IDNeon

Elon Musk can't get anyone to even the Moon.

Do you think space travel is magic? Has anything changed since Apollo? Physics maybe? 

Absolutely not.

dV hasn't changed. Rocket engine thrust hasn't changed. Nothing is "magically" more efficient than it was in 1960s.

So is Musk capable of spending the roughly 30billion dollars per launch it will take to get a small Apollo type craft to the Moon?

No.

2 hours ago, exchemist said:

Yes, this is how it is possible for divers to go down so far, as long as the gas mixture they breathe is at the pressure of the surrounding water

I'm familiar with that but not with the taking a diver from 1atm then exposing them to say....20atm suddenly.

And I'm curious if that's physiologically possible.

For instance if you put a free diver out of a "hydrolock" then do they have their ears rupture? Gasses still inside them burst out rather than squeeze out over time as they descend?

Another way of asking this (more practical in physics) is...

If I have a pressure vessel at 1atm with water filling it, and an outside pressure of 10atm.

If I open a valve....will it take a period of time for the pressures to equalize or will it be instantaneous? 

59 minutes ago, John Cuthber said:

It has a measured half life of 0.098 seconds.

Observation trumps "theory

Lol what? Copernicium294 hasn't been produced in a public setting.

Theory isn't 1000s of orders of magnitude off of reality. If the Japanese Nuclear industry says its expected half life is 300 years then its expected half life is 300 years.

https://wwwndc.jaea.go.jp/CN14/sp/

1 hour ago, John Cuthber said:

It has a measured half life of 0.098 seconds.

Observation trumps "theory".

Observation says that a respected naval engineer who has TS-SCI clearance stated matter-of-factly that Russians are using hundred-twelve element batteries.

How about you look past your own nose and start answering that.

Feel free to explain what kind of logical mistake that could have been.

What else is a "hundred-twelve" element battery.

Did he say element when he meant cells? Do you think THAT is practical? 

But to be honest I thought somewhere I heard 20% of US power was going to aluminum. Maybe that was all industry. Either way I'll reneg some on the idea aluminum is a back breaking consumer.

1 minute ago, swansont said:

15 kwh per kg, or 15,000 kwh per ton

This is what I meant. I'm actually a little preoccupied at this very moment and was driving 10 minutes ago (I have a bad habit).

So I didn't reconstruct my own Google search on this.

But if you just reverse what I originally said with dividing by 1,700,000 it'd come out to that per ton figure. Was just some back of napkin stuff. 

8 minutes ago, swansont said:

Your number is a tad high

It maybe varied with the years? I went with US aluminum tonnage per year. 1.7 million tons smelter.

I based the power use on Alcoas claim of 13kw per ton. Or 15kw per Ton industry average. 

I only picked aluminum as an example of an extremely high single use of electricity. 

Not intending it to be thought of as the sole use of US energy. Perhaps I should have clarified that part.

1.5% of all production for one use is really high.

Just now, swansont said:

TW and GW are units of power, not energy. TW per year is not a meaningful unit

Maybe not but it can be converted. Power plants are rated in terms of exactly that. So how much average electricity is produced by a 1GW nuclear reactor per year? 

Revised figure for aluminum production is 28.9Gwh consumed per year

54 minutes ago, zapatos said:

Now you are just being asinine.

Do you know how many welds have to be reseamed every dry dock just to keep a 20 year HSLA steel hull from breaking apart in moderate to rough seas? (Greater than 8ft waves).

By 35 years of life it takes something like 90% new welds.

Most of the US DDG fleet has already become a fair weather navy

47 minutes ago, zapatos said:

In which case I am not 100% wrong. Thanks for confirming

Why even bring up the Arleigh Burke then? 

The Kirov would literally sink the entire USN fleet of carrier screen Destroyers in one Salvo.

All of them. 

With missiles to spare for the rest of the group.

And there's no good defense against the Granit

Just now, zapatos said:

So you mean in 12 years when we are at "peak mission capability" of the AB? That's when they'll no longer be functional?

I don't care that they are functional now. They won't be continued in the future navy. Their roll is given to submarines.

2 minutes ago, zapatos said:

No thanks.

Are you 60 years old and unable to change? It's literally the Navy lecturing on their next 20 year plan and fleet composition.

2 minutes ago, zapatos said:

So when you said I'd be "100% wrong", you meant I'd be 100% wrong in about 20 years. I can't tell you how shocked I am to learn that a statement I made about our current military capability won't be accurate 20 years from now.

