The external forces acting on the car are gravity and friction. Willis didn't mention those forces. The cruise control can kick in to oppose changes in these forces by introducing an opposing force of the engine. It can add fuel to increase or decrease the engine power, apply brakes to oppose the engine, and shift gears to increase or decrease the power of the engine. It will do this when it detects a change in speed. The change in speed trigger will only come about when there is a change in forcing.
Lets assume that his car is moving forward in a straight line (same horizontal direction). When one or other force changes it will affect the speed. Gravity won't affect the car on the flat, but it will kick in when the car goes up or down a hill. (Gravity will no longer be perpendicular to the velocity of the car.) Adding gravity to the mix affects the speed of the vehicle. The cruise control detects this result of a change in forcing. It detects a change in the speed. In response to the detected change in speed, the cruise control increases or decreases the supply of fuel, and/or applies the brakes and/or changes gears. It can apply an opposing force. It can change the force of the engine.
Under normal circumstances, the Earth doesn't have a fuel tank at its control, despite what Willis might claim. Its supply of fuel is the sun, but that's not controlled by Earth.
However, we humans are very inventive. We've discovered a fuel tank right here on our planet. It's not controlled by natural forces, it's controlled by us. It's called fossil fuel, or coal, or oil, or natural gas. In one form it is the very same fuel as is used in Willis' motor car.
Using Willis Eschenbach's example of a car - think of how our earth has been going along a reasonably flat straight road at a fairly steady pace. Since civilisation began, there've been no big hills - maybe a few gentle undulations now and again. The sun provides pretty well the same amount of energy to keep us on an even keel. Our orbit hasn't caused big bumps. There've been some volcanoes, but nothing drastic. No comet collisions or asteroid strikes.
We're like adolescents who are bored and looking for thrills. So we decide to open up the throttle and inject more fuel. We've added a force in one direction, with virtually nothing to oppose it. We've done that by burning fossil fuels and increasing the amount of greenhouse gases in the atmosphere. This is like stepping on the accelerator while on this flat straight road. The car accelerates. The planet gets hotter. We keep our foot pressed to the floor and the car keeps accelerating, going faster and faster. We keep burning fossil fuel and adding more greenhouse gases, and the earth gets hotter and hotter.
There is no governor to kick in. There is no opposing force. All there is is feedback. We've taken over from the cruise control and put our foot to the floor.
Related reading from HotWhopper
- On forcing and feedback with Willis Eschenbach - July 2015
- Wondering Willis Eschenbach's Thunderstorm at WUWT - October 2013
- Denier Weirdness: Wondering Willis Eschenbach wonders does "an ice age cometh"... - October 2013
- Wondering Willis' Original Weather Hypotheses - December 2013
Another superbly elegant deconstruction by Sou. However I'm unable to sign on to this without running it past a climate expert steeped in the science.
ReplyDeleteDoes anybody know Andy Revkin's phone number?
Sou I hope your going to send what you have written to the Hotwhoppery and replace it with some true understanding and not what you think , Sorry but your not even close when you say the Sun drives temperatures at the surface ,you do know that temperatures fall the high in the troposphere you go until you reach the tropopause were it can get as cold as -80C on the sunny side . http://www.atoptics.co.uk/highsky/htrop.htm
ReplyDeleteThe reason Earth is warm at the surface and not boiling hot is because of our magnetic qualities generated from within http://physicsworld.com/cws/article/news/2011/jul/19/radioactive-decay-accounts-for-half-of-earths-heat creates resistance to the energetic (but cold) solar wind . This interaction turns Earths weak force we call gravity into a strong electromagnetic force . The first line of resistance is the bow shock https://en.wikipedia.org/wiki/Bow_shocks_in_astrophysics
Andy? Is this you?
DeleteGravity turning into an electromagnetic force. Gotta hand it to you, I was getting frustrated earlier by someone suggesting Jupiter caused tidal forces on Earth that were responsible for earthquakes, but this just takes the cake for the musing most detached from reality.
DeleteGravity is nothing more then week magnetism and the way to increase magnetism is to introduce an electric field. Here's a bit more truths https://www.youtube.com/watch?v=PYzEy4GlcQI .
DeleteCoulombs law, to me explains gravity Opposites attract and likeness repels https://en.wikipedia.org/wiki/Coulomb%27s_law
forgot this link to magnetism https://en.wikipedia.org/wiki/Magnetism
DeleteJesus Christ, electric universe quackery... No, gravity is not an electric phenomenon, since neutral particles are affected by it. No, creating a strong electric field does not affect gravity, or vice versa. No, Coulomb's Law is not the law of gravitation, merely an analogue that owes its similarity to Euclidean geometry and the fact that both mass and NET charge scale linearly to produce their forces.
DeleteThis has no place in any serious outlet.
jmorpuss, what I wrote was not that "the Sun drives temperatures at the surface", but that Earth's "supply of fuel is the sun".
