Science: Astronomy, Physics & Public Health

Covering your nose and mouth when sneezing or coughing prevents respiratory droplets from spreading through the air and infecting others. While washing hands is also crucial for hygiene, the immediate action done during the sneeze or cough itself is covering the mouth and nose.

H1N1 influenza can spread through contact with contaminated surfaces called fomites. When virus particles on objects are transferred to your mouth, nose, or eyes after touching a contaminated surface, infection can occur. The claim that transmission occurs only through direct human-to-human contact is incorrect.

Alcohol-based hand sanitizers typically containing 60% ethanol or isopropanol effectively inactivate influenza viruses by disrupting the viral envelope. They are recommended when soap and water are not available, though handwashing with soap is still preferred when possible.

Young healthy adults without chronic conditions generally have stronger immune systems and lower risk of severe H1N1 complications. The other groups listed - pregnant women, young children, seniors, and those with chronic medical conditions - are all recognized as high-risk populations for influenza complications.

Influenza viruses including H1N1 can be transmitted during the presymptomatic phase - infected individuals can shed virus and infect others 1 to 2 days before symptoms appear. This makes containment difficult and contributes to rapid spread in communities.

Crowded places increase the risk of exposure to infectious respiratory droplets from infected individuals. Social distancing and avoiding crowds were key recommendations during the 2009 H1N1 pandemic to reduce transmission rates.

Influenza viruses can survive on hard surfaces like doorknobs and tables for several hours to days with infectivity typically lasting 2 to 8 hours under normal conditions. This survival time enables fomite transmission and makes surface disinfection important.

Staying home when sick with flu-like illness prevents spreading the virus to others in the community. This isolation should continue until fever is gone for 24 hours without fever-reducing medication not necessarily until the disease is completely cured.

WIMPs are Weakly Interacting Massive Particles, a hypothetical class of particles that are candidates for dark matter. They interact through gravity and the weak nuclear force but not through electromagnetic or strong nuclear forces, which explains why they don't emit or absorb light. 'Massive' doesn't just mean large - in physics, it means they have mass (as opposed to being massless like photons). The other options are incorrect expansions of the acronym.

Gravitational lensing occurs when a massive object (like a galaxy cluster) bends spacetime, causing light from distant objects to curve around it. The massive object acts as a lens, magnifying and distorting the light from background sources - galaxies or quasars behind it. This effect, predicted by Einstein's General Relativity, has nothing to do with Earth's gravity interrupting telescopes. It's a powerful tool for studying dark matter and distant galaxies. Options A, B, and D incorrectly focus on Earth's gravity rather than massive astronomical objects.

WMAP (Wilkinson Microwave Anisotropy Probe) was a NASA satellite (2001-2010) that measured the cosmic microwave background radiation across the full sky. These measurements revealed the universe's age (13.8 billion years), composition (dark energy, dark matter, ordinary matter), geometry (flat), and evolutionary history. It wasn't designed to detect comets or measure the Sun's temperature - those are completely different astronomical missions. Option D is wrong because WMAP had a very specific cosmology mission, not multiple purposes.

Just beyond the orbit of Neptune (the outermost planet) lies the Kuiper Belt - a region of icy bodies and dwarf planets like Pluto. Beyond the Kuiper Belt, at the outer edge of the Solar System, is the Oort Cloud - a spherical shell of icy objects that marks the boundary of the Sun's gravitational influence. Comets originate from both regions. While comets, dust, nebulae, and dark matter all exist in space, the specific structure immediately beyond the Solar System is the Kuiper Belt followed by the Oort Cloud. Nebulae are light-years away, and dark matter is distributed throughout the universe, not just beyond our Solar System.

The twin paradox demonstrates time dilation in special relativity: a twin traveling at high speed ages slower than their Earth-bound sibling. This occurs because the traveling twin experiences acceleration and deceleration, breaking the symmetry between the two reference frames. Options A and B describe scenarios unrelated to the actual paradox.

Orion is a constellation - a pattern of stars as seen from Earth - not a galaxy. Andromeda (M31), Sombrero (M104), and Milky Way are all galaxies. Galaxies contain billions of stars, while constellations are apparent star patterns that may include stars at vastly different distances.

The Solar System is located approximately 26,000 light-years from the center of the Milky Way galaxy, in the Orion Arm spur. This distance has been refined through observations of stars, gas distribution, and the galactic center's position. Modern measurements place it between 25,000-27,000 light-years.

The Helix Nebula (NGC 7293) is famously known as the 'Eye of God' or 'God's Eye' due to its striking resemblance to a giant eye when viewed in infrared and visible light. 'Pillars of Creation' refers to structures in the Eagle Nebula, not Helix. It is a planetary nebula about 700 light-years away.

The Large and Small Magellanic Clouds (LMC and SMC) are the Milky Way's largest satellite galaxies, visible from the Southern Hemisphere. M31 (Andromeda) is a separate galaxy, not a satellite. M21 is an open star cluster within our galaxy. The Virgo Cluster is a distant galaxy cluster, not related to our satellites.

Google was incorporated in September 1998 by Larry Page and Sergey Brin. The company was founded on September 4, 1998, though the search engine project began earlier in 1996 as 'BackRub' at Stanford. The domain google.com was registered on September 15, 1997, making September 1998 the correct answer for when the company was officially established.

Larry Page and Sergey Brin founded Google in 1998 while they were Ph.D. students at Stanford University. Option A incorrectly swaps their surnames. 'Stifen Hawkins' appears to be a misspelling of Stephen Hawking, who had no connection to Google. 'N chandrasekharan' refers to N. Chandrasekaran, the current chairman of Tata Sons, unrelated to Google.