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wisdomrays · 4 years ago

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TAFAKKUR: Part 347

THE UNIVERSE IN THE LIGHT OF MODERN PHYSICS

‘The least understood aspect of the universe is its being understandable,’ said Einstein.

These words attempt to pierce the veil of habit that develops in our minds from not looking into the reason for things. The perfection of the order operative in the universe is of such a degree that it prevents us from being aware of it. In the same way, we only become aware of the faultless operation of the watches we have worn on our wrists for years when they stop working.

In the world-view developed upon the foundation of Newton’s laws of motion, the universe was likened to a flawlessly operating watch. Events were tied to one another in a cause-effect relationship and our knowing the laws of this relationship allowed us to predict events with great accuracy. It was possible to determine with mathematical exactness a wide range of phenomena, from the times of eclipses of sun and moon to the amount of fuel and the speed needed to put an object into orbit around the earth. The success of these ‘natural laws’ led many people to believe that they completely expressed and ‘ruled’ the whole order of the universe.

Because God creates and sustains all things and events from behind the veil of universal general laws, because certain events (causes) are followed reliably by similar events (effects) each time they (the causes) occur, it begins to be supposed that the causes are responsible for or ‘create’ the effects. This is, of course, a gross error, as no number of causes suffices to create even a little effect; for every event even the tiniest, the whole universe must be presupposed first, including the laws operative within it. Moment by moment, all things and all events are created and sustained by God, Who wills from an infinite range of alternative possibilities a particular actuality.

The clockwork model of the universe derived from Newtonian or classical physics is not a complete account of the phenomena which we observe in the universe. Already in the late 19th century, scientists had been bewildered by the lines that turned up in the light spectra emitted by heated gases: the steady, stable clockwork model predicted did not happen. Also, there were problems explaining the behaviour of light: sometimes it made more sense as a beam of particles, sometimes as a wave.

Today our understanding of the universe is very far from the ‘clockwork’ model. The shift in understanding occurred in the first quarter of the 20th century, beginning in 1900 with the publication of Max Planck’s work on radiation. The problem Planck worked on for six years was that the actually measured radiation from hot bodies did not conform to the values predicted by the classical theory. He put forward the suggestion that bodies radiating energy did so, not evenly and continuously, but unevenly and discontinuously in tiny packets or ‘quanta’. So startling was this suggestion that, despite confirmation by experiment, Planck himself thought of his theory as solving the problem of radiation by a sort of trick.

But then, in 1905, Albert Einstein published an article using the notion of packets of energy of definite sizes to explain how electrons are ejected from metal when light (radiation) falls on it. Whereas classical theory had predicted that the voltage (measure of the energy of the electrons ejected) would be proportional to the intensity of the light (radiation), Einstein showed that it was proportional instead to the frequency of the radiation. The conformity of this explanation with experimentally observed results gained Einstein the Nobel Prize. (Einstein didn’t receive the prize for his famous theory of relativity.) The significance of these findings and theories was not fully appreciated at the time.

A few years later in 1910, Ernest Rutherford did a ground-breaking experiment. He bombarded a thin layer made up of gold atoms with high energy particles and showed that the atom contained an extremely small positively-charged nucleus with negatively-charged electrons moving around it. Following the classical physics model, these electrons should have been small particles orbiting the nucleus in the same way as the planets orbit the sun, steadily losing energy until they fell on to the nucleus-in other words, the atom should have been unstable. Again it was a rejection of the classical model, three years later, by Niels Bohr, that helped solve the problem. Bohr argued that the electrons must move in fixed orbits until deflected by the absorption or emission of a unit of energy.

Atoms emit radiation after various external signals and only at specific wave lengths. As Einstein said, every different color of light is composed of energy packets inversely proportional to its wave-length (frequency). Because the Planck constant (h) is very small, the energy of these packets is also very, very small. For example, a normal light bulb emits 1020 light packets (photons) a second. Each of these photons is created when an activated atom or molecule passes to its normal or ‘basic state.’ Thus light, which allows us to see and which is a basic building block of life, develops as a result of the motions (in wave form) of electrons. The concepts of classical physics could successfully explain many of the events of daily life, but it couldn’t explain events on the subatomic level.

During those years (1910-1925) physics fell into a state of confusion because of the many measurements that conflicted with general theory and could not be explained by it. This situation was to lead W. Pauli (later to discover the principle fundamental to the understanding of the structure and characteristics of elements) to say he would rather have been a singer or gambler than a physicist. Actually in order to explain the observations being made, the whole way in which physical events had been understood required fundamental revision by wholly new methods. This was achieved by Werner Heisenberg, a 24 year-old physicist described by his teachers as a person who dealt with the essence of a subject rather than getting bogged down in detail, a person with powerful concentration and ambition. Perhaps the success of this young mind can be explained by the critical perspective he developed through reading the works of great men such as Kant and Plato, which was later supported with sound knowledge he got from great physicists. Heisenberg, who relaxed from work by climbing rocks and reading poetry, said: ‘It was around three in the morning when the calculations were completed and the solution to the problem appeared in front of me. First I experienced a great shock. I was so excited that I didn’t even think about sleeping. I left the house and, sitting on a rock, I waited for the sunrise.’

Like the other scientists who established quantum physics, Heisenberg was a philosopher-physicist. The philosophy he accepted and advocated that allowed him to interpret atomic events is as follows: ‘Even though it is successful with classical physics, the language we use to explain physical events in the atom or its surroundings is insufficient. For this reason, after making a specific measurement in a quantum system (for example, an atom), using that knowledge we can get a theory that will tell us what kind of results we can find in the next measurement. But it’s not possible to say anything about what takes place between the two measurements.’

What pushed Heisenberg to make such a statement was that the mathematical tools he used to develop a theory that could explain the observed discontinuity of energy in light and atoms were abstract concepts that had not been used before. In classical physics the numbers we know were used to give value to matter’s position, speed, size, etc. In Heisenberg’s quantum mechanics, these sizes were expressed with infinite dimensional n x n matrices which enabled physicists to calculate the properties attributed to electrons (energy, position, momentum, angular momentum) in an approximate way. Because these abstract mathematical expressions didn’t have an equivalent in everyday spoken language, it wasn’t possible to approach them with a classical understanding. It was observed that in order to measure the position of an electron, the experimenter necessarily altered its velocity. This problem was formally expressed in 1927 in Heisenberg’s famous Uncertainty Principle.

Independently of Heisenberg, Erwin Schrodinger made another significant breakthrough in mathematical description of electrons. Inspired by the hypothesis put forward two years earlier by De Broglie about the wave properties of matter particles, Schrodinger developed a ‘wave mechanics’ by which the movement of particles could be calculated. (figure: 1) But the fundamental question remained as to what these strange and original ‘waves of matter particles’ or ‘waves accompanying matter particles’ were.

The mathematical formulations devised by Heisenberg and Schrodinger are complementary in the sense that physicists use whichever best resolves the particular calculations they are trying to make. There is no formally distinct space between the scientists and the phenomena they are seeking to understand and manipulate: their means of observation and manipulation (the mathematics) in some sense ‘posit’, put in place, the very phenomena whose place (among other properties) they are trying to determine. Alongside the notion of an infinite array of rows and points, as invented by Heisenberg, to plot the position or motion of a sub-atomic particle, physicists and philosophers of physics have begun to speak of arrays of events or ‘stories’ to try to explain, in something resembling ordinary language, the ideas they are handling. This cannot be described as a world-view in the way that the Newtonian physics confirmed and sustained a world-view, but it is nevertheless a clear and distinct disposition which, instead of excluding God as the Force Who wound up the clockwork and then retired from His creation, admits the in-completeness and uncertainty of human knowledge as a structural element of reality-in other words, the uncertainty is not a function of our present ignorance (to be relieved by future knowledge), but an actual constituent of the way reality is.

