Post your science questions here!

seedywagon · 09-09-2012, 12:55 AM

Hi everyone,
I'm not sure if this has been done before, but I'd like to start a thread that provides the opportunity to ask ANY question that is science-related.
So, if you need something explained, or if you have a great explanation for somebody else's question, don't hold back!
Science is a constant journey of discovery, and with the rate of interest in science-related careers dropping, I think it's good to re-invigorate some curiosity as to how this amazing world ticks.

MITCHAY · 09-09-2012, 01:09 AM

Cool idea. Another thing would be to post some interesting facts as well as post questions.

BHDOGS · 09-09-2012, 01:13 AM

Why does the center of the galaxy and the edge spin at the same speed?

XR6T0Y · 09-09-2012, 01:22 AM

What's the meaning of life

seedywagon · 09-09-2012, 01:29 AM

Quote:

Originally Posted by BHDOGS

Why does the center of the galaxy and the edge spin at the same speed?

This is a tricky one, but from what I've read, the velocity of particles 'spinning' in the milky way actually vary depending on distance from it's centre, with particles closer in spinning slightly quicker, but not by much. I think it would have to do with the physics involved when it was actually created, in space, where Newton's law of inertia is king.
My guess is that at its birth, whatever force that caused it to spin in the first place must have been so vast, it was able to accelerate everything in its way at roughly the same rate, and being space, there wasn't much to slow any of it down.

seedywagon · 09-09-2012, 01:31 AM

Quote:

Originally Posted by XR6T0Y

What's the meaning of life

I knew this wouldn't take long :p

MITCHAY · 09-09-2012, 01:32 AM

A little party trick I used to do was to drop a 5c coin and a 50c coin at the same height and get people to bet which one landed first. Then mix up the heights with the same results.

seedywagon · 09-09-2012, 01:36 AM

Quote:

Originally Posted by MITCHAY

A little party trick I used to do was to drop a 5c coin and a 50c coin at the same height and get people to bet which one landed first. Then mix up the heights with the same results.

Yay! Acceleration due to gravity does not change depending on mass, it is and always will be 9.8 metres per second squared.

XR6T0Y · 09-09-2012, 01:37 AM

Quote:

Originally Posted by MITCHAY

A little party trick I used to do was to drop a 5c coin and a 50c coin at the same height and get people to bet which one landed first. Then mix up the heights with the same results.

I've heard that if you drop two things (with wind factor taken out) froma decent height, no matter the weight or shape they will fall at the same speed?

Quote:

Originally Posted by seedywagon

I knew this wouldn't take long :p

Was being serious to

jaydee · 09-09-2012, 01:40 AM

If you are flogging through space in your space ship at night at light speed and turn on your headlights, will you be able to see where you're going?

Madaya · 09-09-2012, 01:42 AM

Check out this You Tube vid. An experiment by Dave Scott, commander of Apollo 15. Very cool.....

http://www.youtube.com/watch?v=KDp1tiUsZw8

seedywagon · 09-09-2012, 01:43 AM

Quote:

Originally Posted by XR6T0Y

I've heard that if you drop two things (with wind factor taken out) froma decent height, no matter the weight or shape they will fall at the same speed?

They'd be correct, with air resistance out of the picture, objects fall at equal rates in free fall.

Was being serious to

Science can theoretically only provide a partial answer to this question I reckon, the other half would be the domain of philosophers and philologers. Einstein tried to find an equation to explain everything in the universe with questionable success.

MITCHAY · 09-09-2012, 01:44 AM

Quote:

Originally Posted by XR6T0Y

I've heard that if you drop two things (with wind factor taken out) froma decent height, no matter the weight or shape they will fall at the same speed?

Was being serious to

Quote:

Originally Posted by seedywagon

Yay! Acceleration due to gravity does not change depending on mass, it is and always will be 9.8 metres per second squared.

Yep of course the only exception is resistance. Obviously a feather and a brick won't land the same time but most things will. My mate used to trip balls over it.

JC · 09-09-2012, 01:44 AM

What weighs more? A tonne of feathers, or a tonne of bricks?

MITCHAY · 09-09-2012, 01:45 AM

Quote:

Originally Posted by JC

What weighs more? A tonne of feathers, or a tonne of bricks?

Funny how many people get this wrong

:

XR6T0Y · 09-09-2012, 01:46 AM

Quote:

Originally Posted by JC

What weighs more? A tonne of feathers, or a tonne of bricks?

I fell for this so many times when I was a kid lol

Science has always intrigued (spelling?) me. Was just never smart enough to persue it

seedywagon · 09-09-2012, 01:49 AM

Quote:

Originally Posted by jaydee

If you are flogging through space in your space ship at night at light speed and turn on your headlights, will you be able to see where you're going?

Due to Einsteins theory of relativity, which he spent ages developing based on a very similar question to what you just asked, my logic would say no, because you're travelling at the same speed as the light you're trying to emit, therefore the light beam from your headlights must accelerate faster than your spaceship in order to 'break free' of it.

