transfer - in one of the early episodes someone (I forget who) tentively sticks their head through the open stargate and it instantly appears poking out of the other gate before they finalyt step all the way through - implying that not only is the transfer instantaneous, the conversion from matter to energy and back to matter is also instantaneous so no actual conversion takes place. You could think of this as sort of a wave-particle duality with the object being simultaneously matter and energy at the event horizon (as far as I know there is nothing in physics to support this). A few episodes have shown what happens to any object that is caught in the forming event horizon before the stable connection is made - they are destroyed (converted to energy and not converted back to matter).
 
O'Neill also commented in one early episode that travelling through the gate is instantaneous but seems to take forever. This is a little like the time dilation at the event horizion of a black hole seen by someone crossing the horizon (it takes forever) and by someone observing it from a distance (it is instantaneous), except here both are percieved by the traveller simultaneously while the observer only sees the instantaneous event). The other feature of the stargate wormhole is that it is a one way street - you can only travel in one direction, to return you need to redial in the opposite direction - you can do this from either end but the direction of travel is preset.
 
There isn't a "how exactly does that work?" explanation for any of this because it only works in fiction - this is one of the suspend-belief moments I mentioned previously - to enjoy the programme I accept the premise and suspend any disbelief I have in the actual physics of it.
 
[For example I'm not sure if how the ancients mamaged to distribute the stargates around the galaxy and beyond is ever explained since to do so would imply they either had another FTL transport system or they did it as using starships of subluminal speed.]
 
This is not the same as Star Trek's transporter where the conversion from matter to energy is stored in a pattern buffer before being transmitted to the destination where it is reconverted back into matter - the transfer and the conversion takes a finite amount of time but does not require a physical buffer and converter at the destination. How it does it is never explained since all analogous systems (fax, email, television etc.) require a reciever at the destination to make the conversion. So in Star Trek they can beam you anywhere in range of the transmitter, whereas in Stargate travel can only occur between two fixed gates but the range is theoretically unlimited.

Originally posted by Finnforest Finnforest wrote:


I assume neither are remotely possible for many hundreds of years.  If they were, I would travel much more than I do. 
Neither are remotely possible. Time is not an issue, physics is. As Pat has already said - quantum teleportation is not physical matter transportation (and in the general sense there is no information transfer either) and I have already stated that what passes through a theoretical astronomical wormhole would not survive. Even if we could deconstruct, transmit and reconstruct matter, how we would reanimate the reconstituted matter with all its memories and knowledge intact is yet another mystery. Of course some SF writers (for example Heinlein, if I recall correctly) don't bother with the physics and simply transfer the knowledge and memories (spirit or soul if you believe in such things) between distant locations. (this is the method used in most fantasy fiction such as John Carter of Mars or The Thomas Covenant Chronicles).
 
In this respect the fictional versions are nothing more than "something wonderful happens", or "magic" as it is often known.
 
Originally posted by Finnforest Finnforest wrote:




By the way, I really enjoyed your responses to the last query.  Much of it was over my head but I read every word.  Thanks for posting them.
You know me - love to show-off. Thanks for the opportunity.


Edited by Dean - July 27 2013 at 11:51
What?
Back to Top
Finnforest View Drop Down
Special Collaborator
Special Collaborator
Avatar
Honorary Collaborator

Joined: February 03 2007
Location: The Heartland
Status: Offline
Points: 16913
Direct Link To This Post Posted: July 27 2013 at 12:30
But wouldn't it just come down to the quality and complexity of the deconstruct/scan?  If you could truly scan and map every detail down to its purest/smallest bit of information, would it not most likely have the same make up when reassembled?  And I know we don't have the physical tools for this to happen but am assuming we did.  Assuming we had elaborate/sensitive enough technology for the steps of the process, is there something else about our bodies and the electrical/chemical components of our brain that would make reassembly with memories/personality impossible?  (this is in response to your second quote response below) 

Fast talking McKay rules...
  LOL

Jackson explains aspects of SG science
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 12:31

To guage some idea of the scale of the problem of converting a human to energy and back again we would need to do this on an atomic level for each atom in the body.

An average human is composed of  3 x 1027 atoms (3 followed by 27 zeros)
 
(This is more than the total number of stars in the Universe (for example) and SI prefixes don't even have a name for this magnitude)
 
To encode this into a form that can be transmitted as data we would need to record the spacial location of each atom (x, y & z location) at a specific moment in time (ie we'd have to encode every atom simultaneously) together with information of what element it was (oxygen hydrogen carbon etc.) and then have some means of rebuilding the body from those elements at the destination this increases the "bit-count" of the data to several times the number of atoms we are converting. To convert the body to energy we would need to further decosntruct the body down to subatomic level and encode each subatomic particle, further increasing the amount of data required.
 
