Fighters can only achieve mach sprints for a few minutes before running out of fuel.

Transports can keep it up for hours (as could the SR71)

" Doing something about the sonic boom would be useful "

Concorde's boom wasn't particularly loud. Noticeable yes. Annoyingly so, no. Not enough to break windows, etc. Much quieter than a passing Harley, as a f'instance.

US overland experiments on boom were conducted using the Valkerie and that was extremely loud, being an old design which predated area rule discoveries and had to be modified during design accordingly.

It was those results which were used to justify banning overland SSTs but the actual reason for the ban was political pressure from USA aircraft makers who didn't have a SST of their own.

Concorde was essentially a V-bomber scaled up and although it first flew in the 1970s the technology was essentially 1950s along with the design techniques.

The engineer station is highly complex and the thing was fragile, with insufficient regard to routing of critical services.

The wingtanks were already known to be vulnerable and should have been fixed long ago. A ladder knocked against one whilst parked at Harefield in Christchurch in the 1980s resulting in several thousand gallons of jet fuel being dumped on the tarmac. In addition the russian lookalike suffered several crashes directly attributable to the same cause that bought down the french one (debris on the runway thrown up and puncturing the tanks), resulting in the russians decertifying theirs for passenger transport - they ended up being the fastest mail planes in the world.

A redesigned concorde would likely be profitable. BA made money out of them right up to the french crash and the primary reason they were grounded was because Airbus refused to service them anymore.

"you can avoid a lot of the cleanliness problems by adequately caring for the homeless population"

Drunks and "disaffected youth" are a far larger problem than the homeless - most of whom go out of their way to avoid drawing attention to themselves.

Unlike USA systems, the LWR reactors run in the UK have their shutdown and disposal costs factored into their running costs.

Reactors being dismantled now are paid out of funds built up during their operational lifespan.

They were definitely economic, even though the UK wasted a fuckton of money making every reactor of slightly different design and thus negating any chance of lowering costs via modularity.

The only non-minor (as in actually involving nuclear materials) nuclear reactor accident in the UK (windscale fire) was in a military reactor being used to produce bomb-grade plutonium. That reactor is still onsite and still hot, although I understand it's periodically assessed to see whether it's practical to dismantle it. Some of the fuel slugs are still jammed into the graphite moderator (which is what caught fire).

"they dumped their waste in the seas, creating more risks and, eventually, costs."

To put something against this:

There are at least 3 old nuclear reactors from the icebreaker "Lenin" dumped in international waters in the Arctic Sea, along with a Soviet nuclear boat which imploded and sank with the loss of all hands, coming to rest about a mile down, complete with nuclear torpedoes loaded in the open forward tubes as well as a reactor which was running at the time of the accident.

Finland has been keeping a close eye on a couple of the Lenin reactors as they're close to their territory. So far they have detected _zero_ radioactivity and _zero_ breakdown products. The reactors are being steadily buried by mud buildup.

Ditto on the sunken submarine. The russians fitted titanium covers over the topedeo tubes to be on the safe side but no radioactivity was detected anywhere near the wreck.

Whilst sea dumping has both appeals and knee-jerk reactions against it, it does appear it's relatively safe - but on the minus side it puts potentially valuable MSR fuel expensively out of reach.

"Thorium reactors for base power, solar for peak"

WHY????

The prime factor which stops LWR reactors load-following is Xenon poisoning when they're turned down - it builds up in the fuel rods and has to decay away before they become usable.

In a MSR the xenon is able to vent into the reactor's surge space and decay harmlessly. This was generated at Oak Ridge in the 1960s. https://en.wikipedia.org/wiki/...

The MSRE system is highly throttleable (almost as fast as hydro systems) and as such you don't _need_ solar, or wind, or peaking generators. All these do is needlessly drive up the complexity and cost of your distribution network as well as adding complexity to the "base power" systems as they have to take account of the spiky nature of "renewables" generation.

"For example, I've heard flanges for molten salt reactors are a potential for failure"

So is pipework in a conventional reactor. Ultra-hot, high pressure, borated water is extremely corrosive - actually more so than fluoride salts.

"one leak and your radioactive fuel is everywhere"

In a molten salt reactor it's not going to go very far before it freezes - and as it's under negligable pressure you're talking drops, not gallons.

With a conventional reactor you now have ~1400 times as much radioactively contaminated steam as the amount of water that got out - and when it condenses you have the added problem of trying to make sure it doesn't wash into a drain and contaminate the local environment. not to mention that because it's under high pressure, it's going to spray _everywhere_, making cleanup that much harder.