Quantum physics, at least figuratively and metaphorically, has became a vehicle for the interpretation of such concepts as matter, beyond-matter, energy, existence and non-existence in a way nearer to Divine sources; and led to many physicists settling accounts with their conscience and turning towards God Who is understood to be simultaneously transcendent and immanent, there and here.

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inkofamethyst · 3 years ago

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June 6, 2021

Alright. Are we actually more intelligent than people in the past by a ton, or do we just have more systems in place where we can store the “intelligence” that we don’t need at all times (ie computers and such). Like, the fact that I have a phone to remember my contacts for me and a calculator to do my math for me and a computer to quickly find information for me... you know?

Like, I’ve been watching ST:TNG for the past few months (I’m smack dab in the middle of season 6 and whew), and these people know so much about everything��in general??? I mean, specifically Starfleet folks who are meant to be the best and brightest, I know, but all of them are just so knowledgeable in a way that I don’t think most humans today are capable of? And like, obviously evolution could could have played some role (but I seriously doubt that 300 or so years would be enough to produce such a substantial change in brain capacity? idk! I’m not a neurologist not am I particularly interested in that field on its own (but potentially as a part of human evolution)), but I mean...

Okay, Captain Picard, right? He’s a whole captain of a ship, but he also has general knowledge in so many different aspects of how to run a starship successfully that, I mean sure there are specialists, but he could probably perform the vast majority of basic maintenance jazz himself, plus piloting and scanning and weaponry and fighting and his knowledge of general scientific concepts is so broad which allows him to carry on with super technical conversations, only needing brush-ups here and there on super specific things.

And, I mean, even the modern American child probably has more general knowledge of the world around them than a common adult back in the 1500s or before (of course, modern children are also less likely to have specialized knowledge related to a job or something), and most college students (tbh, many high school students) end up taking calculus, and I wouldn’t be surprised if the average age of a calculus student continues to decrease over the next few centuries, if not decades.

So it begs the question: are we actually smarter than ye olde folke of olde? Or is something else at play?

I of course have no scientific study to back this up, just my literal own observations and some mildly educated guesses (as in, the guesses are being made by a person who is pretty mildly-educated), but I think that the simple access to general information through ever-present and ever more powerful technology has made humans able to take in more information and solve more complicated problems, compounding on the work of our predecessors with astounding speed in comparison to their rates of discovery and the like.

Like, oh, I don’t know if I have a good example... hm. Okay, so I don’t have to memorize directions or use a map, really, as I’ve got a lil mini computer in my pocket that will tell me exactly where I need to go if needed. My hypothesis is that by freeing my mind of the need to remember something so “trivial” (but which would have been necessary to simply commit to memory by generations who did not have access to this particular technology), I can tell you that, idk, that taking the derivative of a position curve can give you velocity, and that when the velocity of a projectile is zero, it has come to a complete stop and may be changing directions, for example. That’s legit just “common knowledge” that I haven’t dealt with in three years or so, but I recalled it with little difficulty on my own.

I don’t know if I’m making any sense, but it’s something that’s been on my mind for a bit. idk, let me ramble, okay?

anyway,

I finished my jumbo marley twists today! They’re mostly black with some silver strands thrown in for flavor, and I feel kinda boho in them? Definitely feel attractive omg. I feel like a pirate!! From far away they kinda look like dreads lol. Now I gotta sleep in them which should be an experience. Ugh, I always hate the first sleep in a new hairstyle.

Very tempted to do my floral fake tattoo sleeve this week omg it would look so cool

Oh, also, I was the person to claim the pattern from yesterday! Just waiting for the invoice :) (might have to resolve something in Paypal tho :/)

Um, today I’m thankful that I was selected for the thing I interviewed for a few weeks ago! Excited to see where the opportunity leads, and it seems like they were pretty selective with how many people were selected vs. how many applied. Always nice to stroke the ego whenever I can.

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johnmauldin · 7 years ago

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Mauldin: 7 Forecasts from the Brightest Financial Minds I Know

In my fairly upbeat 2018 forecast, I predicted that the US economy and markets will probably hold up well, thanks to tax cuts and deregulation. That’s, of course, assuming the Federal Reserve gets no more hawkish than it already has.

Continuing my series of forecasts, here I’ll look at predictions from some of my most trusted friends and colleagues (subscribe to Thoughts from the Frontline to receive all my forecasts). Some disagree with my own views—and that’s perfectly fine. I want you to see all sides so you can make good decisions for your own family and portfolio.

I’ll let these forecasters speak for themselves in longer quotes than I usually allow, then add my own comments.

The article runs long, but I’m sure you’ll take away a lot from it, so bear with me…

Ben Hunt: No Algorithm Can Predict the Future

Let’s start not with a forecast but with an important story about forecasts from Ben Hunt.

Ben’s wide-ranging essays are hard to summarize or excerpt in a way that captures their breadth and depth.

I’ll give you a tiny snippet, but please, set aside some time this month to read the entire article. It is long but worth your while.

The Three-Body Problem is a famous example of a system which has no derivative pattern with any predictive power, no applicable algorithm that a human could discover to adapt successfully and turn basis uncertainty into basis risk. In the lingo, there is no “general closed-form solution” to the Three-Body Problem. (It’s also the title of the best science fiction book I’ve read in the past 20 years, by Cixin Liu. Truly a masterpiece. Life and perspective-changing, in fact, both in its depiction of China and its depiction of the game theory of civilization.)

What is the “problem”? Imagine three massive objects in space … stars, planets, something like that. They’re in the same system, meaning that they can’t entirely escape each other’s gravitational pull. You know the position, mass, speed, and direction of travel for each of the objects. You know how gravity works, so you know precisely how each object is acting on the other two objects. Now predict for me, using a formula, where the objects will be at some point in the future.

Answer: You can’t. In 1887, Henri Poincaré proved that the motion of the three objects, with the exception of a few special starting cases, is non-repeating. This is a chaotic system, meaning that the historical pattern of object positions has ZERO predictive power in figuring out where these objects will be in the future. There is no algorithm that a human can possibly discover to solve this problem. It does not exist.

And that of course is the basic problem we have in economics and investing. When we say that past performance is not indicative of future results, that aphorism is more than just legalese.

Such ideas can easily discourage us from even thinking about the future. However, the real answer is to think about the future differently.

With that prelude, let’s move on.

Anatole Kaletsky: Inflation and Bond Yields Will Accelerate

If I had to rank economic forecasting groups (as opposed to individuals) for consistent quality, Gavekal would be high on the list.

Here are just a few Gavekal snippets from the opening week of 2018. We’ll start with Anatole Kaletsky, who zooms in on inflation as this year’s key unknown factor.

Will inflation accelerate in the US, but not in other major economies? I think the answer is “Yes”, for the same reasons as above. However, I also expected inflation to accelerate and bond yields to increase last year. Instead, both inflation and growth ended the year exactly where they were.

The simple answer is that US unemployment is now 4.1% instead of 4.8%. I was wrong about 5% unemployment being a non-inflationary growth limit, and maybe 4% isn’t either. But whatever the exact number may be, the US is certainly closer to its non-inflationary growth limit now than it was a year ago. In addition, the Trump tax cuts, if they actually stimulate higher US consumption and/or investment (which they may not do by any meaningful amount) will add to US inflationary pressures, since new production capacity will take several years to boost non-inflationary trend growth.

