For Questions That Don't Merit Their Own Thread

[farmerben]

Question:  What are the oldest functioning batteries?  

Batteries have been a commercial product for close to 150 years now and all sorts of chemistries work, some very heavy by today's standards.  I wonder which ones are the longest lasting with functionality, this is an important question for spaceflight too.  Could you make batteries that last a century?  Is there a tradeoff between longevity and weight?

[StrandedonEarth]

3 hours ago, farmerben said:

Question:  What are the oldest functioning batteries?  

Batteries have been a commercial product for close to 150 years now and all sorts of chemistries work, some very heavy by today's standards.  I wonder which ones are the longest lasting with functionality, this is an important question for spaceflight too.  Could you make batteries that last a century?  Is there a tradeoff between longevity and weight?

Google is your friend...

Oxford Electric Bell - Wikipedia

[magnemoe]

3 minutes ago, StrandedonEarth said:

Google is your friend...

Oxford Electric Bell - Wikipedia

This, note that this is not rechargeable and not efficient but long lasting. with an very tiny power drain. This is not very useful except having an timer running for an probe to wake up for an flyby, problem is that it then had to use some other sort of power source for doing stuff at target. 
Modern batteries are not that horrible in power density if you don't have air and LOX is not an option. 

[kerbiloid]

The Earth is a big RTG, full of isotopes.

[DDE]

So it's more or less understood that tooth fillings have potential as accidental (oh my gosh, that's terrible) AM radio receivers.

Can perceptible sound be induced or by a solar storm (catastrophic magnitudes included), or am I a failure at physics?

Edited March 11, 2024 by DDE

[darthgently]

3 hours ago, DDE said:

So it's more or less understood that tooth fillings have potential as accidental (oh my gosh, that's terrible) AM radio receivers.

I saw that Gilligan's Island episode back in the day.  Good one

[kerbiloid]

16 hours ago, DDE said:

Can perceptible sound be induced or by a solar storm

Only giggling.

Spoiler

 

[Terwin]

I thought that was just having a conductive path through the silver of the fillings that was the right length to pick up radio waves of the right frequency (possibly conducting it to the nerve for lots of fun)

So both radio and solar storms would just add an electric charge to part of the tooth.

 Solar storms received by radios sound like louder static if I recall correctly.

[kerbiloid]

More important question is: can it access the cellphone network, and if yes, how to input the phone number.

[SunlitZelkova]

So I’m assuming when I write some space alternate histories I can take liberties with the way some celestial events happen. For example, I assume asteroids bouncing around the solar system during its early era was so chaotic, an asteroid or comet (I can’t remember which I was told it would be off the top of my head) could have hit Mars and given it the thick atmosphere needed for the 1950s glider missions to succeed.

But what about solar activity? Is that pretty random (like how weather can be plausibly altered in alternate history) or is it something you can expect to happen no matter what? Kinda like how the isthmus of Panama was always going to form, and you can’t really write it away without going into fantasy territory when it comes to tectonics.

I ask because there was a big CME in 1973, which would have ruined the Apollo Manned Venus Flyby project. I’m wondering if an alternate history in which it succeeds would be more realistic writing away the CME or just having the astronauts all die.

Edited March 15, 2024 by SunlitZelkova

[kerbiloid]

https://en.wikipedia.org/wiki/Solar_cycle

https://en.wikipedia.org/wiki/List_of_solar_cycles

[SunlitZelkova]

@sevenperforce, in the SpaceX thread you said fusion propulsion could be done with the political will to do so.

Two questions-

1. Are there any good articles you know of that can introduce a laymen to this particular type of propulsion?

2. About how long has this been feasible? That is, what’s the earliest date we could have started working on it had the political will been there? Asking for my alternate history where there is more dedication to spaceflight in the 20th century and the political will might be there by the 2000s or 2010s.

[kerbiloid]

The oilers would arise in advance.