Sodium-cooled reactors were a really fun idea. Hundreds of tons of coolant which can catch fire on exposure to air. What bright spark thought that would be a good idea?

Lead cooled are similarly silly. They stopped being used pretty quickly because it's hard to dig out fuel rods from several tons of soldified lead.

The elephant in the room about LWR/BWR/PWR is waste - input and output.

More than 1/3 of the mined uranium metal is tossed as useless (but it's still a chemically toxic heavy metal) before it goes inside the reactor and that which did get there has been through extremely energy-expensive operations (gas centrifuges) to get there. On the output side, the burnup of fuel rods is 1-3% when they're "finished" - there's still 97-99% of the input left - this has left waste piles consisting of hundreds of tons of stuff which won't be safe to go near for at least 300 years and which will be fairly dangerous for at least another 20,000.

Nuclear is the only practical way of supplying enough energy for planetary needs - now and in future. Not just those of the rich countries.

Solar and wind aren't good enough, or reliable enough. If you have a MSR, then you don't need them and you don't need peaking capacity generation as MSRs can be turned up/down quickly without suffering Xenon poisoning.

Development of small, safe, portable MSR plants has the potential to "free the world" from deprivation - and that in turn has the potential to stop most wars and most terrorism - both are fed by poverty, even if manipulated by the rich for their own ends.

"Because doing so isn't free. It takes time and resources, which means money."

Only because the system is geared around habitual institutional secrecy.

Open government principles imply that all records are accessible unless there is a good reason not to (and embarrassment of civic officials isn't one of those reasons). Several parts of the world are or have moved to this model.

The USA is only slightly less corrupt than the average west african dictatorship, so it's not that surprising government wants to keep everything secret.

"the fine was justified."

For those who object to this (and some US judges have refused to hear TCPA cases on the basis that they're unfair to businesses, which _always_ results in their butts being kicked if appealed upwards)

The amount is $500 - low charge, but a small claims slamdunk.
The amount is tripled if knowingly done - anything after being told to stop, or calling a DNC listed number is knowingly.

The FCC itself can levy a $11,500 fine PER CALL if it weighs in and has done to take out various industrial-scale operations. Unlike regulators in some countries, they can and _have_ gone after outfits based outside the USA and achieved shutdowns.

The law is deliberately and explicitly written with per call damages to take out the likes of Sanford Wallace - it was actually written specifically with him in mind - companies can fight large value claims, but the death of 1,000,000 papercuts is devastatingly effective at bringing companies to heel.

The TCPA came in over 25 years ago. Some companies are skirting around it by forging their origins, but imagine how much worse the problem would be if that law wasn't there.

What amazes me is that despite all these millions of calls, telemarketers don't occasionally dial someone unhinged and determined enough to hunt them down and murder the entire call centre.

"most of the time they are caller ID spoofing"

This is a criminal act all in itself.

The things to do are

1: record all your inbound calls
2: string them along long enough to find out the name of the company that they're repsresenting.

The TCPA allows you to go after _both_ the company which called you AND the company which hired them. The former may hide but the latter can't - and once you have them in court they can be forced to name who they hired.

How about standing them on a nuclear propelled manhole cover?

"Backed the french" - against a people fighting for their independence.

We all know how that one ended in 1776 for the backers of the colonial power, don't we?

> you totally destroy your credibility with the 3.0 Gs thing.

If you want to mess about with aircraft there are planes you can do this in, and places you can have the altitude to do it. It's harder to lift your arms but not intolerable. In general, unless the passengers are warned in advance it's best not to exceed 0.5G in banked turns and exceeding 2G may pull the wings off some models of light aircraft.

> actually be comparable to a roller coaster.

Roller coasters are deliberately designed to repeatedly throw people around in different directions in order to heighten the sense of danger. High speed banked turns in hyperloop (or anything comparable) are in no way comparable to the feeling of a roller coaster, more like riding in a widebodied air transport (note there that the apparent cabin gravity is also always floorwards thanks to banked turns.)

Anyone who tries to make out that passengers will feel substantial lateral forces is barking up the wrong tree. Even the original vacuum train proposals made use of banking in turns and european HSR systems make extensive use of banking to avoid the same effects (You can feel the apparent gravity pushing you into the seat a little harder in some spots on the Paris-Amsterdam run).

Any credibility loss is borne by those who try to compare the ride quality of a high speed transport system to a roller coaster. The ride on rails is comparable to that of a ship or an aircraft (without pitching and rolling) and in a tube will be even smoother than that of a maglev (try the shanghai airport shuttle sometime. It's like a magic carpet.)

"Do they use a common chassis,"

Yes.