Universe Expansion & Contraction

[tomcat]

Never was I taught anything about expanding or contracting the Universe.  But it is a subject that needs to be brought up and dealt with.

If a rocket is 100 feet high is it the same as a rocket 200 feet high?  Some would say, yes, it will have the same spatial characteristics and do exactly the same thing as the rocket 200 feet high.  Believe me, I have been told this by very respectable people.

All else being the same between the two rockets, i.e., the one is exactly proportional to the other in all regards, then the smaller rocket should only be capable of a payload of 1/2 the larger rocket.  Now, the two rockets are not the same.  The larger rocket carries twice as much payload.

There is a constant at work here.  Namely, you and I.  We have remained exactly the same size regardless of which rocket we are talking about.  Now, a relation has sprung into being with regard to the two rockets.  Relative to us, the smaller rocket is the smaller rocket and the bigger rocket is the bigger rocket, regardless of proportions or calculations.  Therefore, we regard the payload to be 'bigger' on the bigger rocket because the size of the objects in the payload are designed for our use and their size has not changed, but remains constant with regard to us.

A more tricky version of this expansion/contraction problem are the performance capabilities of the two rockets.

Will the bigger rocket out perform the smaller rocket.  Calculations say it should do the same thing since all that has changed is size, not proportion or ratio of fuel and components.  Now we have the problem of 'measurement'.  A 'measurement' has to be constant because you and I are standing at the pads and our size has not changed.  The size of the Earth has not changed, nor has distance to the Moon and various planets.

One foot is one foot, is it not?  The one rocket stands 100 feet and the other 200 feet in length. The Moon is, say, 300,000 miles away.  Or, in terms of feet, the Moon is 1,584,000,000 feet away.  The 100 foot rocket is 15,840,000 lengths from the Moon and the 200 foot rocket is just 7,920,000 lengths from the Moon.  Rocket lengths takes into account the static proportion and should be the same for both rockets.  If, now, the rocket is capable of flying exactly 7,920,000 times its own length then the 200 foot rocket is moon capable while the 100 foot rocket can only go half way.

Why is this?  Because, from the perspective of the rockets themselves, the Universe has changed.  It is 1X for the 100 foot rocket and 1/2X for the 200 foot rocket.  We don't see the Universe as changing because our body's dimensions haven't changed at all.  But the rockets are the same in all regards except for their dimensions.  The two rockets have different dimensions.  The different dimensions makes lengths different relative to celestial distances.  It is simple fact.

The 100 foot rocket will only go half as far as the 200 foot rocket.  This is why a one inch rocket cannot keep up with a Saturn V.  I don't care how hard it tries, it cannot go as far or carry as much.

Universe contraction & expansion is, then, a serious subject because mathematics does not necessairly take into account the constant factor of human size, nor the constant factor of celestial size.

When we build a plane or rocket double size we half the distance in lengths to a given constant position.  Bigger is better, sometimes.



///tomcat///

[martin]

Never was I taught anything about expanding or contracting the Universe.  But it is a subject that needs to be brought up and dealt with.

If a rocket is 100 feet high is it the same as a rocket 200 feet high?  Some would say, yes, it will have the same spatial characteristics and do exactly the same thing as the rocket 200 feet high.  Believe me, I have been told this by very respectable people.

All else being the same between the two rockets, i.e., the one is exactly proportional to the other in all regards, then the smaller rocket should only be capable of a payload of 1/2 the larger rocket.  Now, the two rockets are not the same.  The larger rocket carries twice as much payload.

There is a constant at work here.  Namely, you and I.  We have remained exactly the same size regardless of which rocket we are talking about.  Now, a relation has sprung into being with regard to the two rockets.  Relative to us, the smaller rocket is the smaller rocket and the bigger rocket is the bigger rocket, regardless of proportions or calculations.  Therefore, we regard the payload to be 'bigger' on the bigger rocket because the size of the objects in the payload are designed for our use and their size has not changed, but remains constant with regard to us.

