A Sad Story of Pendulums - Objectivity 114

[@McGeias]

If only you guys could scan that book and make the PDF available online. I would happily get my book binding stuff out and make a copy or three. Almost begs for a final resolution and a chance to be read.

[@donaldasayers]

We know know that you cannot compare two pendulums mounted that close; one on the wall the other standing on the floor next to it. The vibrations from each through the wall will affect the other. Actually both Huygens and Harrison already had encountered this effect. Two pendulum clocks have been shown to affect one another along 13 feet of concrete wall. Kater went slightly mad trying to construct a free pendulum clock, but only using mechanical means, in this he eventually failed, after struggling for many years.

[@nicholasaitken1887]

these are some of the best videos on KZbin

[@kcthewanderer]

Nicholas Aitken agreed. Not sure why it doesn't have more subs.

[@ObjectivityVideos]

Cool idea: if you're ever in London and fancy perusing the 'sad' object.. You could always visit the Royal Society library and ask Keith to retrieve it for you! :)

[@AxcelleratorT]

As someone who has built a galvanometer based on a torsion pendulum, I would love to read that manuscript. (I read about a lot of pendulum based electrical measurement equipment from the late 1800s) I wish they had a scan of it. I can't see myself making it across the pond anytime soon. Thanks for another great Objectivity!

[@slikrx]

Any chance of them scanning and OCR "reading" of the document?

[@philp4684]

Perhaps it could receive some recognition under limited publication as the official unofficial book of Hello Internet, eh?

[@AxcelleratorT]

Phil P, yes! Hello Internet needs to tackle the scanning and publication of this manuscript as a special project. I'm sure CGP Grey would allow an "Old Documents Publication Corner" :-) Whadda' you say Dr. Haran?

[@hindosgottenberg237]

The royal society could publish it now :) ? Or turn it into an e-book.

[@slpk]

Don't comment about his hair! Don't comment about his hair! Don't comment about his hair!

[@FoxDren]

So they saw no interest in a history of pendulums. A history of fishes on the other hand.

[@U014B]

0:37 Oh, he's the guy that invented selling pre-cooked meals for large gatherings!

[@KonradTheWizzard]

No, I believe he is the guy who sold the Germans on the idea that a hangover the morning after the gathering is mandatory. 😁 (In German "Kater" can mean male cat or hangover.)

[@HennerZeller]

Next we know, there will be an official unofficial Hello Internet reprint of that manuscript ...

[@snookzification]

I love you, Brady, you´re amazing, but i really worship Keith. He is such a great example of a classy english gentleman. Great video as usual, gents.

[@Robert_McGarry_Poems]

Quantum computers: No market for the history of the pendulum! What, am I a joke to you?

[@Nilguiri]

How can you measure a pendulum's variations due to local gravity using a clock which also uses a pendulum?

[@Markle2k]

They had the longitude clocks by then. Plus an additional 60 or so years in which they could improve on Harrison's design.

[@Nilguiri]

Ah, I see, that makes sense. Thanks.

[@Mr.Unacceptable]

Has anyone scanned it so we can read it online? If I had that job I'd get nothing done. I couldn't help myself but read everything I came across.

[@lukasdon0007]

You say that now, when everything is still new and exciting for you. After a few years, you get to know the history and context of each artefact/document, and it loses a lot of its wonder. You will automatically start filtering stuff and have a more selective interest.

[@missccarr89]

Lukas don a man after my own thinking although I feel the same as Solder Joe initially.:-)

[@Jerome...]

There is a HUGE lack of glove on those shirts. White text on black shirt, how could you miss this opportunity!?

[@steveno0007]

I'm a simple man. I see a new objectivity video, and I like it.

[@jessemckeown5628]

Just a bit curious: ALL the clocks shown today (live or in pictures) are ... Pendulum Clocks... therefore... if they are being used for timing purposes to reference Pendulums... in various places... how are those Clocks Regulated? Has someone carried about a Harrison Chronometer between these places, or have they been adjusted to local mean solar over the course of a year, or ... ???

[@colleenforrest7936]

Given how easy it is to put things out on the internet, and the nearly 8,000,000,000 there are in the world, you'd might find a few people interested enough in this research to download it. The data inside could be used for other thing than trying to measure a yard. Determining whether there's been any change in Earth's gravity at the locations where the measurements were originally taken to determine if there's been any change in the density of the underlying crust or mantle over time comes to mind.

[@LikelyToBeEatenByAGrue]

Did they ever scan the book? If not, would they allow someone to come in and scan it?

[@slikrx]

How about doing OCR on the document to digitize it (and make it a tad more legible) as a first step?

[@ncooty]

Great sign-off on this one, Brady. :)

[@guilemaigre14]

If this was to be published nowadays, i might be tempted to buy such a publication for the sake of having a copy.

[@BlackHayateTheThird]

Brady has such hip hair. Keith's is always more stylish though :P

[@beetvalley]

Its all about the pendulums Baby

[@BurnabyAlex]

Defining a yard based on the length of a pendulum which swings two seconds... in a pendulum clock which gets its timing from the pendulum. CIRCULAR LOGIC!

[@Stadtpark90]

BurnabyAlex I wish they had commented on that in the video.

[@Tevildo]

No, the clock gets its timing from the sun (or other astronomical observations). The separate pendulum is used so that its effective length can be easily measured.

