Yes, they’re heavy. Quick estimate, based on their dimensions (20cm x 10cm x 5cm) and density (11.29 g/cm2), each one weighs approximately 11.3 kg (24.8 lbs). That wee stack of 15 bricks runs to nearly 170 kg (373 lbs). Pushing them down the hallway on a large cart gets exhausting, quickly.
Let’s all act surprised that they were left behind in a research lab post-retirement.
These are a prime example of something that we keep around, just in case. Plus, they’re expensive. A very similarly-sized bar of lead from McMaster-Carr – 2 in. x 4 in. x 8 in. – will run you $202.42 at this moment. Fair to say that doesn’t include shipping. It might be more cost-effective to drive to New Jersey for pickup.
To our next nuclear physicist, whomever you might be: we’re holding on to them for you. Come get them anytime.