A more tricky version of this expansion/contraction problem are the performance capabilities of the two rockets.

Will the bigger rocket out perform the smaller rocket.  Calculations say it should do the same thing since all that has changed is size, not proportion or ratio of fuel and components.  Now we have the problem of 'measurement'.  A 'measurement' has to be constant because you and I are standing at the pads and our size has not changed.  The size of the Earth has not changed, nor has distance to the Moon and various planets.

One foot is one foot, is it not?  The one rocket stands 100 feet and the other 200 feet in length. The Moon is, say, 300,000 miles away.  Or, in terms of feet, the Moon is 1,584,000,000 feet away.  The 100 foot rocket is 15,840,000 lengths from the Moon and the 200 foot rocket is just 7,920,000 lengths from the Moon.  Rocket lengths takes into account the static proportion and should be the same for both rockets.  If, now, the rocket is capable of flying exactly 7,920,000 times its own length then the 200 foot rocket is moon capable while the 100 foot rocket can only go half way.

Why is this?  Because, from the perspective of the rockets themselves, the Universe has changed.  It is 1X for the 100 foot rocket and 1/2X for the 200 foot rocket.  We don't see the Universe as changing because our body's dimensions haven't changed at all.  But the rockets are the same in all regards except for their dimensions.  The two rockets have different dimensions.  The different dimensions makes lengths different relative to celestial distances.  It is simple fact.

It is a wrong fact. When you change the unit of distance, did you forget to change also units for force of gravitation and force generated by rocket?

The 100 foot rocket will only go half as far as the 200 foot rocket.  This is why a one inch rocket cannot keep up with a Saturn V.  I don't care how hard it tries, it cannot go as far or carry as much.

Universe contraction & expansion is, then, a serious subject because mathematics does not necessairly take into account the constant factor of human size, nor the constant factor of celestial size.

When we build a plane or rocket double size we half the distance in lengths to a given constant position.  Bigger is better, sometimes.

Now I know why americans can get to the moon before soviet union. Moon is 380,000 kilometres from earth, but only 238,000 miles...

Martin

[Bob B.]

The 100 foot rocket will only go half as far as the 200 foot rocket.

This is incorrect. If both rockets have the same mass ratio, payload ratio, thrust-to-weight ratio, ballistic coefficent, specific imupulse, etc., their performances should be the same, i.e. they should attain the same velocity.  If both rockets reach the same velocity, they should both travel equally as far regardless of size.

This is why a one inch rocket cannot keep up with a Saturn V. I don't care how hard it tries, it cannot go as far or carry as much.

I agree that a small* rocket can't carry as much as a larger rocket, but it should be able to go just as far.

* Note that I wrote "small" rocket, not "one inch" rocket.  Let's keep the discussion reasonable and stick with your 100' and 200' example.

[tomcat]

The 100 foot rocket will only go half as far as the 200 foot rocket.

This is incorrect. If both rockets have the same mass ratio, payload ratio, thrust-to-weight ratio, ballistic coefficent, specific imupulse, etc., their performances should be the same, i.e. they should attain the same velocity.  If both rockets reach the same velocity, they should both travel equally as far regardless of size.

This is why a one inch rocket cannot keep up with a Saturn V. I don't care how hard it tries, it cannot go as far or carry as much.

I agree that a small* rocket can't carry as much as a larger rocket, but it should be able to go just as far.

* Note that I wrote "small" rocket, not "one inch" rocket.  Let's keep the discussion reasonable and stick with your 100' and 200' example.

To help prepare you for my answer let me explain that I was educated as a logician.  Logicians look for 'errors' in systems.  The informal fallacies such as 'appeal to authority' or 'poisoning the well' are often taken as legitimate argument, when they are not.  But, there are other fallacies as well, such as overlooked posits, or undue simplification.

Mathematics is a well developed and very exact and exacting science.  1+1=2, but rocket science is a much, much more difficult adaptation of mathematics.  Gravity is tasteless, ordorless, and cannot be physically touched, but it is placed into the math formulas for rocket travel.