If the prediction of higher US inflation turns out to be right, it will be a game-changer. It will produce much more volatile market conditions and even greater under-performance by US equities and bonds relative to assets in Europe and Japan, where inflation is not a risk.

The follow-on question, if Anatole is right about inflation, is how the Fed will respond to it. The ideal response would have been to start tightening about three years ago. That opportunity having past, the remaining choices are all varying degrees of bad.

Louis Gave: Financials and Energy Will Be Top Sectors This Year

Now let’s move on to Louis Gave, who gives us some stock market ideas at the end of a long, thoughtful essay on liquidity.

Putting it all together, 2018 does seem to be starting on a different note than 2017. While the bull market may not be in peril, it is a tough environment for a price/earnings ratio expansion to occur. Such an outcome usually relies on excess liquidity moving into equities. Yet in 2018, equity markets are more likely to be a source of liquid funds than a destination for them. It follows that if a multiple-expansion is off the table then equity gains will rely on earnings rising. The area where such an improved profit picture is likely is financials (higher rates and velocity) and energy (higher prices). The fact that both of these sectors presently trade on low multiples also helps.

If you want specific sector ideas, there are two good ones.

David Kotok: A Shift Upward Will Continue

My friend David Kotok of Cumberland Advisors had some New Year’s Day thoughts on the Republican tax bill’s impact.

Once the transitional shock of yearend is absorbed, we think the tax bill will raise the valuation of US stocks. Simply put, the tax bill will generate a permanent shift upward of somewhere between $10 and $14 in the threshold of S&P 500 earnings. Once you adjust for that permanent shift, you may continue to factor in the earnings growth rate that you expect from a US economy that is going to grow at 3% instead of 2%. We believe that growth rate is likely for a couple of years.

So, S&P 500 earnings should range up to and then above $150 by the decade’s end. They will do so while the Fed is still engaged in a gradualist restoration of interest rates to something more “normal,” whatever that word means. And those earnings will occur while a repatriation effect is unleashing $1 trillion of stagnant cash in some form of robust redistribution (dividends or stock buybacks) or as productivity-enhancing capex spending. Bottom line is no recession in sight for at least a few years; and low inflation remains, so interest-rate rises will not derail the economic recovery, nor will they alter rising stock market valuations.

Years ago we projected a 3000 level on the S&P 500 Index by 2020.

That is considerably more bullish than most 2018 forecasts I’ve seen. Rather than argue with David, I’ll say this: Be ready for anything this year. The future is no more uncertain than it always is, but the consequences of a mistake are growing as the bull market and economic expansion grow long in the tooth.

They will end at some point. That means you need a strategy that will let you both participate on the upside and defend yourself when the bear appears. I reiterate that you should be diversifying trading strategies, not just asset classes.

Paul Krugman: Rising Rates Spell Trouble

Next we turn to Paul Krugman, who is not generally one of my favorite economists. I quote him this time because he sounds a lot like, well, me.

So we’re living in an era of political turmoil and economic calm. Can it last?

My answer is that it probably can’t, because the return to normalcy is fragile. Sooner or later, something will go wrong, and we’re very poorly placed to respond when it does. But I can’t tell you what that something will be, or when it will happen.

The key point is that while the major advanced economies are currently doing more or less OK, they’re doing so thanks to very low interest rates by historical standards. That’s not a critique of central bankers. All indications are that for whatever reason — probably low population growth and weak productivity performance — our economies need those low, low rates to achieve anything like full employment. And this in turn means that it would be a terrible, recession-creating mistake to “normalize” rates by raising them to historical levels.

But given that rates are already so low when things are pretty good, it will be hard for central bankers to mount an effective response if and when something not so good happens. What if something goes wrong in China, or a second Iranian revolution disrupts oil supplies, or it turns out that tech stocks really are in a 1999ish bubble? Or what if Bitcoin actually starts to have some systemic importance before everyone realizes it’s nonsense?

That was from Krugman’s January 1 New York Times column, and his assessment is not far from my own view.

The difference between us is that Krugman has made a remarkable turnaround since the imminent doom he predicted right after the election. So I’m glad to welcome his Damascene conversion.

I hope it sticks this time.

David Rosenberg: We Are 90% Through This Cycle

I don’t know any economic forecaster more prolific than David Rosenberg. I don’t know how he even finds time to sleep, frankly. His Breakfast with Dave is often the same length as my weekly letters, and he writes it every working day.

Dave’s December 29 issue of Breakfast with Dave was a tour de force on world markets, which I can’t possibly summarize and do any justice to the original, so I’ll cut straight to his conclusion.

In other words, expect a year where volatility re-emerges as an investable theme, after spending much of 2017 so dormant that you have to go back to the mid-1960s to find the last annual period of such an eerie calm – look for some mean reversion on this file in the coming year. This actually would be a good thing in terms of opening up some buying opportunities, but taking advantage of these opportunities will require having some dry powder on hand.

In terms of our highest conviction calls, given that we are coming off the 101 month anniversary of this economic cycle, the third longest ever and almost double what is normal, it is safe to say that we are pretty late in the game. The question is just how late. We did some research looking at an array of market and macro variables and concluded that we are about 90% through, which means we are somewhere past the 7th inning stretch in baseball parlance but not yet at the bottom of the 9th. The high-conviction message here is that we have entered a phase of the cycle in which one should be very mindful of risk, bolstering the quality of the portfolio, and focusing on strong balance sheets, minimal refinancing risk and companies with high earnings visibility and predictability, and low correlations to U.S. GDP. In other words, the exact opposite of how to be positioned in the early innings of the cycle where it is perfectly appropriate to be extremely pro-cyclical.

So it’s either about investing around late-cycle thematics in North America or it is about heading to other geographies that are closer to mid-cycle — and that would include Europe, segments of the Emerging Market space where the fundamentals have really improved, and also Japan. These markets are not only mid-cycle, and as such have a longer runway for growth, but also trade relatively inexpensively in a world where value is scarce.

Dave gives us some geographic focus, and it’s mostly outside the US and Canada. He likes Europe, Japan, and some emerging market countries because they are earlier in the cycle.

He’s certainly right on that point, though I think we may differ on how long the cycle can persist. The past doesn’t predict the future.

For the record, in my own portfolio design, we are about 50% non-US equities. My managers are finding lots of opportunities outside of the US.

Byron Wien: “Ten Surprises” List

We’ll wrap up today with an annual tradition: Byron Wien’s annual “Ten Surprises” list.

It always causes me a little cognitive dissonance because by definition you can’t “expect” a surprise. That aside, Byron’s list is always a useful thought exercise. Here it is.

1. China finally decides that a nuclear capability in the hands of an unpredictable leader on its border is not tolerable even though North Korea is a communist buffer between itself and democratic South Korea. China cuts off all fuel and food shipments to North Korea, which agrees to suspend its nuclear development program but not give up its current weapons arsenal.

2. Populism, tribalism and anarchy spread around the world. In the United Kingdom Jeremy Corbyn becomes the next Prime Minister. In spite of repressive action by the Spanish government, Catalonia remains turbulent. Despite the adverse economic consequences of the Brexit vote, the unintended positive consequence is that it brings continental Europe closer together with more economic cooperation and faster growth.

3. The dollar finally comes to life. Real growth exceeds 3% in the United States, which, coupled with the implementation of some components of the Trump pro-business agenda, renews investor interest in owning dollar-denominated assets, and the euro drops to 1.10 and the yen to 120 against the dollar. Repatriation of foreign profits held abroad by U.S. companies helps.

