Light Sail Could Reach Proxima Centauri in 20 Years
Researchers have proposed a light sail design that should be able to survive the stresses of an interstellar voyage.
As part of NASA’s Breakthrough Starshot Initiative, the engineers behind the new light sail design say that their proposed structure could withstand the immense laser light pressures (and heat) needed to accelerate them to 20 percent the speed of light.
INTERSTELLAR TRAVEL AND WARP DRIVES
Space is big. Even flying to the moon takes days, and hopping a rocket ship to Mars takes months. Rockets are wholly impractical for trips to other star systems, with proposed travel times extending into the tens of thousands of years.
Theoretical propulsion concepts like WARP drives might be able to make the trip to another star in the distant future. But at present, the technological capabilities needed to design and build such science-fiction-inspired spacecraft are unavailable.
Now, a group of researchers working on a directed energy propulsion concept that employs a light sail say they have figured out how to manage the heat and stress that lasers powering their craft will experience.
LASER POWERED LIGHT SAIL COULD REACH PROXIMA CENTAURI IN 20 YEARS
To address the heat and pressure issues a laser-powered light sail is expected to experience, a team led by Igor Bargatin, an Associate Professor in the Department of Mechanical Engineering and Applied Mechanics at the University of Pennsylvania, zeroed in on the materials and design specifications that they believe can do the job.
“Reaching another star within our lifetimes is going to require relativistic speed or something approaching the speed of light,” said Bargatin in a press release announcing the proposed sail design. “The idea of a light sail has been around for some time, but we’re just now figuring out how to make sure those designs survive the trip.”
The team’s primary concern is the extreme heat and pressure from the lasers that will power the light sail across the void of space. In a solar sail, where the sun’s light provides propulsion, much like the wind in a conventional sailboat, pressure is a minimal concern.
However, if future Breakthrough Starshot mission planners are correct, an array of powerful lasers will be needed to propel their microchip-sized probe up to 20 percent light speed. Furthermore, according to the press release, those lasers will have to focus their collective energy on “a three-meter-wide structure a thousand times thinner than a sheet of paper.”
In the first of two papers on the subject, the research team determined that their target light sail should not be flat as a drum but instead should be allowed to billow out like a spinnaker on a sailing ship. This shape should enable it to share the tension load of the light pressure more evenly, reducing the risk of ripping or tearing.
“The intuition here is that a very tight sail, whether it’s on a sailboat or in space, is much more prone to tears,” explained Bargatin. “It’s a relatively easy concept to grasp, but we needed to do some very complex math actually to show how these materials would behave at this scale.”
“Laser photons will fill the sail much like air inflates a beach ball,” added postdoctoral researcher Matthew Campbell, a member of Bargatin’s group and lead author on the first paper. “And we know that lightweight, pressurized containers should be spherical or cylindrical to avoid tears and cracks. Think of propane tanks or even fuel tanks on rockets.”
The team also determined that engineers could make the sail from ultrathin sheets of aluminum oxide and molybdenum disulfide, both of which are available materials.
In the second paper, the team looked at the issue of heat dissipation, which is a serious concern since the laser energy hitting the sail will be millions of times more potent than the solar wind that would strike a conventional solar sail. Under this type of intense heat, even the most robust of materials can melt away.
“If the sails absorb even a tiny fraction of the incident laser light, they’ll heat up to very high temperatures,” explained Aaswath Raman, an Assistant Professor in the Department of Materials Science and Engineering at the UCLA Samueli School of Engineering and the lead author on the second paper. “To make sure they don’t just disintegrate, we need to maximize their ability to radiate their heat away, which is the only mode of heat transfer available in space.”
The solution Raman and his team came up with is a “photonic crystal design,” where holes are spaced evenly throughout the fabric matching the wavelength of the incoming light. The sail should also be constructed using individual swatches of fabric, with the spacing of the swatches matching the emission of the thermal wavelength. By combining these two design elements, the authors believe their sail will radiate enough heat into space to avoid melting and disintegration.
