UFO 🛸

Would it not suffice to fire up the rocket, get the ship up to speed, then turn the rocket off and let inertia do the rest?

Tsk!, tsk! Try momentum. That’d do a better job of keeping you going. Inertia is what makes it difficult to get going in the first place.

In a relativistic analysis, if you can tell the difference between momentum and inertia, you’re doing rather well…

I believe that’s how the Warp Drive works, Rick.

And so it just happens that the “PBS Space Time” channel released this week a video on the topic with its principles and the latest theoretical developments. I found amusing that the very first proposal requires actually more energy than the universe contains to warp your local patch of space.

In a relativistic analysis, if you can tell the difference between momentum and inertia, you’re doing rather well…

I rather fancy that Rick wasn’t engaged in relativistic analysis. Come to think of it, neither was I.

Anyone else want to own up? ;-)

;~)

In my younger days I was an avid consumer of SF magazines. Eventually my tastes grew more refined and I concentrated on the writers I admired (Jack Vance, Hal Clement, John Brunner, … ). Very few writers foresaw the digital revolution (though there was one, Frederick Pohl – mobile phones were called joymakers ) and none addressed the problems of scale that the universe presents. They just fudged the problems of interstellar travel and communication. Going between places is perceived by most people as the boring bit, who want to read about what happens when the protagonists get there. For convenience authors assume that all humans everywhere speak a common tongue (honourable exception Jack Vance’s The Languages of Pao). A more recent writer is the late Ian M Banks. See The Culture
and Ship Names .

none addressed the problems of scale that the universe presents

My short story, Anomalous Signals does…in a way… http://clive.semmens.org.uk/Fiction/TempleZ/Anomalous.html

Humans are only just starting with our own Solar system – deep interstellar space is a bit like dreaming of 64bit RO :-)

If only we could just control our numbers with out nature culling us – and us ganging up – and butching each other :-(

deep interstellar space is a bit like dreaming of 64bit RO :-)

More like dreaming of 64Gbyte RO :-) – and that’s the register size, not the RAM size…

I see the smallest explosive is a Atomic Depth charge is called ‘Betty’ – seems there were Atomic Depth charges down the Falklands.

Most of space travel is by machine only – could there be a Arc on Mars :-)

seems there were Atomic Depth charges down the Falklands

Not deployed, fortunately.

Most of space travel is by machine only

For good reasons. Life support systems for machines are far less demanding than for humans, and people don’t get quite so upset when they fail, either.

could there be a Arc on Mars

It wouldn’t surprise me at all if some of the systems there already employ them, but I don’t know whether they actually do.

Not deployed, fortunately.

From the comments of someone who was on one of the two subs down there most of the activity involved dropping off a few “special” passengers at a convenient beach

The probability of a substantial warming of the planet due to anthropogenic production of greenhouse gases is close to 100% – indeed it’s well under way.

There is almost certainly human-induced warming going on, but – at the moment – this is not a strong warming, and certainly not on the way of getting to a catastrophic level. We see 0.1 to 0.15 degrees of warming per decade for the rather short period of human history of precise temperature measurement. It is likely that CO2 climate sensitivity is around 1 degree per doubling (maybe less), and we don’t have enough (cheap) C to burn to arrive at much more than two doublings.

Catastrophic Climate Change is only happening inside the various climate models (at least the model runs that get reported, if cou remember climateprediction.net). These models are unreliable – we know that because we can compare their predictions with reality. And did you ever look at the source code of one of them? I wouldn’t trust them even if their predictions in the last 30 years would have been spot-on. No verification, no validation, no testing, no software engineering best practices to be seen anywhere. That we should base extremely expensive decisions on such lousy pieces of code is laughable. Or sad.

Back to reality: with the mediocre warming on the way at the moment, it is likely that this will be of net benefit to humanity. All the numbers are telling us exactly this.

Exactly how much warming will happen is very uncertain, and how much would be enough to finish civilization is also uncertain. How rapidly will sea level rise, how badly will sea level rise and unpredictable changes in climate (and consequently weather) affect agricultural production, and how well will civilization cope in the fairly likely event that food production is quite badly hit?

We had some warming in the not-too-distant past. It was a good thing for agricultural production, just look at the numbers. Warmer climate has been historically a good thing for humanity. See the Roman climate optimum for example, or the dire things that happened in Europe during the Little Ice Age. It is the one thing you can get historians to agree on.

See level rise has been pretty much constant for at least 100 years. We can easily manage this, ask the Dutch for their proven-in-practice how-to guide.