Perhaps you overstated things just a bit.

Not my fault that you think you're right when you're wrong. 

My specific statement was that the new Virginia type will be taking over the roll of all DDGs in the Navy.

Then you said something along the lines of "what about the Arleigh Burke, still making those."

To which I said you're wrong.

The Arleigh Burke is not a part of the future roll of the Navy.

I don't really care that you think you're right because of 12 years (not 20 years) from now.

45 years for a steel ship is like sailing around on a mouse trap.

The ship is more likely to break in half than make it to its patrol zone.

The bigger problem is there's so much oil they don't care if they get all of it.

There's so little gold they want all of it. 

Usually a microgram per ton.

How will these hypothesizers chelate a ton of impermeable rock?

6 minutes ago, zapatos said:

Got anything besides Youtube?

It's a CSIS lecture from the office of Naval budget 

It's more than sufficient.

6 minutes ago, zapatos said:

When will they be gone?

https://news.usni.org/2018/04/12/navy-will-extend-ddgs-45-year-service-life-no-destroyer-left-behind-officials-say

Because we are running the Arleigh Burke into the ground, literally in some cases. The peak mission capable number of ABs is at 2033.

At which point US will lose 3 a year. Because maintenance of a ship increases with age the attrition rate is actually higher.

But by 2033 the US will have approximately 18 Virginia type replacements to cover the loss of ABs. So they will probably retire 6-12 rather suddenly in 2030s.

The problem I always see in these threads is the solution doesn't work for anything but houses.

It's as if the people think house consumption of electricity is the paramount use of electricity. Makes sense. That's how we are all taught to think. In terms of household kilowatts.

US aluminum production uses 25.5 Terawatts per year.

That's 2,550 Gigawatts.

OK?

That's 2,550 Nuclear power plants on average. 

Rooftop solar isn't going to cut it.

Also lightning destroys grid-level equipment. 

What will you replace SF6 gas switches with? Or anything else needed to transmit power? 

HVDC at 400,000 volts maybe travels a hundred miles or so before it is all lost.

You can't just build a giant lightning rod and then GET that power to your wall outlet. 

You would need a *queue Electroboom* Full bridge rectifier between every node and transmission to convert DC to AC.

And this very sensitive equipment will explode at the some 1million Vots DC hitting a node.

Can we get off the semantics and onto the topic again?

I am interested in the idea but biggest flaw seems to be the 91atm pressure vessel.

How big does it have to be? I have the equation for this if I know the internal diameter. But likely it will be 0.05meters thick of titanium.

Other problem. At what temperature? 

Metallurgy is a limiting factor.

US solved hydrogen problems and the solutions centered around solving metallurgical problems.

Are you keeping hydrogen at 91atm down stream?

If not how does Metallics react to change from -400C to whatever temperature the hydrogen reaches at this pressure? 

Engineering problems always have solutions. 

So I'm less interested in the specifics and more interested in how it integrates into the whole system.

12 minutes ago, zapatos said:

Hmm. I thought we were still building them.

https://en.wikipedia.org/wiki/Arleigh_Burke-class_destroyer

At end I provided citation. Watch it 

Nope. But don't get me wrong. Navy is a COMPLEX machine. Planning usually takes 10 years and ship building another 5 to change gears. So most plans are 15 year scopes.

What you're seeing is a winddown of the Arleigh Burke build-run.

So a few things.

1) Navy has ceased the Destroyer concept in 2017 and will be replacing it with new Virginia type submarines. But the first VPN is laid in 2021 (now).

2) AB construction continues both because it was budgeted some years ago but also because as older keels age out the new keels replace those. So if you have a life span of 20 years and want 80 you need to build 4 a year for the entire time you want to maintain 80.

The US will let the AB age out.

The new fleet is in Flux. 

USN admits we need 1trillion from 2017 to 2027 just to replace the Ohio.

That is their PRIMARY concern.

They have been unable to figure out what to do with the fleet composition problems as a result of this paramount crisis. 

The USN admits this has happened only 2x before in the history of the Navy. It must happen. So they are Willing to sail the conventional fleet right into the shallows if they have to to achieve this transition. 

I think the new fleet composition will be submarine heavy. It won't look le anything of the past.

They want UAV "long arms" to give submarines great aerial operations at depth and they want to put AA missiles on board new Virginia types.

