Terminal Velocity in space?

[Maverick3n1]

<p>Is there a such thing as Terminal Velocity in space?&nbsp; Let me give you an example.</p><p>Lets assume you could fire a rocket with an unlimited fuel quantity, and as it burned fuel, it never changes weight.&nbsp; You fire that rocket on earth, and even though you could burn the engine on that rocket and let it circle the earth for days, it will never go past it's top speed (lets say 500mph) due to the laws of phsyics here on Earth.&nbsp; You have wind resistance, gravity, etc...&nbsp; Now if you did that same thing in space, (this is hypethetical, I know you need oxygen to burn the fuel), would that rocket also top out at 500mph (or since there is no wind resistance/gravity, top out at a grater number), or would it consistantly accelerate as there are no forces working against it, and it's mass is meaningless in space?&nbsp; Assuming that rocket never colides with anything in it's travels, could it potentially reach the speed of light?</p>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Is there a such thing as Terminal Velocity in space?&nbsp; Let me give you an example.Lets assume you could fire a rocket with an unlimited fuel quantity, and as it burned fuel, it never changes weight.&nbsp; You fire that rocket on earth, and even though you could burn the engine on that rocket and let it circle the earth for days, it will never go past it's top speed (lets say 500mph) due to the laws of phsyics here on Earth.&nbsp; You have wind resistance, gravity, etc...&nbsp; Now if you did that same thing in space, (this is hypethetical, I know you need oxygen to burn the fuel), would that rocket also top out at 500mph (or since there is no wind resistance/gravity, top out at a grater number), or would it consistantly accelerate as there are no forces working against it, and it's mass is meaningless in space?&nbsp; Assuming that rocket never colides with anything in it's travels, could it potentially reach the speed of light? <br /> Posted by Maverick3n1</DIV></p><p>I don't think there would be a terminal velocity in space as you correctly pointed out that there is no drag to counter gravity.&nbsp; The only limiting factor would be the how steep the gravity well is.</p><p>As for your hypothetical rocket, Special Relativity tells us that absolutely nothing with a rest mass that is non-zero can be accelerated to the speed of light (C).&nbsp; The close to C you get, the more mass you gain.&nbsp; The more mass you&nbsp; gain, the more energy required to accelerate.&nbsp; Your mass becomes infinite at C, thus requiring an infinite amount of energy to to achieve C.&nbsp; Physically impossible.&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[Maverick3n1]

Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I don't think there would be a terminal velocity in space as you correctly pointed out that there is no drag to counter gravity.&nbsp; The only limiting factor would be the how steep the gravity well is.As for your hypothetical rocket, Special Relativity tells us that absolutely nothing with a rest mass that is non-zero can be accelerated to the speed of light (C).&nbsp; The close to C you get, the more mass you gain.&nbsp; The more mass you&nbsp; gain, the more energy required to accelerate.&nbsp; Your mass becomes infinite at C, thus requiring an infinite amount of energy to to achieve C.&nbsp; Physically impossible.&nbsp; <br />Posted by derekmcd</DIV><br /><br />But as the above message stated.. you have inifinite fuel, and thus infinite energy coming out of the rocket.&nbsp; As for gaining mass, mass doesn't have any meaning in space.&nbsp; You could use one of the verticle thrusters used on our spacecrafts for leveling out the ship, to push a rock the size of texas through space.&nbsp; Mass has no meaning.&nbsp; Thus my original question stands.. since mass doesn't seem to matter in space, with the continuous thrust of the rocket, could that rocket eventually reach light speed and potentially faster?