XR6T0Y · 09-09-2012, 01:50 AM

Quote:

Originally Posted by seedywagon

Due to Einsteins theory of relativity, which he spent ages developing based on a very similar question to what you just asked, my logic would say no, because you're travelling at the same speed as the light you're trying to emit, therefore the light beam from your headlights must accelerate faster than your spaceship in order to 'break free' of it.

But if you're travelling at the speed of light, wouldn't the light beams then travel twice as fast as the speed of light? As to it, it would still be in a stationary position travelling at light speed

seedywagon · 09-09-2012, 02:03 AM

Quote:

Originally Posted by XR6T0Y

But if you're travelling at the speed of light, wouldn't the light beams then travel twice as fast as the speed of light? As to it, it would still be in a stationary position travelling at light speed

It probably depends on how light behaves, which science doesn't know yet conclusively, we do know that it behaves as a particle ( a photon ) and an electromagnetic wave. My thinking is that in order for photons to escape the headlight, which is travelling at the same velocity as the space ship (light speed), they would need to be 'pushed clear' of the craft, or accelerated. For your idea to work, there would have to be a force to create this acceleration.

XR6T0Y · 09-09-2012, 02:07 AM

This is why science intrigues me...

See I thought that a vehicle travelling at lightspeed (base) would be the equivalent to a car doing 0. At 0, the light stays the same distance from the headlight as the car speeds up. Because the car is travelling at a speed, where the light would then travel x times faster than the car to stay ahead. Obviously this would be different for something travelling so fast

seedywagon · 09-09-2012, 02:17 AM

Quote:

Originally Posted by XR6T0Y

This is why science intrigues me...

See I thought that a vehicle travelling at lightspeed (base) would be the equivalent to a car doing 0. At 0, the light stays the same distance from the headlight as the car speeds up. Because the car is travelling at a speed, where the light would then travel x times faster than the car to stay ahead. Obviously this would be different for something travelling so fast

My favorite type of science too, physics.
I often think about these questions too, which are based around a topic called "Non-inertial reference frames" which deals with how things accelerate with respect to eachother.
An elevator is a perfect example of this, imagine one without windows, vibration or any noise travelling at a constant velocity (nOt accelerating). You technically wouldn't even know you're moving!

XR6T0Y · 09-09-2012, 02:22 AM

Quote:

Originally Posted by seedywagon

My favorite type of science too, physics.
I often think about these questions too, which are based around a topic called "Non-inertial reference frames" which deals with how things accelerate with respect to eachother.
An elevator is a perfect example of this, imagine one without windows, vibration or any noise travelling at a constant velocity (nOt accelerating). You technically wouldn't even know you're moving!

'Shroedingers cat' anyone

Couldn't help myself

I always wanted to study physics, but as my old co-ordinator said to me. "Frankly, I find you to stupid to do it"

Honestly, some of the questions that I think of....God, I wish I knew the answers.

seedywagon · 09-09-2012, 02:30 AM

Quote:

Originally Posted by XR6T0Y

'Shroedingers cat' anyone

Couldn't help myself

I always wanted to study physics, but as my old co-ordinator said to me. "Frankly, I find you to stupid to do it"

Honestly, some of the questions that I think of....God, I wish I knew the answers.

Einstein's teachers thought the same thing of him, look at what he discovered.
Many people are great at the maths, but miss the impact of the concepts altogether, but those who take an interest seem to know more.

Madaya · 09-09-2012, 02:35 AM

Jeepers, these are hard questions to ponder at this time of night, and I remember a great barby where we discussed exactly this problem, Einstein would have loved it.
Fact 1, forget about travelling at the speed of light. Can't be done, not enough energy in the Universe to achieve it - and if you talk about warp or hyper drive, fine, but they are realms that are 'outside' our Universe.
You can travel at 99.99999etc% the speed of light, something the folk at CERN would like to do, and indeed get close to, in order to find the Higgs Boson thingy. The energy involved getting there can power a substantial part of Australia for a good while.
Fact 2. Relativity. Yeah, it's still the best we have to describe things flying at near light speed. For you, in your spaceship travelling at 99.9% c (=light speed), it would appear that your headlights are peering ahead as per normal, two little beams, probing ahead into absolute blackness.
To an observer watching, (i.e. us, everyone else on good old planet Earth)your beams would barely emerge from the the head light, and depending on whether you are approaching, passing or receeding you would display peculiar visual effects.
Yeah, we loved that barbeque, we done good stuff that day.

