MIRLI BOOKS
  • Home
  • Books
    • Henry's Trials >
      • Extract from Henry's Trials
    • Smethurst's Luck >
      • Extract from Smethurst's Luck
    • Murder in the Red Barn >
      • Extract from Murder in the Red Barn
    • Reverend Duke and the Amesbury Oliver
  • Talks
    • Talk on Henry's Trials
    • Talk on Smethurst's Luck
    • Talk on Isambard Kingdom Brunel
    • Talk on the Murder in the Red Barn
    • BBC
  • Publications
    • The Amesbury Union Workhouse
    • The Separate System
    • Anatomy of a Bridge
  • Peter Maggs
  • Shop
  • Blog
  • Family History
    • Mirli
    • BM Creeper >
      • The Significance of Stonehenge
      • Educating Ealing I: How Lady Byron Did It
      • Educating Ealing II: Church of England Primary in the 1920s
      • All Because of Crystal Palace
      • Innocent in Ealing - Extract
      • Miss McDonald

Per nuclear ad astra…

5/4/2021

1 Comment

 
A few years ago I presented a course somewhat ambitiously titled A History of the Universe to a number of WEA groups. One of the most interesting sections (to me) was a discussion of the enormous number of stars and galaxies (and their ‘astronomical’ distances), and the fairly recent discovery that many—probably most—stars have a retinue of planets, including rocky Earth-like planets. Could we even find extra-terrestrial life out there, I wondered? 
 
In one of the course modules, I considered the difficulties of travel to the stars. The great physicist Enrico Fermi suggested that life on Earth was unique. If it wasn’t, and considering the vast age and size of the universe, many other civilizations must have arisen millions of years before humanity, developed space travel, and have come to visit us. Since they have not done so, we can safely assume that they do not exist. A most interesting idea (I said), but it has one fatal flaw: the vast distances between the stars mean that manned (or creatured) spacecraft based on any known scientific principles would take many thousands of years even to travel from here to the nearest star.
 
And then, via good old Wikipedia, I came across a declassified Los Alamos paper from 1955 authored by C J Everett and S M Ulam. Stanislaw Ulam, along with Edward Teller, developed the thermo-nuclear ‘hydrogen’ bomb, and suggested the idea of Nuclear Pulse Propulsion. The paper with Everett developed the idea which was, quite seriously, to propel missiles to very high speeds by exploding a series of H bombs behind them…
 
Following the reference trail, I found an article in Physics Today from October 1968. The author was Freeman J Dyson, a renowned (originally English) mathematician from Princeton, who had worked on the defunct Orion project. Project Orion, funded in the US by DARPA, had examined the possibility of nuclear pulse propulsion as applied to a spaceship for travel to the stars. There is more detail on the Wikipedia page, but the basics can be condensed from Dyson’s paper.
 
Dyson proposed a starship propelled by sequentially exploding one megaton H bombs behind a ‘pusher’ plate connected to a shock-absorber. The bombs would detonate every three seconds over a period of ten days or so, requiring around 300,000 bombs. This would produce an average acceleration of one g, with a final velocity of 10,000 km per second—around one thirtieth of the speed of light. The cost of such a ship at 1968 prices would be 60,000 million dollars, around 0.1 US GNP. The shock absorber would ensure that the crew were not squashed by the force of the explosions, and suitable shielding would protect them from radiation from the bombs.
 
Dyson suggested that it would have been much cheaper to send a spacecraft to Mars powered by nuclear bombs, than it was costing to send the Apollo astronauts to the moon. For travel to Mars, only a few bombs would have been needed, so that’s a relief.
1 Comment
Paul Robertson
14/4/2021 12:27:23 pm

Fine. But simplistically, you need just as many nuclear devices at the other end to slow yourself down again. These 'brake-bombs' of course form part of the initial payload, and thus you need more outgoing bombs than brake-bombs.

Er. Unless you want to come back...

Reply



Leave a Reply.

    Author

    Welcome to the Mirli Books blog written by Peter Maggs

    Archives

    April 2025
    December 2024
    October 2024
    August 2024
    July 2024
    June 2024
    May 2024
    March 2024
    February 2024
    January 2024
    December 2023
    November 2023
    October 2023
    August 2023
    July 2023
    June 2023
    May 2023
    April 2023
    February 2023
    December 2022
    November 2022
    October 2022
    September 2022
    August 2022
    July 2022
    June 2022
    May 2022
    April 2022
    March 2022
    February 2022
    January 2022
    December 2021
    November 2021
    September 2021
    August 2021
    July 2021
    June 2021
    May 2021
    April 2021
    March 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    August 2018
    July 2018
    May 2018
    March 2018
    January 2018
    December 2017
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    May 2017
    April 2017
    March 2017
    February 2017
    January 2017
    December 2016
    November 2016
    October 2016
    September 2016
    August 2016
    July 2016
    June 2016
    May 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014
    August 2014
    July 2014
    June 2014
    May 2014
    April 2014
    March 2014
    February 2014
    January 2014
    December 2013
    November 2013
    October 2013
    September 2013
    August 2013
    July 2013
    June 2013
    May 2013

    Categories

    All

    RSS Feed

Website and Contents © Peter Maggs 2025
  • Home
  • Books
    • Henry's Trials >
      • Extract from Henry's Trials
    • Smethurst's Luck >
      • Extract from Smethurst's Luck
    • Murder in the Red Barn >
      • Extract from Murder in the Red Barn
    • Reverend Duke and the Amesbury Oliver
  • Talks
    • Talk on Henry's Trials
    • Talk on Smethurst's Luck
    • Talk on Isambard Kingdom Brunel
    • Talk on the Murder in the Red Barn
    • BBC
  • Publications
    • The Amesbury Union Workhouse
    • The Separate System
    • Anatomy of a Bridge
  • Peter Maggs
  • Shop
  • Blog
  • Family History
    • Mirli
    • BM Creeper >
      • The Significance of Stonehenge
      • Educating Ealing I: How Lady Byron Did It
      • Educating Ealing II: Church of England Primary in the 1920s
      • All Because of Crystal Palace
      • Innocent in Ealing - Extract
      • Miss McDonald