/sci/ - Science & Math

>>2063341

Can you at least TRY doing these questions yourself? They seriously aren't hard. Some basic researching on the internet and common sense will give you the answers.

No idea about what question 4 is asking though :7

Question 4: radiowaves, X-rays from supernovas and blackholes

wat.

what is this basic biology? try these yourself (without internet) and if you still can't get it then I'll help.

heres some help:

Do your own research.

OP Here. It's intro to astrobiology. My answers (without much research, true) are

1. planet needs a hot liquid core for plate techtonics to occur (still no second requirement, not sure how it's necessary for life)

2. yes that's a good way because carbon-14 has a short enough half life to measure

3. ???

4. ???

5. Life as we know it so far needs those things but there could be extra terrestrial life that doesn't. I can't offer a counterexample because nothing has been discovered yet. Except maybe single cell organisms?

>>2063375
Cool answers from the book, bro.

>>2063375

OP, I said try. That isn't trying. Have you googled what plate tectonics is? Do you know anything else about Carbon 14? Jesus.

Plate tectonics allows for recycling of materials. Needs magma and convection currents.

Water could be from meteorites containing bonded hydroxyl groups or comets rich in water vapour.

Oxygen resulted from photosynthesis. This is poisonous but led to ozone which protects us from radiation.

Water needed to sustain life.

That's my pseudo-answers without trying, now go use your brain kid and come back in a year. Or two even.

>>2063375
bullshit on #5

hydrothermal vents and other extreme places have living things that CANNOT cope with oxygen not just dont need it

1. Convection-currents in the mantle and plate boundaries are needed. Without PT the earth would never gain new bedrock, and erosion would scour the surface flat.

2. No, Carbon-14 is a relatively short half-life element. An isotope of Uranium would be ideal for extremely-old objects.

3. Water came from the reaction of oxygen and hydrogen on earth, as well as the water / ice which entered the earth's atmosphere by meteorites.

some water came from comets

also, a primitive meteorite will contain only traces of carbon.

water came from meteorites

oxygen is not necessary- look at plants.
they eat co2 and sunlight and shit o2.
or extremophiles.
an atmosphere might be required depending on how
you look at it.


water is necessary AFAWK

>>2063507
you don't think plants need O2 to survive?

you are so dumb, you are really so dumb, fo real.jpg

>>2063512
as long as there is sunlight a plant has no problem producing enough o2 to feed its own respiration.

it stands as a counter example anyway.

OP, do your own fucking homework...not like these are OMGHARD.

also ITT people don't know shit about geology. there are many different forms of chemosynthesis...some of which SURPRISE! utilize oxygen. chemosynthesis is about the absence of LIGHT since y'know, there ISN'T ANY 1500M BELOW THE SEA SURFACE. archaea use chemical compounds in lieu of light as an energy source.

>>2063517
right, porduces its own, not lives without it.

>oh yea, I live without skin, yea Im pretty cool i dont have to eat any skin to survive I just produce it my self.

>>2063512
Dude. Plants don't need O2.

C14 dating would not be useful for a meteorite. Learn how C14 dating works.

>>2063534
yes they do, oh my god... cellular respiration requires O2 which plants do, they generally take in less O2 then the amount of CO2 they take in which makes people think CO2 and O2 are interchangeable in life giving reactions.

Protip: O2 and CO2 aren't interchangeable

http://www.physorg.com/news189836027.html

life without o2

/eod

>2. You find a primitive meteorite. Would radiometric dating via the decay of Carbon‐14 be a good method to use to date the meteorite? Why or why not?

Carbon-14 gets 'produced' by cosmic radiation smashing into our earth every now and then. The meteorite would have had a way higher dose of particles smashing in to it in space. We don't know how many particles over what period of time, and therefore cant C-14 date it.

So is an atmosphere required for life? it seems as though certain life should exist without it.... like prokaryotes maybe.

Also WTF is number 4 about.

1. Plate tectonics is important for life because it signifies a celestial body (in this case, 'Earth') with a 'live' core which is able to produce heat below the crust. Without internal planetary heat, the Earth would be a similar environment to the Moon; the solar side would be nice and warm, but the dark side would be freezing (our atmosphere helps with this, too.) Also, we would not experience the geological cycle, which shifts minerals from mantle -> crust -> mantle -> crust.

2. No. Radiometric dating via Carbon-14 is only useful in identifying the half-life decay of radioactive isotopes which have developed as a result of processes present in organic matter. This method would be useless in identifying the age of inorganic matter. Also, carbon-dating is only (and somewhat) accurate up to ~14,000 years.

3. Primarily asteroids and comets. Although the near vacuum of space causes water (that is H2O) to boil at extremely low temperatures, the intense pressurization created from celestial collisions creates a forced-fused bonding of hydrogen, which is the primary component of said asteroids and comets, and other heavy metals.

4. I really don't even know what this question means. Oort Cloud?

5. No. Read Dawkins' 'Selfish Gene'. He identifies the principles of life, aka 'replicators'. (As a result, he also gave us the wonderful word, 'meme') Also some years ago National Geographic in combination with NASA published an article on theoretical life-forms which were silicon- vs. carbon-based. Aside from non-carbon based life, there are known extremophiles which are actually quite abundant on Earth (check out the Wiki article on 'Tardigrade')

>>2063631
>>2063631
>>2063631
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>>2063631


Anon, you are a king.

still though missing info on the potential of life without an atmosphere (with an example).

#4 is obviously poorly worded and should be disregarded for now.

[1] no
[2] no half life of C14 dating is only good for 50K years
[3] oxygen and hydrogen in other froms
[4] venus heats up, negative, hmmm don't think there is one its all running down, maybe a wobble or something between planets
[5] no, anerobic bacteria = no oxygen....bubbles = life.