firing gun on the moon

I read somewhere that a working definition of an explosive reaction is one that propagates faster than the speed of sound. (Of course that wouldn't apply on the moon )

The point being that when you say it is rapid combustion, be sure to put the emphasis on rapid.

i know "the moon is a harsh misstress", i am a science fiction geek. nevertheless heinlein was a horrible writer and most of his ideas are out of date.

you still can read some old bester, herbert, dick or assimov but heinlein, never again.

thanks for the effort of trying to answer my questions.

The main reason i asked was to find out if warren ellis is true to actual physics as i am a big fan of the man, but otherwise i do not like science fiction that bends the actual known laws of nature.

The actual idea of leaving the moon via gunshot was from ocean#4, highly recommended(also transmetropolitan). the ellis guy has more good science fiction ideas in 22 pages of comicbook then some other in a 600+page novel(Ben Bova is tha mainsucker). And the ideas are the reason why i love the genre.

freeman dyson and other real scientists are a great source of inspiration too. i wonder if a dysonsphere actually exists somewhere or will one day in the future.



[edit on 9-3-2005 by feyd rautha]

[edit on 9-3-2005 by feyd rautha]

OMG!!!! How dare you speak (err....type) such blasphemous rubbish about the "God of Science Fantasy" writing....ROBERT A. (You Are My God) HIENLEIN! Shame on you feyd rautha!!

Please excuse my ignorance, but what the hell is excape velocity?

In a word, it is the minimum speed you need to reach to be able to "detach" from the gravity of the body you're on. On earth, to be able to break the gravity and go into space, you need to reach 11km/s to do that.

An even better answer is here.

What would happen with a full auto Mg45 when pointing at the ground and shoot? As there is a oxidizer in the gunpowder that isnt a problem and lets say it wont fail or jam and theres virtually unlimited ammo.

Feyd Rautha, perhaps I do not have the breadth and depth of knowledge as you do as a science fiction fan; I read my first science fiction story, entitled "Space Cadet", when I was ten; given my present age, that means I have only been a science fiction "semigeek" for a half-century.

I am surprised to think that you consider Heinlein as a "horrible writer"; most science fiction aficianados that I know consider Robert Heinlein to be one of the greatest (if not the greatest) science Fiction authors that ever lived, precisely because his ideas (again, in the opinion of us less-knowledgeable semigeeks) are not out of date.

You see, Feyd, a great speculative-fiction writer can do two things (in addition to character development, plot, and dialogue) that a mediocre author cannot: use a story line to examine an enduring philosophy, and to develop the characters to reflect the time, place, and situation in which they live.

Heinlein does both: From his very first story ("Gulf", published four years before I was born) he deals with the concept of guarding freedom, a theme to which he returned constantly; In his "The Unpleasant Profession of Jonathan Hoag", he provides a fascinating hypothesis of the creation mythos; and his "The Man who Travelled in Elephants" he paints a emotional picture of a late 19th/early 20th century man on his most imortant trip dealing with love and remembrance.

And these were just some of his novellas!

When you say "...most of his ideas are out of date." surely you can't be talking about his ideas of humanity and its interaction with itself and putative aliens! His technical data based on classical mechanics is as good as anyone (he was an engineering graduate of the US Naval Academy). As a matter of fact, I took the information I provided you on the steel cans, as my colleague Mr. Roark undoubtedly knew when he posted you, directly from "Mistress".

Finally, Mr. Heinlein's philosophy is certainly not a sterile one; proof of that is some of the outrage his books philosophical musing elicit from reviewers. His overall libertarian outlook (epitomized in, not surprisingly, "Mistress" upset many statists, while his militarism and views on the voting franchise, as epitomized in "Starship Troopers", upset even more people. Of course, his Masonic views in "Revolt in 2100" would outrage some of the more hysterical bigots here at ATS.

Finally, I want to make several comments:

First, in my opinion, your writing, at least as seen in your posts on this forum, do not qualify you to make critical judgments of someone like Heinlein;

Second, your questions and confusion about basic physics seem rather jejune when I read your technical-aspects criticism of someone who has forgotton more physics that you will ever know;

Third, Your using comic books to bolster your "street cred" as a science fiction aficianado tells me quite a bit about your overall knowledge of the genre (or lack thereof); and

Fourth, given your comments about Robert Anson Heinlein, I am placing you on permanent ignore.

[edit on 10-3-2005 by Off_The_Street]

There is one problem that I see with this discussion. No one has given the correct definition of "Escape Velocity". Escape Velocity is the speed at which an object has enough energy to overcome the gravity of the celestial mass that it is on, I think that it is about 17,000 for the Earth. You do not have to reach Escape Velocity to leave the Earth. Rutan's Space Ship One reached the fringes of space going no where near 17,000 miles per hour, and the Apollo rockets didn't either. What they did do was to carry enough fuel to maintain the thrust necessary to lift their mass out of the Earth's gravity well. You could reach orbit by going 5mph if you carried enough fuel to keep your velocity constant long enough. A rocket is sometimes called an "impulse vehicle" meaning it gets its payload to a desired velocity and then is shut off or discarded. A bullet is another example of an impulse vehicle.