[AckSed]

The first Z-pinch machine was ZETA, in 1957. It did not end up working, but the British government thought it had: https://www.iter.org/newsline/-/2905

The Centauri Dreams blog has multiple articles on fusion drive: https://www.centauri-dreams.org/?s=fusion

That led me to this Popular Mechanics article from 2012 on pulsed fusion drive (which is what a Z-pinch essentially does - pulses of fusion explosions): https://www.popularmechanics.com/space/rockets/a7715/the-big-machine-that-could-lead-to-fusion-powered-spaceships-9450996/

With regards to an alternate history, fusion is a dense subject that is filled with failures and lessons learned. You would need steady funding, a willingness to take risks with almost certain knowledge you aren't going to get it right the first or fifth time, perhaps a nuclear reactor for power and, ideally, a reasonably-affordable heavy-lift launch system to test it in space.

[ARS]

Since planes have generations (for example, F22 being 5th generation fighter), does warships also have generations on how they developed over the ages? If so, what's the current generation we're currently at?

[SunlitZelkova]

38 minutes ago, ARS said:

Since planes have generations (for example, F22 being 5th generation fighter), does warships also have generations on how they developed over the ages? If so, what's the current generation we're currently at?

No.

Warship classes simply have predecessors and successors.

The reason "generations" of fighter aircraft came about was mainly because of the bird [lol, this is getting auto moderated and changed to bird] for tat development of aircraft during the Cold War. US develops F-100 to counter MiG-15, Soviets develop MiG-19 and 21 to counter F-100 (although bomber interceptor was the primary role), Americans develop F-4 to counter MiG-21, Soviets develop MiG-23 to counter F-4, Americans develop Teen Series to counter MiG-23, Soviets develop MiG-29 and Su-27 to counter Teen Series.

(If the Cold War had not ended, perhaps we would be seeing sixth gen fighters entering service now, having gone through the F-22 vs. MiG-29/Su-27 and then MiG-1.44 or Su-57 vs. F-22 in the 2010s)

A similar dynamic existed with tanks, which is why the M1 Abrams is a 3rd generation MBT. The Americans develop the M60 to counter the T-54, the Soviets upgun the T-62 from 100 to 115mm to counter the M60, the Americans develop the M1 to counter the T-62... later upgraded to counter the T-72. It kinda ended there though, which is why the Abrams' design dates to the 1970s.

The Soviets had a 152mm upgunned T-80 in development called the Object 292, which perhaps might have kicked off the race for a 4th gen MBT in the 90s had it entered service, but it didn't escape the collapse of the USSR.

Tanks like the Type 10 and K2 have been called 4th gen, but it is questionable because they are just better versions of third gen designs (namely the Type 90 and K1).

In contrast, ships have not been designed to specifically counter other nation's ships since the 1930s. Since the end of WWII, new ship classes are mainly designed around carrying new technology for countering all ships, not just one specific class. Ships also vary greatly between nations, for example, with Russian ships focusing on the anti-surface warfare mission, American vessels on land attack and ballistic missile defence, and Japanese ships on ASW.

Edited March 29, 2024 by SunlitZelkova

[ARS]

3 hours ago, SunlitZelkova said:

No.

Warship classes simply have predecessors and successors.

So it's simply about arms race?

[magnemoe]

7 hours ago, SunlitZelkova said:

No.

Warship classes simply have predecessors and successors.

In contrast, ships have not been designed to specifically counter other nation's ships since the 1930s. Since the end of WWII, new ship classes are mainly designed around carrying new technology for countering all ships, not just one specific class. Ships also vary greatly between nations, for example, with Russian ships focusing on the anti-surface warfare mission, American vessels on land attack and ballistic missile defence, and Japanese ships on ASW.

I agree, ships today are not designed to counter  other ships. Think last was the Alaska  class with 12" guns, this was designed to counter enemy heavy cruisers with 8" guns, who was the original battlecruiser idea who fast got battleship level guns, then become fast battleships. 
Now back from the ironclads up to 1930 it was common for ships to basically have generations of cruisers and battleships.  with requirement for gun size armor thickness and speed growing. 

Now its ships designed to counter other ships like, but not on an generation level anymore. All destroyers can hunt submarines, newer or better one simply do this better. 

[DDE]

7 hours ago, ARS said:

So it's simply about arms race?

It's actually about marketing, really. The fifth generation label was invented by LockMart and the rest made up post-factum, although the classification isn't too terrible.