  Gravity is extremely complex:  Certain portions of the Earth have more gravity while other areas have less.  Gravity diminishes with distance.  And, there are many bodies generating gravity "waves" in the neighborhood of Earth.  Even the rocket has its own gravity, a small but not negligible amount.  It has to be taken into consideration for orbital docking.  In fact, no one is quite certain what gravity is.  But it is in the rocket formulas as a static, cut in stone, 32 feet per second squared -- take it or leave it.

Speed is regarded as a simple quantity in those formulas as well. According to the formulas we have to reach escape velocity of approximately 25,000 mph.  Why?  Well, we are escaping from Earth's gravity.  [As explained above gravity has problems too.]  But couldn't we escape the Earth's gravity at a nice steady 1 mph?  If you just keep on going with some kind of steady state propulsion at 1 mph sooner or later you will go so far that Earth's gravity will not bring you back.  It is our propulsion system that is requiring the inertia of 25,000 mph, because it is assumed that the thrust will have to stop soon.  This, gentlemen, is a posit, one not expressly stated anywhere.

Orbital mechanics dictates that we reach orbit first and then transition to another celestial body, the Moon for instance.  Why?  This is saying that we must stop our outward momentum to circle the Earth at approximately 18,000 mph and that, somehow, this is going to make it more fuel efficient to then do a second 'burn' and, then, go to the Moon.  Maybe, it is for the purpose of waiting in orbit for the Moon to come around.  Wouldn't it be better to just use a Moon window in the first place?  Perhaps it is a rest stop for the astronauts so they can get their nerves in order, and a little rest. 

I can see that orbit might preserve the outward momentum, but I fail to see how it enhances it.  Moon gravity is probably the overriding factor here, but we all know of the problem with gravity in these . . . equations.  If we go into a highly elliptical orbit with a very high apogee and low perigee then we might 'bump' into the Moon as long as we don't go so low that we 'burn up' in the atmosphere.  Warp the orbit and gain a little altitude.  This, however, requires a second 'burn'.  Hard to believe it is more fuel economical.  Especially when a third 'burn' is required, then, for lunar transit and a fourth 'burn' for lunar orbit insertion.

Perhaps, it is the motion of the Earth that 'swings' or 'slingshots' the vehicle to the Moon.  But the Earth/Moon system is dominated by the Earth with the Moon going around the Earth.  The Moon would act as the 'slingshot', not the Earth in this instance.  The upshot of this discussion is simply why not get a proper window on the Moon in the first place?  If you want to catch the Moon when it is approaching, so its speed joins that of the approaching vehicle, then simply do it when you are doing the first 'burn'.  Why three more?

Then there is the 'mass ratio' that never changes.  I worry about things that never change.  Mass ratio is a primary determinant of DV.  DV is static for a given task as well.  Our 100 foot rocket has the same ratio as the 200 foot rocket therefore the DV is the same and our 100 foot rocket will carry the same ratio of payload the same distance.  Or, maybe it is the same ratio of payload the same ratio of distance.  Hmmmmm, interesting possibility isn't it?
Would we assume that that the 100 foot rocket is going to carry the exact weight of the 200 foot rocket's payload?  No.  Then one ratio begets another.  Everything is being discussed in this formula as ratios, but this is not expressly stated.  Certainly, our 1 inch rocket cannot carry the same payload as the 200 foot rocket.  And, it won't obtain the speed or go the distance either.  But our 1 inch rocket will carry a ratio payload at the ratio speed the ratio distance.  That we can agree on!

And, while I am smashing marble statues again -- my arms are getting tired -- let's discuss the unfortunate spaceship that can never go faster than the velocity of its rocket exhaust.  If its exhaust exits at 20 miles per second, then the space vehicle is limited to 20 miles per second relative to some body such as Earth.  What is being calculated here is not final velocity.  Rather, it is final acceleration.  Quite a different matter, because the vehicle's speed will continue to rapidly increase just as one would naturally assume.  Again, something got twisted somewhere.  No wonder I get butterflies just thinking about those formulas.  Einstein got paid $50,000 a year back in the 1950's for playing around with formulas relating to pure physics.

