The Time and Space of Uncle Albert

The author Russell Stannard is a retired high-energy particle physicist, who was born in London in 1931. He has written eleven children's books including the Uncle Albert trilogy (The Time and Space of Uncle Albert, Black Holes and Uncle Albert, and Uncle Albert and the Quantum Quest).  

The Time and Space of Uncle Albert is £5.89 via Amazon Prime.  There are cheaper copies there.

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The Time and Space of Uncle Albert - via a different source is here.  There are free books for people with disabilities that impact reading. If you have a disability that interferes with reading printed text then all of these books can be instantaneously available in your browser or via protected download.  There are other access options.

Famous scientist Uncle Albert* and his niece Gedanken* enter the dangerous and unknown world of a thought bubble. Their mission: to unlock the deep mysteries of Time and Space... In this action-packed adventure story, discover why you can't break the ultimate speed barrier, find out how to become older than your mother, how to put on weight without getting fat, and how to live forever without even knowing it. more

* Albert, of course is Einstein.  Gedanken is German for thought.  In physics, the term gedanken experiment is used to refer to an experiment that is impractical to carry out, but useful to consider because it can be reasoned about theoretically.  How else can you become older than your mother?!

A review

In the story Uncle Albert, the famous scientist, needs his niece, Gedanken, to agree to be beamed up into his imaginary spaceship to help him to perform his thought experiments so that they can find out the truth about space and time. She has to try to catch up with a light beam, go on a round trip to Jupiter carrying a digital quartz clock, and judge a race between photons. more

I would mention that the book was published in 1989.  Some TV sets used an aerial on top of the set.  Uncle Albert sometimes needs to tune the TV to point to a specific position in space to allow Gedanken to arrive there.  However, that doesn't detract from the story.

It reminds me of the story when a grandchild sits on his grandfather's knee and asks him to retell his story about needing to change the TV channel (one of two) by walking across the sitting room and back each time.

Other Stannard books here.