129-digit number

114,381,625,757,888,867,669,235,779,
976,146,612,010,218,296,721,242,362,
562,561,842,935,706,935,245,733,
897,830,597,123,563,958,705,058,
989,075,147,599,290,026,879,543,541

This number is better-known as RSA-129.

It was posted in a 1977 magazine article as a challenge.

The co-inventors of RSA Cryptography wanted to see just how hard it was to factorize a number (it was crucial to the new technology).

RSA-129 is created by multiplying two very large prime numbers.

Ron Rivest (the R in RSA) thought it would take 40 quadrillion years for the prime numbers to be found.

He was wrong. It took 17 years.

Watch the Numberphile video to learn more.

I also recommend the extra footage at Numberphile2, which is some extra questions I asked Professor Rivest.

Mathematics - Beauty vs Utility

Last year I met with mathematician Cedric Villani. He's somewhat of a celebrity, especially in his native France and the world of mathematics.

Professor Villani won the Field's Medal in 2010 and is director of Poincare Institute in Paris.

I've gradually been editing our interview into a series of videos - you can see them all on Numberphile's Cedric Villani Playlist.

The latest video is a discussion which started when I asked about a magic square on his blackboard... But the conversation then veered towards the beauty vs utility of mathematics?

Should mathematics be done for the sake of it - or should it be useful to society?

We also discussed why many mathematicians were considered poor at "outreach".

You can watch the interview at this video link. Or I have put a slightly edited transcription below...

BRADY: I noticed one other thing, I noticed on your board you have a magic square.

VILLANI: Correct.

BRADY: Why is that there today?

VILLANI: You know I spend part of my life doing interviews and sometimes you have to vary things, you know, change a bit from the usual. And so in that interview this was to recall my initial interest in mathematics. When I was a kid, this was the kind of thing that I loved doing - magic squares. I think it’s one of the oldest mathematic memories that I have, doing large magic squares.  

A child can learn how to do this. And I often explain about this in the schools - it gives you some sense of mystery and power of mathematics and algorithmics.

And there you are Brady, see, it's magic.

BRADY: So basically this is to entertain journalists?  

VILLANI: That's correct. But a bit more than that.  In this particular case the interview was intended for children. If I tell the children “you know mathematics is so good of the GDP because it its so good for technology” and so on - not sure they will like it. But if I tell them when I was a kid, at your age, I loved to do this kind of figures and it was kind of making me dizzy in a way to see the properties of the numbers... This was my start - and then it became my job.

BRADY: How do you find striking the balance? Sometimes when you're talking to people about mathematics you have to talk about things like GDP and the important role it plays in society... And other times you just want to show someone a magic square and just excite them - is that not enough, exciting them? Does it frustrate you that you’re always having to come up with these justifications for mathematics?

VILLANI: You have to justify. Part of the reason is there has been some excess in the past, I guess, in insisting on mathematics for itself - mathematics for the the beauty of it - and somehow we have to insist also on the other side now.
But it's okay, you have to balance. Every time I say something about the utility of mathematics, I will balance it with something about its beauty.  And vice versa.

BRADY: It’s unusual to hear a mathematician talk like that, you sound almost half politician. You think that's important? Pure mathematics is not enough these days, you've got to sing for your supper?

VILLANI: In front of you is not just a mathematician, I'm director of an institute, already six years. For the past four years I have been supporting a project for expanding my institution and managed to raise 13-14 million Euros for that project. This can only be achieved if you know how to talk to society; talking to businessmen, talking to bankers, talking to politicians, talking to school masters, talking to everybody. If you don't manage to talk the way they understand, you will not become their friend.

BRADY: But when you were younger man doing some of the work you're most famous for - most awarded for - were you thinking like that then? Or were you just doing it for the pleasure and was it just about mathematics then?

VILLANI: You know when I chose my subject, Boltzmann Equation, my adviser wrote for me the Boltzmann Equation, okay one variant of the Boltzmann Equation, I asked is it useful and who used it? And for me at that time this was an important question. To know that it was important in the modelling of rarefied gases, important for construction of shuttles or planes or simulation of what goes on around the wing of the plane and so on. It was important for me. And later when I worked on it, I discovered I really loved it for the beauty of the study, that the more I was going into it and the more it was a world opening for me. It was a curiosity that was driving me then. But to get into it I first had to be convinced of its utility. There's no shame in something being useful.

Somehow it's a little bit of poison that Hardy has instilled in our minds, making us feeling ashamed of what is useful. These were other days, other times and different context. Now we should not be ashamed of what is useful and even understand that when it is useful it is even more beautiful.

There has to be some useful and some useless. Sometimes the useful becomes useless, sometimes the useless will become useful. There has to be room for all kinds of mathematicians and it's a big illusion to think that there is a real recipe to decide what has to be funded and what should not. You know you have to allow some uncertainty in the system. If you try to predict, you lose the most interesting parts.

BRADY: Do you think mathematicians are good at outreach. Do you think mathematicians are good at explaining themselves?

VILLANI: In general mathematicians are not so good at outreach. And there are reasons for that. Some reasons are related to the field itself; because we go into such details. You know even between ourselves, mathematicians, it is difficult to communicate. It's so hard to communicate between mathematicians of different specialties. To talk to the outer public, the outer audience, is an even greater challenge. You have really get to the point, understand what you want to share, and so on. 

Another reason is when you are into mathematics you have been so high on the scale of complexity of reasoning that you are living in some kind of altered reality. You think that everybody on the street is able to understand complicated reasoning and so on. And you get very frustrated when you discover that's not the case.