The USN rightly asses two things. 

In the Era of ship launched ship-to-ship missiles a surface ship is a liability. 

Long range stand off cruise missiles make fleets obsolete in peer-competitor engagements.

So a fleet needs to identify and destroy Russian T-160 bombers bombers 3000 miles away.

A carrier is needed to project US sea power inland.

LDH or LPHs are needed to land divisions in hostile beaches.

That means a carrier screen will be more lethal and much larger range as Virginia Submarines get on station and provide air defense air defense 2000 miles away.

There will probably be a Destroyer replacement but I have no clue what it will look like...most likely massive ASW and point defense.

https://youtu.be/yfrrYcphFBo

Personally I think the US needs a few more LDHs and it should be a hybrid with an VTOL airwing tabletop.

But it needs a wet deck not helicopters.

This type of LDH allows for very massive flexibility which is the only way to cost save. 

The US needs to maintain carrier shipyard skill so it needs one in continuous production. But like a reactor in scram it needs to be at the smallest amount.

Offset that with LDH to compete in depth missions.

In the citation I gave the USN is using the same equipment going into a carrier to put into submarines so the cross compatibility to save cost is enormous.

A few ASW/point defense screen. A super carrier. An LDH. And a submarine AA/Anti-ship screen operating a distant UAV/UUV capability will be the most likely future for USN.

Because the Russians can project power from its borders it doesn't need Aircraft carriers.

So the Kirov makes sense for a capital ship.

The thing is a lion poised to kill a carrier group.

China will probably attempt the hybrid. A BC and Carrier fleet. 

But they haven't worked out the carrier yet and are waiting to see what the Ford does.

Look. Musk is NOT a genius. As a person intimately involved in his Gigafactory debacle:

1) his factory is STILL at 25% capacity. Panasonic rightly took over most of the slack making bank of Musks flaccid manhood.

2) lithium ion tech was ALWAYS a dead-end. It's still a dead end for the same reasons now...there's not enough of it and the Chinese own most of it.

3) Capital structure locks TESLA into a death spiral as technology moves away from Li-ion and other car companies move into hybrid solutions for EV vehicles.

Why does this matter for SpaceX?

1) Dragon capsule is a spruced up Apollo/Soyuz design. Nothing new. Actually it adds a significant problem glass cockpit.

2) SpaceX dV = 1/4th what is needed to get to moon. 

3) SpaceX has NOT moved the cost of orbit per lbs (or more accurately dV(m/s) per kg), one cent.

Not one F-ING cent.

4) SpaceX became so "big" because China took 75% of the orbital launch business in-house. Small fish in a shrinking pond.

5) SpaceX just got its teeth kicked in by Northrup Grumman which just changed space commerce forever with Mission Extension Pods that can repair spacecraft at even Geostationary orbits.

Nobody wants to launch new satellites. They just have to.

Well not anymore. Thanks to Northrup Grumman. Which actually went to the moon by the way. Unlike SpaceX ever will.

So what the HELL is the US giving 1% of the total funds needed to get to the moon and die there? (Approximately 200billion US dollars in FY2021 dollars to build enough dV to get to the moon and not get back).

Why is the US government wasting US tax payer money on a f-k'ing fraud who has achieved nothing new and CANNOT complete the mission?

Corruption at the highest order.

Giving billionaires billions for nothing remarkable. 

The Space Shuttle was remarkable.

Musk is going backwards and begging for a methane rocket so he can cut costs because he can't handle Hydrogen.

But Methane can't handle dV to the moon.

Let alone Mars.

What a charlatan and a waste of US money.

1 minute ago, exchemist said:

If the pressure is equalised throughout the object, i.e. with no spaces at a different pressure, then merely a bit of compression of the materials of which it is made. 

Awesome. My intuition is correct but I wanted to bounce it off more physics minded persons.

The OP will want to watch this:

The US can barely afford to replace its aged out submarine fleet both Virginia and Ohio classes are now "end of life".

The plan is to build 1, OR, 1 VPN each year or 2 VPNs in an off year while maintaining the construction of 1 carrier per every 5-6 years or so.

This commitment has basically prevented the US navy from building any other ships.

Everything you THINK you know about Naval armaments is garbage. Laser beams are my little pony magic rainbows. Rocket propelled artillery....rail guns. Missile to missile interceptors. This is all dog ****.