4. The U.S. economy has a better year than 2017, but speculation reaches an extreme and ultimately the S&P 500 has a 10% correction. The index drops toward 2300, partly because of higher interest rates, but ends the year above 3000 since earnings continue to expand and economic growth heads toward 4%.

5. The price of West Texas Intermediate Crude moves above $80. The price rises because of continued world growth and unexpected demand from developing markets, together with disappointing hydraulic fracking production, diminished inventories, OPEC discipline and only modest production increases from Russia, Nigeria, Venezuela, Iraq and Iran.

6. Inflation becomes an issue of concern. Continued world GDP growth puts pressure on commodity prices. Tight labor markets in the industrialized countries create wage increases. In the United States, average hourly earnings gains approach 4% and the Consumer Price Index pushes above 3%.

7. With higher inflation, interest rates begin to rise. The Federal Reserve increases short-term rates four times in 2018 and the 10-year U.S. Treasury yield moves toward 4%, but the Fed shrinks its balance sheet only modestly because of the potential impact on the financial markets. High yield spreads widen, causing concern in the equity market.

8. Both NAFTA and the Iran agreement endure in spite of Trump railing against them. Too many American jobs would be lost if NAFTA ended, and our allies universally support continuing the Iran agreement. Trump begins to think that not signing on to the Trans-Pacific Partnership was a mistake as he sees the rise of China’s influence around the world. He presses for more bilateral trade deals in Asia.

9. The Republicans lose control of both the Senate and the House of Representatives in the November election. Voters feel disappointed that many promises made during Trump’s presidential campaign were not implemented in legislation and there is a growing negative reaction to his endless Tweets. The mid-term election turns out to be a referendum on the Trump Presidency.

10. Xi Jinping, having broadened his authority at the 19th Party Congress in October, focuses on China’s credit problems and decides to limit business borrowing even if it means slowing the economy down and creating fewer jobs. Real GDP growth drops to 5.5%, with only minor implications for world growth. Xi proclaims this move will ensure the sustainability of China’s growth over the long term.

(https://www.blackstone.com/media/press-releases/byron-wien-announces-ten-surprises-for-2018)

Whatever your predisposition, there’s plenty to both like and dislike in there. On #7, I think 10-year Treasury bonds at 4% or more will look like the end of the world to younger folks.

It’s been more than a decade since we saw any such thing, and at that point they were falling, not rising. But if he’s correct that CPI pushes over 3%, then bond yields have to rise.

Personally, I think I would take the other side of that bet. I think the yield on the 10-year actually has a chance to fall.

On another note: If Byron is right that “speculation reaches an extreme,” the resulting correction will be a lot deeper than 10%. I don’t think we are there yet and probably won’t reach that point in 2018. But we will get there eventually.

All right, my stack of New Year’s predictions is barely any smaller, but we’ll stop here and pick up next week in Thoughts from the Frontline.

Join hundreds of thousands of other readers of Thoughts from the Frontline

Sharp macroeconomic analysis, big market calls, and shrewd predictions are all in a week’s work for visionary thinker and acclaimed financial expert John Mauldin. Since 2001, investors have turned to his Thoughts from the Frontline to be informed about what’s really going on in the economy. Join hundreds of thousands of readers, and get it free in your inbox every week.

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actnoweco · 5 years ago

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Blackboard 2.0 – Science in a bucket!

We are a group of undergraduate students studying Physics of the Earth System. We love science. We love that at Geomar we can study super exciting aspects of the Earth System in very small groups. And we love formulas and mathematics, well to a certain extend at least

This is where the buckets come into play…

Written by Ludwig Bitzan, Sebastian Bubmann & Alex Schmitz

This winter term, we continue with the “Atmosphere and Ocean Dynamics” lecture at Geomar. In the course, we study ways to describe atmosphere and ocean phenomena utilizing mathematics. It is good to see that all the hard work invested into the courses in mathematics and theoretical physics eventually pays off. At the same time, however, we sometimes find ourselves scratching our heads when the Blackboard is covered in formulas. It can be very rewarding to power through a derivation of a formula and prove it to match with observations in the field. But what can be more rewarding than to witness the phenomena first hand?

Now, in this winter term, Mirjam and Torge thought of a great way that allowed us to apply the lessons learned from theory in practice: tank experiments! They spared no effort and prepared an encompassing set of experiments, from convection in stillstanding to rotating tanks simulating Ekman spirals and planetary waves. Lego motors were converted to power a uniform rotation of the round and squared tanks. And to be frank, who does not want to find an excuse to tinker around with Lego?

The playroom

Day 1

The basic recipe for Day 1 was simple: Take a bucket. Put it on a spinning disk powered by a Lego motor. Wait until the frictional forces of the bucket’s walls have accelerated the water column to rotate at the same speed. Use a few drops of food colorants and be stunned by the results:

Day 2

On Day 2 it was all about convective processes in the water column. In both, a non-rotating and a rotating tank, cooling was simulating by using a cold pack or a round glass with frozen water respectively. Areas, where cooling was applied, were marked with blue, the remaining areas with red food color. The results without rotation showed very interesting parallels to water mass formation processes in the open ocean. A layer stratification and overturning circulation patterns were clearly visible. Heavy and cold bottom water was overlaid by intermediate water of medium density, which was formed by turbulent mixing in the cooled area. At the top a warm water sphere layer formed.

Water mass formation experiment

After initial experiments in the green buckets, Torge further optimized the lab’s setup. He procured special glass tanks with vertical walls. These allow to observe the phenomena much better including side views, as can also be seen here.

The new glass tanks allowed for more detailed observations of the experiments

Day 3

Last day of experiments, the grand finale. We had three different tanks to simulate three different ocean conditions and phenomena.

In a square tank, rotating with constant velocity, we observed so called topographic waves by embedding an inclined plexiglas plane. Such topographic waves occur when the ocean exhibits a sloping bottom or at inclined frontal zones between different water masses. Whenever a water parcel tries to move either into a deeper or a more swallow region, the conservation of angular momentum pushes it back by causing a small rotation. In sum, this leads to a drift perpendicular to the slope.

To make such movements visible, we simply put a blue dyed ice cube into the water and watched the molten dye’s path. As you can see in the picture the wave, more specifically the perturbation, spreads westward. Also, the slalom course where the water is forced back is clearly visible.

For the second experiment we changed our square tank to a cylindrical one and, again, set it in rotation for quite some time. We then inserted little crystals, which continuously emit purple color, into the water to make currents visible. As long as the whole tank rotates evenly, the water column inside is following it at the same speed. We call that “solid body rotation”, since water and tank act as one unit. Removing our nifty Lego drive and even abruptly stopping our spinning setup, changes the state dramatically: While the tank stops immediately, the water doesn’t quite get this information yet and keeps rotating. Everyone knows this phenomenon of inertia when one sits in a car that suddenly slows down. The vehicle itself slows down, whereas our bodies still travel further forward, just to be, luckily, held back by the seat belt. The latter in our case is the frictional force between the water and tank. Especially the friction at the border between its bottom and the water column shows a fundamental phenomenon of ocean physics: the Ekman spiral.

The bottom water layer is exposed to the largest frictional forces of the tank’s glas surface, opposing its rotational momentum. At the same time, the bottom layer itself affects the layer above and also slows it down, just a bit less. This layer then, again, slightly slows down the next level, and so on. The rotational velocity is therefore decreasing from top to bottom. Under these circumstances, the water forms purple spirals in the middle of the tank. The additional ascending motion is caused by convection from the sudden lack of centrifugal force

In the real ocean, the setup is however inverted. Here the friction occurs at the water surface (wind stress), so that the velocity decay will be from top to bottom.