DESIGN GROUNDED IN REAL MATERIALS AVAILABLE IN THE LAB TODAY
As for the next steps, Deep Jariwala, an Assistant Professor in the Department of Electrical and Systems Engineering, and another team member said, “Our plan for the future would be to make such structures at small scales and test them with high-power lasers.”
Of course, any practical application of the Breakthrough Starshot teams’ sail design is still likely decades away.
But given the recent discoveries of planets around Proxima Centauri, our closest stellar neighbor, including hints of an exoplanet in that star’s habitable zone (where liquid water could theoretically exist on its surface), it is probably time to start planning for such a mission.
“A few years ago, even thinking or doing theoretical work on this type of concept was considered far-fetched,” concluded Jariwala. “Now, we not only have a design, but the design is grounded in real materials available in our labs.”
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Shinlee Shagowitz
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Quite the vivid imagination that these charlatans posses.
What’s that song again from the Red Hot Chili Peppers again? Oh yeah….how fitting.
Space may be the final frontier, but it’s made in a Hollywood basement.
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Goldysteinberg
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A sail in the “vacuum of “space”? How does that work?
Works like Majik! It’s the Solar wind!
“Well we know that space is vast and………OK, OK it’s all nonsense. But the sheeple are so dimwitted it’s like shooting fish in a barrel.” – NASA “expert”.
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Andy
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Some people seem to have nothing better to do than write inane comments.
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Mr Crabs
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Nobody gets past the dome. This is just silly. Not really Scientific at all. Just silly.
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ЯΞ√ΩLUT↑☼N
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What “dome”? If you can’t prove it exists, it doesn’t.
In any case, if they intend to push this thing with lasers at point of origin, how the F are they gonna slow down? Is Centauri’s light strong enough to act as a brake? Oh yeh, that pic is hilarious. The damn ship’s being pushed into a planet. Not smart.
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Mr Crabs
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You are correct. I cannot prove the dome. But nobody can prove the earth is a globe either. NASA CGI and NASA nonsense does not count as proof.
And as for this space sail nonsense………..really silly.
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Howdy
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“A few years ago, even thinking or doing theoretical work on this type of concept was considered far-fetched,” concluded Jariwala. “Now, we not only have a design, but the design is grounded in real materials available in our labs.”
And
“Of course, any practical application of the Breakthrough Starshot teams’ sail design is still likely decades away.”
Then it’s still the pipe dream it allways was.
OK, supposing they create it. Where are the lasers going to be mounted that will propel it? I assume there will be more than one in order to effect attitude and steer the thing The further away the 3 metre sail gets, the more accurate the targeting will need to be. That means motionless anchor if you ask me.
“a three-meter-wide structure a thousand times thinner than a sheet of paper.”
What measures will be in place to prevent damage from random objects destroying it, or even unbalancing it?
“we’re just now figuring out how to make sure those designs survive the trip.”
You can’t since the future can’t be known. Its an Impossibility to even realize the scenarios that could occur. Best guess on the unknown means nothing, and I see the device is running on hope.
@ ЯΞ√ΩLUT↑☼N
I think the only way to slow it is to swing 180 degrees, like reverse thrust.
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Howdy
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“I think the only way to slow it is to swing 180 degrees, like reverse thrust.”
On reflection, not really since it is still pushed. Perhaps a reflector could be added to accomplish it?
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Jerry Krause
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Hi PSI Readers,
Howdy wrote: “The further away the 3 metre sail gets, the more accurate the targeting will need to be.” This is undebatable Truth!!! And a practical reason that this idea is unlikely to ever work. But there is second undebatable Truth. The author of the article never defines what Prox·i·ma Cen·tau·ri | ˌpräksəmə ˌsenˈtôri actually is. According to the Oxford Dictionary is “a faint red dwarf star associated with the bright binary star Alpha Centauri. It is the closest known star to the solar system (distance 4.24 light years). If a star, even if small (faint) with its own light, must be huge relative to a “a three-meter-wide structure” without any light of it own. So it seems another practical, ,undebatable Truth that if one cannot see this structure that one cannot aim the lasers at it.