 

[baulten]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>But as the above message stated.. you have inifinite fuel, and thus infinite energy coming out of the rocket.&nbsp; As for gaining mass, mass doesn't have any meaning in space.&nbsp; You could use one of the verticle thrusters used on our spacecrafts for leveling out the ship, to push a rock the size of texas through space.&nbsp; Mass has no meaning.&nbsp; Thus my original question stands.. since mass doesn't seem to matter in space, with the continuous thrust of the rocket, could that rocket eventually reach light speed and potentially faster? <br /> Posted by Maverick3n1</DIV></p><p>It's an unrealistic situation.&nbsp; It would take a massive object an infinite amount of time to accerate to light speed with an infinite amount of fuel.&nbsp; Regarding the basic laws on the universe, it would accelerate indefinitely, but never surpass light speed.&nbsp; You can accelerate a constant rate of acceleration and never pass the speed of light due to the length contraction. </p>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Is there a such thing as Terminal Velocity in space?&nbsp; Let me give you an example.Lets assume you could fire a rocket with an unlimited fuel quantity, and as it burned fuel, it never changes weight.&nbsp; You fire that rocket on earth, and even though you could burn the engine on that rocket and let it circle the earth for days, it will never go past it's top speed (lets say 500mph) due to the laws of phsyics here on Earth.&nbsp; You have wind resistance, gravity, etc...&nbsp; Now if you did that same thing in space, (this is hypethetical, I know you need oxygen to burn the fuel), would that rocket also top out at 500mph (or since there is no wind resistance/gravity, top out at a grater number), or would it consistantly accelerate as there are no forces working against it, and it's mass is meaningless in space?&nbsp; Assuming that rocket never colides with anything in it's travels, could it potentially reach the speed of light? <br />Posted by Maverick3n1</DIV></p><p>derekmcd noted the speciala relativity limit, which is valid and absolute.&nbsp; You cannot exceed c.</p><p>In addition there is a problem with your example.&nbsp; Rockets by their nature change mass.&nbsp; If you have an unlimited fuel supply you also have an infinite mass.&nbsp; That is a bit of a problem, since you cannot accelerate an infinite mass.</p><p>In the absence of gravity, and drag the ideal rocket equation gives you the velocity change:</p><p>delta V =&nbsp; Isp*ln(initial mass/final mass)</p><p>Isp is in&nbsp;(lbf -sec/lbm) which is simply the velocity of the exhaust gas relative to the rocke.&nbsp; Isp is often quoted as "seconds" by (strictly speaking incorrectly) cancelling lbf with lbm in which case you need to multiply by 32.2 to get velocity in feet per second.</p><p>So in reality the velocity that can be obtained is limited by the specific impulse (Isp) and by the mass fraction (how much of the mass can be propellant and how much is inert weight).&nbsp; This is bit different from the notion of terminal velocity in the atmosphere which is&nbsp;a function of aerodynamic drag and gravity. </p> <div class="Discussion_UserSignature"> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>But as the above message stated.. you have inifinite fuel, and thus infinite energy coming out of the rocket.&nbsp; As for gaining mass, mass doesn't have any meaning in space.&nbsp; You could use one of the verticle thrusters used on our spacecrafts for leveling out the ship, to push a rock the size of texas through space.&nbsp; Mass has no meaning.&nbsp; Thus my original question stands.. since mass doesn't seem to matter in space, with the continuous thrust of the rocket, could that rocket eventually reach light speed and potentially faster? <br /> Posted by Maverick3n1</DIV></p><p>You would need to use an infinite amount of energy (force) all at once to accelerate your nearly infinitely massive ship from .999~ C to 1.0 C.</p><p>Mass most definitely does matter even in a vacuum.&nbsp; The only difference between a craft in space and a craft on earth is on earth you have additional forces such as atmospheric drag and gravitational drag.