Well . . . I am curious as to what replies I will receive.  Hope nobody tries to poison my well!  And, maybe I am wrong.  I hope so, in a way, because if I am right on any point then there has been a lot of waste and foolishness going on.  And, while I talk, mankind is still glued to the Earth!



///tomcat///

[Bob B.]

It's late and I'm tired, so I only want to respond to one thing at the moment:

let's discuss the unfortunate spaceship that can never go faster than the velocity of its rocket exhaust.  If its exhaust exits at 20 miles per second, then the space vehicle is limited to 20 miles per second relative to some body such as Earth.

This is not true; a rocket is not limited to the velocity of its exhaust.  In fact, the exhaust velocities of most rocket engines/motors are in the range of 5,000 to 10,000 mph.  Remember the Tsiolkovsky equation?

delta-V = Ve*LN(Mo/Mf)

Delta-V is equal to the exhaust velocity times the natural log of the mass ratio.  If the log of the mass ratio is greater than one, then the rocket will achieve a velocity greater than its exhaust velocity.  The number whose natural log is equal to one is the mathematical constant e, which is approximately equal to 2.718.  This mass ratio is easily achieved.

[tomcat]

It's late and I'm tired, so I only want to respond to one thing at the moment:

let's discuss the unfortunate spaceship that can never go faster than the velocity of its rocket exhaust.  If its exhaust exits at 20 miles per second, then the space vehicle is limited to 20 miles per second relative to some body such as Earth.

This is not true; a rocket is not limited to the velocity of its exhaust.  In fact, the exhaust velocities of most rocket engines/motors are in the range of 5,000 to 10,000 mph.  Remember the Tsiolkovsky equation?

delta-V = Ve*LN(Mo/Mf)

Delta-V is equal to the exhaust velocity times the natural log of the mass ratio.  If the log of the mass ratio is greater than one, then the rocket will achieve a velocity greater than its exhaust velocity.  The number whose natural log is equal to one is the mathematical constant e, which is approximately equal to 2.718.  This mass ratio is easily achieved.

You did not say that, I know.  I read it someplace.  Actually, I seem to remember that it said the spaceship would reach some constant velocity, not necessairly the thrust velocity.  Maybe, it was the Relativity thing of close to the speed of light.  But I don't think so.  It was, I believe, a claim that speed must max out in a vacuum away from gravitiational affect.



///tomcat///

[Bob B.]

You did not say that, I know. I read it someplace. Actually, I seem to remember that it said the spaceship would reach some constant velocity, not necessairly the thrust velocity. Maybe, it was the Relativity thing of close to the speed of light. But I don't think so. It was, I believe, a claim that speed must max out in a vacuum away from gravitiational affect.

I really don't recall saying directly that there's a maximum velocity that can be achieved.  What I did say was that there are practical limitations to how high you can make the mass ratio, which of course limits the velocity.  From what I've seen, I'd say the maximum mass ratio is about 20, but this is with no payload and using dense fuels with lower specific impulse than obtained with lightweight liquid hydrogen.  About the highest Isp I've seen from a fuel other than LH2 is about 350 s.  Therefore, we can achieve from this,

delta-V = 350*32.17*LN(20) = 33,735 ft/s.

Of course this is just a single stage.  By using multiple stages a higher total velocity can be achieved.  I've never stopped to figure it out, but I'm sure there's a practical speed limit.  The more velocity you need the less payload you can carry, thus you reach a point where it is just not worthwhile to continue.  This limit, however, is due to engineering and manufacturing - not any physical barrier.  One solution to these limitations is to use trajectories that take advantage of gravity assist.

[tomcat]

You did not say that, I know. I read it someplace. Actually, I seem to remember that it said the spaceship would reach some constant velocity, not necessairly the thrust velocity. Maybe, it was the Relativity thing of close to the speed of light. But I don't think so. It was, I believe, a claim that speed must max out in a vacuum away from gravitiational affect.