And Howdy also wrote “That means motionless anchor if you ask me.” without noting the fact that nothing in the universe is motionless.
Howdy, some might be critical of what you right but believe you have a great ability to comprehend what you read and have seen.!!!
Have a good day, Jerry
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Howdy
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Jerry, I would like to run a related question by you.
Supposing this vehicle was used over a shorter distance and the lasers could be used, My guess is that 4 lasers would be required for the attitude adjustment, centred on each side of the sail edge. Now supposing you wanted to go nose-up attitude to change course, you could reduce the output of the top laser, which would push the ‘nose’ up, but would it do any more than that? I’m thinking the course could change, briefly, in an arc probably, but only slightly since continued operation under those laser conditions would cause a skew, or even rotation. I believe the only way it can work for course changes is on-board propulsion, or move the laser station so it once again hits directly behind.
Even if you don’t know definitively, what do you think? Thanks.
Just something I thought about. Like you say, this idea is a pretty tall order.
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Jerry Krause
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Hi Howdy,
It is easy to respond to your proposed problem. My simple response is I do not know. For what know is my mind cannot image 3-d space. From experience I have to have a physical model to see. Again from experience I accept there are those who can imagine 3-d space in their minds or look at a mathematical equation and imagine of what it is a picture. But not me.
I will stop here and maybe later tell what I a story about what I finally discovered about my organic chemistry students near the end of my teaching career from which my administration was dismissing me (so I retired with a golden parachute because they had not dotted the i’s and crossed their t’s to justify their attempt to dismiss me.
What got me in trouble was that I had reduced the number lectures in the introductory course required for many other majors from 5 per week to one per week and offered office hours of 40 hours per week for any questions that a student might have about the textbook questions and problems which I had assigned. For while I had always attended my lectures I knew I only learned by doing the homework which had been assigned by my science and mathematics professors.
Thank you for your problem because I have wanted to share this experience with PSI Readers. Because I consider it is very related to the TIME in which we are living. Authorities and the rest of us.
Have a good day, Jerry
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Howdy
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OK Jerry, Thanks.
I’ll have a look in a bit.
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Howdy
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Please forgive my stacked replies.
“in order to effect attitude and steer the thing”
Still doesn’t work, because if you tilt the attitude up say, it needs axial thrust from the device itself to cause forward movement in the new direction.
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Jerry Krause
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Hi Howdy and PSI Readers,
Older people tend to fall more than they did when they were younger. I from experience know this is because we loose physical strength and there is no exercise to prevent this happening. I just had violent fall getting out of bed during the night and the next day I could not walk without hanging on to a railing or I would immediately fall less violently. I enjoy doing physical work and I knew that these days were suddenly over if the problem created by the violent fall was not corrected.
Because of my Father’s experience I knew there were ‘chiropractors’ who could maybe correct the problem and from my experiences with ‘chiropractors’ who probably could not correct my problem. For there are these modern chiropractors do not try to only correct the alignment of the spinal column by physical adjustment like the chiropractor my Father drove 60 miles, one way, in the 1920s (or 30s) to have his ‘knee’ problem taken care of because he knew about the experiences of others.
Hence, this comments has two central purposes. The first is to inform PSI readers that there are good chiropractors that can maybe solve problems caused by violent ‘impacts’ upon one’s body by adjusting the spinal column with his special ta forceful, quick jerks (for lack of a better word). Much like those which caused the problem in the first place. This physical treatment takes no longer than 5 minutes and usually less. And the good chiropractors will never claim what the result of his adjustments will be. He is a good SCIENTIST and knows that only the result of the treatment will supply that information. However beyond this information about ‘good’ chiropractors is that I am learning about friends who do not even know that chiropractors exist.