DeleteWithout the sun's energy there'd not be any day (or night), or weather. There'd not be any coal to burn either, because there'd not have ever been any life, let alone plant life.
Given that there is a constant supply of energy on Earth, the atmosphere and oceans interact so there is weather and climate. Given the sun as the supply of energy, it's oceans and atmosphere that determine the temperature at the surface. Without the air and seas we'd not be here (there'd be no life). There'd be no weather to speak of either - just dark and cold followed by light and hot at any one place on the surface.
As for your magical physics - what Alexander Coulter said. You know that HW is about science, it's not for pseudo-science fiction and wizardry and alchemy and microwave mirrors.
What? jmorpuss has unified electromagnetism and gravity! My god, Einstein worked the last decades of his life in vain, yet a blogger in his underwear has solved one of the toughest problems in physics.
DeleteWho needs quantum theory or Riemann geometries when we already have a solution?
Oh wait ..... maybe he's just another wobbly idjit with a case of D-K unlikely to be cured anytime soon ....
Sou When you discover or accept that the main driver here on Earth is electricity/electrons and then things can start to fall in place , like ocean evaporation created by salinity allowing current to flow like in this simple to understand video https://www.youtube.com/watch?v=wwGx7qqQe-Y
Deletejmorpuss the Hayden Planetarium's Neil deGrass Tyson will tell you that he doesn't know what a gravity wave is but he's working hard to find out.
DeleteMore often than not, science is incomprehensible to me but there's one aspect of science I find quite easy - assessing its current state of knowledge. I do that by going to science based sites like Hotwhopper, SkS, Open Mind, The Reddit Journal of Science - sites that only deal with published research or debunk those that don't.
jmorpuss if you are genuinely interested, give the conspiracy hobbyists a swerve and go straight to the scientists. There is so much shit on the internet but when you learn where the skill and the rigour hang out, filtering shit becomes automatic.
jmorpus, you wouldn't happen to be the Chair of Santa Bunny Physics at the University of DKE, would you?
Delete"like ocean evaporation created by salinity allowing current to flow"
DeleteIn the video the guy is dissociating water molecules into hydrogen and oxygen gas. This is not evaporation. Clearly you have a lot to learn jmorpuss, and I would recommend not using phrases like "When you discover or accept [rubbish]" until you do so.
jmorpuss might be enthralled by his or her computer, thinking the electricity/electrons that drive it, also drive the world. (They might drive jmorpuss' odd notions, but not the weather.)
DeleteWhat I do accept is that jmorpuss is either playing Poe or the genuine article. Evidence here and elsewhere supports the latter.
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DeleteOh yes. And when the clouds obscure the sun and we think it gets colder as a result, its really because the earth's magnetic field takes a quick holiday.
DeleteBanned from posting? I hope you are not allowed to use sharp implements.
Why would a question about Australian weather modification and John Cooks silence about Atlant (cloud ionizer) get deleted from Hotwhoppers site and SKS. I can only surmise the two sites are tared with the same propaganda brush .
DeleteWhy? Because you were extremely rude. Please address me as Sou.
DeleteBTW if you think straight, mainstream science is "propaganda", then it's no wonder you were banned from SkS. Given your attitude, you're lucky to be still allowed to comment here. It won't last I expect. This is a science blog. It's not a freeby notice board for whatever wacky "theory" quacks want to promote.
Well, it's an ill wind....
ReplyDeleteI at least learned something by following the link to the Physics World article concerning heat from the earth's core. That was new to me (lack of science background showing again). SkS explains why that heat does not control climate: http://www.skepticalscience.com/heatflow.html
In this video https://www.youtube.com/watch?v=zYS9kdS56l8 I see the sun as the battery and the motor as Earth. Charged particles from the sun interacting with Earths magnetic field to create a strong electromagnetic force (spin)
Deletejmorpuss this exchange is finished. I believe you are sincere and there are many hobby sites that will welcome your sincerity. This site is a science site and it does not.
Delete"Foul weather electric fields can reach values of well over 10,000 volts per meter at the ground during a storm. " http://www.missioninstruments.com/pages/learning/elec_fields.html
DeleteYou "see" it as a battery but you have no evidence. You also don't even understand how a battery works, with a net charge flow being created by potential differences across a distance. But the solar wind is net neutral, since we do not observe the Sun globally gaining charge (that would be a very unstable scenario too). While the solar wind does provide particles which interact primarily within our ionosphere to create a global electric circuit, that does NOT mean that it creates events like global warming, does NOT mean it impacts the water cycle at the surface, and certainly does NOT mean that gravity is somehow related to the electric force at any temperature that exists in the present universe.
DeleteYou need to do better than giving us videos of absolutely unrelated concepts and then saying "see how this is like that?" They are not alike. There are very different principles at play here, very different energy scales, and since you won't do better I would ask that for the sake of the quality of commentary on this site you stop.
