- #1
Mabcs
- 1
- 0
Why are black holes black even though light(photons) has no mass? Gravity shouldn't affect it.
Why do black holes have such strong gravitational pull?
- Context: High School
- Thread starter Mabcs
- Start date
-
- Tags
- Black holes Holes
Click For Summary
Discussion Overview
The discussion centers around the nature of black holes and the reasons behind their strong gravitational pull, particularly focusing on the interaction between gravity and light. Participants explore theoretical concepts related to gravity's effect on massless particles like photons, the bending of space, and the implications for understanding black holes.
Discussion Character
- Exploratory
- Technical explanation
- Conceptual clarification
- Debate/contested
Main Points Raised
- Some participants assert that gravity does affect light, referencing historical figures like Isaac Newton and Albert Einstein to support this view.
- One participant describes the modern understanding that mass bends space, affecting all entities, including massless particles like light.
- A metaphor involving a trampoline and a bowling ball is used to illustrate how mass warps spacetime, which some participants find helpful in understanding the concept.
- Another participant introduces the idea that energy is equivalent to mass, suggesting that light, having energy, can be considered to have mass in a certain context, though it lacks rest mass.
Areas of Agreement / Disagreement
Participants express varying interpretations of how gravity interacts with light, with some agreeing on the fundamental principles while others present alternative views on the implications of these interactions. The discussion remains unresolved regarding the nuances of these concepts.
Contextual Notes
There are limitations in the discussion regarding the definitions of mass and energy, as well as the implications of light's interaction with gravity, which are not fully explored or agreed upon.
- #2
ImaLooser
- 487
- 4
Mabcs said:
Gravity does affect light. I think even Isaac Newton suspected that. Albert Einstein calculated the effect of gravity on light, and he was right. As far as we can tell, black holes behave quite as he predicted, even though he neither knew nor believed they existed and didn't like the idea.
The modern view is that mass bends space. Everything is effected by that, mass or no mass. In fact, all masses move through space the same way. It doesn't matter how heavy or dense they are, what shape, etc. Space bends the same for everything, light included.
It takes a little getting used to, but it makes sense.
- #3
Yosty22
- 182
- 4
Thinking about a typical representation of gravity in the classroom, just picture a trampoline with a bowling ball on it. The mass warps the fabric of space time. As stated above by ImaLooser, Einstein calculated the effect of gravity on light. Since light is affected by gravity, it is then easy to see how black holes are black. Once you can understand that light, although massless, is affected by gravity, the rest of your question falls into place.
- #4
tiny-tim
Science Advisor
Homework Helper
- 25,837
- 258
Welcome to PF!
Hi Mabcs! Welcome to PF!
energy is mass, mass is energy
light has energy, so light has mass
(it doesn't have rest-mass
)
Hi Mabcs! Welcome to PF!
Mabcs said:
energy is mass, mass is energy
light has energy, so light has mass
(it doesn't have rest-mass
)Similar threads
- · Replies 1 ·
Stargazing
Merger of two black holes (video)
- · Replies 7 ·
High School
Confusion regarding black hole spin
- · Replies 40 ·
- · Replies 20 ·
- · Replies 17 ·
- · Replies 5 ·
High School
Analogue Black Holes: Disposal?
- · Replies 2 ·
- · Replies 4 ·
- · Replies 4 ·
- · Replies 9 ·