The last experiment’s objective was to show convection of warm and cold water masses. Therefore, an experiment from Day 2 was repeated, but now with a much smaller rotational speed to cause less coriolis force induced turbulence. The effects were quite remarkable and very interesting to look at. The blue colored (cooled) water and the red colored (warmer) water form meandering fronts and show instabilities, just like the polar front, where similarly warm and cold air masses meet.

Conclusion

It is fair to say that we learned a lot by supplementing the theory with these experiments. Not only is it a lot of fun, the exercises do further give us a good thought-provoking impulse. They let us discuss what we have learned from the books more lively. We want to thank Mirjam and Torge for the cool experience. Also, Baloo the dog wants to thank everyone. Whilst being asleep most of the time, he now claims to be amongst the most well-educated of his kind.

source https://www.oceanblogs.org/teachingoceanscience/2020/01/27/blackboard-2-0-science-in-a-bucket/

#plasticpollution #plasticfree #zerowaste #plastic #environment #savetheplanet #recycle #pollution #ocean #nop

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smoothshift · 6 years ago

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Collecting feedback: Stick Shift FAQ Update via /r/cars

Collecting feedback: Stick Shift FAQ Update

"Granny shifting, not double-clutching like you should."

I suppose it's time to re-write the FAQ a bit (yes, we totally have a FAQ about manual transmissions and you should read it if you want to learn how to drive stick.)

There are, as usual, two components to driving stick well: theory and practice. Understanding theory makes it far easier to understand why you're doing something, and practice ... well, without practice, you're just bench racing.

I can't teach you the practice, so this'll be theory - though you should check out the three-part video on driving it -

How To Drive a Manual Transmission - Part 1: The Very Basics

How To Drive a Manual Transmission - Part 1.5: Hill Starts, Reversing, And Rev Matching

How To Drive a Manual Transmission - Part 2: Heel and Toe

This post is intended to gather feedback and corrections before it enters the FAQ, never to be touched again. And by never, I mean like four years, since that's how long it's been since the last meaningful update.

Let's get on with it!

Some Terminology

A general glossary of terms:

Engine: your engine, vroom vroom. Burns fuel and sends power and torque (rotational force) out.

Clutch: an assembly that, using friction, connects or disconnects the engine from the rest of the drivetrain.

Transmission: a device that allows the engine's rotational output to be geared up or down.

Differential: a device, after the transmission, that 1) provides a gear reduction ratio, and often 2) limits the slip angle between two outputs (axles).

Acceleration: how quickly you increase your speed (velocity)

Force: the amount of "push" getting put out

Torque: the "rotational force" (as measured a distance away from the axis of rotation) getting put out by things that spin

Power: energy put out per second; work over time; specifically for engines, it is torque multiplied by angular velocity (spinning speed)

Horsepower: A specific imperial unit: the product of the torque measured in pound-feet (pounds-force at a foot away from the axis of rotation), multiplied by RPM divided by 5252.

Let's start with three pictures

Transmission overview

Synchronizer overview

Transmission animation

What Does A Transmission Do?

For this section, we hope that you've played with gears before.

Gears mesh with other gears to accomplish a number of tasks. In a transmission, their main function is to 1) allow one rotating shaft to rotate another shaft, and 2) allow a speed and torque difference between those shafts.

A gear of a different size than another gear will change the rotational speed, and inversely change the torque.

For example: if you have a 1:2 ratio between gear circumferences, that means that an input gear rotates once and the output gear rotates twice (thus, twice as fast), but at half the torque. Torque multipliers are inversely proportional to speed multipliers. Double the speed, halve the torque. Triple the speed, cut the torque by three. Inversely, halve the speed, double the torque. You get it. I hope.

A transmission allows multiple ratios of gears to exist at the same time, and chooses between them to select the one you want.

First gear is a "short" gear, meaning the speed is reduced and the torque is increased.

Top gear is a "tall" gear, meaning the speed is increased and the torque is reduced.

We get our cars going in first gear - slowly, but with a lot of capacity to accelerate - and we cruise in a higher gear - much quicker, but less able to accelerate quickly.

(Acceleration, of course, is force multiplied by mass, and force is derived from torque and lever arms. The more torque, the more force, if your output circumference [wheels] stay the same size.)

The Components

Let's go through and explain what we see, starting with the transmission overview picture:

From the left, we have our input shaft (the green section marked 'from engine), which is always engaged through an input gear and a counter gear (also called the constant gear, driven gear) to the countershaft (also marked as the layshaft), in red.

The red countershaft has, in addition to the counter / constant / driven gear, a number of forward gears (in this diagram, five forward gears) and one reverse gear.

These forward gears are, in this diagram, arranged logically in size and number: the first gear on the countershaft is the smallest, and the biggest gear (fifth gear in this case) is the biggest. This means that a lower gear increases torque but decreases rotational speed at the wheels, and a higher gear does the opposite.

There is one more gear on the countershaft: the reverse gear. These are generally fairly small, as the reverse gear is a relatively "short" gear, in comparison to the higher gears - you know this because reverse limits your car to a fairly low speed.

Remember, any time the input shaft (green) is spinning, the countershaft (red) is spinning, and all the gears on it are spinning as well.

Just as the countershaft gears are always spinning with the countershaft, the output shaft gears are always spinning with the countershaft gears. These gears are always fixed! And they are all spinning, at any time that the input shaft is spinning.

However, because they are all different gear ratios, that means they are not engaged to the output shaft (out to the differential, or to a transfer case.)

The output shaft has the same number of forward gears as the countershaft (in this case, five), and a reverse gear.

Note that due to an idler gear between the layshaft and output shaft reverse gears, the output shaft reverse gear spins backwards from the rest.

And of course, note that just how the first gear of the countershaft is the smallest and top gear (fifth gear in this case) is the biggest, the gears on the output shaft are sized the opposite way: first gear on the output shaft is the biggest, and top gear is the smallest.

You can calculate gear ratios from the physical dimensions of these gears. For example, if your first gear has a 3:1 ratio, that means for every 3 rotations of the input shaft (and thus countershaft), the output shaft's first gear spins once. Your top gear ratio might be, for example, 0.70:1, which means that for every 0.7 revolutions of the input shaft, the output shaft's top gear spins a full 1 revolution.

Intermission

Hopefully you now have a picture in mind of this in action. Let's imagine you're standing still: your car idling with the clutch engaged, where the input shaft is spinning, the countershaft is spinning, all the gears on the countershaft spinning at the same rate, all the gears on the output shaft spinning at various ratios, and the output shaft not moving at all.

Gear engagement

How do you get moving?

Let's take a look at the gear engagement.

In the above image, this is the purple section. Let's take a closer look at the hub and synchronizer elements.

These hubs are fixed ("splined") to the output shaft.

(A spline is where a cylindrical shaft has a bunch of symmetrical grooves cut down its length, and something with matching grooves is mated to it in a way that it can slide along its length.)

So for every 1 rotation of the synchronizer hub (purple), you get 1 rotation of the output shaft to which it is splined.

There are two elements to gear engagement: engaging the dog teeth, and synchronizing the shaft speed. (In the past, synchronizers did not exist. Now they do. Except on the reverse gear, because you're supposed to be stopped to reverse.)

Engaging the dog teeth is fairly simple: you can see the little teeth on the right side of the gear (blue) in the image, and how they fit directly in the slots in the left side of the synchronizer (purple). When they are fully engaged, the output shaft (splined to the synchronizer hub) becomes engaged to the gear. That means the output shaft spins at the same rate as that specific gear and power goes out to the wheels!