&nbsp;&nbsp; You still need a required amount of force to accelerate mass even in space.</p><p>Newton's 2nd law is F=ma</p><p>The formula that doesn't allow you to reach C is:</p><p>E=mc^2/sqrt [1-(v^2/C^)] </p><p>If you work out that your velocity (v) equals the speed of light (c), you will find the the right hand side of the formula is undefinable (infinite).&nbsp; v=c is not allowed.&nbsp; If your velocity equals zero, you just end up with E=mc^2. </p><p>So, as you can see, as you scale your velocity up, you must also scale up your mass and energy as they have an equivalence through E=mc^2.<br /> </p><p>&nbsp;</p><p>&nbsp;</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[Maverick3n1]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You would need to use an infinite amount of energy (force) all at once to accelerate your nearly infinitely massive ship from .999~ C to 1.0 C.Mass most definitely does matter even in a vacuum.&nbsp; The only difference between a craft in space and a craft on earth is on earth you have additional forces such as atmospheric drag and gravitational drag.&nbsp;&nbsp; You still need a required amount of force to accelerate mass even in space.Newton's 2nd law is F=maThe formula that doesn't allow you to reach C is:E=mc^2/sqrt [1-(v^2/C^)] If you work out that your velocity (v) equals the speed of light (c), you will find the the right hand side of the formula is undefinable (infinite).&nbsp; v=c is not allowed.&nbsp; If your velocity equals zero, you just end up with E=mc^2. So, as you can see, as you scale your velocity up, you must also scale up your mass and energy as they have an equivalence through E=mc^2. &nbsp;&nbsp;&nbsp; <br />Posted by derekmcd</DIV><br /><br />The ship wouldn't be nearly infinitely massive.. my concept is a recyclable energy source... thus is why fuel wouldn't matter.&nbsp; The fuel would continually be recycled and re-used, and since my idea doesn't involve combustion of any sort, the fuel source isn't damaged, or changed in a manner that would cause it to degrade, the ship would thus not change mass, yet still have an unlimited fuel source.&nbsp; Thus a space ship equiped with this particular system would remain the same weight in mass, while still being able to continually accelerate.</p><p>My issue I'm having a hard time understanding is why it is being deemed by people to be impossible to break the light barrier in a vacuum.&nbsp; Today's science is based on the speed of light being the maximum speed possible, but why must that be the maximum speed?&nbsp; Because we haven't seen anything go faster?&nbsp; We also thought the world was flat.&nbsp; Until we sailed around it.&nbsp; Just because to our knowledge, nothing has ever traveled faster than the speed of light doesn't mean nothing ever will.&nbsp; Light travels that speed as that's the speed it's initially projected at.&nbsp; It doesn't accelerate because once it leaves the light source, it's no longer being driven by that source, much like a bullet leaving a gun.</p><p>So if you take an object.. lets say it's mass was the mass of our current day Space Ship, and we launch that ship into space, and lets say we have a recyclable/reusable fuel source that doesn't decay over time, and that fuel source puts out as much force as the main thrusters of today's Space Ship when it initially launches off of the platform on Earth.&nbsp; Based on that output from those engines, through space where there is no resistance and no drag, isn't the output force of those engines great enough to eventually push that space ship to, and potentially past the speed of light?&nbsp; Since there are no opposing forces on it, wouldn't the hull remain in tact, undamaged, as the only forces it may have to handle would be the vibrations from it's own engines?&nbsp; What force would oppose that spacecraft from accelerating past the speed of light?&nbsp; From what I'm understanding from your above posts, you are stating that the ship would accelerate indefinately until it hit .999 C and then stop accelerating, almost like something physically grabs the ship and holds it from going any faster...&nbsp; Why there?</p>

