h a l f b a k e r yFaster than a stationary bullet.
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
browse anonymously,
or get an account
and write.
register,
|
|
|
Time Machine Curing
Transfer terminally ill person on a time machine to the future, where treatment is likely available. | |
Today, we know of at least two ways to travel to the future.
One
relies on cryonic preservation, another, on Einstein's special
relativity, the time dilation.
Let's say we want to transfer a terminally ill patient 5 years
into the future, because they have reasonable expectations
to
have
effective treatment by then.
With 0.9973582c, we could do it in less than 5 months.
t0 = 12960000 # / 86400 = 150 days
v = 299000
c = 299792
t0/(sqrt(1-v^2/c^2)) # / 86400 = 2064.361 days
However, the energy required to accelerate a 50 kg object
from
rest to this velocity would be:
m = 50 # kg
(m*c^2)/(sqrt(1-v^2/c^2)) - m*c^2 # 5.736903e+13 J # =
15935 MWh
We have quite a lot of that energy. A single nuclear power
plant
may produce that amount of energy in a day. However, in
order
to use the space technology as medical technology, we
would
certainly need a efficient way of converting it into kinetic
energy...
Time dilation calculator
http://keisan.casio...c/system/1224059993
[Mindey, Mar 21 2016]
Kinetic energy of relativistic objects
https://en.wikipedi...rgy_of_rigid_bodies
[Mindey, Mar 21 2016]
Joules to MWh
http://www.wolframa...736903e%2B13+joules
[Mindey, Mar 21 2016]
Suspended Animation
Suspended_20Animation
I think I'll vote for this method; uses lots less energy and likely could be implemented sooner. [Vernon, Mar 22 2016]
Acceleration time > 2 years.
http://www.thenaked...s/question/1000139/
[scad mientist, Mar 24 2016]
Please log in.
If you're not logged in,
you can see what this page
looks like, but you will
not be able to add anything.
Destination URL.
E.g., https://www.coffee.com/
Description (displayed with the short name and URL.)
|
| |
See help file under 'magic'. |
|
| |
I don't think it counts as magic. The idea proposes sending
terminally ill people on long journeys at near light-speed,
thereby using time dilation to allow medical technology to
advance enough to cure them before they die. |
|
| |
The only "magic" component is the last sentence, about
harnessing available energy to accelerate the sick person to near
light-speed (and to slow them down afterwards, I guess).
However, the idea would still stand without that last sentence. |
|
| |
As to the idea - [+]. However, I'd give it more than 5 years; some
medical technologies are very slow to develop. |
|
| |
" A single nuclear power plant may produce that amount of energy in a day " |
|
| |
" we would certainly need a efficient way of converting it into kinetic energy " |
|
| |
WIBNI, and certainly preheated in science fiction. |
|
| |
//preheated// ummm... cite ? |
|
| |
Since I've not the opportunity to back up the assertion at this time, I will withdraw the preheated. |
|
| |
I think that we are somewhat missing the point,
which is to use relativity as means of prolonging life
pending medical innovation. On the other hand, the
Halfbakery has a long and noble tradition of not only
missing points, but deliberately aiming off to one
side of them, often with unexpected results. So
carry on. |
|
| |
Yeah, I tend to take things at face value, which is probably an error in this application. If you just delete the parts of the idea that aren't substantiated it will work fine. |
|
| |
[nz] all of the "save later" plans were freezing, that I've read - just wondering. |
|
| |
What was the scifi where all the heads frozen for future cures were cured, installed on robots and used as slaves? |
|
| |
Here is scifi premise: the ill ones return to earth but civilization has crashed. In their final months of life, the ill ones use the tech on the ship and their own knowledge to cure thousands from plague and rescue civilization from a dark age. |
|
| |
// ... = 15935 MWh //
Mindey, you’re using the right formula, but your result is too low by a factor of 10^5. The actual energy is 1,593,599,398 mWh, which is about the same as the world’s yearly electrical output. |
|
| |