The second purpose is about old people who have lived an ‘active’ life and therefore have had many more experiences than a younger person could have yet had. And because there are many poor SCIENTISTS they conclude that one cannot believe what one plainly has seen (experienced). I know from experience what I did not know before I read Galileo’s well-known book as translated by Crew and de Salvio (1914). And I know what I was not seeing before I read Lane Cooper’s book ‘Louis Agassiz As A Teacher’ (1917). Hence, I see that many young do not respect the knowledge and wisdom of the Old just as many do not respect that which I bring to their attention about SCIENCE.
Therefore, I urge all PSI Readers, for if you are reading this you must, regardless of your background, have some interest in things SCIENTIFIC. Therefore please take the time to read at least portions of these two books. For you may be amazed at which you can understand that these two GIANTS of SCIENCE have written.
Have a good day, Jerry
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Howdy
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I never bothered with books much Jerry, preferring a hands-on approach to see for myself, though the Haynes vehicle manuals are a boon.
Perhaps If science was shown on TikTok it could fare better?
An entertaining video that is also something of a history lesson: Explosive Science – with Chris Bishop
https://www.youtube.com/watch?v=uFQdcKJUijQ
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Jerry Krause
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Hi Howdy,
You wrote: “I never bothered with books much”. That is a problem for it means that you are living in a world that you create. It’s called ‘Tunnel Vision’!!!
Lewis Agassiz, who claimed his greatest achievement was that he taught some of his students to OBSERVE (See). His scientific speciality as a naturalist was the study of ancient fossil fishes. So he lost his reputations as a scientist when he tried to refute Darwin’s idea of the evolution of life with the ARGUMENT that the ancient fishes had the same body structure as modern fishes.
I am certain that Agassiz had read “So God created the great creatures of the sea and every living and moving thing with which the water teems, according to their kinds and every winged bird according to its kind.” Genesis 1:21 (NIV) as translated by some one at an earlier time.
Hence he overlooked the easily seen fact that bird eggs must be inculcated for baby birds to hatch from the eggs. Which observation requires no argument. Agassiz had tunnel vision.
What I write has been criticized because it wanders. However, my mind has to wander to see everything that might be SEEN!!!
Have a good day, Jerry
Have a good day, Jerry
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Howdy
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“That is a problem for it means that you are living in a world that you create. It’s called ‘Tunnel Vision’!!!”
Tunnel vision? Hardly.
Sorry Jerry but you don’t don’t know me well enough to make such a wholesale accusation.
Actually, I do live in a world that I create. To do otherwise is to live by another persons values, standards, and definition of living. I’m an individual. I don’t need anybody else to tell me how to act, or whether whatever I know is enough or even relevant. I don’t need heroes to adore.
I move to the beat of my own drum. The opposite is oppression, dependency, and need. Not for me thanks.
“my mind has to wander to see everything that might be SEEN!!!”
You didn’t see that one can download and read a pdf rather than an actual book did you? Indeed, there are other avenues of learning, and these days we have the internet too, which beats any library..
When younger, I couldn’t afford luxuries like books, but I’ve made up for it since. Remember, not everybody has the opportunities you did.
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Jerry Krause
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Hi Howdy,
I will put the words you just wrote in a single paragraph. “Tunnel vision? Hardly. Sorry Jerry but you don’t don’t know me well enough to make such a wholesale accusation. Actually, I do live in a world that I create.” So was I ‘wrong or correct’ about your case of ‘Tunnel Vision’? I live in world reading books, articles, essays by authors who have bio in a world in which I have had experiences and therefore I have a bio also. Some of which I have from time to time shared with anyone who cares to read what I have written here at PSI. I don’t have a philosophy that if I haven’t read it; that it wasn’t important anyhow. As it seems you do, how do I pretend to know this? I just read what you have written.
My most valuable books are old and used and cost me very little. And if a book is expensive I find a library where I can read it. Thank you for informing me who you ARE. I am always so hopeful to find someone who knows my heroes and understands that they (my heroes) have made mistakes just as I have. We are all human.
