This question

[UncleAl]

If gravitational and inertial masses of a body diverged, General Relativity would have a falsified founding postulate (the Equivalence Principle). Breaking General Relativity should be good for a Nobel Prize/Physics. One presumes this highlights the enormity of the task.

[maddog]

Originally Posted by Ben

I am confused! Suppose I sit atop a photon as it leaves Sol, and time how long it takes me to get to Earth, what will my clock read on arrival? Zero? Infinity? I don't think so. I suspect I will have timed it at roughly 8 minutes.
Am I wrong?

Depends. Were you to sit on the photon. Your watch is stopped. Were you see the photon
as it left the surface of the Sun via reflection (initial time) and to travel on it's original
path to the Earth. You could then signal to a partner (in communication with) on the
Earth, who would capture that said photon -- yes, 8 minutes later.

The difference is Special Relativity (SR). It depends where you are in the observation.

maddog

[maddog]

Originally Posted by Jay-qu

Sorry but this question is flawed.

Since inertia implies motion and all motion is relative, you only have inertia relative to something else. Therefore when you say 'negate' you would have to say 'equate' your inertia with some other object, this would make you stationary in that frame only.

Then making many such negations of inertia between reference frames would essentially be performing Lorentz boosts between reference frames, with infinite acceleration.

As I misunderstood earlier, I think the originator of this thread was thinking like Author of
the Sci Fi series I mentioned, Doc E.E. Smith -- Lensman series. That was the propulsion
of the spacecraft in the series was based upon an "inertialess" drive. Note: this was fiction. Somehow when the drive operated, the mass of the craft lost "all inertia" in "all
reference frames". I am not saying this would obey any laws of physics. This is fiction.

You can make up what you want. It's behavior would be as described, acceleration at
the slightest touch.

Lawrence Krauss wrote a book about the Physics of Star Trek. Maybe someone needs to
write a book on the Physics of Super Heroes. Hmmm.

maddog

[lemit]

This is a science site, isn't it? I thought that in the "Hypography Superhero Series" (Tormod?) all the superheroes would be required to obey the established laws of physics. That would be what made them special.

--lemit

[TheBigDog]

Originally Posted by Pyrotex

Yup, you're absolutely right!

So our superhero opens the front door,
gets hit by sunlight,
immediately accellerates to the speed of light,
immediately is stopped by a carbon dioxide molecule,
gets hit by sunlight,
immediately accellerates to the speed of light,
immediately is stopped by an oxygen molecule,
gets hit by sunlight,
immediately accellerates to the speed of light,
immediately is stopped by a nitrogen molecule,
gets hit by sunlight,
immediately accellerates to the speed of light,
immediately is stopped by a dust particle,
...

I had been thinking along these same lines recently, although not as inertia, I was thinking of a person with variable mass. Imagine you had a throttle that could control your inertia from near zero to near infinite. So you could ride a beam of light, or be an immovable object. You could become lighter than air and fly, or become heavier than a building and collapse a bridge. Now there is a superhero!

Bill

[lemit]

Originally Posted by TheBigDog

I had been thinking along these same lines recently, although not as inertia, I was thinking of a person with variable mass. Imagine you had a throttle that could control your inertia from near zero to near infinite. So you could ride a beam of light, or be an immovable object. You could become lighter than air and fly, or become heavier than a building and collapse a bridge. Now there is a superhero!

Bill

I think you may have violated copyright of a few Broadway musicals there, but you've probably also created a superhero I can't immediately debunk, and who probably could be realized as a character.

I can actually see that as a cartoon. That doesn't usually happen.

And you've already got some lyrics for a theme song.

--lemit

[Don Blazys]

Our superhero needs a name.

How about "MASSMAN" !?