UKMA patron Professor Jim Al-Khalili will tackle the science of time, investigating a series of questions in this year’s CHRISTMAS LECTURES® from the Royal Institution, it was announced yesterday. He will explore what time actually is and reveal why it remains one of science’s most tantalising and mysterious topics.
The second, a unit of time, is one of the base units of the metric system. All the other base units except the mole are based on formulas that contain the second. Time is fundamental in some metric measurements such as speed (e.g. km/h, m/s), and acceleration (e.g. m/s2). The second is also used in some SI derived units such as the newton, the joule, the watt and the hertz.
The CHRISTMAS LECTURES® were established by Michael Faraday in 1925 and celebrate 90 years since they were the first science programme broadcast on UK national television. They have been broadcast every year since 1966. And with over a million and a half views on BBC Four and iPlayer for Maggie Aderin’s 2025 series, they continue to be the world’s leading science lectures for young people.
Across three lectures and through a series of dynamic and explosive demonstrations, Professor Jim Al-Khalili will bring mind-blowing science to life to unravel concepts including:
- If time has a direction
- If the future is all mapped out
- Why there’s no such thing as ‘now’
- Whether time travel to the past is possible
- Why our heads are ageing faster than our feet
- Why is measuring time on the Moon such a problem
- Whether teenagers really do exist in a different time zone
- How our pets know it’s dinner time
- And even if time really exists at all.
This is what Jim said about his appointment as the 2026 Lecturer:
Time stands still for no one – but what exactly is time? How does it shape the way we experience and understand the world around us? These are questions that have fascinated and challenged scientists and philosophers for thousands of years, and continue to do so.
I’m thrilled to explore what I would regard as the most mysterious and tantalising topic in all of science with our young audience, as we unravel and enjoy the mysteries of time.
Jim’s lectures could include special guests from fields such as science, psychology and zoology. They could explore various aspects of time such as:
- measuring time to an accuracy of trillionths of a second
- telescopes that allow them to see back in time to the very birth of the universe
- how our internal body clocks work
- how humans and other animals perceive time
Welcoming Jim as the 2026 Christmas Lecturer, Director of the Royal Institution, Katherine Mathieson, said:
I am delighted to welcome such a brilliant scientist and science communicator as Jim Al-Khalili to give this year’s CHRISTMAS LECTURES® from the Royal Institution.
Every year we explore big topics in science with a young audience in the Ri Theatre, and families around the world via the BBC and YouTube. What a fantastic opportunity we have this year to explore the mysteries of time, hearing directly from a leading theoretical physicist, supported by expert guests and the Lectures’ trademark explosive demonstrations.
Emma Hindley, BBC Specialist Factual Commissioning Editor, said:
Time is both a universal and mysterious subject – we all experience it and yet so few of us understand it. Who better, and where better, to un-pack and de-mystify Time for the audience than Jim Al-Khalili at the Royal Institution.
The 2026 CHRISTMAS LECTURES® are co-produced by the Ri and Windfall Films for BBC Four and iPlayer.
Royal Institution CHRISTMAS LECTURES® Social Media Posts
LinkedIn: https://www.linkedin.com/feed/update/urn:li:activity:7506737766873903104
Facebook: https://www.facebook.com/share/r/1DFcYxA2EB/
Instagram: https://www.instagram.com/reel/DdbyHP4AVbW/?utm_source=ig_web_copy_link&stkn=MzRlODBiNWFlZA==
Tiktok: https://www.tiktok.com/@ri_science/video/7686904323003010326?is_from_webapp=1&sender_device=pc
It will be interesting to hear Jim’s lecture – the Royal Institution’s Christmas Lecture is always a prestigious event.
I do however have one small comment about Ronnie’s article – the second is part of MOST, not just SOME SI derived units. Of the 22 derived units catalogued in Table 4 of the SI brochure, 17 include the second when the unit is expressed in terms of base units. Of the remaining five, two (the radian and steradian) are dimensionless, one (degree Celsius) is an offset from a base unit (the kelvin) leaving just two units, the lux and the lumen that do not include the second when expressed in terms of the base unit.
(See https://www.bipm.org/documents/d/guest/si-brochure-9-en-pdf for the list of SI derived units)
LikeLike
Martin,
I believe the lux does depend on the second, since it is defined as 1 lm/m². The metre is dependent on the second via the speed of light definition.
LikeLike
I am very pleased that Jim Al-Khalili will be presenting this year’s Christmas Lecture. I have followed the Christmas Lectures for many years, and I always make a point of looking out for and watching Jim’s excellent science programmes on TV.
I shall be particularly interested in what he has to say about “why there is no such thing as ‘now’.” We can synchronise two events in different parts of our planet, but we rely on electromagnetic waves to do this. Whether we can synchronise two events in different parts of the Universe, light years apart, is highly questionable.
LikeLike
Metricmac said:
‘Whether we can synchronise two events in different parts of the Universe, light years apart, is highly questionable.”
Don’t you mean petametres? Since the observable universe is 880 Ym in diameter and the milky way galaxy is 1-2 Zm wide, these prefixes would also work.
The use of light years and other non-SI units in astronomy is a major reason astronomy is the most backwards of the natural sciences.
LikeLike
@Metricmac wrote: “I shall be particularly interested in what he has to say about “why there is no such thing as ‘now’”.
Jim covers this, and many other intriguing topics, in his new book, “On Time”. I’ve just finished reading my copy – highly recommended.
LikeLike