Nov 24, 2025 05:58 PM
https://www.space.com/astronomy/does-the...lain-sight
EXCERPTS: One of the biggest puzzles facing modern physics is the "hierarchy problem." Basically, the force of gravity is way too weak. It's billions upon billions of times weaker than any of the other fundamental forces, and we have no idea why.
One weird possibility is that gravity gets to do something special that the other forces don't. Perhaps there are more dimensions than our familiar space-time — all of the other forces are stuck to space-time, but gravity gets to spread out to extra dimensions. This would dilute gravity so much that it would make it appear weak in our normal everyday experience.
[...] But this opens up a major question of its own: Where, exactly, are these extra dimensions? [...] The only answer is that the extra dimensions must be curled up on each other at scales so small that we don't notice them...
[...] Surprisingly, there are ways to peer into hidden dimensions without having to access them directly. Imagine rolling up a tube of paper really tightly and then sending a massless particle, like a photon, down the edge of the tube. That particle will travel lengthwise, but it will also go around the circumference of the tube.
If you look at the tube from far enough away, you won't be able to see its curled-up dimension. You will see the photon making its way down, but because some of its motion will be in a dimension we can't see, it will appear to move more slowly than light. But particles that are slower than light have mass, which means if photons could access extra dimensions, they wouldn't be massless at all.
[...] But despite physicists' searches, we haven't found any. This doesn't rule out extra dimensions, but it does make the idea unappealing. To fit within current observational constraints, the extra dimensions have to be really, really tiny — far tinier than needed to explain the weakness of gravity... (MORE - missing details)
EXCERPTS: One of the biggest puzzles facing modern physics is the "hierarchy problem." Basically, the force of gravity is way too weak. It's billions upon billions of times weaker than any of the other fundamental forces, and we have no idea why.
One weird possibility is that gravity gets to do something special that the other forces don't. Perhaps there are more dimensions than our familiar space-time — all of the other forces are stuck to space-time, but gravity gets to spread out to extra dimensions. This would dilute gravity so much that it would make it appear weak in our normal everyday experience.
[...] But this opens up a major question of its own: Where, exactly, are these extra dimensions? [...] The only answer is that the extra dimensions must be curled up on each other at scales so small that we don't notice them...
[...] Surprisingly, there are ways to peer into hidden dimensions without having to access them directly. Imagine rolling up a tube of paper really tightly and then sending a massless particle, like a photon, down the edge of the tube. That particle will travel lengthwise, but it will also go around the circumference of the tube.
If you look at the tube from far enough away, you won't be able to see its curled-up dimension. You will see the photon making its way down, but because some of its motion will be in a dimension we can't see, it will appear to move more slowly than light. But particles that are slower than light have mass, which means if photons could access extra dimensions, they wouldn't be massless at all.
[...] But despite physicists' searches, we haven't found any. This doesn't rule out extra dimensions, but it does make the idea unappealing. To fit within current observational constraints, the extra dimensions have to be really, really tiny — far tinier than needed to explain the weakness of gravity... (MORE - missing details)
