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View from a Scope | August 25, 2019

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Questions & Answers

Space

Why is there no oxygen in space?

There is oxygen in space, although the density of it is about 100-billion-trillioniths of the density in the Earths atmosphere. Oxygen is actually the third most common element in the universe

Which came first – Time or Space?

According to Albert Einstein, space and time are different aspects of the same entity now called “spacetime”. It therefore seems plausible that they came into existence simultaneously. That said recent research combing Einstein’s work with quantum theory has led some theorists to conclude that space may actually give rise to a phenomenon we experience as time.

When will the Milky Way and Andromeda collide?

It has being known for decades that our nearest galactic neighbor the Andromeda galaxy has been heading towards us at a rate of 120km/s. It was only recently that astronomers were sure whether or not Andromeda would score a direct hit.

While its is relatively easy to measure the approach speed it is far more difficult to measure its exact direction of motion. But a few months ago astronomers using the Hubble telescope finally pinned down its trajectory.

The Andromeda Galaxy is going to score a direct hit with the Milky Way in about 4 billion years time.

 

Could an Astronaut be rescued if he/she became untethered on a space walk?

NASA has developed a sort of jetpack called SAFER (Simplified Aid For EVA Rescue) which fires compressed nitrogen from 24 thrusters to steer the astronaut back to safety if they become detached.

Theoretically, astronauts could also vent some gas from their suits or even throw a tool in the opposite direction to push themselves forward.

But the problem is unless the thrust is exactly in line with the astronauts centre of mass, they will start spinning uncontrollably and very quickly become disorientated.

SAFER automatically detects rotation and uses its jet to keep the astronaut orientated the same way.

What does Dark Energy do?

Dark Energy, identified by astronomers in the 1990s, acts like a form of anti-gravity. While its origins are unknown, observations reveal that it has a repulsive effect that is negligible at human scales but which gets stronger with distance, propelling the expansion of the Universe over the largest distances.