Alexander, People think that a PHD makes you smart, but smart is a process of thought and something you can't learn from a book .There's lots of laws in science that keep people like you locked away in a cage like a parrot who only repeat what their heard from their owner, so who owns your words ? " Electricity in the Universe has been identified from beneath our feet, in animals and plants, our biosphere, and out to the furthest reaches of the Universe. In general, electricity is present wherever we find plasma, and since 99.999% of the visible universe is in the plasma state, magnetic field and electric currents are nearly everywhere. " http://www.electricuniverse.info/Introduction This may help you step out of the dark and into the light. Tesla wanted to give humanity free energy back in the 19th century , WHY has science sense then been failing us. We need to stop the power supply (the grid) monopoly that fossil fuels hold over our everyday lives. If there was more scientist working on hydrogen fuel cell technology the fossil fuel monopoly would collapse . Why not get your university to through some funding at things like this and do us all a favour . Here comes another youtube clip as a starting point. From simple starting points big things grow. https://www.youtube.com/watch?v=ZXjNvZAwfSk
DeleteAre you smart jmorpuss?
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Deletejmorpuss - are you familiar with the term Dunning-Kruger Effect?
Deletehttps://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
Have you considered the possibility that it describes one jmorpuss?
We've all considered it and - speaking only for myself of course - it seems appropriate.
We're like adolescents who are bored and looking for thrills.
ReplyDeleteAnd we're conditioned to stay that way forever, because it keeps us consuming. That's the underlying core of the root of the problem (society's dependency on an economy that must grow exponentially forever).
Although I accept the analogy, Sou—it's a good one—there are a number of specific automotive elements within it that are technically wrong. As an example, you say "...apply brakes to oppose the engine, and shift gears to increase or decrease the power of the engine." The brakes don't 'oppose the engine', they oppose gravity; and the gears don't 'shift to increase the power of the engine', they shift to alter the effective torque of the engine.
ReplyDeleteI know this might appear to be nit-picking but unfortunately these inaccuracies can and will be seized on by deniers as proof the analogy as a whole is wrong (which it's not).
The brakes oppose gravity? Please elaborate.
DeleteJohn, I see where you are coming from. I'd hope the deniers picked on Willis before picking on this article though.
DeleteAs I said, it was a simplified picture - does that give me an out? :)
One more nitpick - the brakes no more oppose gravity than they oppose the engine. The brakes apply friction, which slows the rotation of the wheels, which I guess opposes the force of gravity if going downhill, though it supports gravity if going uphill. And you could just as easily say they oppose the direction the engine is driving you in.
As for gears, strictly speaking you're right, Still gears do affect the car's speed, and torque and power are related.
:D (all in good fun)
Yes, I should have said the brakes oppose gravity and momentum. The point is that the brakes are never on at the same time as the engine: whether manual or automatic, fuel is cut off as the brakes are applied. And most cruise controls don't apply the brakes anyway. Oh dear, I'm digging a deeper hole.:-)
DeleteAs a general point I think it's best to keep analogies simple. Trying to make them fit too much usually ends up in nit-picking. Which is what I've done. Maybe I should have just kept quiet. :-)
Yes analogies are useful for explanation, not in depth analysis. Anyone remember analogue computers from before the days of digital computers?
DeleteThe real take home message is that the CO2 concentration in Earth's atmosphere is the control knob for temperature equivalent to the speed control of a cars cruise control. Everything else is just feedbacks and minor temporary forcings.
Variation in the Sun's luminosity is a forcing but it is very stable and can easily be accounted for.
When the Sun was much younger its luminosity was about 70% of current. Even then CO2 concentration in the atmosphere controlled Earth's temperature by the cycle of geological sequestration of CO2 and later emission by volcanoes.
Deniers just cannot face the fact that CO2 in our atmosphere is THE control knob for temperature. Their tiny minds will argue from false analogies to rationalise their absurd beliefs. Bert
Sou if I was trying to show the analogy between a car's cruise control and the Earth's energy balance I would assign the following 'equivalents'.
DeleteEarth's surface temperature Car's speed
CO2 concentration Speed setting
Gravitational kinetic energy (hills) Ocean heat content
Friction Radiation out to space
Aerosols Volcanic dust Road surface
PDO El Nino etc Prevailing wind
Even now this is not a real equivalence as it can never be. Bert
Willis always roughed me up for being an Obama apologist and suggests I should go back to being a staunch Republican and party with him. I've seen the ladies he parties with and I cannot ride with someone else driving... so no thanks
ReplyDeleteI just watched Prof. Richard Alley's National Academy of Sciences presentation on the history of CO2 and it's a fascinating exposition of what we now know about how CO2 effects climate and how the Earth does regulate its temperature over millions of years.
ReplyDeleteMoney quote at 11:47 is "if you've got a half a million years to wait, then no worry!"