I really don't recall saying directly that there's a maximum velocity that can be achieved.  What I did say was that there are practical limitations to how high you can make the mass ratio, which of course limits the velocity.  From what I've seen, I'd say the maximum mass ratio is about 20, but this is with no payload and using dense fuels with lower specific impulse than obtained with lightweight liquid hydrogen.  About the highest Isp I've seen from a fuel other than LH2 is about 350 s.  Therefore, we can achieve from this,

delta-V = 350*32.17*LN(20) = 33,735 ft/s.

Of course this is just a single stage.  By using multiple stages a higher total velocity can be achieved.  I've never stopped to figure it out, but I'm sure there's a practical speed limit.  The more velocity you need the less payload you can carry, thus you reach a point where it is just not worthwhile to continue.  This limit, however, is due to engineering and manufacturing - not any physical barrier.  One solution to these limitations is to use trajectories that take advantage of gravity assist.

One of the best ways of meeting the DV requirement is to lighten the load.  Dry mass can be taken to practically nothing by using the correct materials.  A bird's bones are hollow, or almost so.  Titanium is now readily available and easily manufactured into any shape.  Titanium also mixes well with most other metals, allowing for incredible alloy possibilities.  Ceramics are lightweight with incredible thermal properties.  Now they can be bonded directly to metals without glue, or other bonding materials.  The Dept. of Energy found out how to do this with lasers and are trying to sell the metal ceramic bonds to steel manufacturers.

Today, it is possible to make a spaceplane 1/3 lighter than before.  The shuttle not only uses aluminum, a very questionable material for anything subjected to high temperature but is, overall, high in weight compared to what can be done today.  Building a new shuttle, or waverider, twice as big as the current shuttle using the new materials should make quite a difference in the mass ratio and DV.

It may turn out to be a SSTO, but a 'snap in' fuel tank, or two, in orbit and it could go anywhere.  If it turns out that the new design is SSTO then it will probably have a real 2X++ load carrying capacity.  The double size will ensure plenty of room and supplies for an eight person crew.




///tomcat///

[Bob B.]

I agree with much of what you say.  We certainly have more material options than we've had in the past.  Carbon composites are also a strong contender.  The greater strength versus weight of these materials should allow high mass ratios, or alternatively, greater payloads.  I believe SSTO is a very real possibility, but we're not there quite yet.

[tomcat]

I agree with much of what you say.  We certainly have more material options than we've had in the past.  Carbon composites are also a strong contender.  The greater strength versus weight of these materials should allow high mass ratios, or alternatively, greater payloads.  I believe SSTO is a very real possibility, but we're not there quite yet.

Composites of various kinds are an option, I agree.  Nanotubes show great promise in this regard.  The requirements for a spaceplane outer hull are extreme:

1.  Strength -- The material must be able to take direct hits by meteors!  Bulletproof is a minimum requirement.  Polycarbonates are strong but have a problem with their thermal properties.

2.  Thermal --  The material must be able to withstand 20,000+ degrees F!  And, even more incredibly, be able to stay flexible, or at least non-brittle, at near absolute zero.

3.  Radiation -- Materials that stop radiation include lead and beryllium steel.  Lead is very heavy, however, so it must be alloyed in small percentages.


These are tough requirements!  But certain materials in combination or composite may fill the bill.  They are:


1.  Ceramic -- especially corelle because it can really take the heat and, for a ceramic, is tough and strong.  It is used on ballistic missile nose cones.  Silica tiles have a bad reputation but not for reflectivity and light weight.  In those two categories they shine.  So, a combination of these two materials, corelle and silica tiles, make sense.

