Category: Physics

A Question on the Economics of Space Energy

I’ve been convinced, reluctantly, for some time by an argument regarding inter-stellar travel. The possible means we might have for traveling between the stars within reasonable time frames imply a command of massive energies. Wormholes, warp-drives, and hyperspace all imply direct manipulation of space-time in a way that we can observe does not currently occur routinely. Necessarily, such technology (if it were possible) would require scientific know-how we do not have but also massive energy.

The sad conclusion of this argument is that interstellar travel can never be the basis of a galactic civilisation of the kind we see in our space operas. Having gained the necessary pre-requisites of large-scale energy manipulation, humanity would have no need for interstellar trade or indeed much need for interstellar exploration for reasons other than pure curiosity. Put another way: faster-than-light travel implies a post-scarcity civilisation and almost god-like technology.

I’m a tiny bit more sceptical of that chain of thought now though.

I think it is partly shaped by our current perspective on energy. It is easy to see energy as the core limitation of our economy. You need the energy to do anything. To enact any kind of change, to hold off entropy, to shape things requires energy. Simply to stay alive and warm and fed requires energy. Our view of energy in modern society is one that sees energy as a limited resource that is inherently expensive. However, that is misleading.

In space and in the universe in general, massive sources of energy are plentiful. Simply looking up on a cloudless night will show you a practically uncountable number of active fusion reactions boiling off photons into space. Energy itself is plentiful, what is rare or difficult to acquire is energy that is usefully constrained at a scale that is useful for human purposes.

The canon was invented before the steam train. The fusion bomb was perfected before the fusion reactor. Deploying huge amounts of energy is not necessarily technically difficult, what is difficult is deploying huge amounts of energy without wrecking stuff. Of course, that doesn’t mean making wormholes in space to travel to distant planets is feasible but it does make me think it might not require a level of finesse over physics that could be applied to more subtle things.


Not a How To Time Travel

This post sort of follows this, this, and this. I don’t many impractical suggestions of how to time travel. Let me explain.

Time travel is either easy or impossible. It is easy because essentially time is just another dimension of space-time and travel in the other three is easy and we are already all travelling in time (just in one direction and locally at the same rate). On the other hand, time travel appears to imply paradoxes. Paradoxes of causality worry me less than issues such as conservation of energy/matter.

Causality worries me less because I suspect cause and effect isn’t everything we might think it is. However, if I disappear from one time period and reappear in the next, then my new time period has more matter in it than it did before and worse, that matter will hang around going forward into the future. Perhaps time travel requires some physical exchange of matter between time periods? If so, then what in the universe is keeping track?

A different issue with time travel is the speed of light. Even approaching (but staying within) the speed of light has some weird temporal consequences. Actual time travel would provide ways of in-effect travelling faster than light and likewise FTL travel also implies a degree of time travel. If the speed of light is a hard unbreakable rule of the universe then it follows that time travel is impossible also.

One method of time travel escapes most of these issues: perception. In Kurt Vonnegut’s Slaughter House 5, Billy Pilgrim becomes unstuck in time due to the allied bombing of Dresden in World War 2. However, the time travel here is how he perceives events. Billy’s body isn’t popping in and out of time periods, instead, he is experiencing his life out of sequential order. This kind of mental time travel avoids issues of causality on the grounds that everything has already happened. Events are what they are but perhaps the order in which we experience them is an illusion of the human mind.

Unfortunately for stories, there aren’t many writers who can make a narrative work where no decisions can possibly matter. Which takes me to a topic for another time: how should time travel stories work?

Don’t Forget Climate Change: Chapter 5 Bob Carter – Precambrian Conservative?

Previously…chapter by chapter I’m reading a dodgy book in which people try to pretend climate change isn’t really anything to worry about…

Intro, Ch 1, Ch2, Ch3, An Aside, Ch4, …

Robert M Carter was an Australian geologist and academic. He died earlier this year As is conventional in a review, I’ll talk about him in the present tense when describing the text.

Funded in part by the Heartland Institute, Bob Carter was an early adopter of the ‘global warming has stopped’ argument based on the relatively low level of warming since the 1998 El Nino.

Carter aims for a clearer structure in this chapter by using what he describes as:
“In this chapter, four basic scientific facts are described that provide an essential context for intelligent discussion of the global warming”

“Context 1— error bounds on reconstructing the global average temperature from thermometer data”

Carter starts with a criticism of the HadCRUT temperature data. We encountered HadCRUT in Chapter 2 where it was the preferred choice of Patrick Michaels when discussing climate models. You’ll remember from that chapter Michaels treated the temperature data as a given and indicated no kind of error bars/confidence intervals for the temperature data but only for the models. Ah, but that was a different chapter and a different sceptic. For Carter, the issue is that HadCRUT has error ranges in its data. This is true, there is necessarily error in the data set and the size of that error for any given point can be quite larger – larger (as Carter points out) than the additional warming caused by anthropogenic greenhouse gases.