Having obtained our astromically large amount of data we now need to transmit it. If we assume that we could encode 3 x 1027 atoms as 3 x 1028 bits of data (and that's only ten bits per atom, which is inadequate IMO) and could transmit that at 1TBd (one tera baud) it would take almost 1 billion years to transmit the entire pattern. So even if it were possible (which it isn't) it would be impractical.
What?
Back to Top
Finnforest View Drop Down
Special Collaborator
Special Collaborator
Avatar
Honorary Collaborator

Joined: February 03 2007
Location: The Heartland
Status: Offline
Points: 16913
Direct Link To This Post Posted: July 27 2013 at 12:33
Damn, you're faster than McKay.....how did you type that fast?LOL

Gotta run to the store...be back soon
Back to Top
Gerinski View Drop Down
Prog Reviewer
Prog Reviewer
Avatar

Joined: February 10 2010
Location: Barcelona Spain
Status: Offline
Points: 5154
Direct Link To This Post Posted: July 27 2013 at 12:33
I believe that Stargate gates are supposed to be some sort of wormhole. Wormholes are only a theoretical and extremely speculative possibility which, although do not strictly speaking violate the known laws of physics, require stretching the known theory to its very limits. And even if the theoretical principle is allowed, it seems close to impossible that we could ever achieve that sort of technology for any practical-size object.

In wormholes the stuff really disappears at some point in spacetime and just appears out of nothing somewhere else.
Consider that you paint 2 dots on a sheet of paper. Through the paper you can only go from one point to the other crossing a line between them, but if you can fold the paper, you can position the 2 dots on top of each other and now the 2 points have become the same point. Assuming that the paper thickness does not really exist, you could walk on one side of the paper, and at the point choose to switch to the other side of the paper and continue walking there. For someone not being able to see that the paper has been folded, your path would seem to vanish at one of the points and suddenly reappear at the other.
General Relativity tells us that the paper (our spacetime) can indeed be bent. Completely folding it so that we could connect the 2 points seems nearly impossible but there are some very extreme theoretical situations in which the 2 points could indeed 'touch' each other.
That is the scientific concept the gates are based on.

Needless to say that even if that were possible in principle (which we certainly do not know at all) the challenges involved in practice are tremendous, and having anything bigger than a fundamental subatomic particle pass through without its structure being destroyed in the process would be close to impossible.

However the biggest obstacle which seems to make such gates impossible even in theory is related to time violation issues (the gates would be time machines).

EDIT: I took long to write and had not seen Dean's much more extensive and focused on the actual movie-series stuff replies.


Edited by Gerinski - July 27 2013 at 12:36
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 12:44
Originally posted by Finnforest Finnforest wrote:

Damn, you're faster than McKay.....how did you type that fast?LOL

Buffering....
What?
Back to Top
BaldFriede View Drop Down
Prog Reviewer
Prog Reviewer
Avatar

Joined: June 02 2005
Location: Germany
Status: Offline
Points: 10261
Direct Link To This Post Posted: July 27 2013 at 12:44
Originally posted by Dean Dean wrote:

Originally posted by Gerinski Gerinski wrote:

Originally posted by Dean Dean wrote:

Thanks, that was really constructive. I would just perhaps argue that, travelling at precisely the speed of light and looking back at where you come from, you would still see a still picture rather than just black nothingness. You would see black nothingness if you exceeded the speed of light by any fraction. But you are welcome to argue that, I'm not 100% sure.
No, you would see nothing. The photons of EM radiation would be travelling at exactly the same speed as you are so they would never reach your eyes.
 
/edit: You can never see a still image - that is impossible. Once the photons hit your retina to form an image they are "spent" - our persistence of vision will maintain that image for 1/25th of a second and then it to will be gone. There will be no more photons arriving because they cannot travel faster than light.
 
Originally posted by Gerinski Gerinski wrote:

Regarding what we might "see" ahead of us, I get your points and yet I'm not sure of what a practical interpretation might be (regardless of the fact that we know that we can never achieve the speed of light in practice). I understand that we can not receive a photon before it has been emitted, in the hypothetical case of travelling at c towards the light source we would receive the photon just at the same time it was emitted.
There is no practical interpretation over what I have stated -
So no. You will see it after it has been emitted even if that "after" is septillionth of a second after, it will still be after, it can never be just at the same time.
 
 
Originally posted by Gerinski Gerinski wrote:


But if we agree that as we travel faster and faster we will see the events in front of us unfolding quicker and quicker, what is the limit when we approach light speed? what does it mean "watching the events happening in front you extremely fast but still not before they happened"? I assume it means seeing events simply as they truly happen, without any time delay due to the distance they are being observed from, so actually they would end up not looking fast-forward at all but at the same speed we perceive them now, just without any delay. But since we said that events would appear to happen quicker and quicker the faster we travel, I still have some doubts as to what might that mean in practice. Things would just appear to happen without any delay at all. Would that have any practically appearance effect? How would events shift from appearing to happen fast-forward (with increasingly smaller delay) to appearing to happen at normal speed (without any delay)?
You are making the mistake of speeding up the light relative to the source not the observer - it is the observer that is moving relative to the emitted light from the source, relative to the source the light is unchanged.
 
So, there is always a distance between event and observer even if the observer is moving so the light still has to cross that distance. That takes a finite time so you will never see the event as it truly happened. At faster than light speeds you will be travelling that fast but the light coming towards you will still be travelling at the speed of light. If you are 1 light year from Sirius and travelling at 2c \; the light from Sirius will have taken a year to reach you, if you are travelling at a septillion times faster than light and are 1 light year from Sirius the light from Sirius will still have taken a year to reach you.
 