2.  Metal -- Metals can't be beat for flexible strength and have a reasonable ability to take heat.  But they tend to be heavy.  For a spaceplane's skin tungsten with its ability to take 4500 degrees F without melting is one metal to be considered.  Titanium is almost as light as aluminum but can withstand 2000 degrees F instead of less than half that for aluminum.  Titanium has many very good properties.  Great strength, flexibility, non-corrosive are just a few.  So, titanium makes a good mixer for alloys.  Generally speaking titanium is better than any of the iron steels because the iron steels are heavier and a little weaker.  Beryllium steel is an option.  The government uses it for nuke casings.  It is light and strong and non-corrosive.  It also reflects neutrons which is good for a spaceplane's hull.  Other metals include lead which might alloy in small percentages, otherwise the weight would be too high, with other metals and add to radiation barrier ability of a spaceplane.

3.  Glass -- Sometimes cameras or people just have to 'see' outside the spaceplane.  Glass, then, has to be used.  Polycarbonate is used in planes, but can't take thermal shock, so important if a spaceplane -- hot from reentry -- passes through a cloud bank or lands on a liquid on some alien planet.  Pyrex can take thermal shock and withstand extremes of temperature because it heat sinks when used in large quantities.  It is also extremely strong.  I once took a 'eagle hit', i.e., an eagle slammed into an experimental canopy made of pyrex at extreme speed.  The eagle is a 35 pound bird so it hit hard.  The canopy had no damage whatsoever.  Ordinary canopies break apart with eagle hits, normally.

4.  Carbon -- Nanotubes are a kind of carbon, but still experimental.  They hold great promise, however.  Carbon carbon is used on ballistic nose cones.  This is soft fibrous carbon layed over stiff hard pressed carbon like skin over ribs.  Extremely heat capable, but not as strong as one would like.  If this was, in turn, backed by metal, say tungsten plate, then the carbon could take and stop enormous heat.  Tungsten carbide is used in blast furnaces and drill bits and this combination of tungsten metal and carbon might have uses on the surface of a spaceplane.  It may be a brittle material, however.  This would need to be checked out.


All in all, the materials problem of the outer hull of a spaceplane is immense.  But I believe that much better materials than those used on the space shuttle can be found. 

The shuttle skin is essentially aluminum -- very low meltpoint -- with silca tiles protecting it from the heat.  Silca tiles, however, are very soft and brittle so they tend to break easily.  No really satisfactory method of securing them to the aluminum was ever found, so sometimes they just drop off!

I suspect that a nanocarbon composite skin backed by thin tungsten plate should make the base of the spaceplane's skin.  Finally, ceramic -- corelle with thin slices of silica tiles embedded within it -- should cover the nanocarbon composite to stop the really horrendous 20,000 degree heat of reentry.

There should also be an outer hull and an inner pressure hull.  The inner hull doesn't have to be as tough but should be plenty heat resistent.  Between the two hulls, perhaps a foot apart, air should flow at subsonic speed to remove the intense heat and let it flow out the back of the plane.  The inside of the inner hull should be nomex to stop up to 1000 degrees F.  It would be the last thermal barrier other than the nomex in the astronauts flight suits.  Titanium should be used for practically everything inside because of its reasonable heat taking ability combined with lightness and great strength.



///tomcat///

[tomcat]

If a jogger is 5 feet tall and can jog 5000 feet, then if the jogger is 7 feet tall, and he is exactly the same in proportion to when he was 5 feet tall, wouldn't he be able to jog 7000 feet?  Each distance is exactly 1000 times his height.   Don't older, and bigger, boys run faster and farther than younger, and smaller, boys? 

Why did the Army develop a 155 millimeter cannon when they had a 105 millimeter?  Wasn't it because the larger shell in the 155 millimeter went farther and had a heavier more powerful shell?

But, based on the DV and Mass Ratio formula, we are supposed to believe that size makes no difference when it comes to rockets and aircraft.  We are supposed to believe that you can't double the size of the space shuttle and get significantly greater range and payload.

Doubling size to get significantly greater range and payload would have a profound affect on our military.  If we doubled the size of the f-22 raptor and it flew twice as far with twice as much, wouldn't that be significant?