 

[Mee_n_Mac]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>&nbsp; From what I'm understanding from your above posts, you are stating that the ship would accelerate indefinately until it hit .999 C and then stop accelerating, almost like something physically grabs the ship and holds it from going any faster...&nbsp; Why there? <br />Posted by <strong>Maverick3n1</strong></DIV><br /><br />Your understanding isn't quite right.&nbsp; What happens is you continue to approach C but at an ever decreasing rate. Strictly speaking you aren't limited to 0.999C nor 0.9999C it just takes forever (literally) to get to 1.0C.&nbsp; This isn't a barrier like the old "sound barrier", it's more that just some experimental limit we've run across.&nbsp; Maxwell's equations which describe how EM waves propagate can be used to show C is the speed at which EM propagates in a vacumn. You ask why someting with mass can't exceed C (or even attain it) and that's&nbsp;a fair question.&nbsp; I don't know why but it seems to be true, both by experiment and by physics (math).</p><p>Perhaps someone else can better explain WHY the Newtonian mechanics you want to use won't work.</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> <p>-----------------------------------------------------</p><p><font color="#ff0000">Ask not what your Forum Software can do do on you,</font></p><p><font color="#ff0000">Ask it to, please for the love of all that's Holy, <strong>STOP</strong> !</font></p> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Your understanding isn't quite right.&nbsp; What happens is you continue to approach C but at an ever decreasing rate. Strictly speaking you aren't limited to 0.999C nor 0.9999C it just takes forever (literally) to get to 1.0C.&nbsp; This isn't a barrier like the old "sound barrier", it's more that just some experimental limit we've run across.&nbsp; Maxwell's equations which describe how EM waves propagate can be used to show C is the speed at which EM propagates in a vacumn. You ask why someting with mass can't exceed C (or even attain it) and that's&nbsp;a fair question.&nbsp; I don't know why but it seems to be true, both by experiment and by physics (math).Perhaps someone else can better explain WHY the Newtonian mechanics you want to use won't work.&nbsp; <br />Posted by Mee_n_Mac</DIV></p><p>If you look at how the Lorentz transformation is derived you find that if there is any phenomena that propagates at a fixed velocity, call it "x", in all inertial reference frames then you find that 1) you have the Lorentz transformation with "x" in the role of "c" and nothing (including information) can be transmitted faster than "x".&nbsp; Then we have the experimental observation that "c" is in fact constant in all inertial reference frames, and it plays the role of "x".&nbsp; From the constancy of the speed of light one logically deduces that it is a limiting speed.&nbsp; It is also the case that Maxwell's equations predict that the speed of light is constant in all inertial reference frames, so one has an independent check on experiment.&nbsp; <br /></p> <div class="Discussion_UserSignature"> </div>

 