You’d need a very advanced space travel system – there are lots of engineering challenges to accelerating something to 0.9973582 c – but you’re right in principle that doing so is a way to travel forward in history at about 13.77 times the normal rate. No magic involved, just good ole century old physics. |
|
| |
/Century old physics/
I have questions. |
|
| |
1. Does time stay slowed for them when they are coming home at the same high velocity they left? I think yes. |
|
| |
2. If #1 is true then if they went in tight circles very fast in our own solar system would time slow? Again I think yes. |
|
| |
3. If they went to the moon (less air resistance, you know) and vibrated back and forth very fast would time slow? It should! |
|
| |
I know the directional changes would be tough on a body. But here is a scheme to reduce that. Imagine I am moving in tight circles at a percentage of the speed of light (and so slowing time for me). Inertia will be perceived by me as a vector force outwards, like gravity: this like the ring-shaped spaceships that use this effect for artificial gravity. |
|
| |
But I am actually moving in 2 circles. Like a planet which both spins and orbits, I am also moving in a larger circle, and even faster than the smaller circle. I complete both circles in the same time. The rotation is timed such that the vector forces of large and small rotations cancel out completely, and I float in zero gravity. Feeling pretty good about myself. Sassy, even. |
|
| |
//The rotation is timed such that the vector forces of
large and small rotations cancel out completely, and I
float in zero gravity.// Isn't this what people
sometimes refer to as "an orbit"? |
|
| |
[bungston] If the person is feeling 0 G from that
combination of spinning, then they are not accelerating.
This means that they are either moving in a straight line
or not moving at all. |
|
| |
What we need is a medium-small black hole to orbit
around. That has the additional benefit of augmenting
the speed based time dilation with gravitational time
dilation. The size should be chosen to be as small as
possible so it doesn't need to be that far away from our
solar system, but it must be large enough that tidal
forces are not unmanageable when orbiting close enough
to the event horizon to get our desired time dilation. I
think it would be most useful to aim for having just
enough tidal force that there is 1G force away from the
black hole on the far side of the space ship and 1 G
towards the black hole in the near side of the ship.
Thinking about how wide to make the ship is interesting,
but I'm not going to go into details here. |
|
| |
Getting in and out of orbit would require a lot of energy.
Ideally this would be set up with well paced objects in
orbit that could be used for gravitational slingshots. If
they are set up very cleverly, energy is simply exchanged
between various objects as ships come and go, resulting
on no massive energy usage. I'm not sure that would be
possible since you'd probably need to slingshot around
black holes to get anywhere close to fast enough. Maybe
a system of multiple black holes of various sizes could be
made to work. |
|
| |
Isn't that the idea behind cyrogenics? |
|
| |
//Isn't that the idea behind cyrogenics?// |
|
| |
Yes, but the point is that this would work. As yet,
we don't know how to freeze a person in such a
way that they can be revived. |
|
| |
But relativistic travel would achieve the same
result as cryogenics. We could sit down today and
design a way to do this, and it would work. We
could design a purely chemical rocket that would
get you up to 0.9999 C. It would be completely
impracticable, but we know it would work. |
|
| |
How long would it take to accelerate to light speed using
a traditional rocket? |
|
| |
While a person might withstand 5 Gs for short periods of
time, this acceleration will take days so I think we better
limit it to 1 G. According to <link> it will take 2 years to
get to 0.97c. I hope this is a slow moving disease. |
|
| |
Accelerating with gravitational slingshots is nice because
it isn't felt by the person acceleration since all their
atoms are accelerated uniformly (except for tidal
effects). That could allow you to accelerate much faster. |
|
| |
Another option might be to use diamagnetic levitation in
the spacecraft to support passenger during acceleration.
