# About the Starship Titanic and joules/accelerations.

• blakean87
In summary, the Starship Titanic was a luxury space liner that was destroyed on its maiden voyage due to a miscalculation of joules and accelerations. This incident led to the creation of a virtual world where players could explore the ship and solve puzzles. The game was based on the novel by Douglas Adams and featured humorous and satirical elements. It received mixed reviews but gained a cult following for its unique concept and engaging gameplay.
blakean87
Upon discovering the Starship Titanic while doing some research about time travel, I was wondering what joules would be necessary to accelerate even faster to attempt a more severe time dilation: Namely, a 50,000kg ship to 99.999999999%C. Am I correct in my calculations that this requires app. 1x10^30 joules?

If not, what are the joules required to do so? And what would the peak wattage be if I am accelerating said ship over 1 year?

Thanks.

blakean87 said:
Am I correct in my calculations that this requires app. 1x10^30 joules?

Show us the details of how you worked it out, and someone will be glad to tell you whether your basic method is correct and whether you carried out the arithmetic properly.

The relativistic kinetic energy [1] of an object with (rest-) mass m is Ek = (γ-1)mc2, where γ is the Lorentz factor [2], so you should be able to estimate the minimum amount of energy you need to accelerate that ship of yours and from there the average power needed if this has to take a year. If the energy is stored in a fuel and brought along the ship you may want to take a peek at the relativistic rocket [3] to see what high speeds means for the fuel mass to payload mass ratio.

[1] http://en.wikipedia.org/wiki/Kinetic_energy#Relativistic_kinetic_energy_of_rigid_bodies
[2] http://en.wikipedia.org/wiki/Lorentz_factor
[3] http://math.ucr.edu/home/baez/physics/Relativity/SR/rocket.html

Last edited by a moderator:
Thanks for the links, they were very helpful. I should have added the caveat that my figure was an approximation. In it, I had extrapolated from the link at the bottom and (despite nagging doubts) saw a relatively linear relationship from 99.9-99.9999%C, which resulted in my guess of ~1x10^30. I had initially feared the actual, more accurate math would be much more complicated, but I had already actually seen the Lorentz transformation formula regarding time dilation (which is why I wanted my ship to go that specific velocity). Just didn't know that the formula could be used this way.

http://www.circlon-theory.com/images/starshiptitanic.gif

How is your rightmost column calculated? Assuming an instant acceleration to the final speed? If so, your astronauts will not age at all, they will die smashed to pulp on the very first day of the trip.

I'm not sure if it accounted for acceleration, probably was just calculated to illustrate the amount of time dilation. The reason I used a year for my acceleration was because that's approximately how long it would take to accelerate to my velocity at 1G.

1G for a year will only get you about 0.77c. You answer is only true if you neglect relativistic effects. Reaching 0.99999999999c will take much longer longer than a year at 1 G.

blakean87 said:
Upon discovering the Starship Titanic while doing some research about time travel, I was wondering what joules would be necessary to accelerate even faster to attempt a more severe time dilation: Namely, a 50,000kg ship to 99.999999999%C. Am I correct in my calculations that this requires app. 1x10^30 joules?

If not, what are the joules required to do so? And what would the peak wattage be if I am accelerating said ship over 1 year?

Thanks.

I assume that you're doing this as a relativistic rocketry problem. I'll call the rapidity of the rocket θ. This is related to its velocity by $v=ctanh\left(\theta \right)$. Let's say the ship has an initial mass including fuel of $m_{i}$ and a final mass $m$. It will have a ship frame exhaust port exhaust velocity of $v_{ex}$ which relates to the specific impulse $I_{sp}$ of the fuel by $v_{ex}=gI_{sp}$.
A change in the rapidity of the ship will then be given by
$\Delta \theta =\frac{v_{ex}}{c}ln\left(\frac{m_{i}}{m}\right)$
You find the change in the rapidity from this formula and calculate the final velocity from the rapidity according to the first equation. In the case of zero initial velocity you can compose these as
$v=ctanh\left(\frac{v_{ex}}{c}ln\left(\frac{m_{i}}{m}\right) \right)$
I like this version as its easy to crunch numbers on a scientific calculator, but if you want you can use log properties and the hyperbolic trig version of Euler's identities to write this without the hyperbolic trig function like at a site someone else linked.
In the case of an ideal matter anti-matter rocket $v_{ex}=c$.
As for the question of power, this final velocity - mass ratio relation for the rocket is independent of the flow rate at which you choose to burn it off. Burn it off how you like. However, it is common to analyse the case that you are burning off the fuel at a time dependent rate such that it accelerates at a constant "proper acceleration". This is where the occupant feel like they undergo a constant "g-force" or in otherwords, if one stood on a weight scale it would read a constant weight for the cosmonaught for the whole burn. If the proper acceleration is $\alpha$ then the ship time rate of the mass burn relates to the proper acceleration generally by
$\alpha =\frac{v_{ex}}{m}\frac{dm}{dt'}$, and for constant proper acceleration this integrates to result in
$\alpha \frac{\Delta t'}{c} =\frac{v_{ex}}{c}ln\left(\frac{m_{i}}{m}\right)$
You can then replace this into the equation for the velocity to get the velocity as a function of ship time for constant proper acceleration. If you want more information about this, just let me know.

## What is the Starship Titanic?

The Starship Titanic is a fictional spaceship that was featured in the book "Starship Titanic" by Douglas Adams. It is a luxury cruise ship that was built by the people of the planet Krikkit.

## Is the Starship Titanic a real ship?

No, the Starship Titanic is a fictional ship created by Douglas Adams for his book. It has never been built or launched in real life.

## What are joules/accelerations?

Joules and accelerations are units of measurement used in physics. Joules measure energy, while accelerations measure the rate of change of velocity. They are often used to describe the movement and forces involved in space travel.

## How fast can the Starship Titanic travel?

In the book, the Starship Titanic is capable of travelling at speeds faster than light, using its Infinite Improbability Drive. However, this is purely fictional and not possible according to current scientific understanding.

## What is the purpose of joules/accelerations in space travel?

Joules and accelerations are important in calculating the energy and forces involved in space travel. They help scientists and engineers design and understand the movements of spacecraft and the effects of gravity, inertia, and propulsion systems.

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