Doubling size can be done quickly and inexpensively.  Quickly, because blueprints can be refurbished to reflect size increases without new theory or flight testing.  Inexpensively, because today's sophisticated weapon systems have the amortization of the R&D included in their price tags.  The R&D accounts for a larger percentage of the price than the materials.

This has been known for a very long time.  Why did engineers design the B-29 to carry the heavy A-Bomb.  Why not a pint sized version of the B-17 instead?

To understand what is going on with size increases yielding increased capabilities, that is the real question here.  All that I can think of is that everything remaining size X when a vehicle becomes size 2X shrinks distance and increases payload weight because the ratio between X and 2X is not the same as X and X.  With X and 2X you either multiply by 1/2 or by a factor of 2.  When the original is considered everything is X to X, or 1 to 1.  So, 2X isn't the same as 1X -- is it?

That makes sense doesn't it?  1 is not equal to 2, or have the rules of mathematics changed since I was in school?

Is a dog the same as a cat?  Do car salesmen tell the truth?  Are we living in a black hole?  Ask the smile without a cat about that one!  And, by the way, which side of the looking glass are we on?  Both sides.  Really!


///tomcat///

[Bob B.]

Why did the Army develop a 155 millimeter cannon when they had a 105 millimeter? Wasn't it because the larger shell in the 155 millimeter went farther and had a heavier more powerful shell?

In a vacuum and at the same muzzle velocity, a 155 mm shell will travel the same distance as a 105 mm shell.  A 155 mm shell travels farther through air because it has a higher ballistic coefficient (Cb).  Drag decelerates a projectile with a high Cb less than one with a low Cb.  Remove drag from the equation, and size no longer matters.

In rocketry you want to get above the atmosphere as quickly as possible to mitigate the effects of drag.  Most of the acceleration is done above the thick atmosphere.  Once in orbit, all subsequent maneuvers – TLI, LOI, and TEI for example – are performed in a vacuum, so drag is a non-factor at this point.

Why To understand what is going on with size increases yielding increased capabilities, that is the real question here.

Size does increase payload capability, but not necessarily velocity.  And it is velocity that determines how far you can go.

Let’s say we’re on the Moon (so that we don’t need to worry about drag) and we through a rock straight upward at an initial velocity of 10 m/s.  Since we know the acceleration of gravity on the Moon is 1.62 m/s², we can easily calculate the height to which the rock will rise before it starts to fall back to the ground.

v = at ----> t = v/a

t = 10/1.62 = 6.2 s

d = at²/2

d = 1.62*6.2²/2 = 31 m

The rock will rise to a height of 31 meters; it makes no difference what the rock’s physical dimensions are or how massive it is.  All that maters is how much initial velocity we gave it.

[Satanic Mechanic]

  Why did engineers design the B-29 to carry the heavy A-Bomb.  Why not a pint sized version of the B-17 instead?

Actually the B-29 was originally designed under the 10,000 mile range/10,000 lb bomb load plan in 1939 (came up short).  Enola Gay and Bock's Car were B-29's that were modified/stripped down to practically nothing to accomadate Little Boy and Fat Man.

[tomcat]

  Why did engineers design the B-29 to carry the heavy A-Bomb.  Why not a pint sized version of the B-17 instead?

Actually the B-29 was originally designed under the 10,000 mile range/10,000 lb bomb load plan in 1939 (came up short).  Enola Gay and Bock's Car were B-29's that were modified/stripped down to practically nothing to accomadate Little Boy and Fat Man.

Little Boy and Fat Man were big bombs.  Later A-Bombs and H-Bombs were much smaller and lighter. 

The B-29 was an impressive plane.  I still am impressed when I see it in the movies, flying high with vapor trailing from its wings.  It kept the United States safe for many years.


///tomcat///

[Bob B.]

Enola Gay and Bock's Car were B-29's that were modified/stripped down to practically nothing to accomadate Little Boy and Fat Man.

Bockscar's current home is here in Dayton at the USAF Mueseum.  It's an eerie feeling to stand next to it knowing it is the actual plane to drop Fat Man on Nagasaki.