Right now the US would grossly lose a naval war to Russia and maybe even China but china's strike power comes from land based assets still. They haven't been able to put their most capable antiship missiles to sea. But Russia has and Kirov shows it off extremely well.

Russia and China both invested in the future of Naval warfare while 20 years of low intensity conflict in the middle east drove the US to develop longer strike power against static, no moving, non-reacting and non-technically competent terrorist targets 200+miles inland.

Now the US has THAT advantage. But it needs to play catchup to Russia in particular. Which built a navy to sink the US Navy while the US Navy built a Navy to blow up airfields in Syria.

The USN next big step is to replace the Destroyer fleet commitments with Virginia Submarine replacements firing 40+ cruise missiles thereby replacing the loss of Destroyers as they age out.

On 4/12/2021 at 9:24 PM, zapatos said:

I suspect ballistic missiles and cruise missiles from submarines are not very cost effective and will be limited in number

Your suspicion is 100% wrong ironically.

To save cost the US is retiring the surface DDG fleet and offloading all of its capabilities to submarines.

On 4/10/2021 at 2:15 PM, Moontanman said:

A battleship was once supposed to be used for fighting other ships but that seldom happened, only once or twice in WW2

This is a gross misunderstanding of Naval warfare in WW2.

Battleships and fleet engagements were common and destructive. Sources of damage seemed almost random and luck of the draw at the time.

The Japanese midway task force was badly beaten by dive bombers.

But the Allied fleet at Savo Island was badly destroyed by a Japanese Destroyer.

Japanese Submarine I-19 sank one US fleet carrier, one battleship and one Destroyer in one shot.

The USS Tang is the only Submarine gifted the honor of blowing itself up with a circular-misfired (imbalanced propulsion) torpedo.

So the idea that battleships didn't just line up broadside and shoot each other in the face is irrelevant. 

It's a team effort and the WHOLE team has to he 100%

On 4/12/2021 at 10:37 AM, SergUpstart said:

For example, there have been reports on the Internet that China is developing ballistic anti-ship missiles with a range of 2,000 km

How are you going to coordinate this attack from 2000km away. You have to find the fleet. You have to communicate its course. You have to hit it with a nearly 100% CEP. And it still doesn't achieve Chinese grand strategy of securing the 2nd and 3rd island chains?

The course is most important. It's one thing to plot a firing solution against a target 2 minutes away. It's another to plot a firing solution. For a target 1 hour away.

How powerful are these 2000km bombs? 300kg maybe?

Each one MUST strike its target and each target is 2 miles apart. (2NM is the usual MINIMUM distance of fleet ships spacing, all courses are determined by this principle).

There's things that sound cool on paper. 

But you can generally see what the US is concerned about in their public hearings on budget matters.

They are principally concerned about acoustic superiority and maintaining mission tempo.

They aren't concerned about Chinese land based ballistics. 

The Russians have solved this problem but for much shorter ranges. 100km mostly.

Or better said...10 minutes distance.

What are the stresses imposed on any object when equalized this way? It seems there would be very little?

This is where the island of stability is an important statement I buried in there.

Turns out Cn-294 has the "theoretical" half life of 300+ years. But really it just depends upon WHICH of the stable isotopes is most easily synthesized. I haven't found the "theoretical" synthesis of those isotopes yet. 

But it's most likely been found. There's no way around what was said. And this wasn't some "high school" teacher either. They're an expert in their field with a Top Secret SCI clearance.

OK. I really want to know something about equalizing pressures at deep ocean.

Specifically what happens if you are in a hydrolock (as I'll nickname it, think of an airlock) and you fill the hydrolock with water and absolutely no airbubbles remain, then you open even a small valve to the outside pressure to "equalize the pressure".

What I described is a torpedo tube. And it stands to reason that nothing happens.

But my mind keeps going back to the engineering principle of waterhammer.

If you have water at 1atm and you have water at 100atm and you bring them together, how do you NOT get a waterhammer?

So in the torpedo tube example what is the forces inside the tube when you have it completely flooded at 1atm, then expose it to 100atm.

Water is non-compressible so in theory NOTHING happens. But then:

1) you have an equalizing valve (why?)

2) the noncompressibility is precisely the waterhammer problem on pumps when you take water at lower pressure and stop its flow cause a spike in pressure.

Can someone discuss the nuances in this example?

So what happens when you have to build an actual ramp and it doesn't look flat at all?

