describe anit-matter, cosmological constant and the posibility of extraterrestrial life.?

Answer 1

Anti-matter - matter that is composed of only anti-particles (opposite or mirror images of the subatomic particles we are familiar with in normal matter).

Cosmological constant - proposed by Albert Einstein as a modification of his original theory of general relativity to achieve a stationary universe.

Extraterrestrial life - if you mean some form of life on other worlds, it's certainly possible (perhaps even inevitable). That life could be life-as-we-know-it and be bacteria, molds, plants, fish, or anything else. It could life-as-we-don't-know-it and we may never even recognize it as life even if we find it.
It's simply a matter of looking for it.
If you mean intelligent aliens that have come to Earth in spacecraft - then until there is scientific evidence and proof (not stories like "I was abducted by aliens" or "I saw a light in the sky and it wasn't a plane so it HAD to be a UFO"), I refuse to buy into the whole aliens-among-us malarkey.

Answer 2

anti-matter are basically subatomic particles that have positive mass, but all of the other features of their matter counterparts reversed. For example, an anti-electron (positron) has the mass of an electron, but is positiviely charged. When an anti-particle and its counterpart collide, they combine into energetic photons (energy).

The cosomological constant is a term in the Einstein field equation for gravitation. Depending on whether this constant is negative, zero, or positive, the universe is expanding, static or contracting.

I leave speculation of aliens to the Drake equation and your own opinion.

Answer 3

In 30 words or less.....

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