Have a good day, Jerry
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Howdy
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“I will put the words you just wrote in a single paragraph”
You didn’t. You only quoted the words you can use that fit your view of life, the world, and what you view as the correct way to proceed. All the important words that tell the truth about your existence, and what you have sacrificed because you’re so involved in trying to be somebody, you left out.
“I live in world reading books, articles, essays by authors who have bio in a world in which I have had experiences and therefore I have a bio also.”
I don’t care about having a bio! Don’t you understand life at all?
It’s only a world that means something to you because it gives your life purpose. There is so much more than self importance, a list of achievements, and other people’s recommendations. You are a slave to it.
Oppression, dependency, and need, as I previously stated, that you choose to ignore, because nobody likes to hear it. It’s ‘tunnel vision’ on your side just the same.
“that it wasn’t important anyhow As it seems you do”
Now you stab in the dark Jerry, and again, because you see something interesting, does that mean others should, just because you deem it so?
Have you studied electronics for years? Read certain authors on the subject? If not, why not? That is the stance you push on me. I’m not you, I’ll do as I please. your blessing not required.
“Thank you for informing me who you ARE. I am always so hopeful”
I haven’t, and you conveniently didn’t quote the part that matters, you see what you are allowed to see, but you believe what you like. That’s one of the good things about being individuals, because one is not tied to the expectations of others. Freedom it is called. Try it sometime.
Jerry Krause
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Hi Howdy,
Maybe you are correct about freedom. You clearly do your think and I clearly do my thing. Which are not the same things. I write to try to inform readers what I KNOW, based upon my life experiences, that SCIENCE is based upon what one SEES and you it seems you demonstrate that your science is based upon debate (argument as was commonly done before Galileo. Who risked his life to confront his Pope with observations that the Earth could not STANDSTILL.
So, PSI readers I hope you see the difference between what Howdy writes and what I write. For as Howdy correctly writes, you should exercise your freedom to make your own decisions, given both sides of a question.
Have a good day, Jerry
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Herb Rose
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For every action there is an equal and opposite reaction. Any force the laser’s light exerts on the sail to push it in one direction will result in the laser being pushed in the opposite direction with an equal force.
To call this proposal stupid is to give it too much credit.
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Jerry Krause
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Hi Herb,
You seem to be in agreement with those who maintain that rocket ‘engines’ will not work (function) in space because there is nothing to push against .
Now I ponder the airplane contrails I have watched. Only the plane appears to move and not the contrail which is left behind. And the more I ponder themore confused I get about “will result in the laser being pushed in the opposite direction with an equal force.” I must admit I am a bit confused.
Have a good day, Jerry
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Herb Rose
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Hi Jerry,
A rocket will work in space because a rocket carries both fuel and an oxidizer. When they are combined during combustion they produce a great deal of energy which force the combustion products ash, water, CO2, and other molecules through the rocket nozzles with great force. The recoil from those ejected particle produces a re-action (for every action there is an equal opposite re-action) on the rocket propelling it upwards. If you were to attach a plate to the rocket which absorbed the energy from the particle being ejected by the engines, the rocket would not rise as the force striking and pushing the plate and the rocket down would be equal to force of the. escaping molecules pushing the rocket up
A jet airplane does not carry an oxidizer but forces oxygen in the atmosphere into the combustion chamber with the fuel. When the fuel is burned the water produced by the combustion is forced out the exhaust creating the contrails as it pushes the plane forward.
A propeller engine at high altitude will also produce contrails from combustion but in this case it is the turning of the propeller pushing air backwards that cause the plane to fly, not the recoil from the waste products due to combustion..
Herb
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Jerry krause
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HI Herb,
What you wrote might seem logical, however you have not explained why (how). are the contrails not seen to being moving backwards with the same speed with which the plane appears to be moving forward.
Have a good day, Jerry
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Howdy
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If you oppose that laser against reverse movement, the net thrust is forward, on the sail. (For completeness of information to others)
@ Jerry
“Only the plane appears to move and not the contrail which is left behind”
Can’t find the answer my self, so I’ll say the Force from the engines has equaled the force required to keep the aircraft moving forward fast enough to fly and the trail air is left in equilibrium.
