# The Sound of Thunder **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [September 29, 2004, 11:27pm UTC](https://boards.straightdope.com/t/the-sound-of-thunder/266756 "2004-09-29T23:27:45Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [September 29, 2004, 11:27pm UTC](https://boards.straightdope.com/t/the-sound-of-thunder/266756/1 "2004-09-29T23:27:45Z")
[Could one day propel space probes.](http://www.newscientist.com/news/news.jsp?id=ns99996419) Yeah, I know what you’re thinking, I thought the same thing, but it _is_ a legit source for the story. > [@](#): > > Thunderous sound waves could one day propel spacecraft to the edge of the solar system, say engineers who have developed a new type of acoustic engine. > > Current long-range spacecraft - like the US-European Cassini probe now orbiting Saturn - roam too far from the Sun to use solar power so instead carry plutonium bricks to fuel their engines. As the radioactive plutonium decays, it generates heat that produces an electric current between two different types of metal. > > This system uses no moving parts - an advantage since these can fail - but the bricks are large, heavy, and difficult to produce. And these engines yield efficiencies of just 7%. > > So NASA is funding research into Stirling engines, which use temperature differentials between reservoirs of gas to create electricity. Conventional Stirling engines are an old technology, invented in 1816 as a safer alternative to steam engines. ---
**Author:** ![Sunspace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sunspace/32/1250_2.png) [@Sunspace](https://boards.straightdope.com/u/Sunspace)\ **Post date:** [September 29, 2004, 11:36pm UTC](https://boards.straightdope.com/t/the-sound-of-thunder/266756/2 "2004-09-29T23:36:04Z")
What’s wrong with New Scientist? It’s a respectable British science weekly, as far as I can tell from the issues on local newsstands… Or do you question the appearance of the story rather than the source? ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [September 30, 2004, 12:13am UTC](https://boards.straightdope.com/t/the-sound-of-thunder/266756/3 "2004-09-30T00:13:58Z")
> [@Sunspace](#): > > What’s wrong with New Scientist? It’s a respectable British science weekly, as far as I can tell from the issues on local newsstands… > > Or do you question the appearance of the story rather than the source? Shield’s down, captain! If I were to come up to you and say that I had found a way to propel a spacecraft using _sound waves_, would you think I was serious or a bit daft? Remember, sound _can’t_ be propagated in a vacuum, so on the face of it, I’d say it was a hoax, **but** _New Scientist_ is a legit source for information (unlike, say, _The Weekly World News_), and in reading the details, it sounds plausible. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [September 30, 2004, 2:35am UTC](https://boards.straightdope.com/t/the-sound-of-thunder/266756/4 "2004-09-30T02:35:15Z")
“He adds that the sound does not escape the engine” ---
**Author:** ![Papermache\_Prince](https://avatars.discourse-cdn.com/v4/letter/p/f05b48/32.png) [@Papermache\_Prince](https://boards.straightdope.com/u/Papermache_Prince)\ **Post date:** [September 30, 2004, 2:50am UTC](https://boards.straightdope.com/t/the-sound-of-thunder/266756/5 "2004-09-30T02:50:10Z")
Spaceflight? . . . . oh . . . . So we’re not using a time machine to hunt dinosaurs? ---
**Author:** ![Tuckerfan](https://avatars.discourse-cdn.com/v4/letter/t/eada6e/32.png) [@Tuckerfan](https://boards.straightdope.com/u/Tuckerfan)\ **Post date:** [September 30, 2004, 3:52am UTC](https://boards.straightdope.com/t/the-sound-of-thunder/266756/6 "2004-09-30T03:52:07Z")
> [@Papermache Prince](#): > > Spaceflight? . . . . oh . . . . So we’re not using a time machine to hunt dinosaurs? Of course not, then this would be in Cafe Society.