NASA spacecraft captures 1st photo of its giant solar sail while tumbling in space

[Admin]

NASA's testing a solar sail system in space, and the spacecraft that brought the tech there has snapped a photo.

NASA spacecraft captures 1st photo of its giant solar sail while tumbling in space : Read more

 

[orsobubu]

hahhhaha massless photons.... great hole in the standard theory, possibly why they are not making any progress from decades

 

[SilverStar Heggisist]

hahhhaha massless photons.... great hole in the standard theory, possibly why they are not making any progress from decades

They still have momentum, it's why radiation damages DNA

 

[Fire-Starter James]

Of course photons have no mass, only energy. A bit of mass traveling at the speed of light would become relatively infinite. The momentum can be calculated by setting the mass to m=E/c².

 

[geemy]

hahhhaha massless photons.... great hole in the standard theory, possibly why they are not making any progress from decades

a photon with mass would have infinite energy. there's no hole. photon has finite momentum and energy but going speed of light (duh) it must have zero mass. it's all in relativistic equation and the theory works pretty well, being confirmed in all observations, unlike non relativistic theories that are easily proven wrong.
it's still a theory but it explains microscopic and macroscopic interactions, and like every theory it's waiting to be improved.
fundamental physics is pretty remote from the physics we know at our scale, you can't expect it to sound natural. It's also heavily based on complex maths, and pretty unique in history because theory has advanced faster than the measures and was confirmed after the fact instead of the opposite. it's exceedingly complex on an experimental level to "see" elementary particles which is the reason why theory advanced so slowly.
it's also complex to fund research on this field because it's not profitable and any industrial applications is decades away which stock market is not interested in.

 

[JWPlanck]

NASA's testing a solar sail system in space, and the spacecraft that brought the tech there has snapped a photo.

NASA spacecraft captures 1st photo of its giant solar sail while tumbling in space : Read more

"Protype"? Prototype. "Sunlight particles"? Solar photons.

Otherwise, COOL!

 

[Helio]

And don't forget light sail propulsion comes with a 2 for 1 special. The momentum of the photon pushes the sail when it impacts it, and the reflection (scatter) momentum pushes the sail as the photon is emitted.

 

[Unclear Engineer]

And it is not just a push in one direction. By angling the sail to be off-perpendicular to the direction of the incoming light, the reflection effect can provide a sideways push in any direction required.

Too bad it can't tack up-(solar)-wind though, like a sailboat can go as little as 45 degrees off the direction that the wind is coming from. In sailing terms, a solar sail can't quite get to a "beam reach" and is basically a "broad reach" and "downwind" sail.