And, from the "size really doesn't matter that much" faction, the neutrino just arrived...

What prevents Superman from being able to see through lead but not concrete?

Aren't Gamma-Rays impossible to stop even with lead? You can only weaken them.

They come and just keep going.

Comic book authors

If you're talking about the neutron it's because concrete has a lot of hydrogen. Alpha particles, beta particles, and light (gamma rays in this picture) interact with electrons, with the probability of being stopped increasing with electron density. Lead has a lot of electrons (its lower on the periodic table, called a "high z" element).

Neutrons, however, don't care about electrons and instead interact with the nucleus, with the probability of being stopped depending on the spin state of the nucleus and the neutron. This doesn't follow a specific pattern on the periodic table, but hydrogen has a big chance of interacting with the neutron while lead doesn't. Cadmium, boron, and I think lithium 7 also would stop neutrons easily (there are more of course but those are what I remember offhand).

Gamma rays are stopped by things with a lot of electrons, so a sufficiently thick block of lead will stop it

EDIT: higher energy light has more penetration power (so gammas are quire penetrating), but it's a finite value

Tell me more about how you're unstable, full of bugs and need to finish your development

The Neutrinos? From Dimension X? They're so cool they're frozen!

Well, duh. Did you not notice the blonde constantly chasing him?

Nah, that's not what they're talking about. Superman's vision is capable of penetrating concrete, but gets reliably stopped by lead. None of the particles here (or, I'm guessing, anywhere) have that property.

Gammas might be able to penetrate a little bit of concrete, since concrete has lower electron density than lead

Gamma rays kinda do, you need 10x more concrete to block them than lead: https://en.wikipedia.org/wiki/Half-value_layer

How much concrete do you actually need to stop a neutron with probability 1/2? Is 1 lightsecond enough?

Tbf you actually want 0 penetration. Its already a hole, you just want to insert yourself into said preexisting hole.

Making a new one is probably a bad idea

Yeah I'm a Neutron Male

"Oh, that's-"

The speaker was crushed as OPs sudden extreme gravity ripped the earth asunder

I am a gamma male.

I see you've met my cat

what do neutrons care about though? how do we appeal to that demographic?

Phew, good to know. I was beginning to think Superman isn't real.

Gotta blast!

Sweet, Dr. Banner is on the Fediverse!

Gives new meaning to Jimmy Neutron

The madder they get, the stronger they get.

Yeah! Well if i get inside your body 🥵 (IF) I can rip your DNA to shreds unlike any of those other beta or gamma particles 😤

And they're so insanely positive all the time that they can rip the negativity out of you twice in such a way that it scrambles your DNA.

Never underestimate the toxic positivity of an alpha particle...

Neutron Male don't interact with nuthin'.

https://youtu.be/3dkKcf40YfE

Yet 2 meters of water will stop neutrons. Water is pretty cool.

or 4 morbid humans on each direction

And unfit for the pubic to interact with.

This is why you need to drink a lot of water

Sure, but just because it's chock full of Hydrogen, which happens to be about the same mass as a neutron and thus takes up a lot of its energy per collision. Plastic, being a hydrocarbon, does the same thing.

That being said, water is pretty cool. You could use 2 inches of lead to stop 90% of gamma radiation, or 2 feet of water for the same effect. On top of that, metal is terrible at slowing neutrons (due to metal not being hydrogen), but that same 2 feet of water will slow down the neutrons by about 99.5%.

Narrativium

Hydrogen's cool man. It's just like, one little proton out there in the universe, with his Jiminy Cricket Electron buddy circling around all times, making sure he stays balanced. An unfathomable number of them, more than anything else. All exactly the same yet repelled by each other, like speed dating at comic-con.

It is because of the hydrogen, but it's not really to do with the mass, but rather because a "collision"/interaction is much more likely. For instance, ^58^Ni has the same likelihood to interact as hydrogen, while deuterium has only a fifth. ^135^Xe meanwhile has some millions of times the absorption power of hydrogen and it's quite a lot heavier. It's just not very practical as an absorber.