Just a note that I'm sure is covered in the text: When using the Stefan-Boltzmann equation, T is raised to the fourth power so it must be expressed in an absolute temperature scale. This is true for any multiplication or division of temperatures. It's a bit annoying when someone says something like "Today was twice as hot as yesterday".

People are using the terms “Celsius” and “Centigrade” as the same. One is a version of the other, but they are NOT the same Also, please use the term “small calories” and “large Calories” When you just say “calories “ , we don’t know which one you are saying, and they are 1000 times different

I missed the answer. Can you tell me what 4 x 2 is?

Large powerplant boilers can be 100 meters in total height. They are hung from the top so that they expand downward. From room temperature to full operating temperature the downward expansion is about 1 meter.

3:40 From a country where Celsius is the scale normally used, both in everyday life and in engineering: we always call it "Centigrade", never Celsius.

8:42 "The square root of *2*25 would be 15..."

1:04 Thanks! This was a very simple and clear explanation.

I enjoy the introduction chapters/videos because I'm not lost yet! 😂

I was never introduced to SR's until a good friend of mine passed away, and his wife gave me his. (Sun Post Hemmi, student model) I now have three, a Fedra and an Accumath all student models (the Picketts are harder to find) Ok. thats my background, now my opinion: I wish the use of this marvelous tool had never been removed from the schools. Had I been taught its use while in highschool, I would have understood the numbers and the maths much more intuitively. Learning to use this tool has enlightened me in just how the number play together, how they relate over spreads, and in such a way, the confusion 'clears up'. Fact is, we are doing a disservice to our progeny if we allow the current trends in math (as the one commentor states about' -3 is opposite 3 teaching' garbage out now) I will be practicing the use of this tool as much as I can while I await my grans to reach the age where they can fully grasp the concepts.

You know Fight the Flat Earth?

thanks bob i just got my first slide rule

Wow that’s a lot I’ll have to study more ❤thanks I have seen these for years and I finally found out the name today so I’m looking forward to more information 😁

I can’t even do math on a calculator, I’d de fucked

🙏😊💙

This is a superb video.

I did my first solution of a quadratic equation with a slide rule last evening. What a great way to do it. Awesome!

Wow! Thanks. That was great!

Where can I get one of these?

You should keep your slide rule clean and pretty for the cameras. I saw some dirt on the slide and the cursor.

I wanted to check out your playlist on the slide rule from the beginning, but the playlist seems to be presented in INVERSE order (newest to oldest) which is not a convenient play order.

I used a slide rule in the early 1970s as a physics student. I made calculation errors all the time because I lost track of the decimal point. I loved my slide rule, but I missed questions on exams that I knew how to solve due to calculation errors. My first calculator, a TI SR-10, completely solved my problem, and I never went back to the slide rule. I later upgraded to an HP-65 and after that an HP-41C. I still have my old slide rule and admire it from time to time, but it's a real dinosaur.

Thank you for making this video series. I've been poking through it in no particular order. Would you consider rearranging the order of videos in your playlist to streamline the presentation? Thanks again!

Great video. I used to look longingly at the bright spark of jet airliners cruising west at sunset when my daughter was far from home going to school in Seattle. I missed her terribly. I used to wonder how far you could actually see the jets before they dipped below the horizon, but I didn’t, and still don’t, have the math to figure that out. Maybe with some more study I can get grip on the math……

📏 📐

hi bob i think you are very good in explaining celestial nav to the non pros i liked your way its simple and neat , i'm a navigation officer n i have over 15 yrs experiance in navigation practices as i worked only as a third and 2nd officer although i have my master's degree but i love being the navigator officer with duties on navigational equipment and bridge equipment and i was thinking of giving simple lessons on navigation with some tips on emergency navigation for new boat owners and non professionals and i think i like your work and how you make it simple to newbies , n while in the marine academy i heard about the concept of the artificial horizon but honesty never used it like that only used it with some infra red sextants and water bubble sextants i saw at a friend who was an astronomer and had a telescope to watch celestial events with an arttificial horizon water bubble scale to set the zero line but that plate method is actualy very good n very cheap too n i bet it produces great results as you say three miles is actualy a great result the best navigators avreage 2 to 9 n.m for an error on a site so a consistent three is honestly great work , i salute you n you earned a new subscriber :) cap.Mo_Karim 2nd officer

Nice slide rule watch.

