Citat:
Ursprungligen postat av
billigost
Stjärnorna och solen skiner starkare på Antarktis jämfört med Sverige jo. Vad gäller luftföroreningars vara eller icke vara och hur det påverkar har du ingen aning om.
Jag frågade Grok.
"is the stars brighter at antarktica?"
Grok;
Citat:
Yes, the stars can appear brighter in Antarctica compared to many other places on Earth, and there are a few reasons for this:
1: Minimal Light Pollution: Antarctica is one of the most remote and least populated regions on the planet. With no cities, towns, or significant human settlements (just a few research stations), there’s virtually no artificial light to interfere with stargazing. This lack of light pollution allows the stars to shine more vividly.
2: Clear, Dry Atmosphere: The air in Antarctica is extremely cold and dry, especially in the interior where the elevation is higher (like the Antarctic Plateau). Less moisture in the atmosphere means less scattering of starlight, resulting in sharper and brighter views of the night sky.
3: Long Polar Night: During the Antarctic winter (roughly March to September), the continent experiences months of continuous darkness. This extended night provides ideal conditions for stargazing, free from sunlight interference.
4: High Altitude: Some parts of Antarctica, like the South Pole or the high plateau, are at elevations over 9,000 feet (2,700 meters). The thinner atmosphere at higher altitudes reduces distortion and enhances the clarity of celestial objects.
Astronomers actually take advantage of these conditions—facilities like the South Pole Telescope and other observatories are located there because the skies are so pristine. So, if you’re comparing it to, say, a city or even a rural area with some light pollution, the stars in Antarctica would indeed seem brighter and more striking. Have you ever been somewhere with really dark skies to see the difference yourself?
Jag frågade Grok igen.
"Is there any more places on earth where stars are that bright?"
Grok;
Citat:
Yes, there are other places on Earth where the stars can shine as brightly as they do in Antarctica, thanks to similar conditions like minimal light pollution, clear skies, and high altitude. Here are some standout locations:
1: Atacama Desert, Chile: Known as one of the driest places on Earth, the Atacama has incredibly clear skies due to its arid climate and high elevation (parts reach over 8,000 feet or 2,400 meters). It’s far from urban centers, and the lack of moisture minimizes atmospheric distortion. This is why it’s home to major observatories like the Very Large Telescope (VLT) and ALMA.
2: Mauna Kea, Hawaii: Sitting at 13,796 feet (4,205 meters) above sea level, this dormant volcano offers a thin atmosphere and dark skies, well above the clouds and light pollution of lower elevations. It’s another hotspot for astronomers, hosting telescopes like the Keck Observatory. The isolation in the Pacific Ocean helps keep artificial light at bay.
3: Namib Desert, Namibia: This remote desert has vast stretches with no human habitation, resulting in negligible light pollution. Its dry air and clear nights make it a stargazing paradise, often highlighted by the stunning views of the Milky Way.
4: Tibetan Plateau, China: At an average elevation of 14,800 feet (4,500 meters), this high-altitude region has thin, dry air and is far from major cities. The skies here can be exceptionally clear, especially in less populated areas away from the eastern urban zones.
4: Sahara Desert, North Africa: In its more remote sections (like parts of Algeria or Libya), the Sahara offers dark, unpolluted skies and a dry climate. Bedouin nomads and travelers have long marveled at the starry vistas here.
5: Outback, Australia: The vast, sparsely populated interior of Australia has some of the darkest skies in the Southern Hemisphere. Places like the Uluru region or the Simpson Desert provide brilliant star views, enhanced by the lack of nearby lights.
These spots share Antarctica’s key advantages: isolation, altitude, and arid or stable weather. However, each has its own flavor—Mauna Kea’s volcanic perch, the Atacama’s otherworldly dryness, or the Outback’s endless horizons. The brightness of stars in these places isn’t just about intensity; it’s the sheer number you can see, down to fainter magnitudes, that makes them jaw-dropping. Have you got a favorite remote spot you’d like to check out for stargazing?
Jag frågade Grok igen.
"Can light travel through 40000 km of dense atmosphere?"
Grok;
Citat:
To answer whether light can travel through 40,000 km of dense atmosphere, let’s break it down with some reasoning and context.