Originally posted by JIMC5499
There is one problem that I see with this discussion. No one has given the correct definition of "Escape Velocity". Escape Velocity is the speed at which an object has enough energy to overcome the gravity of the celestial mass that it is on, I think that it is about 17,000 for the Earth. You do not have to reach Escape Velocity to leave the Earth. Rutan's Space Ship One reached the fringes of space going no where near 17,000 miles per hour, and the Apollo rockets didn't either. What they did do was to carry enough fuel to maintain the thrust necessary to lift their mass out of the Earth's gravity well. You could reach orbit by going 5mph if you carried enough fuel to keep your velocity constant long enough. A rocket is sometimes called an "impulse vehicle" meaning it gets its payload to a desired velocity and then is shut off or discarded. A bullet is another example of an impulse vehicle.

I'm not sure about what you say... Did you read the explanation given in the link I provided? Unless there is some obvious bia I stayed in, I think my definition (though very basic) is still correct, and by the way, the definition and explanation provided in the link should be way enough to convince everybody. I'll stick to it so far. Convince me of the contrary and I'm OK with it.

[Edit]
Oh, and by the way, 17,000 as such means nothing, and also, IS nothing. According to the definition I'll stick to, escape velocity on earth is 7 mi/second, 11 km/sec, 25,000 mi/hr or 40,200km/s, approximately, each number representing about the same speed. I don't see well where your 17,000 is...

[edit on 10-3-2005 by SpookyVince]

SpookyVince's link is an excellent one; the speed to leave the Earth's gravitational pull is about 25,000 miles/hr.

The 17,000 mi/hr speed you gave is for orbital velocity, whihc is the speed required to stick a spaceshift in an orbit with enought distance and lateral speed so that, as it falls towards Earth, it keeps moving around the earth, and thus stays at a particluar altitude.

Typically most planetary spacecraft, like Apollo and all the other robotic explorers are sent into an orbit; then, when the systems check out, the engines fire again, providing the spacecraft with the 8,000 mi/hr delta to go somewhere else.

But what if a object is steadily going upwards at say 5 miles an hour? wouldnt it get away from earth's gravitational field after a while?

Besides, even if the bullet did fly all the way around the Moon, it still wouldn't hit you in the back of the head, because, in the 30.55 hours it would take the bullet to make the trip, you would've probably gone back into the spaceship for lunch and a nap.

and I thought that I had too much time on my hands...

(kidding, wish I did)

Originally posted by Gazrok

Besides, even if the bullet did fly all the way around the Moon, it still wouldn't hit you in the back of the head, because, in the 30.55 hours it would take the bullet to make the trip, you would've probably gone back into the spaceship for lunch and a nap.

and I thought that I had too much time on my hands...

(kidding, wish I did)

LOL @ Gazrok!!!

Any body (not anybody) with some gravity would anyway pull the bullet back to its ground, unless the bullet itself is equipped with anti-gravity device, a thing that we can not yet do!

Originally posted by feyd rautha
i know "the moon is a harsh misstress", i am a science fiction geek. nevertheless heinlein was a horrible writer and most of his ideas are out of date.

Somebody tell me he didn't say that.

Not only should you be banned but tarred and feathered, burned at the stake, beaten, stoned, hung, and gang probed by a bunch of drunken Grey's

Just kidding

Heinlein was, as mentioned, one of the greatest, alongside Herbert and Asimov.

[edit on 10-3-2005 by Amuk]

Originally posted by Amuk
(...)
Asminov.

Uh...? Asimov? Sorry, don't mean to be bad!

Originally posted by SpookyVince

Originally posted by Amuk
(...)
Asminov.

Uh...? Asimov? Sorry, don't mean to be bad!

No problem....LOL

With the meds I am on I am lucky to spell MY name right.....LOL

Originally posted by SpookyVince
In a word, it is the minimum speed you need to reach to be able to "detach" from the gravity of the body you're on. On earth, to be able to break the gravity and go into space, you need to reach 11km/s to do that.

An even better answer is here.

Awsome thanks a bunch, I feel enlightened!

@off the street

english is not my first language, german is. this should explain my lacking language skills(but i m quite happy with those skills, even worked as a translator one time english to german) . maybe i read a bad translation of heinlein. nowadays i read only english books. i find it unfair of you to discredit comicbooks, basically the medium doesn´t matter. the writer, his language skills and most of all his ideas are important. as an Expert you sure will know that Neil Gaiman´s mainjob is writing comics but he has also won several Hugos amongst them one for best novell for American Gods(highly recommended). i have some of warren ellis work as jpegs, if you are interrested i can send you a copy.

maybe you can suggest to me what you consider heinleins best work? i hope it is not stranger in a strangeland or starship troopers(haldeman wrote a far superior novell about spacewar).

I critizised his writing style mostly, because of the very bad written lovescenes and his very out of date idea of the maincharacter beeing from the moon(or was it mars?).

anyway i think i have at least read one book of every important science fiction writer of the last 50 years. i prefer hard to soap and my favorites are the younger ones like baxter, simmons or banks and P.K. Dick. Favorite book is a tie between Frank Herberts "Dune" and Dan Simmons "Hyperion".

William Gibson deserves a special mention for coining the term cyberspace and that he envisioned both the internet and virtual reality before either existed.


Favorite sciencfition Flick:Event Horizont and 2010. favorite tv: the new Battlestar Galactica and Deep Space9. Hope that rama and war of the worlds will be good.





[edit on 11-3-2005 by feyd rautha]

As everybody is ignoring me. Ill ask again why is it impossible to escape from earth when going up at a steady speed of 5 kmph or so.

Perfection is hard to come by, but yesterday I achieved it.

In my last response to Mr. Feyd Rautha, I made a perfect fool of myself.

I made some incredibly foolish assumptions, and I wish to apologize to Mr. Rautha and the rest of the members for my outburst.