[a_lost_packet_]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>..&nbsp; From what I'm understanding from your above posts, you are stating that the ship would accelerate indefinately until it hit .999 C and then stop accelerating, almost like something physically grabs the ship and holds it from going any faster...&nbsp; Why there? Posted by Maverick3n1</DIV></p><p>I usually don't enter into these conversations but, I'll make an exception here.&nbsp; Maybe I won't screw it up. &nbsp; </p><p>I want you to <u>look</u> at the equation derekmcd posted.</p><p><em>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>You would need to use an infinite amount of energy (force) all at once to accelerate your nearly infinitely massive ship from .999~ C to 1.0 C......</em></p><p><em>Newton's 2nd law is F=ma</em></p><p><em>The formula that doesn't allow you to reach C is:</em></p><p><u><strong><em>E=mc^2/sqrt [1-(v^2/C^)] </em></strong></u></p><p><em>If you work out that your velocity (v) equals the speed of light (c), you will find the the right hand side of the formula is undefinable (infinite).&nbsp; v=c is not allowed.&nbsp; If your velocity equals zero, you just end up with E=mc^2. </em></p><p><em>So, as you can see, as you scale your velocity up, you must also scale up your mass and energy as they have an equivalence through E=mc^2.</DIV></em></p><p>Now, what is that?</p><p>First of all, that IS exactly what you are describing.&nbsp; Math does equate to reality here.&nbsp; It'd not just an equation without meaning.&nbsp; It exists.&nbsp; Read through his explanation.&nbsp; Look at the variables listed there. </p><p>(I can't get super/subscripts to work so ^ denotes "superscript.")&nbsp; </p><p>First, you will notice Einstein's famous equation E=mc^2.&nbsp; This equation is for calculating the energy of a stationary mass bearing body.&nbsp; If it is not moving, the amount of energy represented is E=mc^2.</p><p>The amount of energy represented by a moving mass bearing body is equal to E=m (v^2/2 ).&nbsp; Where the energy necessary is to move a stationary massive body whos mass is (m) to a velocity (v).</p><p>However, in <u>relativity</u>, a Loretz equation must be used where:&nbsp; <u><strong><em>E=mc^2/sqrt [1-(v^2/C^2)&nbsp;</em></strong></u>&nbsp; (What dereckmcd posted)*</p><p>This is what derekmcd is describing to you.&nbsp; And, <u>THIS</u> is what is actually occurring.&nbsp; It does work.&nbsp; That equation really does seem to describe what is happening. </p><p>As the object approaches the speed of light which we plug in as "v", then v^2/c^2 approach 1.&nbsp; Why?&nbsp; Because, you wish to go a "v" equal to the speed of light!&nbsp; "c" is equal to the speed of light in this Lorentz equation.&nbsp; Therefore, v^2/c^2 is equal to 1 for "lightspeed."</p><p>But, what happens then?&nbsp; Well, in order to do the maths right, you must subtract v^2/c^2 from 1! &nbsp; What happens when you subtract 1 from 1?&nbsp; You get... 0 (zero.)&nbsp; What happens when you divide by zero? ... . You get... INFINITY.&nbsp; It breaks!</p><p>It's really easier to see on paper or, in a properly formatted way.&nbsp; Yet, I can't find anything suitable so I will upload something:</p><p><br /> <img src="http://sitelife.space.com/ver1.0/Content/images/store/1/8/8186a9ab-af46-4cdf-88fa-e6cd26f9e520.Medium.jpg" alt="" /></p><p>See the "v" in the Lorentz portion of the equation?&nbsp; If you wish it to equal the speed of light, which also happens to be "c" then you will end up dividing by zero!&nbsp; That can't be allowed!&nbsp; Now, look at "m."&nbsp; If "m" is equal to a positive number, then you are describing a mass bearing body. So, in short, as "v" <u>approachess</u> the speed of light the amount of energy necessary to propel ANY body with mass <u>approaches</u> infinity!&nbsp; This is a dynamic event that is being described here.&nbsp; As "v" increases, so the Energy represented increases.&nbsp; Plug in some easy to manipulate numbers and you can watch it change for yourself. </p><p>(A word about "mass." - Mass is NOT the same as weight.&nbsp; That is important to remember.&nbsp; "Weight" is a measure of gravity's effect on mass.) </p><p>(A word about F=ma.&nbsp; As you approach the speed of light, acceleration occurs in increasingly smaller increments.) </p><p>PS - I was on the phone in the middle of the night handling a crisis at the same time composing this.&nbsp; So, I think I have it right.. but, I extend no warranty beyond which I think the concept is basically understandable as outlined.&nbsp; If you have specific questions about the maths and what they mean, you'd be much better asking derekmcd or DrRocket.&nbsp; I'm just a neophyte.</p><p>*derekmcd I changed/added the "^2" in the Lorentz equation because I thought it was left out accidentally.&nbsp; If it was done on purpose, I apologize and probably bungled it.