But this is a statistical shell game he is playing. The error of an individual measurement is not the same as the error in the size of the warming trend. Simply put, aggregating measurement data that has error can reduce the amount of measurement error. It’s why statistics works.

“Context 2— natural temperature variations over geological time”

We haven’t heard much yet in this book about the paleoclimate record but it will loom large later. However, Carter is just knocking down the same straw man we’ve seen before – essentially that past changes in temperature show that temperature can change for reasons other than carbon dioxide levels. This undoubtedly true – other things can cause climate change. However, we know (see Lindzen in Chapter 3 because he agrees) that carbon dioxide CAN cause changes in global temperature and we know that levels of CO2 have increased significantly.

This rather like a defence lawyer saying that their client didn’t commit a murder on the grounds that other murders have happened in the past which their client couldn’t have committed.

Still, Carter perseveres with a graphic Greenland air temperatures for the last 10,000 years. Interestingly for this data set, Carter does not seem to be concerned about any error ranges – I guess measurement error became unfashionable somewhere between the end of the last section he wrote and the start of this one. The data for the graph is from a paper whose abstract and data can be read here

One thing to note is the time axis of the graph is in Years Before Present. This is a standard use in collecting data using things such as radiocarbon dating or the techniques used with estimating temperatures using ice-core samples. However, “present” here does not mean 2016 nor does it mean 2000 when the study was published. It means specifically 1950 CE as it is a technical term for a fixed point. The data does not address late-twentieth-century warming. However, the more recent instrument record (which Carter doesn’t trust) is shown as a thin grey line.

In addition, Greenland is far from typical as far as the Earth’s climate goes. In Carter’s first section he expresses scepticism about temperature sets taken from multiple sites world wide and in the next section points to a single indirect set of measurements from one part of the globe. Greenland is not the world.

“Context 3— carbon dioxide variations over geological time”

“It is widely misrepresented in the public domain that Earth’s current levels of atmospheric CO2 are dangerously and atypically high. Such claims are false, because modern CO2 levels lie near to an all-time low as assessed against the geological record.”

At this point, Carter slides from disingenuous to laughable. CO2 levels are atypical for human history. Yes, sure, a civilisation of trilobites might regard current CO2 levels as a tad low but this hardly seems relevant.

“500 million years ago, before land-plant photosynthesis was operating, atmospheric CO2 attained about fifteen times present day levels”

😩! In what way is that sentence reassuring? Never mind the imagined trilobite civilisation, let’s just consider a time when the first multicellular creatures were hanging out. Essentially Carter out-conservatives every other conservative on earth by waxing nostalgically for the good-old-days of the Precambrian, leading to the classic line:

“Utilising coal as an energy resource simply returns the CO2 to the atmosphere from whence it came in the first place,”

i.e. burning coal returns CO2 to the atmosphere bringing Earth close to the atmospheric conditions that prevailed when early plants first colonised the land? Quite what Carter is trying to prove at this point is unclear. Yes, it is a sound argument against a claim that burning coal will destroy all life on Earth (it won’t) but that really wasn’t the issue.

“Context 4— efficacy of warming caused by extra carbon dioxide”

This is the climate sensitivity argument again. However, Lindzen did it better and Carter gets in a muddle.

“Because of this logarithmic relationship, the amount of warming caused by increasing quanta of CO2 depends upon the level of CO2 already in the atmosphere, and diminishes steadily in a ‘less-temperature-bang-for-every-incremental-carbon-dioxide-buck’ pattern. Given the pre-industrial starting point of 280 ppm of atmospheric CO2, only minor additional warming will occur in response to the much-feared doubling of CO2 to 560 ppm.”

Yup, Carter gets logarithms wrong. The logarithmic relationship doesn’t diminish the impact of a DOUBLING of a quantity. A doubling is MULTIPLICATIVE. Seriously Lindzen already explained this back in Chapter 3:

“ Because of the logarithmic dependence of the radiative impact of CO2, it doesn’t matter what the starting value for the doubling is.” Lindzen Chapter 3

Carter closes the chapter with a more general note, essentially that governments should worry about all kinds of possible climate change and not just warming. Quite what governments should do in this regard he doesn’t say but let’s consider the issue of burning fossil fuels. If Carter is right and CO2 from burning fossil fuels has no net warming effect then burning them does not prevent global cooling. If Carter is wrong about CO2 and CO2 does have a warming effect but right about possible global cooling then it would make sense to conserve fossil fuel reserves so that they can be used later to counteract the possible future cooling.