We have successfully globalized agricultural production in the last 70 years, and we have much better yields at much lower water consumption than ever before. This makes the production much more robust than in previous epochs of mankind. We even have the technology to replace the sun as our most important source of energy. Basically – if we really tried – we can live our whole life underground. Not that I’d want to, or that I think this will become necessary. But it is possible. It was not possible a century ago.

I’m not saying that’s certain death for civilization, but I’m sure it’s a very significant risk – far more so than asteroid strike.

I still see no evidence at all for that “very significant risk”.

Sorry, Steffen. That’s just wrong. What you write was an arguable case fifteen or twenty years ago – just about. It certainly isn’t today.

This is a subject I’ve studied in depth over the last fifty-odd years. See http://clive.semmens.org.uk/Climate/GlobalWarming.html – numerous pages linked from there, which I don’t intend to repeat here.

Sorry, Steffen. That’s just wrong.

Which part of “that”? The statistics that show that we produce ever more agricultural products and that there is no problem in sight to feed even more people?

That most people on earth are better off now than ever before in history?

That all current climate models have been severely wrong in the past (and almost always have overstated future warming)?

That crop yields are much better than some decades ago?

That it is unlikely that we have enough C to burn to arrive at an atmospheric CO2 concentration above 1000ppm?

That CO2 sensitivity is likely not much more than 1 degree per doubling?

Or something else? Or all of that?

What you write was an arguable case fifteen or twenty years ago – just about. It certainly isn’t today.

What I have written is based on well-established facts. You might choose to deny those, and come to any strange conclusion you want. Like Malthus in the dim and distant past, or Meadows in the 70s.

If you can provide data that proves something different – show me the data. E.g. the reduction in food production because of the climate warming of the last 40 years. Should be easy if what you write is true.

Or let us start with data on the warming on the past few decades. I wrote that we are currently seeing a temperature trend of around +0.10 to +0.15 degrees per decade. Even Wikipedia seems to agree with me, see the temperature trend line here: https://en.wikipedia.org/wiki/Satellite_temperature_measurements

Do you disagree with Wikipedia data?

This is a subject I’ve studied in depth over the last fifty-odd years. See http://clive.semmens.org.uk/Climate/GlobalWarming.html – numerous pages linked from there, which I don’t intend to repeat here.

I have read a lot of words and conclusions on your various pages, but very little data that you are basing your conclusions on, it reads more like an activists’ account than something based on science. It might well be that you have studied the subject in-depth, but I have too (including reading most IPCC reports and many many papers on the subject), and we come to completely opposite conclusions.

I also don’t agree with your conclusions about nuclear power. If you really think that CO2-induced climate change is a problem, surely using nuclear power could be at least one important part of the solution. If you arbitrarily choose to not want one of the possible solutions to a problem, then that climate change thing seems not really that dangerous. According to your own choice.

I’ll take one of your paragraphs as an illustration from your “Nuclear Power?” article:
“Nuclear power could only deliver a modest percentage of the energy we want, and the industry would take a long time to grow enough even to do that – much longer than the alternative energy industry would take to achieve the same growth given the same level of investment.”

OK, now we compare that to reality. Compare the nuclear build-up in the past (e.g. in France, Japan, Germany, USA, South Korea, China) and the cost of it with the cost and result of the renewable energy build-up (excluding water power of course, which was built when the world was still a much saner place). Reality does not match your assertions at all.

What is the reason why we cannot do – country by country – the same as France did back in the 80s with their nuclear build-up? We could even keep the same electricity grid, which is surely easier than what we would need to build (in addition to the many wind turbines etc.) when we want to go say 80% renewable.

And what is more, nuclear power can be used to produce all kinds of necessary energy: electricity, heat (both for domestic heating use and process heat for industrial application) and fuel for mobile use (synthetic carbon-based fuels as well as hydrogen). It could easily provide a large part of all of our energy use. How do you arrive at “could only deliver a modest percentage”?

We here in Germany are soon going to shut down the few nuclear power facilities that are still running. Those have been running for 30+ years without any noticable problems. And they could easily run a further 30 years with minimal costs and without making the nuclear waste problem (if you believe that it is more than an imagined problem) significantly more problematic. And yet, they will be shut down. Seems to be not much of a problem, that CO2 production thing. According to the German government.

I’m with Steffen on this one.

This is getting to be a bit like Religion :-((

Seems to me – some would have us wrapped up in blanket’s – in front of a fire with one lump of coal burning.

