Seems like the answer to “does light have mass” is a huge resounding “maybe.”
Since light cannot pass through a black hole does that mean light has mass? Also why does light form a singularity in a black hole? Is that like a fixed point on a map or something?
Submitted 3 hours ago by Patnou@lemmy.world to [deleted]
Comments
HotsauceHurricane@lemmy.world 3 hours ago
davidgro@lemmy.world 3 hours ago
It’s “yes, but not rest mass.” - light has energy and energy is mass. (Specifically m=E/c²)
In theory a sensitive enough scale could measure the difference between a charged battery and a drained one* without the battery gaining or losing any matter. Not even electrons, since each one leaving the negative end is replaced by one going in the positive end, and vice versa when charging. This is the type of mass light has, just pure energy.
*I did the math a while back and if I remember right for a typical AA size Ni-MH battery the difference would be about the weight of a bacterium.
skankhunt42@lemmy.ca 1 hour ago
So I’m just an idiot when I guess if a battery is good by weight vs other batteries I have. Two heavy ones must be good!
Maybe I should actually get a battery tester…
lung@lemmy.world 57 minutes ago
Look man Ive spent many years tryna understand this shit and in fact nobody does. Event horizons aren’t really even a fixed place, and you could pass one without realizing if the BH is big enough. Then there’s time dialation. Speed of light is relative to the observer
My rec is to expect no answers but if you find it fascinating, then spend the next year watching PBS Spacetime on Youtube and stay rock hard, nerd metaphorically
heydo@lemmy.world 3 hours ago
Black holes warp the fabric of space so much that not even light can escape once it passes the event horizon.
It has nothing to do with speed, it’s simply that all possible paths lead into the black hole. Photons travel through the fabric of space like a car on a road. The car can’t go off the road, so if the road curves, the car will have to curve with the road.
There’s a lot more to it, but the most simple way to think about it is that a black hole’s gravity is so strong, it warps space itself. And this warping of space basically acts like a funnel that funnels everything to the center of the black hole. Once an object or particle or whatever passes the event horizon (the point of no return) it is basically being funneled into the black hole by the fabric of space being twisted into the black hole.
Patnou@lemmy.world 1 hour ago
Forgive me still have a knowledge boner…no sarcasm. But in your comparison then if a black hole is like a funnel then at the edge of it has a certain speed and speeds up when you keep going deeper? So in someway (hate to bring up fiction) Interstellar was correct or semi correct in it’s portrayal of a black hole going into it? (not the timey wimey stuff). But with gravity being so strong if it warps space then that mean’s just looking at one should give a viewpoint of something that is distorted to all around it? But the question I ask is the event horizon of a black hole…is that the way we can view speed through that lense, but with that said any event horizon at least should have an escape velocity like we have on earth? …on a side not thank you for having a civilized discourse with me. It’s hard to find. …much love and if I don’t reply have a great weekend.
OhmeHose@feddit.org 56 minutes ago
Interstellar was somewhat correct about the event horizon. In theory there also could be an escape velocity but since nothing moves faster than light nothing can escape it. Since light (speed). is the ultimate barrier for velocity.
And every mass bends the space, the small the mass the small the dent.
In science fiction and with a real theorem people “move” faster than light. But using the Alcubierre drive would require so much energy that it is (for now(?)) impossible to achieve. The drive also doesn’t propel the spacecraft faster than light but bends the space around it, so technically you would more so move the space around you, instead of traveling though space.
leraje@piefed.blahaj.zone 3 hours ago
I think photon’s don’t have mass but they do have energy and that can mean they act in the same way? In that they are subject to gravity. That could be very wrong though, I’m going off my own non-scientist memory of a popular science book.
GoofSchmoofer@lemmy.world 41 minutes ago
To piggy-back off your question - Is a black hole a funnel or a ball? It’s always shown as a funnel in diagrams but it lives in 3-D space so it’s a sphere, right?