&nbsp; I'm really terrible with all this physics maths stuffs things.. stuff. </p> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[a_lost_packet_]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If you look at how the Lorentz transformation is derived you find that if there is any phenomena that propagates at a fixed velocity, call it "x", in all inertial reference frames then you find that 1) you have the Lorentz transformation with "x" in the role of "c" and nothing (including information) can be transmitted faster than "x".&nbsp; Then we have the experimental observation that "c" is in fact constant in all inertial reference frames, and it plays the role of "x".&nbsp; From the constancy of the speed of light one logically deduces that it is a limiting speed.&nbsp; It is also the case that Maxwell's equations predict that the speed of light is constant in all inertial reference frames, so one has an independent check on experiment.&nbsp; Posted by DrRocket</DIV></p><p>Thank you for that! </p> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I usually don't enter into these conversations but, I'll make an exception here.&nbsp; Maybe I won't screw it up. &nbsp; I want you to look at the equation derekmcd posted.Now, what is that?First of all, that IS exactly what you are describing.&nbsp; Math does equate to reality here.&nbsp; It'd not just an equation without meaning.&nbsp; It exists.&nbsp; Read through his explanation.&nbsp; Look at the variables listed there. (I can't get super/subscripts to work so ^ denotes "superscript.")&nbsp; First, you will notice Einstein's famous equation E=mc^2.&nbsp; This equation is for calculating the energy of a stationary mass bearing body.&nbsp; If it is not moving, the amount of energy represented is E=mc^2.The amount of energy represented by a moving mass bearing body is equal to E=m (v^2/2 ).&nbsp; Where the energy necessary is to move a stationary massive body whos mass is (m) to a velocity (v).However, in relativity, a Loretz equation must be used where:&nbsp; E=mc^2/sqrt [1-(v^2/C^2)&nbsp;&nbsp; (What dereckmcd posted)*This is what derekmcd is describing to you.&nbsp; And, THIS is what is actually occurring.&nbsp; It does work.&nbsp; That equation really does seem to describe what is happening. As the object approaches the speed of light which we plug in as "v", then v^2/c^2 approach 1.&nbsp; Why?&nbsp; Because, you wish to go a "v" equal to the speed of light!&nbsp; "c" is equal to the speed of light in this Lorentz equation.&nbsp; Therefore, v^2/c^2 is equal to 1 for "lightspeed."But, what happens then?&nbsp; Well, in order to do the maths right, you must subtract v^2/c^2 from 1! &nbsp; What happens when you subtract 1 from 1?&nbsp; You get... 0 (zero.)&nbsp; What happens when you divide by zero? ... . You get... INFINITY.&nbsp; It breaks!It's really easier to see on paper or, in a properly formatted way.&nbsp; Yet, I can't find anything suitable so I will upload something: See the "v" in the Lorentz portion of the equation?&nbsp; If you wish it to equal the speed of light, which also happens to be "c" then you will end up dividing by zero!&nbsp; That can't be allowed!&nbsp; Now, look at "m."&nbsp; If "m" is equal to a positive number, then you are describing a mass bearing body. So, in short, as "v" approachess the speed of light the amount of energy necessary to propel ANY body with mass approaches infinity!&nbsp; This is a dynamic event that is being described here.&nbsp; As "v" increases, so the Energy represented increases.&nbsp; Plug in some easy to manipulate numbers and you can watch it change for yourself. (A word about "mass." - Mass is NOT the same as weight.&nbsp; That is important to remember.&nbsp; "Weight" is a measure of gravity's effect on mass.) (A word about F=ma.&nbsp; As you approach the speed of light, acceleration occurs in increasingly smaller increments.) PS - I was on the phone in the middle of the night handling a crisis at the same time composing this.&nbsp; So, I think I have it right.. but, I extend no warranty beyond which I think the concept is basically understandable as outlined.&nbsp; If you have specific questions about the maths and what they mean, you'd be much better asking derekmcd or DrRocket.&nbsp; I'm just a neophyte.*derekmcd I changed/added the "^2" in the Lorentz equation because I thought it was left out accidentally.&nbsp; If it was done on purpose, I apologize and probably bungled it.&nbsp; I'm really terrible with all this physics maths stuffs things.. stuff. <br />Posted by a_lost_packet_</DIV></p><p><br />The formula that you have here is correct, if you take the mass to be the rest mass.&nbsp; In the usual way of looking at E = mc^2 you don't divide by sqrt(1-v^2/c^2) but you do have to use the relativistic mass, which is just the rest mass divided by that expression.&nbsp; So what you said is correct if you are careful about what you mean by "m", and the "m" that you used is what you would measure in a laboratory that is at rest for the purpose of this discussion.<br /></p> <div class="Discussion_UserSignature"> </div>