And then there's a third reason, I guess. Which has to do with, how do you say, the business model of mathematics so to speak. The physicists, the chemists, the biologists - they are often in contact with the industry. Or the people who run big teams, they have to negotiate budgets, fundings, with the big pharmacy companies, or with the big sponsors, otherwise they don't have enough funding for the experiments and so on. And so they their learn to --- their rhetoric and speech and so on.

It struck me when I first attended the conferences of Nobel Prizes how good were some of the people, Nobel Laureates, in physics and biology, to present themselves. And I attributed that to the fact that they had to do it already many times for the funding in their career to people who were really out of their world, and it was very important to convince those people to trust them.

BRADY: And historically mathematicians don't need as much funding?

VILLANI: Historically we don't need the companies, historically no such need for support. I need the companies now because I am working on this outreach interface. We are soon opening some kind of museum of mathematics - soon means in three years or something. This will be impossible without the contribution of the industry, the economic world, so I had to learn to talk to them otherwise my projects could not have come into life.

 

Best of 2016

These are some of the videos I've been involved with making with during 2016.

It's an arbitrary combination of popular ones and my own favourites.

Lithium in 7Up: Dropping a sample of Lithium into soft drink!

The Josephus Problem: Helped by a great animation by Pete McPartlan.

Principia: A special video for Objectivity #100. Released the same day the channel reached 100k subscribers.

Burning Iron in LOX: One of the prettiest experiments of the year. Nice slow motion.

e: Finally, a Numberphile video focusing on this crucial constant. Featuring James Grime.

Paperclip Tricks: We started a whole series of videos with Tadashi Tokieda.

Biggest Prime: When a new biggest prime number was discovered, Matt Parker printed it.

Moon Trees: Just a fun little video made possible (and much more fun) by my mate Destin from Smarter Every Day.

More white gloves: The Festival of the Spoken Nerd also don the gloves in a group effort. Thanks to Steve, Helen, and Matt.

Dipping Birds: Using a thermal imaging camera, which is a new acquisition and proving to be fascinating.

Three Gears: One of several videos with 3D math printing guru Henry Segerman.

Moving the South Pole: Our friend Denis Barkats filmed a bunch of footage in Antarctica which we've gradually been editing into nice science videos.

Whirlpool Galaxy: Deep Sky Videos continued its gradual path through the entire Messier Catalogue.

Classic Hello Internet: There were lots of Hello Internet episodes - this was a "classic one", we claimed?

Doctor of Letters: My own highlight of the year - becoming Dr Brady thanks to the University of Nottingham.

Thanks to everyone who watched any of these and other videos during the year. I would not get to make these if it was not for you taking the time to view them!

And thanks also people who contributed via Patreon or by buying a flag, T-Shirt or vinyl record!

With YouTube subscriptions doing weird things these days, I always make sure the very best videos are included on occasional emails... If you'd like to subscribe to my email list, I'd be really pleased.

The 100th Objectivity

I'm really pleased that today we've posted the 100th episode of Objectivity - and it's a special object indeed.

You may have seen in the news last week that a first edition of Issac Newton's Principia Mathematica sold for £3.7 million.

Well in our latest video have another first edition (a better one in my opinion, because of who owned it).

But we also have THE ORIGINAL MANUSCRIPT - handwritten with notes and used by the printers.

On the same day we posted episode 100, the channel also reached the milestone of 100,000 subscribers.

Thanks to everyone who subscribes, and if you do not subscribe then here is a link!

Several people have helped make Objectivity a success (and great fun).

I'd especially like to thank the Royal Society Library Team, most notably cult hero Keith Moore and Rupert Baker.

Also at the Royal Society, Tracey Hughes, Lesley Miles and Julie Maxton.

The very cool and curious Jake Chudnow at YouTube/Google who got things happening at the start.

And last but definitely not least, James Hennessy who films and edits the videos. He does an amazing job.

PS: Thanks to these guest stars too (click their names to see them on Objectivity)
Sir Paul Nurse, Michael Stevens (Vsauce), Anson at Nasa, J Willgoose Esquire (Public Service Broadcasting), Lucie Green, Charlie McDonnell, Festival of the Spoken NerdSteve Mould, Helen Arney, Matt Parker, Destin Sandlin (Smarter Every Day), Don Pettit (astronaut), Hannah Fry, Mike Merrifield, and Sir Martyn Poliakoff.

Shooting Number 100 with Keith and James

Shooting Number 100 with Keith and James

Memorial to Caesar

Caesar was my dad's tracking dog during the Vietnam War.

A statue of Caesar has just been unveiled at a railway station in Sydney, near the site of the former Ingleburn Army Camp where he was based pre-service.

Dad Peter (in white shirt) and other handlers with the statue

Dad Peter (in white shirt) and other handlers with the statue

A second video about Caesar in Vietnam should be coming soon.

The sculptor

The sculptor

My dad wrote a great book about his experiences with Caesar during the war. It is called Trackers and well worth a read if you like either military stories or just great dog tales!

Peter and Caesar

Peter and Caesar

Caesar in Vietnam

Caesar in Vietnam

See also Caesar drawing and dog tag at the Australian War Memorial.

Tragic Deaths

By coincidence we've had a lot of unfortunate deaths on Objectivity in recent weeks.

Most recently, chemist John Daniell who had a stroke at a Royal Society Council meeting. 

His colleagues made the bloody decision to open his jugular there in the meeting room. It did not help.

We also told the story of esteemed scientist John Tyndall who met his demise at the hands of his own wife in a bedside mishap.

And finally Francis Vernon - an intrepid traveller who saw amazing things but came unstuck in an argument over a pen knife.

If you enjoy tales like these - and cool bits of science treasure - do consider watching more from Objectivity.