It is apparently not harmful to frogs at 1G, but I would
worry a little about using it for long periods at a much
higher G level. I guess we could test it by building the
large superconducting electromagnets needed onto a
huge centrifuge so we can use the centrifuge to simulate
many Gs, but cancel all but one with the magnet and see
if there are any ill effects on test subjects. |
|
| |
Hey, if that works, build a centrifuge ring around the
earth... Never mind, it' will take an acceleration of 1.4
Billion g to keep someone in a centrifuge of earth radius
at light speed. |
|
| |
WIFRT I thought of prosciutto. |
|
| |
// 1. Does time stay slowed for them when they are coming home at the same high velocity they left? I think yes.
/
2. If #1 is true then if they went in tight circles very fast in our own solar system would time slow? Again I think yes.
/
3. If they went to the moon (less air resistance, you know) and vibrated back and forth very fast would time slow? It should! //
Yes/yes/yes. |
|
| |
However, for case 3, the force needed to produce noticeable time dilation if far greater than flesh or machine could survive. For case 2, the circle couldn’t be very tight – for example, to experience an force about the same as Earth’s 1 gee surface gravity, the circle would have to have a radius of about 1 light-year (10^16 meters). If it was about the orbit of Pluto, the force would be about 2000 gees, which would reduce a person to goo and separate it into its different cells like a lab centrifuge. |
|
| |
I just had a thought, or at least a puzzlement. |
|
| |
If a person accelerates from standstill to 10m/s in 1
second, they will experience a force of 1g. |
|
| |
However, if they are at 99.9% the speed of light, and
accelerate by a further 10m/s in 1 second (as viewed by
an outside observer), then it's different. To the outside
observer, they will experience 1g. However, they
themselves will experience the same delta-v in only a
fraction of a second (due to time dilation). So, does this
mean that they will subjectively experience a much
higher force than 1g? |
|
| |
To put it another way: if someone accelerates at a
constant 1g (as viewed by an outside observer), won't
they experience a subjectively increasing g-force as they
get closer to c? |
|
| |
If spinning counts, does vibration count? Heat is just a form of atomic vibration. If it does, hot things should age slower than cold things on account of their component molecules moving at a greater fraction of the speed of light. |
|
| |
Physicists love nothing more than making very hot things and very cold things, and then writing scholarly papers which contains one entire pageload of author names. Yo pageload! Make something hot and something cold and see if you can tell a difference in aging rate! |
|
| |
[bungston]
Whereas biological systems are concerned, reduced temperatures slow down metabolic processes and higher temperatures increase metabolic processes. |
|
| |
//If a person accelerates from standstill to 10m/s in 1 second, they will experience a force of 1g.
However, if they are at 99.9% the speed of light, and accelerate by a further 10m/s in 1 second (as viewed by an outside observer), then it's different. //
No, it’s not. |
|
| |
One of the great beauties of Special Relativity is that it’s built from 2 simple principle: that the laws of physics are the same regardless of your speed; and the speed of light is the same regardless of your speed relative to the light’s source. This means you don’t have to do complicate arithmetic to figure out how nature works for frames with different velocities. It works the same everywhere at every speed. |
|
| |
// If spinning counts, does vibration count? Heat is just a form of atomic vibration. If it does, hot things should age slower than cold things on account of their component molecules moving at a greater fraction of the speed of light.//
Yes. Nonzero relative velocity of any kind results in time dilation, but the speeds involved in heat is so small compared to the speed of light that the time dilation is tiny. |
|
| |
For example, if you were made of light stuff like hydrogen and as hot as the core of the Sun, you parts would have an average speed of about 0.0014 c. If you could sustain some sort of biological metabolism at that temperature (rather than getting reduced to your component atoms) you’d age about 31 seconds less per year than a similar organism at room temperature. |
|
| |
Now I'm imagining an organism that lives near black holes and uses time dilatation in part of its life-cycle |
|
| |
// A single nuclear power plant may produce that amount
of energy in a day. […] we would certainly need a efficient
way of converting it into kinetic energy // |
|
| |
Just put the nuclear power plant on the spacecraft. See
nuclear rockets (thermal and others). |
|
| |