Subject:
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Re: Hypothetical design question
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Newsgroups:
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lugnet.space
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Date:
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Wed, 25 Jun 2003 14:45:20 GMT
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Viewed:
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555 times
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Theoretically, any engine in deep space could allow you to travel to light
speed or very close to it, assuming you have enough fuel and time on your
hands to accelerate that long. Granted, the FASTER you want to accelerate,
the more engery you’ll have to use.
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Ask your dad about that again. My comment was based on readings from Stephen
Hawking’s “Brief History of Time” and “Universe in a Nutshell”, as well as
various online physics FAQ.
Granted, in space you don’t have to worry about air friction or gravitational
pull (relatively), but burning fuel won’t accelerate you to just any speed you
desire.
using some of newton’s theories, it takes a certain amount of energy to move an
object a certain distance. or to say it in vacuum terms, it takes a certain
amount of energy to accelerate an object to a certain speed. NASA’s rockets
will accelerate you up to a given point, allowed they have enough fuel to burn.
this is the amount of energy that the oxygen-hydrogen engines produce.
However, when accelerating towards light speed, the amount of energy required to
accelerate increases. getting close to light speed, the amount of energy
approaches infinity. and the more mass you have (like extra fuel) will increase
the amount of energy needed to accelerate.
this is why only light (ie, mass-less photon) travels at light speed.
here’s a page about mass moving at light speed:
http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
and another on black holes that has something to say about energy and speed:
http://math.ucr.edu/home/baez/physics/Relativity/BlackHoles/blackfast.html
-lenny
i’m not trying to say your dad is wrong, but perhaps some of the conclusions
you’ve come to from your conversation with him are being taken out of context.
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Message has 1 Reply:
 | | Re: Hypothetical design question
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| (...) I hadn't really thought about this problem before, but I can see how it would be a problem. If your propellent has an exit velocity of 2mph, it shouldn't ever be able to make you go faster than 2mph. Once you've hit that point, the propellent (...) (21 years ago, 25-Jun-03, to lugnet.space, FTX)
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Message is in Reply To:
| | Re: Hypothetical design question
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| In lugnet.space, Leonard Hoffman wrote: -snip- (...) -snip- (...) Now I'm going to start this off with the fact I'm no physicist. I'm not an expert. And everything I'm about to say is relayed from endless conversations I've had with my father about (...) (21 years ago, 25-Jun-03, to lugnet.space, FTX)
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