Synchronization At Speed

However, there is a wrinkle:

If your car is moving, the output shaft is rotating too. The output shaft goes to the differential, which through a gear reduction goes to the wheels, and this of course applies in reverse - if you are moving, the wheels rotate, the axles rotate, the differential's gears are rotating, the output shaft is rotating.

When you want to change a gear, the engine must now spin faster or slower, because the ratio between input and output is changing - but recall that the different gears on the output shaft are all rotating at different speeds, thanks to the different ratios to the input and countershafts.

So unless your new engine RPM (and thus, your new input shaft rotational speed and countershaft rotation speed) is perfectly aligned to your new gear choice, there will be a difference in the rotational speed between the output shaft and the gear to which it must be engaged.

And those dog teeth, well, they look kinda big and blocky, right? Will they allow themselves to be forced in?

You can think of this as, say, driving past a white picket fence and trying to throw a ball through the slats. If you're going slowly, you can do it. If you're going fast, it's a lot harder. You have to either make the gaps bigger to compensate ("faceplated gears", or a "dog box", usually used for race applications), or you need to slow down the difference in speed.

This is where the synchronizers come in. The synchronizers will use things like conical brass components and little physics tricks to do two things: first, speed up or slow down the gear riding on the output shaft to match the rotational speed of the output shaft, and two, prevent the sleeve of the synchronizer from moving too far and engaging with the dog teeth until the speeds are properly synchronized (to avoid that grinding sound and feel.)

This "blocker ring" is what stops you from pushing a car into gear if the engine is running and sending power to the transmission - for that, you need to use the clutch pedal to disconnect the engine from the rest of the drivetrain.

Sometimes Won't Engage When Idling

Have you ever been stopped, went to shift into first or reverse, and the gear just seemed to ... not go in? Weird feeling. Sometimes it feels like a gear lockout, sometimes it might grind or slip out. And then to fix it, maybe you lifted your foot off the clutch pedal, then put it back down and tried again, and it worked?

Sometimes, the dog teeth are misaligned, and with the car not moving (output shaft not moving, therefore synchros not moving) and the clutch not engaged (input and countershaft not moving, therefore gears on the output shaft not moving), those dog teeth don't have a chance to get aligned, and the synchronizer can't do anything for you (since there is nothing to synchronize). By re-engaging the clutch, you move the input shaft, and the countershaft, and the gears, changing the alignment of the dog teeth.

So if your car sometimes doesn't want to go into gear from being stopped, don't force it, just lift off the clutch pedal and try again.

Transmission Recap

The input shaft comes from the engine output (through the clutch.) It spins along with the countershaft. The gears on the output shaft spin along with the countershaft, along with the input shaft. The synchronizers on the output shaft spin with the output shaft. When you shift, they synchronize the specific gear you are engaging to the same speed as the output shaft, then engage the two together fully.

And put together, this is sort of how it looks.

Differential

As mentioned above, the output of an engine goes through a clutch to the transmission, and the output of the transmission goes to a differential, and the output of a differential goes to the axles (which go to the wheels).

(Note: We're not talking about transfer cases and AWD/4WD right now. Just two driven wheels, front or rear.)

Sometimes the differential and transmission are part of one unit, or bolt together to kind of be one unit, and are together called the transaxle.

The differential provides a "final drive" or "final reduction" to the engine output. Common values of gear ratios include (just a small list): 2.93:1, 3.03:1, 3.42:1, 3.73:1, etc. These are often revered to without the "to 1", or ":1" designator. Spoken, they are often referred to by just the numbers, eg, "three seven three gears."

The "shorter" the gear, the "bigger" the number (the bigger the reduction); the more torque, but less top speed. That is, highway cruisers might be available in a 2.93 gear, but a light sports car might have a 4.03 final drive.

Engine RPM To Ground Speed

Sometimes people ask, "How fast am I going at X RPM and Y gear?"

The math for this is simple.

Take engine RPM. This is rotations per minute.

Multiply by 60 to get rotations per mile.

Multiply by your transmission's selected gear ratio (eg, in 4th gear, this is usually 1:1, in 6th it might be 0.65:1, in 1st it might be 2.70:1). These are often expressed as reductions, so you'd multiple by (eg) 1/2.70, which means you divide by 2.70 for first gear; for 6th gear, you divide by 0.65.

Multiple by your differential ratio (eg, multiple by 1/3.73, divide by 3.73).

This number is the "wheel rotations per hour."

Plug your tire details (eg, 225/45R16) into an online calculator to get the circumference.

If your circumference is in the wrong "unit," convert. For example, if you get inches, convert to feet (divide by 12) and then to miles (divide again, by 5280).

Multiple your "wheel rotations per hour" by your "wheel circumference in desired unit" to get "units per hour."

Example:

I have 305/30R19 tires on my rear wheels (82.31 inch circumference). I have a 3.42:1 rear gear ratio. My second gear ratio is 1.78:1. Let's say I'm doing 6000 RPM in 2nd gear:

6000 * 60 = 360000 RPH out of the engine

Divide by 1.78 second gear = 202247 RPH out of the transmission

Divide by 3.42 final drive = 59137 RPH out of the differential

Multiply by 82.31 inches = 4867534 inches per hour

Divide by 12 = 405627 feet per hour

Divide by 5280 = 77 miles per hour.

The Clutch Components

When you drive stick, you do two things you generally don't do in an automatic car: you play with the shift knob (don't do it too much or you'll go blind), and you press the clutch pedal.

I suppose it's more accurate to say that you control the clutch pedal. We'll get to that. First, let's talk about what the clutch is.

Here's a blown-apart image of a clutch assembly.

Let's discuss this image, left to right.

Not pictured on the left side is the engine. The flywheel bolts to the engine output (the crankshaft.) The flywheel is usually made out of steel or aluminum, and when new, has a big surface on it that is very flat and smooth. The flywheel has a geared edge to it, which is where the starter engages and starts the engine. It also has a hole in the middle; the pilot bearing / bushing (not shown in this diagram) sits on the crankshaft, and can be seen through the hole in the middle of the flywheel. Sometimes the flywheel is a "dual-mass flywheel," meaning that rather than a solid piece of metal, it has some internals to it that reduce vibration and driveline shock.

Next up is the clutch disc, also called the driven plate. The clutch disc is a round disc with friction material on both sides of it riveted down to it, all around the portion of the disc closer to the edges. This friction material will grab onto the flywheel surface, as well as the pressure plate surface (up next). The clutch disc also has a splined hole (hub) in the middle, through which the transmission input shaft (not pictured) mates. That means that as the clutch disc spins, so does the input to the transmission. Finally, a clutch disc often (but not always) has springs (such a disc has what is called a sprung hub) to reduce vibration and shock.

The pressure plate, like the flywheel, mates to the friction surface of the clutch disc. This means that when the clutch is engaged, it is friction-bound to both the pressure plate and the flywheel.

The clutch cover is attached to the pressure plate and bolted through to the flywheel; this means that basically the entire "clutch kit assembly" (as it usually ships) rotates together, except for the clutch plate, when the clutch is disengaged. That is, if you take off the bell housing and look at the clutch kit, it mostly seems to rotate together, at least visibly. The clutch cover has a diaphragm spring as part of it; this diaphragm spring, when pressed down, allows the pressure plate to come up and no longer press down on the clutch disc and flywheel.