Madaya · 09-09-2012, 02:53 AM

What wierds me is this.
Jump in your Ford (after all, this is what the Forum is really about - thanks to the 'owners for letting us play)..start it up, press the accelerator and whether it is a Festiva or a FPV, you get pressed back in the seat a bit.
Light (a photon), gets emitted from an atom (and understand, the computer screen, room, every article in the vicinity, either in visible light, UV, IR, radio wave or whatever, even your own self) is emitting trillions of photons every second, some of which enter your eye and get translated into something that enables you to read the very words that you are reading right now - the brain works all this out somehow, and get this...
A car accelerates from zero to 100kph in several seconds, you get a nice push in the back. A photon accelerates from 'nothing - i.e. not zero to 1,074,325,550 kph in no time at all.
Mind blowing - trillions of them - every second.

Vincenzo · 09-09-2012, 03:33 AM

Quote:

Originally Posted by XR6T0Y

What's the meaning of life

Answer = 42 Check with the Monty Python boys.

This is my one and only scientific statement repeated from an unknown source

HELL EXPLAINED BY A CHEMISTRY STUDENT

The following is an actual question given on a University of *Washington *chemistry mid-term exam.

The answer by one student was so 'profound' that the professor shared it with colleagues, via the Internet, which is, of course, why we now have the pleasure of enjoying it as well :

Bonus Question: Is Hell exothermic (gives off heat) or endothermic (absorbs heat)?

Most of the students wrote proofs of their beliefs using Boyle's Law (gas cools when it expands and heats when it is compressed) or some variant.

One student, however, wrote the following:

First, we need to know how the mass of Hell is changing in time. So we need to know the rate at which souls are moving into Hell and the rate at which they are leaving. I think that we can safely assume that once a soul gets to Hell, it will not leave. Therefore, no souls are leaving. As for how many souls are entering Hell, let's look at the different religions that exist in the world today.

Most of these religions state that if you are not a member of their religion, you will go to Hell. Since there is more than one of these religions and since people do not belong to more than one religion, we can project that all souls go to Hell. With birth and death rates as they are, we can expect the number of souls in Hell to increase exponentially.

Now, we look at the rate of change of the volume in Hell because Boyle's Law states that in order for the temperature and pressure in Hell to stay the same, the volume of Hell has to expand proportionately as souls are added.

This gives two possibilities:

1. If Hell is expanding at a slower rate than the rate at which souls enter Hell, then the temperature and pressure in Hell will increase until all Hell breaks loose.

2. If Hell is expanding at a rate faster than the increase of souls in Hell, then the temperature and pressure will drop until Hell freezes over.

So which is it?

If we accept the postulate given to me by Teresa during my Freshman year that, 'It will be a cold day in Hell before I sleep with you,' and take into account the fact that I slept with her last night, then number two must be true, and thus I am sure that Hell is exothermic and has already frozen over.

The corollary of this theory is that since Hell has frozen over, it follows that it is not accepting any more souls and is therefore, extinct ...... leaving only Heaven, thereby proving the existence of a divine being which explains why, last night, Teresa kept shouting 'Oh myyyyyy God.'

THIS STUDENT RECEIVED AN A+.

ohzone · 09-09-2012, 10:32 AM

You are driving a car and have a helium balloon floating inside and in the middle of the car you accellerate fairly quickly, what happens to the balloon

FCleader · 09-09-2012, 11:14 AM

If anyone wants to watch some good science videos that are explained well watch this guy http://www.youtube.com/user/1veritasium/videos

He did his PhD in teaching people physics using multimedia, the videos are well explained using common misconceptions as a starting point then moving on the the reality of a situation.

He has also been on ABC's Catalyst a few times as well.

seedywagon · 09-09-2012, 11:38 AM

Quote:

Originally Posted by Madaya

What wierds me is this.
Jump in your Ford (after all, this is what the Forum is really about - thanks to the 'owners for letting us play)..start it up, press the accelerator and whether it is a Festiva or a FPV, you get pressed back in the seat a bit.
Light (a photon), gets emitted from an atom (and understand, the computer screen, room, every article in the vicinity, either in visible light, UV, IR, radio wave or whatever, even your own self) is emitting trillions of photons every second, some of which enter your eye and get translated into something that enables you to read the very words that you are reading right now - the brain works all this out somehow, and get this...
A car accelerates from zero to 100kph in several seconds, you get a nice push in the back. A photon accelerates from 'nothing - i.e. not zero to 1,074,325,550 kph in no time at all.
Mind blowing - trillions of them - every second.

We are still discovering how things operate at the atomic level, I find it absolutely fascinating that scientists such as Mohr and Rutherford were able to theorize the model of an atom in a time where there wasn't any sophisticated equipment like we have now.

Ducati888 · 09-09-2012, 11:53 AM

Quote:

Originally Posted by MITCHAY

Yep of course the only exception is resistance. Obviously a feather and a brick won't land the same time but most things will. My mate used to trip balls over it.

No exceptions. Items will fall at the same rate in a vaccuum. Feather or brick or elephant. It's not a theory it's a fact. Mass is irrelevant.

The equations and tests are pertinent to a perfect vaccuum only.