Thanks! Great video. Just finding out this tool exists after listening to Sam Cooke's Song (Wonderful World) 😆

Hey I'm curious if a slide rule would work the same in a different base number? Can anyone help?

I'm 14, I'm bored at class and I wanna have some fun, thanks.

The way I understood the concept was “Newton’s first law of motion is the reason we don’t do ballet in the nude.”

I was wondering, would it be possible to get a small manufacturer (China?) to produce a batch of 1,000 of those nifty slide rules? The ones I find in Brazil are mostly in poor condition, and most eBay sellers of slide rules don’t ship to Brazil.

I remember a question on a Physics test back in 1976. If Lois Lane fell off the top of the World Trade Center and Superman was at the Empire State building, could he catch Lois before she hit the ground. We were given the height of both buildings and the distance between them. How fast would Superman have to travel to save her? The answer was that it was possible for him to get there, but the impact would kill her 😂.

Anyone watching this video would already know their Trig. I think ur second video explains the first over cooked it. But I’m assume as I watch more this is more of a maths class tutorial and not sextant usage

When walking on ice, is it safer (a) to slide ones feet, or (b) make each step as vertical as possible? Judging by your video, (b) is definitely safer. I have had this argument with someone; (but have not collected experimental data).

I think we call it dynamic friction in the UK.

Like your pen!

Could you make a video about conservation of momentum? Thank you. Also I would like to see a join button.

Very nice "straight forward" forward presentation, if you get my drift bob? But, I noticed you neglected to mention the concept of *Mass* in motion or the principle of Inertia. _(Although you may have done, as i didn't actually watch the whole thing! 😅)_ That is essentially Newton's first law. This equation is simply *F=ma* in a different form, so maybe you should have started at the very beginning with a description of *Inertia.* As I've found that is where most people slip up when discussing projectile motion or the orbital motion of planets and tides. Good luck.

Can I ask a simple question I went on line and downloaded the Simulated Picket N3. How do I “make it work”. Can’t get the curser or slide to move.

a very interestimg video. great!

Trivia - the log-log scale was conceived, contrived, created, designed, developed, devised, formulated, innovated, invented, originated by Dr. Peter Roget.

May I remind a trick I already mentioned here, allowing to calculate the norm (or length) of a vector, which is the square root of the sum of the squares of its coordinates. Here in the 2D space, that would be the square root of x^2 + y^2. - Align the value of y^2 on the mobile B scale under the fixed 10 of scale A - Read the value m on fixed A scale, in front of x^2 on mobile B scale. - Mentally compute 10 + m, and align the cursor on fixed A scale at the result position. - On that alignment, you can read the sum x^2+y^2 on scale B and its square root on scale C.

Thank you for another great video with a practical application for slide rules! You’re right, vector calculations are much easier and faster with a slide rule than a digital calculator! I have one question: What type of fountain pen do you use in your videos?

Well bob its me again, 1400-1642 math time a time of , simple people,small number,then,refined now,1950s era math great,ours greatest of all man's math now common without hate,here,keep it here only library and library way, book kept,many copies only, now...John.

Thanks Bob, try this logic, .25 a b/c4=? 4parts multiple what? Of .25, makes 1, 1/4.so 1/16= 4*4=16. Base change.

I use (x-90),(x-180) with cos-1 c/b , a/b=angles sometimes use. +90, brg=+180 too. John.

Try double x,x angle,then double y,y angle, sin-1(C/B),cos-1(A/B),cos-1(C/B). Y ,cos-1(A/B),cos-1(C/B),sin-1(C/B). Double angles. John.