Secondly the scenario you described (of taking 90 years to cover the 9 lightyears to Sirius at 0.1c \;) was a snapshot at t=0 (99 years compressed into 90). At half the distance you are 45 years away and see the light emitted 4.5 years in the past so you have compressed 49.5 years into 45; at three quaters of the way there you have 22.5 years left to travel and are seeing events on Sirius that happened 2.25 years ago so you will have compressed 74.25 years into 67.5... When you are one day away from Sirius you will be seeing events 2.4 hours in the past. So the closer you get to Sirius the events you are seeing are nearer to the present until the moment you arrive at your destination and you see things in realtime. No matter how fast you get there, you can only arrive at realtime, you can never overtake it.
 
Hope that's clearer.
 

I just want to mention that it is equally impossible to become invisible. Or rather, it is possible but with a serious "but": Anyone who is invisible automatically becomes blind.

As to speed of light: It can be argued that everything moves at the speed of light, on,ly in four dimensions, the fourth being what we notice at time. The Lorentz transformations make immediate sense when one thinks of them as the projection of four-dimensional movement into three-dimensional space. What's more: This view can also explain the duality of wave and corpuscle; you just have to think of a different concept of corpuscle. Instead of "mass bends time-space" you have to think of "mass IS bent time-space". We don't get the fluctuation of these waves though because as we move through that fourth dimension we lways stay at the peak of the wave, therefore it appears to be steady.

Anti-matter is just out of phase by 180°; thus wave peak and wave hollow extinct each other.

This model very nicely explains why nothing that has a mass can ever reach the speed of light in our three dimensions, because no matter how you increase thhe spedd in our three spatial dimensions there will always be a rest of speed along the fourth axis time. The relativistic corrective SQRT(1- v"/c") , or as I prefer to write it (SQRT((c"-v")/c") actually is the sinus of the angle the wave has with the time axis (any mathematician worth his salt should immediately spot the similarity of that corrective and the Pythagorean theorem with c being the hypotenuse and v one of the cathetii of a rectangular triangle).

This may all sound strange at first, but calculate it through. It works!


Edited by BaldFriede - July 27 2013 at 12:45


BaldJean and I; I am the one in blue.
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 12:55
Originally posted by Finnforest Finnforest wrote:

Assuming we had elaborate/sensitive enough technology for the steps of the process, is there something else about our bodies and the electrical/chemical components of our brain that would make reassembly with memories/personality impossible?
Biology is outside my sphere of interest, I seldom ever watch medical dramas (except House) and never watch medical documentaries for example, but as far as i know there is no way of resuscitating a human once "brain death" occurs and resuscitation were the brain has been starved of oxygen results in memory and faculty loss, so it is fair to assume that a reconstituted brain would be impossible to reanimate with any memory or personality intact.
What?
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 12:57
Yay! We have our own Kari Byron aboard here on SF Mythbusters Big smile 
What?
Back to Top
Dean View Drop Down
Special Collaborator
Special Collaborator
Avatar
Retired Admin and Amateur Layabout

Joined: May 13 2007
Location: Europe
Status: Offline
Points: 37575
Direct Link To This Post Posted: July 27 2013 at 13:56
Originally posted by BaldFriede BaldFriede wrote:

I just want to mention that it is equally impossible to become invisible. Or rather, it is possible but with a serious "but": Anyone who is invisible automatically becomes blind.

There is another form of invisibilty and that's the Klingon cloaking device, a mechanism which bends light around the object being concealed. The prinicples of this have been demonstrated at single EM frequencies and it does work, however broadband versions may prove to be impossible due to refraction and masking every single footprint the ship leaves behind may also prove to be impossible.
What?
Back to Top
Gerinski View Drop Down
Prog Reviewer
Prog Reviewer
Avatar

Joined: February 10 2010
Location: Barcelona Spain
Status: Offline
Points: 5154
Direct Link To This Post Posted: July 27 2013 at 14:22
Originally posted by Finnforest Finnforest wrote:

Assuming we had elaborate/sensitive enough technology for the steps of the process, is there something else about our bodies and the electrical/chemical components of our brain that would make reassembly with memories/personality impossible? 
Regarding the information encoding problem, I guess that compression techniques could be developed, I mean you would probably not need to encode the precise position and type of every atom in the body. Our DNA is quite good at telling the body how to be and to behave with a limited amount of information.
Since I assume that memories and personalities arise from material atoms and processes allowed by the laws of physics, I don't see why it should be totally impossible. A completely identical reproduction of you right now should in principle think the same you do and have the same knowledge and memories as you do right now. The only thing possibly preventing it is if quantum processes are involved and relevant in the mind processes, quantum events are in principle impossible to know with absolute certainty so this might pose a fundamental difficulty to achieve the absolutely precise duplication of your mind state.
Back to Top
 Post Reply Post Reply Page  <1 34567 23>

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.141 seconds.
Donate monthly and keep PA fast-loading and ad-free forever.