What are Significant Figures, Precision & Accuracy in Chemistry & Physics?

[@TamsinJones]

You are the science teacher I wish I had had in school!

[@ClumpyLemons]

As an aside: the speed at which this man draws and sheaths his dry erase markers is truly impressive.

[@natashamushitu1680]

This has really helped me ❤

[@bobvines00]

I remember (I'm dating myself now! ;) arguing with another Engineer about significant figures when he had just learned to use a spreadsheet on one of the first PCs we had at work. (This was _way_ before Microsoft Excel!) He had learned how to cause the spreadsheet to display numbers/results to a set number of places, but had chosen to display _everything_ to two decimal places (in this example) because he wanted everything to "look good" when he printed it out for a report. However, some of his "input data" was good to only one decimal place. It took a while, but I finally got him to realize his error & accept that he simply couldn't submit a report with bogus "accuracy"/significant figures that were simply a figment of his imagination. What Jason presents here is very important!

[@frankroper3274]

Chemistry and physics are my favorite subjects since they are the foundations of the world we live in. I of course dont understand it all but it is fun to learn about...even better than a fiction novel!

[@aayangoverski3437]

13:30. Significant figure rules start

[@menamohamed5582]

Thank you for your efforts

[@ShmeegleSon]

awesome thank you!

[@tresajessygeorge210]

THANK YOU... SIR...!!!

[@yusufshibi9113]

Thanks for help

[@주명화-w3c]

Strange ideas of significant figure for today lesson, to take 3000 for example to show how wierd this principle is acting in real situation. We figure out which numbers are significant and which are not. It says that 3 trailing zeros in 3000 are not significant for the zeros following after the exact number 3 are not considered to be so. But in reality the zeros after 3 have a certain meaning in that number obviously whether in its quantity or quality or whatsoever in comparison with just single number of 3. But on the contrary, how about the trailing zeros of any number in digits after decimal? Obviously we would ignore the amount of meaning in that position just because they are not so significant to consider in real situations. But also we will put some values in the leading zeros before or after decimal, because they can be converted into the form of percentages. And percentages have a significant meaning we shouldn't ignore. So the leading zeros should be considered to have real values in real situations while the trailing zeros have little or null meaning in reality. Cause there's no significant difference between 3 and 3.0 and 3.00. They are all equal to 3. So this is rather strange lesson full of distorted ideas about real significance of numbers in real values.

[@ArtisanTony]

10 x .5 = 5 and 10 x .05 = .5 so how are leading zeros after a decimal insignificant? Would you rather have 5 grams of cyanide or .5 grams of cyanide? One will take you out, you can survive the other :)

[@MHShah17]

Quantity does matter, but those are scale which can be replaced by scientific notation. The trailing ones after a decimal are precision, without a decimal, the trailing zeros are scale The significant figures are about precision and rounding

[@shelter3099]

I appreciate you sir,how much full course of Maths

[@ferengiprofiteer9145]

Thank you! I felt sure ancient tree rings contained no significant figures for temperature. You just proved it.

[@anelax.forsythe2387]

thanks, this is helpful.

[@kidzfromthebloc]

I don't understand why the number of microseconds in a week is not exact. The second is an SI unit which means it has a standard so the microsecond by extension is an SI unit and yes with leap years we have 366 days per year instead of 365 but how does that affect your seconds? There's still 1000,000 microseconds in 1 second and 60 seconds in a minute. Those are all just conversion factors therefore exact numbers

[@MarkInLA]

If we're all scientists employed in a professional situation, who/why would insignificant numbers be present, to begin with ?

[@robertwatson818]

having worked in a retail gun shop for five years I can say the average firearm owner has difficulty understanding any of this. Most customers are influenced by myths and misconceptions about firearms in general. The worst one is the misconception that projectiles rise after leaving the barrel. I used to draw diagrams for the customers in an effort to show them what actually happens. ALL of them rejected the information. Each would quote some article they read which they believed to be correct and this contradicted what I showed them---so they rejected my information. Ignorance abounds and the public desperately clings to it.

[@ArtisanTony]

They don't rise per se. The barrel is point up to some degree because of sigh alignment depending on the distance of the zero. But I get what you are saying. Of course most people who argue about this have never shot a firearm :)

[@robertwatson818]

@@ArtisanTony A projectile traveling through the bore is following what is known as "the line of departure". The center of the projectile and the center of the bore are aligned with each other. The instant the projectile is unsupported by the barrel it falls below the line departure---never to cross it again. In flight it travels through a "drooping arc"--slight at first but drooping ever more steep as it goes away from the gun. In most center fire rifles this droop begins to be VERY pronounced between 300 and 400 yards. Mounting a rifle so the bore is five feet above the earth and the barrel level--will find the projectile striking the ground less than 400 yards from the muzzle.Elevating the barrel a half inch will raise the point where it strikes the earth several hundred yards.

[@ArtisanTony]

@@robertwatson818 We are saying the same thing dude. You just like sounding right lol

[@drumtwo4seven]

Nice 👍

[@hemarajue2736]

I think 020 has one significant digit and placing decimal point at the end doesn't make a difference.

[@ArtisanTony]

The truth may also just be a goal you have set to reach because we do not always know the truth :)

[@alicegoodman4544]

Proof and make the equation true.

[@ArtisanTony]

@@alicegoodman4544 no you :)

[@romanporsche]

So it is not possible for a thing to have high accuracy and low precision.

[@ShmeegleSon]

I was thinking that as well but I think you can, as if you shot at the dart board and hit every corner exactly it would have high accuracy (each corner) but low precision (not hitting center). That's how I think about it

[@alicegoodman4544]

H-2-0

[@wouldbfarmer2227]

I ain't buying the trailing 0s significance explanation you give....