The flame nebula is seldom seen in toto, because it’s six times as wide as the full moon. It looks … organic.

Mars rocks from Curiosity. There, just right of center, what is that? The surface of Mars keeps revealing new surprises with the recent discovery of finger-like rock spires. Small nearly-vertical rock outcrops

Fun game” for those who like to crash planets together.

Ship tracks from MODIS

The original smiley. The centre of the Virgo cluster.

One of my paintings, but better done. The Falcon 9 crosses in front of the Sun.

mollwollfumble said:

The flame nebula is seldom seen in toto, because it’s six times as wide as the full moon. It looks … organic.

Mars rocks from Curiosity. There, just right of center, what is that? The surface of Mars keeps revealing new surprises with the recent discovery of finger-like rock spires. Small nearly-vertical rock outcrops

Fun game” for those who like to crash planets together.

Ship tracks from MODIS

The original smiley. The centre of the Virgo cluster.

One of my paintings, but better done. The Falcon 9 crosses in front of the Sun.

some nice pictures there

mollwollfumble said:

One of my paintings, but better done. The Falcon 9 crosses in front of the Sun.

Why does the rocket plume not allow light to pass through it when a candle flame does?

mollwollfumble said:

Mars rocks from Curiosity. There, just right of center, what is that? The surface of Mars keeps revealing new surprises with the recent discovery of finger-like rock spires. Small nearly-vertical rock outcrops

Kingy said:

mollwollfumble said:

Mars rocks from Curiosity. There, just right of center, what is that? The surface of Mars keeps revealing new surprises with the recent discovery of finger-like rock spires. Small nearly-vertical rock outcrops

My question is: Is there any actual explanation for the weird fingers? I can’t think of one right now. I would have thought that the wind and sand would have sandblasted anything like that into oblivion by now.

Kingy said:

mollwollfumble said:

One of my paintings, but better done. The Falcon 9 crosses in front of the Sun.

Why does the rocket plume not allow light to pass through it when a candle flame does?

I would hazard a guess and say the density and amount of the particulates. In the candles case sweet FA, in the rocket’s case a shitload.

sibeen said:

Kingy said:

mollwollfumble said:

One of my paintings, but better done. The Falcon 9 crosses in front of the Sun.

Why does the rocket plume not allow light to pass through it when a candle flame does?

I would hazard a guess and say the density and amount of the particulates. In the candles case sweet FA, in the rocket’s case a shitload.

I like your guess, but I would like to counter it by saying that the plume is hydrogen and oxygen, so there is not likely to be any particulates. Note: I am not a rocket surgeon.

Perhaps it is a lensing effect, where the light is diverted by the circular plume and the photons are redirected elsewhere.

Kingy said:

sibeen said:

Kingy said:

Why does the rocket plume not allow light to pass through it when a candle flame does?

I would hazard a guess and say the density and amount of the particulates. In the candles case sweet FA, in the rocket’s case a shitload.

I like your guess, but I would like to counter it by saying that the plume is hydrogen and oxygen, so there is not likely to be any particulates. Note: I am not a rocket surgeon.

Perhaps it is a lensing effect, where the light is diverted by the circular plume and the photons are redirected elsewhere.

I think water vapour or steam can still be considered a particulate.

sibeen said:

Kingy said:

sibeen said:

I would hazard a guess and say the density and amount of the particulates. In the candles case sweet FA, in the rocket’s case a shitload.

I like your guess, but I would like to counter it by saying that the plume is hydrogen and oxygen, so there is not likely to be any particulates. Note: I am not a rocket surgeon.

Perhaps it is a lensing effect, where the light is diverted by the circular plume and the photons are redirected elsewhere.

I think water vapour or steam can still be considered a particulate.

Rockets often have solid rocket boosters which produce exhaust loaded with particulates

Kingy said:

sibeen said:

Kingy said:

Why does the rocket plume not allow light to pass through it when a candle flame does?

I would hazard a guess and say the density and amount of the particulates. In the candles case sweet FA, in the rocket’s case a shitload.

I like your guess, but I would like to counter it by saying that the plume is hydrogen and oxygen, so there is not likely to be any particulates. Note: I am not a rocket surgeon.

Perhaps it is a lensing effect, where the light is diverted by the circular plume and the photons are redirected elsewhere.

You’ve never seen a schlieren photograph?

I suppose not. It’s one of the most fun things about fluid dynamics.

The effect of the changing refractive index of the air.
https://petapixel.com/2017/06/16/schlieren-photography-lets-us-see-invisible-world/
https://www.optica-opn.org/home/newsroom/2020/august/visualizing_coughs_the_schlieren_way/

You can see shock waves in supersonic flow.

You can see heat from a fire.

And, with difficulty, you can also see air movements cause by flying insects.

Here’s a cough.