In the meantime credible evidence exists that the anthropogenic global warming is occurring and while the trilobites might be OK with that, those of us from a more recent geological time have cause to be worried.

Slow and Quick: two contrasting videos

The first is this video of work down to mitigate the damage done by a relatively fast lava flow.

The second is a video of a journey out from the Sun through the solar system at light speed.

I think the two show interesting perceptions of time. In the first we see geology happening quickly – which is far from our normal experience of geological events. Even here lava is not rapid but it is remorseless and its molten motion is sort of creepy.

In the second speed gives a sense of distance. The video has a hypnotic quality but not a lot happens for long stretches because the space between planets is big. Even traveling at light speed, you are going to want a magazine to read on the journey.

Evil SJW Message Fiction! A cat reviews The Hot Equations

[The Hot Equations by Ken Burnside is a Puppy nominated contender for Best Related Work in the Hugo Awards. My fictional talking cat Timothy, has asked that he presents his review. As his little cat paws are built for “fighting not typing” as he puts it, the review is presented as an interview. Audio of the conversation is unfortunately not available due to poor sound quality (there being no actual sound). Please note: the views expressed by Timothy are largely nonsense and do not reflect the views of Camestros Felapton or the Felapton Corporation or any similar talking cats.]

[Camestros] Hi Timothy. This is your first Hugo review and you have chosen ‘The Hot Equations’ by Ken Burnside. Can you tell me why you picked this work to review?

[Timothy] I strongly disliked your review of Wisdom from My Internet and I thought it only fair that I picked on something you liked and gave it a bad review.

[Camestros] I didn’t particularly like The Hot Equations I…

[Timothy] It was one of your highest ranked puppy works. You put it 18th out of 22 where 22 is the best. You LOVED it. Basically you wanted to marry it and have its babies because it was full of science stuff.

[Camestros] You are reading a lot into a ranking but yes, I did like that it looked at aspects of science fiction from a detailed scientific perspective. I think it would be a useful guide for a writer. Also I think it matched a lot of the stated aims of the Puppy campaign – it is a positive sort of Puppy in that it added something rather than just trying to be negative. However this isn’t my review, you need to tell me what you think.

[Timothy] Sure but first why is your text bold and mine is plain?

[Camestros] That is just the standard convention with this style of post. Your bits should end up being longer and people don’t want to read long paragraphs in bold-face text. It looks odd at the moment because you haven’t really said anything.

[Timothy] OK well I hated it. Firstly science fiction is about transparent text, plot and characters, This supposed essay was about obscure physics. Basically Burnside want writers to put their genuine creativity aside and devote all their time to calculating heat transfer ratios or the enthalpy of rail gun or the mass/weigh ratio of a rocket drive. Nobody wants to read that stuff. Imagine you are in the middle of an exciting story of space adventure and all of a sudden BANG! The writers goes off on a tangent about physics.
I don’t want that in my reading. I want great stories told in a great way with great characters – not dull physics textbooks were even the explosions are supposed to follow rules. Good grief! Explosions don’t follow RULES! It is insane. It is like those idiotic pedants who object to the sound effects in Star Wars. Seriously? If you have a problem watching one of the greatest SF movies of all time because of a few zap-zap noises in the vacuum of space PRESS THE BLOODY MUTE BUTTON for bast’s-sake. The you can watch your la-dee-dah, oh-so-correct space opera with the awesomeness turned down to zero.

It is FICTION people! Fiction! The spaceships aren’t real!

[Camestros] OK,. I’m not sure Burnside is really saying that the physics has to be mandatory. I think he is just offering advice for people who want realism.

[Timothy] Yeah, that is what the SJWs always say but it is the constant push and all of a sudden your favorite books just have all this political stuff in your face. It is bias.

[Camestros] It is thermodynamics Timothy – not some evil leftist plot.

[Timothy] I have my own views on thermodynamics, as you well know.

[Camestros] (groans) This isn’t the Sky Dragon thing again is it?

[Timothy] Now that you mention it, I do believe that there are number of distinguished scientists with very credible views that have successfully challenged the so-called ‘consensus’ on global warming. I was most impressed with some of the insights in the work you mentioned.

[Camestros] You obsessed over it for months. Seriously Timothy, I thought we’d moved past this. The sun is NOT made of iron. Look even major anti-warmist website like Watts Up With That think the Sky Dragon stuff is pseudo-scientific nonsense.