 

[kg]

<p>&nbsp; What happens when you subtract 1 from 1?&nbsp; You get... 0 (zero.)&nbsp; What happens when you divide by zero? ... . You get... INFINITY.&nbsp; It breaks!</p><p>&nbsp;<font size="2">This is true.&nbsp; I actually blew up CERN and buggered the electrical grid of Europe in a thought experiment earlier this summer!&nbsp; </font></p><p><font size="2">&nbsp;You can't go faster than the speed of light because no matter&nbsp;how much you accelerate light coming from behind you will always pass you like you are standing still.&nbsp; What you will find is that distance to where you are going&nbsp;actually decreases the faster you go.</font></p>

 

[CalliArcale]

<p>The relativity stuff is over my head, but I can address a couple of minor points about your post, Maverick: </p><p>As for gaining mass, mass doesn't have any meaning in space.&nbsp; You could use one of the verticle thrusters used on our spacecrafts for leveling out the ship, to push a rock the size of texas through space.&nbsp; Mass has no meaning.</p><p>This is not actually true -- mass has a great deal of meaning in space.&nbsp; Just because you are weightless in space does not mean that you are massless as well.&nbsp; In fact, this can be a serious problem for spacewalking astronauts -- they can push a 200-kg object around, but that's mostly because they don't have to fight against gravity or friction.&nbsp; It still has 200 kg of mass, and if they're not careful, that can crush somebody.</p><p>Also, it's not effortless to push 200 kg around in space.&nbsp; It's doable, but not effortless.&nbsp; The more massive something is, the more energy you need to change its velocity vector.&nbsp; This is why it takes more propellant to get an Apollo spacecraft to the Moon than it does to get a small robotic orbiter to the Moon. </p><p>The ship wouldn't be nearly infinitely massive.. my concept is a recyclable energy source... thus is why fuel wouldn't matter.&nbsp; The fuel would continually be recycled and re-used, and since my idea doesn't involve combustion of any sort, the fuel source isn't damaged, or changed in a manner that would cause it to degrade, the ship would thus not change mass, yet still have an unlimited fuel source.&nbsp; Thus a space ship equiped with this particular system would remain the same weight in mass, while still being able to continually accelerate.</p><p>Rockets don't work the same way as cars.&nbsp; Cars combust fuel with oxygen from the air to produce energy to turn a crankshaft which in turn is used to turn the wheels of the car.&nbsp; The fact that the combustion byproducts escape out the tailpipe is an unfortunate happenstance, but has little effect on the car's operation.&nbsp; Rockets are different.&nbsp; Rocket engines are a type of motor called a reaction motor, which means they operate on the principle of every force having an equal and opposite reaction.&nbsp; In all cases, propellant is made to accelerate to high speed and blast out the back of the engine, producing thrust and shoving the vehicle forwards.&nbsp; Most engines are chemical bipropellant engines -- they combust a fuel and an oxidizer to produce a vigorous exothermic reaction that propels the products of combustion out the back, and the rocket forwards.&nbsp; There are other types which do not rely on combustion, such as ion drives.&nbsp; Ion drives electrically excite a propellant such as xenon gas, causing it to fly out the back of the engine, pushing the vehicle forwards.&nbsp; The thrust is very, very low -- barely enough to flutter a piece of paper.&nbsp; But it is very very efficient.&nbsp; This may be the ideal engine for your hypothetical ship, because although it takes a long time to accelerate, you can do it for remarkably little expenditure of propellant.&nbsp; But you do expend propellant.&nbsp; Reaction mass is lost as you accelerate forwards.&nbsp; On the plus side, as your vehicle gets lighter, it accelerates more rapidly.&nbsp; ;-)</p><p>However, neither of these affect the fundamentals of your thought experiment, I think.&nbsp;&nbsp; They're just the few things I could find that I could actually speak to!</p> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>*derekmcd I changed/added the "^2" in the Lorentz equation because I thought it was left out accidentally.&nbsp; If it was done on purpose, I apologize and probably bungled it.&nbsp; I'm really terrible with all this physics maths stuffs things.. stuff. <br /> Posted by a_lost_packet_</DIV><br /></p><p>Good catch.&nbsp; It was an accidental omission on my part and if it wasn't I'd never admit otherwise. <img src="http://sitelife.space.com/ver1.0/content/scripts/tinymce/plugins/emotions/images/smiley-wink.gif" border="0" alt="Wink" title="Wink" /> </p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[a_lost_packet_]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Good catch.&nbsp; It was an accidental omission on my part and if it wasn't I'd never admit otherwise. Posted by derekmcd</DIV></p><p>If I can change helium into deuterium at will, you certainly can downshift for a few more rpms while traveling at lightspeed. </p> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If I can change helium into deuterium at will, you certainly can downshift for a few more rpms while traveling at lightspeed. <br /> Posted by a_lost_packet_</DIV></p><p>Heh...</p><p>*cough* hydrogen *cough* *cough*</p><p>Of course, we'd make a great team of superheroes if you could do helium to deuterium.&nbsp; My infinite velocities without even reaching C and your free energy at will.&nbsp; We'd get all the chicks.</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[a_lost_packet_]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Heh...*cough* hydrogen *cough* *cough*Of course, we'd make a great team of superheroes if you could do helium to deuterium.&nbsp; My infinite velocities without even reaching C and your free energy at will.&nbsp; We'd get all the chicks. <br /> Posted by derekmcd</DIV></p><p>I'll have to remember to bring my Philosopher's stone with me...&nbsp; And a bucket of "start paying attention to what you type" as well. &nbsp; I'm on a roll! &nbsp;</p><p>Don't worry, you can do all the talking. </p> <div class="Discussion_UserSignature"> <font size="1">I put on my robe and wizard hat...</font> </div>