Not happy with that because it feels too simplistic, and turbulence is also at play, but contrails are so far away, it cannot be seen for me. Best I can do.
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Howdy
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Another? Some contrails do balloon out over time ( I know temperature is a major factor also)., so maybe the distance cloaks what could be similar to blowing air through a smoke mass? The mass, viewed off-angle, appears still, while the area subject to airflow moves back, and drags incident smoke with it due to drag. Now use a straw so the airspeed is higher, but affected area smaller.
Still simplistic, but you can try that for yourself. The smoke replaces atmosphere here.
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Jerry Krause
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Hi Howdy,
I cannot find an answer to why the contrails immediately behind the jet plane do not appear to move but I can offer an explanation why (how) “contrails do balloon out over time ( I know temperature is a major factor also”.
The contrails forms from the exhaust of the jet engine; a heat engine whose exhaust is primarily composed of water vapor and carbon dioxide and the waste energy (heat) of a heat engine which cannot be converted into useful work (keeping the plane flying at a constant speed and elevation). The contrail is a cloud of condensed water droplets as the exhaust mixes with the very cold atmospheric air at the elevations where jet powered planes usually cruise. And if if this cold atmosphere is already near water vapor saturation the contrails will persist for a long time and the atmosphere containing the cloud droplets is still warmer than the surrounding cold air so warmer atmosphere diffusing into the surrounding colder atmosphere. So this is the influence of temperature to which Howdy referred. But as Howdy noted the plane is long gone when we see the contrail ballooning.
I believe the engineers who design jet engines could explain how it is that the exhaust of the jet engine is exiting the engine with the velocity at which the plane is flying. For if it was exiting at a faster velocity than the plane much turbulence would be created and there is little evidence of such a turbulence.
Hence the action which action is pushing against the front of the jet engine (or of a rocket in space). I could be wrong but an engineer who designs the jet engine or rocket could more practically explain this than a scientist. Not a scientist like Newton or myself.
Have a good day, Jerry
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Howdy
| #
“I cannot find an answer to why the contrails immediately behind the jet plane do not appear to move”
I’m hoping my smoke example was some sort of reason for that, which also relates to your third paragraph.
Yes I’ve seen what you explained about contrail formation in my research.
I would say the exhaust is much faster than the forward movement of the aircraft. Indeed, a stationary aircraft on the ground with engines at idle still produces a powerfull blast even though no forward movement occurs, because it has to push against a displaceable medium rather than a solid object. If fx, an air hose, or similar pipe emitting fast flow through a nozzle is held, one can feel the push against the nozzle, but can still hold it. If the nozzle is then brought toward a solid surface and is attempted to stifle the flow, it becomes progressively harder to hold in place as contact becomes intimate and the air cannot disipate into the surrounding air easily.
Jerry Krause
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Hi Howdy,
As I have written before that I do not like short lines so hopefully this will end up right after you short line comment in which you wrote: “Indeed, a stationary aircraft on the ground with engines at idle still produces a powerfull blast even though no forward movement occurs, because it has to push against a displaceable medium rather than a solid object.” No forward movement occurs because of the observed principle termed INERTIA: ‘stationary bodies tend to remain stationary and moving bodies tend to keep moving.’
Have a good day, Jerry
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Howdy
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Yes, I’m aware of inertia Jerry, My comment illustrates that even under thrust, the aircraft remains stationary. Were the forward movement equal to the thrust as I previously speculated in flight, this couldn’t happen, that’s all.
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Jerry Krause
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Hi Howdy,
“this couldn’t happen”. What is this? The contrails we see are when the plane is cruising at altitude (elevation) where the magnitude of friction upon the streamlined plane is small, so the thrust which is required to maintain a constant speed and altitude is small and maybe not sufficient to even overcome the inertia of the plane sitting stationary on the ground.