[Timothy] I am not a number (or an equation) I am free man. I have my opinion and you have yours. I am not asking you to agree with me but I am asking that writers respect my views. I think that is reasonable. You wouldn’t like it if a writer suddenly decided General Relativity was wrong…

[Camestros] …actually that happens all the time…

[Timothy] OK well something like denying the mathematical existence of Cantor’s transfinite numbers.

[Camestros] Fair point. I love my transfinites.

[Timothy] Exactly. Message fiction. The Hot Equations is a major left-wing manifesto. It is essentially saying that science fiction should be forever pandering to left wing views and messages – and…and! That prose, plot and character should be secondary to whatever pet theory is popular with the left at the moment.

[Camestros] I’m having some trouble getting my head around this. You think an essay which is nothing more than a set of tips to help military-science fiction writers keep their physics realistic is a LEFT WING work?

[Timothy] Absolutely! If you stuck a beret on this, you could put it on a t-shirt and call it Che Guevara.

[Camestros] I’m not seeing it and I can’t imagine Ken Burnside would see it that way either.

[Timothy] (sigh) OK let me show you how perfidious this Trojan Puppy is.
It looks innocent enough – oh yeah, all military spaceships and guns and explosions but that is just the surface. What is it truly saying?
REALISM matters.
Think about that for a moment. Whose realism? Mine? No, I disagree with a number of politically motivated interpretations of thermodynamics. What Burnside wants is to push readers like me out of Science Fiction. Why? Well it is part of the whole SJW agenda. Sure lots of conservative minded people (foolishly) take thermodynamics at face value so they don’t see the underlying problem.

Wait, wait follow me on this.

Sure this book is all ‘physics’ and nobody questions physics because it is the big brutish bully of the sciences – the Josef Stalin of the disciplines. It is all numbers and scary but it is just the start. So we make our physics in science fiction thermodynamically correct. What’s next I ask you? Does the chemistry have to be right too? If we are logically consistent then sure – no more unobtanium ‘poof!’ Avatar is gone – sorry Mr Cameron! What’s next? Biology? Yeah, so who is going to check that every alien species conforms with modern biology? And look who is now in the big SF tent – welcome on-board Mr CHARLES DARWIN! Oh, creationist readers? Evangelical readers? Nope no room for you in SF/F any more. Bye-by diversity and religious tolerance!

What does the SJW-realism fairy say next? What’s that? It is incontrovertible fact that 50%+ of people are women? Hey – even I accept that fact. So now under the guise of factual realism, that all started with Mr Burnside’s retro-virus attack, we suddenly have to have women in the novels! What is SF/F too good for good old fashioned misogynists? This country was built by misogynists!

[Camestros] I think that last comment isn’t so much wrong as wholly incoherent…

[Timothy] Oh I’m not done! Once people start having to judge their fiction against actual facts then it will have to have people of all sorts of sexualities, various different kinds of gender identifications. Why? Just because these are actual facts about our society that anybody can go and check and see that we live in a world of multiple different types of people! Political correctness GONE MAD!

[Camestros] I am getting a bit concerned that you are wandering off character from satirical right-wing talking cat to just sounding like me being sarcastic…

[Timothy] OK, OK how about economics? Do you want REALISTIC economics in your fiction mr-socialism-never-really-hurt-anybody?

[Camestros] As it happens I do like realistic economics in both science fiction and fantasy. I like to distinguish between facts and opinion.

[Timothy] Yeah and it just so happens that your ‘facts’ are the ones that suit your opinions.

[Camestros] Enough Timothy – we are supposed to be reviewing an essay not rehashing our Sunday afternoon beer tasting arguments. Can you sum up because I suspect what readers we do have may be tired of this format already.

[Timothy] The Hot Equations is the thin end of the leftist wedge. It purports to be a handy guide to using thermodynamics in science fiction but it is actually a manifesto for left-wingers to police fiction for correctness. Once you insist on some adherence to truth in fiction then you accept the right of self-appointed guardians of truth to start policing your writing and telling you what you can and cannot say or think. Just say ‘NO’ people.

[Camestros] Thank you Timothy and let’s decide now to never do this ever again.

Mad physics

In a discussion on File 770 I was rude about the physics of faster-than-light travel while defending some of the madness of Doctor Who’s Kill the Moon episode and commenter “ccm” replied:

FTL spaceships? Hah! What about a freakin Time Machine that can grow and jettison rooms as needed, produce pretty much anything you need, can travel anywhere and anywhen with no concerns about fuel, weight, etc….and seems to be some kind of living creature as well.

Well fair point.

But I still think that FTL drives are as bad and in someways the madness of whovian physics makes more sense. The absurdity of the Who reality is a kind of realistic realism.

Now that will require some justification. Continue reading