 

[derekmcd]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>I'll have to remember to bring my Philosopher's stone with me...&nbsp; And a bucket of "start paying attention to what you type" as well. &nbsp; I'm on a roll! &nbsp;Don't worry, you can do all the talking. <br /> Posted by a_lost_packet_</DIV></p><p>You should upgrade to the Alchemist's stone... better stats.&nbsp;</p> <div class="Discussion_UserSignature"> <div> </div><br /><div><span style="color:#0000ff" class="Apple-style-span">"If something's hard to do, then it's not worth doing." - Homer Simpson</span></div> </div>

 

[DrRocket]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>The ship wouldn't be nearly infinitely massive.. my concept is a recyclable energy source... thus is why fuel wouldn't matter.&nbsp; The fuel would continually be recycled and re-used, and since my idea doesn't involve combustion of any sort, the fuel source isn't damaged, or changed in a manner that would cause it to degrade, the ship would thus not change mass, yet still have an unlimited fuel source.&nbsp; Thus a space ship equiped with this particular system would remain the same weight in mass, while still being able to continually accelerate.My issue I'm having a hard time understanding is why it is being deemed by people to be impossible to break the light barrier in a vacuum.&nbsp; Today's science is based on the speed of light being the maximum speed possible, but why must that be the maximum speed?&nbsp; Because we haven't seen anything go faster?&nbsp; We also thought the world was flat.&nbsp; Until we sailed around it.&nbsp; Just because to our knowledge, nothing has ever traveled faster than the speed of light doesn't mean nothing ever will.&nbsp; Light travels that speed as that's the speed it's initially projected at.&nbsp; It doesn't accelerate because once it leaves the light source, it's no longer being driven by that source, much like a bullet leaving a gun.So if you take an object.. lets say it's mass was the mass of our current day Space Ship, and we launch that ship into space, and lets say we have a recyclable/reusable fuel source that doesn't decay over time, and that fuel source puts out as much force as the main thrusters of today's Space Ship when it initially launches off of the platform on Earth.&nbsp; Based on that output from those engines, through space where there is no resistance and no drag, isn't the output force of those engines great enough to eventually push that space ship to, and potentially past the speed of light?&nbsp; Since there are no opposing forces on it, wouldn't the hull remain in tact, undamaged, as the only forces it may have to handle would be the vibrations from it's own engines?&nbsp; What force would oppose that spacecraft from accelerating past the speed of light?&nbsp; From what I'm understanding from your above posts, you are stating that the ship would accelerate indefinately until it hit .999 C and then stop accelerating, almost like something physically grabs the ship and holds it from going any faster...&nbsp; Why there? <br />Posted by Maverick3n1</DIV></p><p>&nbsp;A recyclable energy source is thermodynamically impossible.&nbsp; It violates the first and second laws of thermodynamics. <br /></p> <div class="Discussion_UserSignature"> </div>