The ability to abstract is the point of all education. Generalization is the goal of mathematics.

Some things are more easily understood if not abstracted or generalized but then how are you any better than a sheep herder counting stones to keep track of all his sheep? 

A sheep herder would never make it to the Moon.

Remember. Egyptian mathematics was binary based and ingeniously simple for mental calculations.

Look what they accomplished with it.

Absolutely nothing. 

The pyramids got us as close to powering a light bulb as it did to getting us to the moon.

If the pyramid were built atop Everest then maybe some new accomplishment could be recorded in the history of the world.

If I had a choice of flying on an airplane in turbulence with screaming babies or a crackling tesla coil that moves like a wobbly hoverboard....I'd choose the f-ing jet engine.

OK?

Technology is people dependent.

I don't want to sail a submarine on hydrogen peroxide either. Sure it's fantastically better physics. 

But it explodes easily.

Which is why the Russians called such submarines cigarette lighters and the UK sailors literally named theirs "the Exploder".

Neither Navies continued the effort because people wouldn't put up with them.

So your ionocraft is a waste of time. No one wants to fly to see Grandma in a Faraday cage being struck by lightning 1000x a minute. 

Did anyone see "Ford vs. Ferrari"?

Really great movie. Can you imagine selling the ideas to the CEO of Ford? 

"People are going to love it. Real fast car. Just punches you in the crotch ultra fast. Blows your ear drums. Amazing speed. Phenomenal technology. Ruptured testes."

I think a saucer has as much relationship to anything as my idea of blowing smoke rings will make a toroidal plasma magnetic bottle work.

I.E. not at all related. Just because something looks related (a smoke ring looks like a toroid) doesn't mean it'll make a more efficient torus.

The work in a fusion reactor (mathematically) happens mostly in a small part of a torus and looks like a banana.

Does that mean I should throw bananas into my reactor to improve its yield? 

I personally don't think wormholes are at all practical and is stupid waste of braincells.

"Throw your self into a blender. Because your blended self contains all the same information as a pre-blended self, arriving to cousin Vinny's house in a seeping box of blood and torn flesh and pulverized bone is the same as showing up black tie for Christmas dinner!"

Worm holes are some of the most useless ideas in physics.

The fact that all it does is attract people like bongbOng is pretty evident of the vacuous uselessness of it.

We should figure out how to get to a wormhole in a single lifespan of a star, before we bother theorizing how to go through one.

It would take more than one trillion years to reach the center of the Galaxy using even solar sails optimally.

Hate to tell you but that's like 100x older than the universe. 

I don't know where to post this but physics is most popular and these batteries are "high powered".

I don't think they are theoretical either. I think they are highly classified and I'll save you the story but I think someone in a lecture on deep sea submarines accidentally revealed their existence. 

Their words "...and two, one-twelve element batteries..." was casually stated in listing off the specifications of a declassified briefing on a specific Russian submarine.

This got me thinking what was meant. I'll spare the research and give you the conclusions. I'd love to see others help reverse-engineer this hypothesis further.

Tl;Dr-

291Cn + 6HF -> CnF6 + 6H(+)

I'm not prepared to share every source I found to come to this conclusion but I'll summarize.

Copernicium is stated to be a relativistic noble liquid same as Lead-Acid therefore one paper briefly suggested it is possible it behaves chemically similar to lead-acid.

Lead-acid reduction potential is 1.69v.

Cn(2+)/Cn reduction potential is 2.1v

Already comparable to the stronger grid-level storage batteries (molten salt).

Lead-acid yields 2O(-) ions in the reaction.

CnF6 would yield 6F(-) which beats the pants off Li-ion.

CnF6 is theorized to be stable. As is CnF4 (and theorized to behave like HgF4).

Cn is supposedly highly radioactive but it's only alpha decay so that should be manageable right? 

291Cn and 293Cn are theorized to be islands of stability. They should have half lifes greater than 10 years. 

So in my estimation...a 291(293)CnF6 battery is completely possible and the only reason it's not well known is its expense to create makes it limited to governments who have a specific need for it.

Higher reductive potential means better batteries. 6F(-) means huge kilowatts per weight. In terms of molten salt grid storage a Cn battery could be 150% better than those.

Which would explain why the US government has politely disregarded the molten salt potential.

300kw = 400hp roughly and can provide 5knots.

That is more than achievable with lead-acid so for submarines needing more tactical speed, a flouride battery makes more sense.