The release bearing, also known as the throw-out bearing (TOB) presses down onto the spring diaphragm and disengages the clutch. Note that as it presses on the springs, it experiences wear and various forces (so don't sit at stop lights with the clutch pedal down.) When released, the pressure plate presses back down onto the clutch disc, onto the flywheel, locking the engine output to the clutch disc.

The release shaft, or release fork, or clutch fork, presses down on the throw-out bearing. This is actuated with a cable or a hydraulic line, by the clutch pedal, as you press it down.

Not pictured: the transmission input shaft, splined to the clutch disc, which goes through the pressure plate and clutch cover and out to the transmission. It is also aligned onto the engine crankshaft by the pilot bearing / pilot bushing.

Here it is assembled.

Here is a real clutch kit.

The three main parts sold here would be called the flywheel, clutch disc, and pressure plate (the clutch cover, pressure plate, diaphragm springs, etc, are collectively colloquially called the "pressure plate" or "pressure plate assembly."

Diagram of engaged clutch

Diagram of disengaged clutch

Animation of clutch engaging and disengaging

Another animation and view

Clutch and Shifting Basics

As seen in the diagrams above, when you put your foot on the clutch pedal and down to the floor, the clutch is disengaged - the clutch disc is not being pressed in between the pressure plate and flywheel. At this time, the engine spins, the flywheel spins, the pressure plate assembly spins ... the clutch disc does whatever it wants.

The transmission input shaft is splined to the clutch disc so it doesn't get power either. So you can be engaged in first gear, clutch pedal in, clutch disengaged, you don't move. Nice!

In other words, the clutch pedal down disconnects the engine from the transmission.

When your foot is off the pedal, the clutch is fully engaged, and the clutch disc spins at the same exact speed as the engine. That means the transmission input shaft does too.

The clutch pedal up, clutch engaged, means the engine is driving the transmission.

If you try to switch gears with the clutch engaged (foot off clutch pedal), the synchronizer will attempt to force the output shaft gear to the same speed as the output shaft. However, the output shaft gear is being driven by the countershaft, which is driven by the input shaft, which is driven by the clutch disc, which is driven by the flywheel, pressure plate, and engine crankshaft - that is, you're trying to use a little brass cone to change the engine speed. (Also, you're trying to change the car speed, through the output shaft.) Neither the engine nor the car are going to listen to a little brass cone, so the transmission will not be able to engage the gear - however, it will make a lovely grinding noise.

Put your foot on the pedal, down all the way, and it only has to synchronize a much smaller weight, without any power being applied. Much easier job.

What's Double Clutching, Granny?

Remember how I said older cars didn't have synchros? You don't need them when you're stopped to get into first or reverse, but when driving ... that's a problem!

This section is really only for fun. Cars don't require this anymore unless you're racing something interesting, or your synchro is worn out (3rd or 4th are common enough), or you're trying to avoid wear from very high-rpm shifts and skipping gears.

There is another way to synchronize the input and output shafts: double-clutching.

Imagine your engine is spinning at 3000 rpm, and you up-shift so that it should only spin at 2000 rpm, while perfectly maintaining your car's speed.

If your car's speed is maintained, the transmission output shaft speed is constant.

Clutch in, shift to neutral, clutch out. Use gas pedal to change engine speed down to 2000 rpm.

Now, the output shaft speed is still constant. The input shaft is now at 2000 rpm, down from 3000 rpm. However, no gears are engaged, so the input shaft and countershaft speed, and thus the speed of the gears on the output shaft, was changed by the clutch disc friction material absorbing the differences in speed, instead of the synchronizer friction material absorbing the differences in speed.

Now if you shift into your desired gear, as long as your input shaft rpm is close to correct, you will be able to engage the dog teeth!

With very precise control of the RPM, one could even shift without using the clutch. Not recommended for most cases :)

Back To Important Stuff: Slipping The Clutch

Now that we talked about grannies and double clutching, let's get back to the basics: clutch control.

As mentioned above, part of clutch control is engaging and disengaging it, but there is more to it: what happens when it's only partially engaged?

Consider this: if you are stopped and shift into first, and very quickly let go of the clutch, the car will either jerk forward, or the engine will slow down to stalling, or both. However, you could transmit only some of the power through the clutch, and thus have only some of the torque of a heavy object (a car) resisting the engine's torque output acting back on the engine, if you only partially engage the clutch.

This is called slipping (or sometimes feathering) the clutch. To take off, disengage the clutch, shift into first or reverse, use the gas pedal (or don't) to raise RPMs to a desired point, then slowly raise the clutch pedal off the floor. At a certain point, the clutch disc will bite, but it will slip because there is not enough pressure on it to fully engage it. If you hold that point, the car will speed up to a couple miles an hour. If you let it go a little more, the car will speed up a little more. If you do it slowly, hold a little, then release, you should be rolling at maybe five miles an hour, fully engaged, perhaps without even touching the gas pedal.

Of course, there's a downside: clutch friction material does not last forever; friction material inevitably wears out. The more you slip, the faster it wears out. You want to slip as little as needed, but also not be afraid to slip when needed. It's a skill you'll learn from practice.

Bringing Theory Together

Last section! You made it.

Get in a car. Put the transmission in neutral. Start the engine, often with your foot on the clutch pedal, as a safety mechanism to make sure the car won't jump forward/backward.

Want to get going? Take off the parking brake, then:

Remember, you can change gear with the engine off without a clutch, but if the engine is on, and the clutch is engaged, the input shaft is being driven. You use the clutch pedal to make the transmission input free, shift to first or reverse, let the clutch pedal out to drive it slowly, then let it out fully to fully drive the transmission input shaft. You're rolling!

If you need to change direction (reverse to first, or first to reverse), stop the car so that you're not fighting more than you need to be.

When you need to shift up, remember, if you don't use the clutch, you will be again trying to use a little synchronizer to try to move a huge weight and force (torque). Don't do that. Clutch pedal in to disconnect the driveline, change gears, let synchros do their work! Then clutch out, but generally much quicker than trying to get moving. You don't need to launch off a stop, so you can let it out faster.

If you shift too slowly (wait too long to re-engage the clutch), your RPMs will fall and upon engaging the clutch you will be dragging the engine speed upwards. This feels weird, like the car lurches forward.

However, if you shift too fast (engage the clutch very quickly), your RPMs may be a bit too high and you'll pull the engine down. It feels like the car "skips" a little.

The best RPM at which to shift depends on your car, your desired gas mileage, your desired acceleration, how warm your engine is ...

This all comes down to practice.

A car with a smaller engine will generally prefer being revved up higher before shifting, eg, 2500 or 3000 rpm. A car with a big torquey engine may be happier shifting at 2000 rpm, perhaps even lower. A cold car will usually feel like it resists higher RPMs and asks you to shift it at a lower RPM. A nicely warmed up car will feel happy shifting higher. A sports car with a "rev-happy" engine feels like it calls to you to ride it out. A truck with a low of low-end grunt feels like it wants you to keep the RPMs lower. Of course, these are just generalizations - you'll figure it out from a lot of practice.

Rev Matching, Heel-Toeing

Advanced topics! Because I promised the above was the last section.

We went over upshifting in the last section, and I mentioned that if you do it too slowly your engine RPMs fall too low and need to be brought back up. Well, what happens when you downshift? Your desired engine RPMs are higher than they currently are (because you're going to be going the same speed but at a lower gear, thus higher engine speed to maintain it), so if you just downshift without anything special, you'll always have to be using the clutch friction surfaces to pull the engine RPM up.

Truth is, in most commuter cars, this is ... fine. Like, the cars are designed to do this okay. You kinda feel a bit of weirdness but it's not too grabby, not too lurchy, it just works. Also, in most day to day driving, you will start-upshift-upshift-upshift-upshift-brake-stop-start, no downshifting required, quite often; sometimes you slow way down, then just shift with your engine basically idling without much of an RPM mismatch.