Have a good day, Jerry
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Herb Rose
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Hi Jerry,
Wind resistance. the droplets collide with air molecules transferring energy to them. When they first come out of the jet engine they are an invisible gas which then condense into droplets when cooling (tea kettle) and then slow as they collide with more air molecules.
Herb
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Jerry Krause
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Hi Herb,
I edit you last sentence: “When they (gas molecules) first come out of the jet engine as a hot gas which then condense into droplets as they (the gas molecules) collide (mix) with cooler air molecules.”
Have a good day, Jerry
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Howdy
| #
NASA says contrails are ice, not water droplets.
PDF: https://www.nasa.gov/sites/default/files/atoms/files/contrails_k-12.pdf
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Jerry Krause
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Hi Howdy,
NASA’s comment causes me to ponder. We (I) know that ice can sublime (directly transition from the solid phase to the gas phase at temperatures below 0C(32F). So I ask myself, can water molecules in the gas phase at temperatures above 0C(32F) directly transition from the gas phase to the solid phase without first cooling to 0C(32F) where the gas phase of water might (should?) directly transition to liquid liquid before it cools further to transition to transition to solid water (ice).
So I conclude that water molecules in the vapor phase at a temperature above the melting temperature of water solid cannot directly transition to the solid phase without first transitioning to its liquid phase. Irregardless of what NASA writes.
Have a good day, Jerry
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Herb Rose
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Hi Jerry,
You have finally accepted that the thermometer is not an accurate instrument that can be used in the atmosphere and yet you still believe the temperatures it records are accurate.. Use the inverse of density to find the energy of molecules at different altitudes.
Herb
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Jerry krause
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Hi Herb,
“You have finally accepted that the thermometer is not an accurate instrument that can be used in the atmosphere ” Where did I write this? For I am not aware that I did. Yes I am old a blame my many writing errors on this problem. So if I wrote what you seem to have concluded I need to correct such an error.
Have a good day, Jerry
Have a good day, Jerry
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Howdy
| #
I believe the PDF did state such:
Contrails are a type of ice cloud, formed by aircraft as water vapor condenses around small dust particles, which provide the vapor with sufficient energy to freeze.
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Jerry Krause
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Hi Howdy,
Did you really mean to write: “as water vapor condenses around small dust particles, which provide the vapor with sufficient energy to freeze.” Yes, I forgot that water molecules (vapor) have to condense on ‘condensation nuclei’.if the atmosphere, at a given temperature, is not to become super-saturated with water molecules. However, I understand that water molecules must loose sufficient energy (cool) in order to ‘freeze’. But I guess the confusing issue is once the phase transition from gas to liquid or solid occurs the latent heat of condensation is released which immediately warms the condensed matter up to the solid’s melting temperature, if any solid water has ever condensed, and melts the solid phase back to the liquid phase.
Sutcliffe (Weather & Climate) introduced a reader to a critical concept (or whatever word(s?) which could be used to define the word–mechanism–routinely used to describe how certain molecules can react with other molecules to form different new molecules. The mechanism I use to explain this creation of new matter (molecules) is a step by step procedure how the atoms of reactants are actually rearranged, one by one, to form, one by one, a new different molecule.
I have no idea if what I just wrote and what Sutcliffe wrote has any meaning to a reader. For I know that chemist have been generally considered to be ‘poor’ teachers. I conclude this is because the critic fails to understand that the teacher cannot LEARN the student.. Learning is something a student must do and it is hard work. And I read that Galileo, a teacher, had learned “We cannot teach people anything; we can only help them discover it within themselves.”
Have a good day, Jerry
Relative to the topic–The Winds of the World–he wrote: All this may seem a far cry from the general circulation of the world’s atmosphere but the detail serves to point the moral, that one cannot explain the broad features of world climate if one does not know the actual MECHANISMS involved.”
Have a good day, Jerry
Have a good day, Jerry
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Howdy
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I quoted from the PDF Jerry.
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