[@starwarsjk99]

If it was circular logic the yard would be undefined. Two seconds was already defined in terms of the sun, as opposed to our current Cesium definition. All pendulums of the same length should have the same period, but that is not perfectly true. (The amplitude of oscillation matters a little because the small angle approximation breaks down for larger amplitudes. Air resistance and gravity variations also matter.) The "unique" length that provided an oscillation of 2 seconds was defined to be the yard.

[@ArmyGrunt1986]

Brady will now to try to convince Grey to have an unofficial official pendulum manuscript.

[@MiguelGonzalez-hi5nq]

Keith's voice is extremely relaxing

[@RenshawYT]

I want to know whose desk it was that Brady commandeered for his pendulum viewing.

[@jay24july]

keep up the good work

[@VampireSquirrel]

Are there any copies of this manuscript I can view online?

[@eidolor]

Scan those pages and put it online!

[@TheLaurentDupuis]

Were they looking to make a gravity model of the earth for maps accuracy? This is used to calculate elevation.

[@notavailable8130]

so your saying that manuscript is not available on amazon used?

[@social3ngin33rin]

The part that I could never figure out is why the writing of everyone, back in the day, absolutely astonishingly nice compared to mine?

[@Robert_McGarry_Poems]

They didn't have computers...

[@andrewmertzenich2316]

Is there a way to get a copy of the manuscript?

[@andywander]

What exactly were they looking at with the small telescope? The pendulum, or the hands of the clock, or...

[@alexandervonzoller-sakharo6386]

horologists would have a field day with that book. Have it published. I would buy it.

[@PinkChucky15]

Wow, he put a lot of work into that.

[@Sholei33]

Henry is an instrument in measurement specialist? I had a good laugh there.

[@maxiewawa]

Where do I get a t shirt

[@ObjectivityVideos]

+maxiewawa link in video description

[@JackFChannel]

Would someone be able to shed some light on why Brady notes that the image through the telescope appears "upside down of course"? Was the ability to rotate the image from a telescope a later development?

[@fatsquirrel75]

A smple refractive telescopes will flip the image. There were upright refractive telescopes before this time but I'd guess the quality of the image wasn't as good, or cost was a factor. Considering they are just looking at a pendulum swing past a point it being upside doesn't matter.

[@JackFChannel]

fatsquirrel75 Ah interesting! Thank you, just the answer I hoped for :)

[@johndrachenberg2254]

Fascinating. You should have an intern transcribe it!

[@alanmellerick]

Hey - is Brady wearing Official Hello Internet Sneakers?

[@CheshireTomcat68]

What would be the cheapest way to get a copy online, just so it could be read, if someone wanted to? (not offering to transcribe for free!)

[@320466]

This is science even though it was wrong he still tried to make constant. I respect you sir even your bones are dust your knowledge helped us forge the modern age

[@DaBoff99]

Amusing ending

[@PThaVi]

Keith's voice makes me hungry..

[@mojosbigsticks]

I'm interested in the history of catering.

[@willrun4fun]

I prefer the black and white line drawing.

[@neddyladdy]

I thought the plural of pendulum was pendula.

[@renerpho]

Both forms are acceptable, although "pendula" is much rarer than "pendulums".

[@tramsgar]

😢 and now a small bit of all the viewers' lives were also wasted. but in a good way.

[@fernandoschuindt1665]

Make a video about Keith! Love him :D

[@erictaylor5462]

Well, much the same thing was said about the writings of a teenage girl when her father tried to have them published. Frankly, (pun intended) I think Anne would have been horrified to learn her diary was going to be published and read by millions of people, beyond 70 years after they were written.

[@wierdalien1]

Keith is back!. Fabulous tie.Wait, they were measuring the local gravity with a pendulum whilst measuring time with a pendulum driven clock. That seems a bit redundant

[@ragnkja]

I hope they weren't using pendulum clocks to time this, because then the clock would be affected just the same way as the pendulum, making it impossible to get any useful data out of the experiment.

[@ZornsLemon671]

Alistair Shaw The time period squared is directly proptional to the length of a pendulum. Such that the constant of proportionality is (4pi^2/g). So you measure the time period of an oscillation of a pendulum for multiple lengths in order to determine a value for g.

[@ragnkja]

My problem with this is that the device used to measure the time period is itself a pendulum, making _its_ measurements dependent on what the local gravity is.

[@ZornsLemon671]

Oh I get what you mean now, Im guessing they would use a different timer to measure the time period.

[@wierdalien1]

samuel mercer yes that exactly my problem with it that the clock would suffer from the same systemic errors

[@felixpelletier7185]

Am I seeing HI sneakers!?

[@gephc4]

I think you might be right. 4:46 and 5:18

[@WouterWeggelaar]

Yes, and he has also been wearing them to VidCon!

[@MartKencuda]

Pendulum will shift with just a little bit of pressure Move too slow and the pendulum will getcha! Show you, mow you, gonna throw you aroOOOooOOund

[@venkateshsubramanian3578]

Wait...Is that the HI sneakers?

[@WouterWeggelaar]

Yes! He was wearing them to VidCon EU as well in Amsterdam I believe. They did look slick Brady, and yes, we noticed ;)

[@yetanotherjohn]

Obviously, some interstellar space drive system will eventually be derived from the History of pendulums. Oh, how we waste our time.

[@mikehocksbig]

Can you just turn up to the Royal Society?

[@DeanJ1984]

I believe so, yes

[@ObjectivityVideos]

yep!

[@hectors03]

ooh the irony.

[@TheAlfieobanz]

Who is the Peaky Blinder hosting Objectivity?

[@ondudengrund]

yarh, but how about captain Clock´s cook !?