Reddit mentions of The Science of Mom: A Research-Based Guide to Your Baby's First Year

My husband is also a scientist (space/engineer flavor) and he really enjoyed "The Expectant Father" and "The New Father" by Armin A. Brott. They are basically male versions of "What to expect when you're expecting" but with more research citations and less fluff. Your husband will probably also like "The Science of Mom: A Research-Based Guide to Your Baby's First Year" by Alice Green Callahan although it is written from a mom's perspective. It really emphasizes how child development is researched and tries to avoid opinion based commentary. I loved it personally. I also really enjoyed "Baby Meets World: Suck, smile touch, toddle" by Nicholas Day which is research heavy but also has a lot of the history of parenting and infant development.

Also because I'm a librarian I always recommend Jim Trelease's "The Read-Aloud Handbook". If you're unsure of how to read out loud to your children or just want some great recommendations for children's literature beyond the basics of "Good Night Moon" and "The Very Hungry Caterpillar" this is a great book. Note most of the book is recommendations with several short chapters regarding child development and parenting.

It's not about fatherhood, really just about the first year of baby's life, but I recommend The Science of Mom (yeah, ok, the title literally says 'mom' not 'dad' - but ignore that bit!). It's an evidence-based guide on the first year of life, she goes over many studies and meta-analyses about many different parenting topics.

I've also heard great things about What's Going on in There?, but I haven't had a chance to read it yet.