Dear Diana and Family, While I've already done so through email, I want to send you my deepest sympathies and regrets. Mark was a wonderful collaborator and friend, a trusted colleague through the years. It was my joy to work with him for two decades, and our field is much the poorer at his passing. He will be greatly missed.

Dear Diana, accept my deepest condolences - I pray you find the strength and courage to go through this difficult times. Mark was an amazing human being and will greatly be missed - a kind and gentle soul who will not let a day go by without a smile on his face. Personally it's been an honour and a real privilege for me to know Mark and work under his supervision - I can't speak highly enough of him - he was simply every PGR student's dream supervisor. Rest well, Mark...!!

From 3A in Portsmouth Grammar in 1966, to sharing a tent in an Arctic inter-rail trip, we shared so much of our formative years. Our recent occasional reunions were times to treasure. I am grateful for the privilege of having known Mark, and for the friendship we shared.

Having known Mark since the 1960s, it is hard to believe that he is no longer around. Although we have not met up so regularly in the last couple of decades, I remember with great fondness the time we spent playing golf (and playing records!) in the 1970s and my visits to Concord, Massachusetts in the 1980s and early 1990s. And I always looked forward to receiving Mark's annual round-up of news in his instantly recognizable handwriting.

Dear Diana, heartfelt condolences! I met Mark and you last year at the Busan IAU-GA. He was all with ideas, science discussions, etc., etc. I am saddened by his sudden and untimely death. He will be missed.

Only just heard about Mark's loss. Diana, all my sympathies and best wishes. Mark was a brilliant and thoughtful colleague over so many years and I learnt so much from him.

Condolences, Diana. Mark was a wonderful man and I enjoyed when you both were in town. Sending you love and prayers.

Dear Mark, I have so enjoyed working directly with you these past few years, jointly supervising several Masters students, and seeing you regularly in the halls. I miss your friendly face, positive approach, support over many, many years of being colleagues and collaborators - on both sides of the Atlantic - and your seemingly bottomless well of knowledge and ideas - particularly on every radio source ever mentioned in our discussions. I promise I WILL (with Diana's help) finish the papers we have been working on for years! Our field is much the richer for your presence, and much the poorer for early departure from us. Miss you so much

My deepest sympathies, Diana. Mark was a joyful, warm, kind, and honorable friend and a wonderful role model to many.

My profoundest sympathies Diana, Mark was a close friend and wonderful scientist to know and work with these twenty years since we first met. He supported me in all my endeavours at Bristol and I shall miss him very much, especially the many scientific discussions we had over many years.

My deepest sympathies, Diana. Mark was a wonderful advisor and an all-around good person. I am fortunate to count him among my friends and mentors. I look back on the days when we we were collaborating very fondly. Waking into his office on the top floor of A building around 1989: "We did this computation, and I've always thought we should be able to get it fully general relativistically..." I still occasionally read his astronomy 145 unpublished notes from my undergraduate days. A model of clarity. I will miss him a great deal.

I will be one of Mark's longest scientific colleagues, sharing accommodation with him as an undergraduate at St John's College in the early '70s, and doing our PhDs together at the Cavendish Laboratory 1976-1979. I was expecting to see him at our College's 50th year anniversary of matriculation next month. His passing, too early in his demanding and successful life, is a sad reminder of how unfairly tragedies strike. Our condolences to all who knew him, particularly to his family, and with our warmest thoughts to Diana.

Mark was a member and Vice-President of the Bristol Astronomical Society for many years. He joined us every year to give an interesting and well presented lecture to the society. He was always so kind and generous, with a smile on his face. He will be greatly missed by all.

Deepest condolences to Diane, Andrew, Anne, Jenny and extended families on the passing of Mark. Ar dheis De go raibh a hanam.

We were saddened to hear of Mark's death at a relatively young age. For a man of his outstanding intellect, he was very modest about his achievements. We extend our sincere sympathy to Diane, Andrew, Ann and Jenni and the extended Birkenshaw and Worrall families. May Mark rest in peace

A terrible shock, always enjoyed Mark's lectures at the Bristol Astronomical Society. Sincere condolences to his family. May he rest in peace.

We were shocked and saddened by Mark’s sudden and untimely death. I’m not sure it has really sunk in. I have always been slightly awed by Mark’s intellect and suffice to say himself and Diana made a formidable pairing during Christmas games of Trivial Pursuit! I looked forward to those family gatherings and greatly enjoyed Mark’s company. He retained a real enthusiasm for his work and there is some solace in knowing that he spent his life doing something he loved. Mark’s passing leaves a deep void in our family. May he rest in peace.

Mark was always so kind, both to the Bristol Astronomical Society and to me, personally. He sponsored my Fellowship of the Royal Astronomical Society. He will be greatly missed.

Thank you for setting up this memorial to Mark. We hope that you find it a positive experience developing the site and that it becomes a place of comfort and inspiration for you to visit whenever you want or need to.

I am I and you are you, whatever we were to each other that we still are. Speak to me in the easy way which you always used. Why should I be out of mind because I am out of sight? Life means all that it ever meant, it is the same as it ever was.