And note it gets a bit colder in Germany.

in front of a fire with one lump of coal burning.

One lump of coal? Luxury. When I was a lad we had to make do with a photograph of a lump of coal…

Are you sure it wasn’t a black stone.

I wonder when someone first thought of burning rock :-)

[Edit]
Coal use.

In China – about 4000 BC
Written about in Ancient Greece – Romans used it.

Written about in Ancient Greece – Romans used it

Since pretty much everything the Romans did was “borrowed” from Greece or Carthage¹ the Romans using coal after the Greeks is pretty much a given.

¹ Largely unknown/undocumented but recent discoveries suggest that the Greeks, Romans and others learned from Carthage. Apparently, sometimes the learning was a bit of a forceful extraction.

When I was a lad we had to make do with a photograph of a lump of coal…

Photograph? Luxury.

When I was a lad my grandad told me about these glowing lumps of rock. But I could only imagine such things.

That most people on earth are better off now than ever before in history?

If by “most people on earth” you mean predominantly western countries (and their (ex-)colonies), then yes, I guess we are. But that’s probably down to the lessening of power of the religious and the royals and the increased concept of democracy and fairness.

Though, as an example, a worrying number of religious Republicans are pushing for abortions to be illegal, and in some states, have been successful; and this is the same country where we celebrate the conviction of a murderous police officer in the same week that police officers slaughter four other black people… So “better off” for some is not better off for all.

That all current climate models have been severely wrong in the past (and almost always have overstated future warming)?

So that’s why the weather forecast is never right…

Seriously though, the climate is a very complicated thing. It simply isn’t possible to say “all hell will break loose by 2067” any more than its possible to say “there will be a severe thunderstorm in Brighton on the morning of June 17th”.

That crop yields are much better than some decades ago?

Genetic modification? Increased use of pesticides? A better understanding of ecology for how to maximise yields? Tearing down rainforest to have more room to plant crops?

An example from here. In the past decade or so, wheat has been a short stubby crop rather than the previous stuff that used to come up to my waist. Less time growing tall, more time growing seed, the heads are larger and plumper.
That, along with a pathological desire to tear down anything that resembles a hedgerow (two metres extra planting room and no pesky shade!) mean that crop yield on a single field jumped up.

But given that he doesn’t give a crap about GMO or neonics, the question is increased crop yield, but for how long?

There are notably fewer bees around these days, and sadly most of the ones that I see are often lying on the ground slowly dying. Yay! We can’t use glyphospate any more, but farmers can use something even worse…

That it is unlikely that we have enough C to burn to arrive at an atmospheric CO2 concentration above 1000ppm?

That’s the egotistical approach of thinking that the warming is entirely our fault, and that stopping belching CO2 into the atmosphere will bring this to a halt.

It won’t.

The earth has been colder, and it has been warmer. It is warming up a little. Our actions aren’t helping, but if we went to become a nomadic hunter gatherer society as of tomorrow, it’ll still warm up. It might just take a few decades longer.

Do you disagree with Wikipedia data?

Yes.
If there’s a citation, point is at the source.

“Nuclear power could only deliver a modest percentage of the energy we want

What!?
There was a time when nuclear provided about 85% of France’s power requirements.

And yet, they will be shut down.

I think it’s a mixture of Chernobyl and Fukushima mixed with the “new world” in which acts of terrorism are based upon renegade religious factions rather than disagreements with countries.

I don’t want to think about the effects if some twat managed the blow the lid off Flamanville (insert any convenient German reactor here). At least in the Ukraine it seems as if Pipryat was sort of remote. That’s not the case in Europe, and an immediate forced evacuation and decontamination of any major city in the path of the prevailing wind (which could include the English south coast) would be chaos.
Not to mention that radiation is something that can kill you that cannot be seen or felt. A lot of people have a lot of misconceptions about it. Did I mention it’d be chaos?

Nuclear may be safer and better than dead dinosaur, but it’s a political minefield.

Nuclear may be safer and better than dead dinosaur, but it’s a political minefield.

It seems that there’s some dissatisfaction with the rides at the Barry funfair in S.Wales. The local council has just submitted an expression of interest for a fusion reactor power station.

It seems that there’s some dissatisfaction with the rides at the Barry funfair in S.Wales. The local council has just submitted an expression of interest for a fusion reactor.

Well, I suppose if the experimental reactor goes pop (or rather much more) at least it’s Barry that gets wiped off the map.
Nominations for other deserving candidates to follow.

Nominations for other deserving candidates to follow.

Where’s the largest concentration of Brexit voters?