First, "dense atmosphere" isn’t precisely defined here, so I’ll assume you mean something like Earth’s atmosphere at sea level, which has a density of about 1.225 kg/m³. Earth’s actual atmosphere thins out significantly with altitude, becoming negligible beyond 100 km (the Kármán line, often considered the edge of space). For comparison, the planet’s circumference is about 40,075 km, so 40,000 km is roughly the distance around Earth—far more than the atmosphere’s typical thickness.
Light’s ability to travel through a medium depends on absorption, scattering, and the medium’s opacity. In a dense atmosphere, these factors are influenced by the composition (e.g., nitrogen, oxygen, water vapor, dust) and the distance traveled.
Key Considerations:
1: Earth’s Atmosphere as a Baseline: Normally, sunlight reaches Earth’s surface after passing through about 10-15 km of dense atmosphere (from the top of the troposphere down). On a clear day, we see the Sun brightly, though some wavelengths (like UV) are filtered out by gases like ozone. Scattering (why the sky is blue) and absorption reduce intensity, but visible light still gets through.
2: Scaling to 40,000 km: If we imagine light traveling horizontally through 40,000 km of Earth-like atmosphere at sea-level density, the sheer distance amplifies scattering and absorption exponentially. Each kilometer adds more particles to interact with—molecules, aerosols, water vapor. In physics, this is modeled by the Beer-Lambert Law:
I = I_0 e^{-\mu x}
, where ( I ) is the transmitted intensity,
I_0
is the initial intensity,
\mu
is the attenuation coefficient, and ( x ) is the distance.
For visible light in Earth’s atmosphere,
\mu
varies by wavelength and conditions, but a rough estimate for clear air is around 0.01 to 0.1 km⁻¹. Over 40,000 km,
\mu x
becomes massive (400 to 4,000), making
e^{-\mu x}
effectively zero. Light would be completely absorbed or scattered long before reaching the end.
3: Real-World Analogies:
On Earth, sunlight dims significantly near the horizon (a path of ~300 km through denser air), turning red as shorter wavelengths scatter out. At 40,000 km, this effect would be orders of magnitude worse.
In dense fog or a dust storm, visibility drops to meters because particles block light. Scaling that to 40,000 km is like stacking thousands of such barriers.
4: Exceptions: If the “dense atmosphere” were less opaque—say, a thin gas like interstellar hydrogen—light could travel farther. But you specified "dense," so I’m sticking with Earth-like conditions.
Conclusion:
No, light wouldn’t travel through 40,000 km of dense atmosphere like Earth’s at sea level. It’d be extinguished by scattering and absorption well before that distance—likely within a few hundred kilometers, depending on exact conditions. Even in the clearest air, the cumulative effect over such a vast span is insurmountable.
If you meant a specific scenario (like a planetary atmosphere or a hypothetical setup), feel free to clarify!
Does this tie into your stargazing questions somehow?
Jag svarade Grok.
"Im just need the info because i'm arguing with a flat earther"
Grok;
Citat:
Got it! Debating a flat Earther can be a wild ride—good luck with that. Here’s the key info distilled for your argument about light traveling through 40,000 km of dense atmosphere, tailored to counter flat-Earth logic:
1: Light Doesn’t Make It: In a dense atmosphere (like Earth’s at sea level), light gets scattered and absorbed fast. Over 40,000 km—roughly Earth’s circumference—it’d be completely blocked long before getting through, probably within a few hundred kilometers. This is why we don’t see infinitely far on Earth; the horizon cuts off due to both curvature and atmospheric effects.
2: Flat-Earth Counterpoint: They might claim the atmosphere isn’t that thick or that light travels forever on a flat plane. But if the Earth were flat and the atmosphere extended 40,000 km horizontally with consistent density, you’d never see the Sun or stars—everything would be a murky haze. We see them clearly because the atmosphere is a thin shell (about 100 km high), not a sprawling flat layer.
3: Real-World Proof: Sunsets turn red and dim because light passes through more atmosphere (up to ~300 km near the horizon), scattering blue light out. Multiply that by 100+ times for 40,000 km, and no light survives. On a flat Earth, this wouldn’t happen consistently with distance—it’d be a mess.
Keep it simple: “If the Earth were flat and the atmosphere stretched out 40,000 km, light couldn’t travel through it to let us see stars or the Sun. It’d all get lost in the soup.” Tie it to what they can see—like the horizon or a sunset—and watch them squirm. Need more ammo? Just ask!
