Video yükleniyor...

Video Yüklenemedi

Ana Sayfaya Dön

Gravitational lensing, also known as an Einstein ring This occurs when the strong gravitational pull of a massive object warps spacetime around it so much that light and other forms of electromagnetic radiation are deflected from a straight path. For example, animations show how a black hole passing in...

11,651 görüntüleme • 4 ay önce •via X (Twitter)

0 Yorum

Yorum bulunmuyor

Orijinal gönderinin yorumları burada görünecek

Benzer Videolar

When a nuclear reactor is switched on for the first time, an intense, almost hypnotic blue glow appears in the water surrounding the reactor core. This light is neither fire nor heat; it is Cherenkov radiation, a physical phenomenon that occurs when charged particles, such as high-energy electrons produced during nuclear fission, travel through a transparent medium faster than light can propagate within that same medium. While nothing can exceed the speed of light in a vacuum, light travels more slowly in materials like water. When a charged particle surpasses this reduced speed, it emits a coherent shock-like electromagnetic wave, often described as an optical analogue of a sonic boom. This radiation produces the distinctive blue glow. The colour arises because Cherenkov radiation is strongest at shorter wavelengths, which are dominated by blue and ultraviolet light. The phenomenon was first observed experimentally in 1934 and later explained theoretically, work that led to the Nobel Prize in Physics in 1958. Its explanation confirmed how relativity and electromagnetism operate in material media. Today, this deep blue light is both a warning and a scientific tool. It signals the presence of intense ionising radiation, while also being exploited in particle detectors, nuclear reactors, and neutrino observatories. It provides a rare, visible manifestation of subatomic processes that are otherwise hidden from direct human perception. #GottaLovePhysics #Physics

Erika 

275,878 görüntüleme • 6 ay önce

When a spacecraft leaves Earth, it doesn’t just fire its engines and head straight to its destination. In many missions, especially those going beyond low Earth orbit, there’s a more subtle and elegant strategy at play, one that uses gravity itself as part of the navigation system. This is often called a gravity assist, or a slingshot maneuver. But in the case of missions like #Artemis II, what’s being used is a closely related idea known as a free-return trajectory. At first glance, it might sound simple: the spacecraft goes to the Moon, loops around it, and comes back. But the physics behind it is anything but simple. Instead of relying on continuous propulsion, the spacecraft follows a carefully calculated path through the gravitational field of the Earth–Moon system. It is launched with just the right speed and direction so that, as it approaches the Moon, the Moon’s gravity bends its trajectory. The spacecraft is effectively flung around the Moon, redirected onto a path that naturally brings it back toward Earth. No major engine burn is needed for the return. Small trajectory corrections may still be required, but gravity does the heavy lifting. That’s the key. This kind of trajectory is not just efficient, it’s also safe. If something goes wrong with the spacecraft’s engines or onboard systems, gravity itself ensures the return. It’s an inherent backup plan, built into the trajectory from the very beginning. The same fundamental idea appears in gravity assists used across the Solar System. When a spacecraft flies past a planet, it can gain or lose speed by exchanging momentum with that planet. From the spacecraft’s point of view, it’s as if it has been accelerated without using fuel. In reality, it has borrowed a tiny amount of orbital energy from the planet itself. That’s how missions like Voyager reached the outer planets, and how probes continue to explore regions far beyond what their onboard fuel alone would allow. But there’s an important distinction. An interplanetary gravity assist is typically used to change speed and direction, often increasing the spacecraft’s energy. A free-return trajectory, like the one used in Artemis II, is designed for something more specific: a path that naturally loops back to Earth without requiring additional propulsion. It’s less about gaining energy, and more about shaping a trajectory that guarantees a return. To understand why this works, it helps to stop thinking in straight lines. In space, motion follows curves defined by gravity. The spacecraft is constantly falling, first toward Earth, then toward the Moon, and then back toward Earth again. What looks like a loop is really a continuous free fall through a changing gravitational landscape. This way of navigating space reveals something deeper. We tend to think of engines as the drivers of motion, but once a spacecraft is on its way, gravity does most of the work. The art of spaceflight is not just about thrust. It’s about knowing when not to use it. #GoodLuck #Artemis NASA Artemis

Erika 

234,769 görüntüleme • 3 ay önce

Mummy of Pacheri : It is the mummy of a man about 1.65m tall, who lived during Ptolemaic Period (305-30 BC). It called 'Mummy of Pacheri', although the reading of the name remains problematic. The quality of its embalming, as well as the state of conservation make it a specimen noticeable and worthy of notice. The mummy is a perfect example for anyone wanting to understand the technique of embalming, and that is probably why it attracts such fascination from visitors. What adds to the charm of this mummy, is also its location in the museum. Indeed, located in a small niche at the back of the large sarcophagi room. At the top of the so-called Osiris crypt, the mummy is only visible in a certain dim light and remains well hidden, isolated from other artifacts, as if rest was a necessity for it in such a busy museum. According to the results of an X-ray analysis, this mummy is that of an adult man. His name, written hastily, can be read as either Pacheri or Nenu; the interpretation is still uncertain. The wide used collar covering his chest is formed of several rows of beads and includes falcon-headed clasps. The apron covering the body features various scenes arranged in registers, notably the mummy lying on a bed, surrounded by the goddesses Isis and Nephtys, and the four sons of Horus. Finally, the casing around the feet has two images of the funerary god Anubis. Louvre Museum (N 2627) 📽️© antiqua_archeologia (IG) - Subscribe for Weekly Newsletter - #archaeohistories

Archaeo - Histories

57,028 görüntüleme • 2 yıl önce

The Milky Way and Andromeda are currently separated by about 2.5 million light-years. Drawn together by gravity, Andromeda approaches us at roughly 110 km/s. Though this speed is immense, the vast cosmic distances mean the process will unfold slowly over billions of years. Recent studies using data from Hubble and Gaia suggest the long-predicted merger is not certain: there's roughly a 50% chance the galaxies will collide and merge within the next 10 billion years, with only a small probability of it beginning in the classic ~4–5 billion-year timeframe. As the galaxies interpenetrate, powerful gravitational tides would eject enormous streams of stars, gas, and dust—forming glowing tidal tails that trail across space like celestial ribbons. New star formation would flare in compressed gas clouds, lighting up the chaos with brilliant nebulae. Despite the dramatic term "collision," individual stars are so sparsely distributed that direct crashes would be exceedingly rare. Instead, gravity would gently reshuffle orbits: some systems flung to the outskirts, others spiraling toward a shared center. At the hearts of both galaxies lie supermassive black holes—ours at ~4 million solar masses, Andromeda's far larger. Over eons, they would inspiral and coalesce in a cataclysmic union, unleashing ripples of gravitational waves across the cosmos. In the end, the spirals we know would dissolve into a single, grand elliptical galaxy—a transformed beacon in the Local Group, born from one of the universe's most patient spectacles. 🎥 skywolf400

Dreams N Science

365,923 görüntüleme • 6 ay önce