But if you want to drive a bit more aggressively, or if your car punishes you for a "mismatched" downshift, you need to "rev-match":

Left foot on the clutch. Shifter hand into neutral, then into the lower gear. Right foot "blips" the throttle to send the engine RPMs up, maybe a thousand RPM or so, and at the peak of that "blip" your left foot releases the clutch. Done properly, it feels completely transparent and makes a cool noise. Done improperly, no big deal, it just feels like you were too fast or too slow and you go practice more.

That's all there is to rev-matching! Blip the throttle on the clutch release (which can be timed immediately after the gear shift) and practice.

Heel-toe is a name given to a different maneuver: your right foot hitting the brake and gas at the same time. Now, why the hell do you want to do that? And when?

Consider if you want to 1) slow down hard, and 2) downshift at the same time. For example, let's say you're coming fast into a turn, and you want to drive hard through the turn in a lower gear at a lower speed. You can do the simple thing: brake to lower speed, then downshift with a nice rev match.

Or you can brake and shift at the same time, and rev-match that shift, meaning you need to brake, clutch, and give gas at the same time! Your right foot uses the heel on one pedal (brake), and toe on the other (gas), or vice versa, depending on your comfort level and the geometry of your pedals. This requires a lot of practice, and is a learned behavior. You perform a smooth brake, then in the middle of holding the brake do a quick blip, continue braking ... and when you're done, you're in a higher rpm and a lower gear than you would be otherwise. Very neat.

Breathe

You got theory, go practice.

Sit down. Foot on brake. Take off parking brake. Shift in neutral. Clutch in. Start the engine. Shift into first or reverse. Clutch out, maybe a bit of gas. Ride it a little. Get going. Fully engage the clutch. Accelerate. Let off gas, clutch in, second, clutch out. Accelerate. Let off gas, clutch in, third, clutch out. Accelerate. You get it.

#reddit #autonews #auto #cars

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topsolarpanels · 7 years ago

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Offshore breeze, clever concrete and fake meat: the top climate change innovations

Trumps climate schemes have sparked fury and upset but business are receiving alternative solutions. Oliver Milman runs down todays best climate innovations

People in the US and beyond concerned about climate change may be alarmed at the Trump administrations policies and positions but there are plenty of businesses and innovators doing work at various scales.

From solar to fake meat and low-carbon concrete , Oliver Milman explores some of the best examples of climate change-tackling innovations and innovators.

Community solar

Large-scale solar is a booming industry in the US, with the sector now applying twice the number of people involved with coal mining. But the decarbonization of Americas energy system is happening at a more local level, too.

There are 25 countries with at least one community solar project online, in agreement with the Solar Energy Industries Association, and 2016 was a bumper year, with 218 MW added.

Its picking up velocity, and theres a lot in the pipeline, so itll be a mainstream driver of solar in the future, said Alex Hobson, a spokesperson for the association. There is room to grow and theres a lot of interest from people who never was just thinking about solar, such as those renting or who are moving out of their houses in the near future.

Community solar works by allowing several people, such as those in a house with several apartments, to derive energy from a solar project installed on their house or elsewhere. Some utilities offer customers the ability to purchase the renewable energy from a shared facility, while in other cases groups of people band together to take advantage of state and federal incentives to stimulate the investment themselves. California, Colorado, Massachusetts and Minnesota are currently leading the way.

How to switch to solar power in your home and why now is the time

Vegetarian meat

Agricultural activities currently contribute about 10% of Americas total greenhouse gas emissions each year, largely due to the methane expelled by cattle.

Americans are eating less beef than they did ten years ago, but further reductions would be handy if the US is to reduce its emissions to levels that would help avoid dangerous climate change. A raft of new meatless meat options have been made available for those who are reluctant about running vegetarian but cant quite stomach the impact of meat production.

The Impossible Burger, a fake meat offering, has gained plenty of headlines due to the fact it hemorrhages much like the real thing. The $12 burger, backed by investors including Bill Gates and Google, has confused some diners but its hoped it will help make people cut down on beef, saving land, water and emissions in the process. There is plenty of competition, too, from brands such as Beyond Meat, Gardein and the venerable Tofurky.

Low-carbon concrete

Worldwide use of concrete is soaring, largely due to a building boom in China and, to a lesser extent, India. In fact, China has employed more cement since 2011 than the US did during the entire 20 th century.

The greenhouse gas emissions in its production are significant, prompting researchers to come up with a greener alternative. In February, Rutgers Universitys Richard Riman announced a new technology that they are able make a variety of materials, including concrete. Blended with cement, the product can reduce the carbon footprint of cement and specific by up to 70%, according to the university.

I looked at how shellfish build ceramics at low-temperature, like carbonate crystals, and then looked at what people can do with water to make landing strips in Alaska, and I said we should be able to do this with ceramics, but use a low-temperature chemical process that involves water, Riman said.

When you can develop technologies that are safe and easy to utilize, its a game-changer.

Lawn treatments

A technology company called WISErg has developed a product “ve called the” Harvester, which transforms food waste into fertilizer than apply in respect of lawns. The product, launched in 2014, has helped the company get more than $30 m in investment.

In the same area, a startup in Connecticut is working on replacing gasoline-run mowers with a solar-charged alternative that, for each lawn, saves emissions equivalent to those of a automobile on the road for 12,000 miles.

Offshore wind

Wind currently furnishes around 5% of Americas electricity but the sector is on the up thanks to the introduction of offshore wind farms.

In December, the first US offshore gale turbines started turning near a small island off the coast of Rhode Island. The Block Island wind farm is small capable of powering about 17,000 homes but has opened up the way for further developments along the coast.

Donald Trump isnt a fan he has fought a losing combat to prevent a gust farm near one of his golf courses in Scotland but the falling cost of turbines is constructing offshore wind more competitive. Maryland is currently mulling two different proposals for offshore gust which would dwarf the Block Island development.

Electric cars

Electric vehicle sales jumped 70% in 2016, following a disappointing previous year, with more than 30 different models on sale by the end of the year. Tesla, Chevrolet, Nissan and Ford lead the way, with more than half of marketings occurring in California, which mandates a certain slice of auto sales must be electric.

Electric vehicles are parked at a charging station. Photograph: The Washington Post/ Getty Images

Continued growth could depend on whether a federal tax credit is extended but the electric vehicle marketplace is maturing from a niche oddity to a competitive international field. The Chinese government is calling on auto manufacturers to sell more electric vehicles to improve air quality, with Ford announcing it will electrify 70% of the vehicles sold in the country by 2025. Theres still a long way to go many drivers still worry about the availability of recharging stations but this is yet another clean energy marketplace that America could lead in.

Geoengineering

Even the sober assessment of the UNs Intergovernmental Panel on Climate Change( IPCC) leaves much to guesswork when it comes to meeting emissions reduction goals. If the world is to avoid 2C or more of warming, as-yet undeveloped technology will need to be used to extract carbon dioxide from the air at some phase, due to the patchy progress in cutting emissions.

One desperate intervention could be solar engineering, which is being studied by a team led by David Keith at Harvard University. The researchers are looking at how chemical compounds, such as limestone dust, can be dispersed in the ambiance, thereby scattering sunlight and sparing an region below from its hot.

How this can be achieved, and whether it is even desirable to do so, is an ongoing debate. But if we continue to cook our planet, then governments may have to turn to the likes of Keith to assistance forestall the worst.