# Particles in deep space query

• B
• bland
In summary, the conversation discusses the number of particles in deep intergalactic space and whether they are ejected from objects or leftover from the formation of the universe. The speaker also questions the possibility of measuring the motion of an object in relation to the particles in this space. They conclude that all velocities and positions are relative in space.

#### bland

I hear that deepest void of intergalactic space may contain say one particle per cubic cm. I don't want to quibble the amount but let's take that as close enough for my purposes.

Now is this figure a statistical average so that if it were correct that each cubic kilometre of deep space would contain say a quadrillion particles and if we took random samples of cubic kilometres say from a cubic light year of deep space, that we would find more or less a quadrillion particles in each of these cubic kilometres. Or is this not the right way to think of the figures given for deep empty space.

You see I'm wondering if these quadrillion particles would have all been ejected from stars or similar object and by the time they are out there they're still moving through at close to their original ejection speed. Or are none of these particle there from galaxies because they never were able to escape the galaxy's gravity and they are in fact just left over particles from the original formation of the universe as the nearly uniform particle gas began to clump. In which case I then wonder are they sitting there as would particles of hydrogen in a 3k box. And if the latter, could we then speak about the motion of an object in deep intergalactic space relative to this thin gas.

I hope I've put that clearly.

I'm not sure what your actual question means but
bland said:
could we then speak about the motion of an object in deep intergalactic space relative to this thin gas.
that is reasonable; The mean velocity of the particles in your "thin gas" has to be 'relative to something' and that something could be your object. But it works both ways according to your choice of frame. The mean velocity of the particles, relative to their centre of mass will be zero.
All velocities and positions are relative; there is no graph paper reference in 'space'.

bland

## 1. What are particles in deep space?

Particles in deep space refer to tiny, subatomic particles that exist in the vast expanse of outer space. These particles can include protons, neutrons, electrons, and photons, among others.

## 2. How are particles in deep space studied?

Particles in deep space are studied using various methods, including telescopes, satellites, and space probes. Scientists also use data from cosmic rays and other high-energy particles to learn more about particles in deep space.

## 3. What is the significance of studying particles in deep space?

Studying particles in deep space can help scientists understand the origins of the universe, the formation and evolution of galaxies, and the fundamental laws of physics. It can also provide insights into the potential for extraterrestrial life.

## 4. How do particles in deep space interact with each other?

Particles in deep space can interact with each other through various forces, such as gravity and electromagnetism. They can also collide and produce new particles, which can provide valuable information about the nature of these particles.

## 5. Are there any risks associated with particles in deep space?

While particles in deep space are an essential part of the universe, they can also pose some risks for spacecraft and astronauts. High-energy particles can damage electronic equipment and pose a radiation hazard for humans in space.