Warships mostly had eras. If we go cross out the Age of Sail for simplicity's sake, it becomes mostly a matter of main armament. It's a bit chaotic, but after an initial era of slow-firing and inaccurate early rifles, you have the Hail of Fire era when quick-firing guns were only available up to 6 inches and so everyone would have those and only a couple larger guns. Then comes the Dreadnought era where long-range gunnery becomes possible, alongside turbine propulsion, and so there is a new focus on consolidating and maximizing main gun firepower. It lasts until the post WWII-period, punctuated by post-war force reductions and arms control treaties. The subsequent Missile Era can also be subdivided into before and after late 1980s as single or twin launcher arms with below-deck magazines are replaced with VLS cells. Frankly, this is comparable to the rise of the dreadnought because the number of 533 or 620 mm weapons carried per each ship has increased drastically.

3 hours ago, magnemoe said:

I agree, ships today are not designed to counter  other ships.

This was still a thing during the First Cold War. I know for a fact that Project 956 went from a mostly artillery-focused destroyer to a (very overloaded) general combatant  in response to the rise of the Spru-Can.

Also, the Iowas were unmothballed largely citing Soviet Project 1144 heavy cruisers, IIRC.

[kerbiloid]

A big progress, if compare to the 0th gen warships like trieras.

Being 35 m in length (Olympias triera) and armed with bows (30 m accuracy distance) and catapultas (85 m in the BBC study, and after several shots it was crashed).
Having a ram as a part of the keel, and thus ramming right with keel beam into keel beam (flimsy envelope meets inertial shock, and then the enemy torches, thrown just from zero distance by hands).
Somehow they were bombing even coastal fortresses, placed on high ground and separated with two hundred meters of coastline reefs and rocks.

[SunlitZelkova]

12 hours ago, DDE said:

This was still a thing during the First Cold War. I know for a fact that Project 956 went from a mostly artillery-focused destroyer to a (very overloaded) general combatant  in response to the rise of the Spru-Can.

Also, the Iowas were unmothballed largely citing Soviet Project 1144 heavy cruisers, IIRC.

That may be true about the Sarych, but he said designed to counter other ships. The Iowa class were designed to counter the Kongo class, certainly not the Pr.1144 which wouldn't exist for another forty years.

Edited March 30, 2024 by SunlitZelkova

[Gargamel]

Help my Google fu.  
 

I need a chart showing surface temperature of a modern rocket vs time during ascent.   
 

Coworker is vehemently claiming rockets are covered in heat shields head to toe since “The surface friction on  the way up is hotter than the inside of a hydrogen bomb.”     A triple Phd nasa Scientist told him that.  

This one will do:

https://ntrs.nasa.gov/api/citations/20090008664/downloads/20090008664.pdf
 

But of course, the response is “That’s a fake website you found”.  

[darthgently]

27 minutes ago, Gargamel said:

Help my Google fu.  
 

I need a chart showing surface temperature of a modern rocket vs time during ascent.   
 

Coworker is vehemently claiming rockets are covered in heat shields head to toe since “The surface friction on  the way up is hotter than the inside of a hydrogen bomb.”     A triple Phd nasa Scientist told him that.  

This one will do:

https://ntrs.nasa.gov/api/citations/20090008664/downloads/20090008664.pdf
 

But of course, the response is “That’s a fake website you found”.  

Ask him if craft generate plasma on ascent, and if he thinks so could he provide pics of this occuring.  And if he acknowledges they do not then ask him why returning craft only have heat shielding on the prograde portion when they are enveloped in plasma much hotter than any ascending rocket.

[JoeSchmuckatelli]

2 hours ago, Gargamel said:

That’s a fake website you found

Um...  Some people should not be engaged - much less argued with. 

They're passionate about their misperception and committed to conspiracy. 

Can't win. 

 

[Gargamel]

2 hours ago, darthgently said:

Ask him if craft generate plasma on ascent, and if he thinks so could he provide pics of this occuring.  And if he acknowledges they do not then ask him why returning craft only have heat shielding on the prograde portion when they are enveloped in plasma much hotter than any ascending rocket.

Oh no.... he contends the entire craft is heat shielding.  All of them.    Every single rocket ever.