Space-time is kind of a big deal. As we discussed in class, when distorted by matter (massive bodies like planets, moons, etc.), it creates the sense of gravity. Earth's gravititational tug-of-war with the moon in turn is responsible for causing the Earth's tides, plus gravity causes light to bend, streeeeeetching our perception of time.
Don't worry!....both concepts take awhile to get one's head around. Here's your assignment:
Watch the video (to the right) about space-time (http://www.youtube.com/watch?v=AAqSCuHA0j8) and watch the full animation about tides (below) -- the total viewing time is less than 5 minutes. Then post a SPECIFIC question you have about EACH concept that you want answered in class.
(That means two questions from everyone. Oh, and by the way, "I don't get space-time?" doesn't count as a good, specific question!) ;)
We'll discuss your questions in class during our following meeting and get to the bottom of these topics.
http://www.onr.navy.mil/focus/ocean/motion/tides1.htm
Why is it called neap tide, what does neap mean, and is neap tide high or low?
ReplyDeleteIn the Relativity/ gravity video, there was a picture of the solar eclipse. I know the main point of it was the stars around the outside, but there were also what appear to be stars in the center of the moon. What is that?
Space-Time Extravaganza!:When the astrophysicist Neil Tyson talks about how gravity is a fabric/shape of space-time, and we move along the curves of these shapes and the straight line bends as orbits, trajectories and pathways through the cosmos…what does he mean by trajectories? (What are trajectories?)
ReplyDeleteTides Animation:
When the moon is closer to one side of the Earth, it pulls the water towards it, creating a high tide…but why is there a high tide on the opposite side of Earth? Nothing is pulling the opposite side of the Earth since the moon is on the other side…
In the Space - Time video when they were talking about the the moon covering the sun and being able to see stars that were behind it, did they mean that you could literally see through the sun? Or did they mean that you could see around the sun?
ReplyDeleteIn the Tides video, is the water the only thing on earth that is effected by the gravity of the moon in this way? And if not, how come?
When they say that you can see the stars moving past the sun and bending space time, why isn't the gravity of the sun just attracting those close stars and sucking them into itself making it bigger?
ReplyDeleteFor the tides, How come if even though the moon is closer and it orbits us, why does it have a greater affect on our tides if the sun has a stronger gravitational pull and we orbit it?
Space-Time Video: In one of the animations (during the part where the circus muisc played) it portrayed the bigger mass in the center and the less massive ball was rolled unto the "fabric of space-time". How come it did not orbit? - it just curved a little and kept going. In class, we saw that by doing the same thing, the less massive ball orbited the larger ball.
ReplyDeleteTide Animation: it says: "The key to tides is the varying strength of the Moon's gravitational pull on different parts of the globe. The Moon pulls most on the water nearest to it, creating a high tide bulge of water. On the opposite side of the planet, about 7,926 miles (1,2760 km) away, the Moon's pull is much weaker and the water is left to form another high tide bulge". WIll this concept change from their point of view/perspective as opposed to ours? (b/c the Earth revolves)
Space-time extravaganza video:
ReplyDeleteWhat does he mean by light cant even escape the effects of gravity? Does light have mass?
Tides:
When is the difference between high and low tides greatest? When is it the smallest? Why is there a smaller difference between the high and low tides when the moon, sun, and Earth form a right angle?
In space time, why does the smaller mass orbit around the bigger mass first rather than just going directly to the bigger mass a stopping completely?
ReplyDeleteWhat happens when the sun and the moon form a 180 degrees angle (straight line)?
1) How exactly does general relativity modify special relativity -- what are the effects on space time?
ReplyDelete2) Why does gravity affect the qualities of light? How did Arthur Edington's experiment of photographing the solar eclipse prove that gravity affects light?
Why did seeing objects behind the sun prove that space-time could be morphed?
ReplyDeleteWhy does the straight line of the earth, moon, and sun create large tides?
1) Rather than simply being sucked in by a bigger mass's gravity, why does a smaller mass orbit around a larger mass?
ReplyDelete2) In the animation, why does it show a tidal bulge on the side of the Earth not facing the moon, which is creating the tidal bulge in the first place?
Space Time:
ReplyDeletehow is the image of the stars behind the moon bent around the sun, and from how far back are stars visible?
Tides:
Do tides get bigger or smaller when the moon is on the opposite side of Earth from the sun?
In the video, the man says that "gravity is not really a force". I thought gravity was a force.
ReplyDeleteWhat does he mean by this?
What did Krauss mean by special and general relativity?
What is the difference between the two?
I know light does not have a mass, but why do they treat light as if it does?
Why is the word "neap" used when describing tide? and is it low tide or high tide?
FORGOT ONE QUESTION!
ReplyDeleteAlso, doesn't the sun affect tides like the moon affects tides?
Doesn't the sun have a greater "gravity" pull?
Space Time:
ReplyDeleteHow is it possible that you could see the light of a star that is behind the sun?
Tides:
What are three specific characteristics of tides?
Space Time: If space and time could contrapt in the presence of matter; would there ever be a time where matter does not effect the outcome of space and time? For example, would there be a case where instead of the smaller ball being bounced off the bigger one and moved to the other direction, instead of that would there be a moment when they just collide?
ReplyDeleteTide: How come the low tide does not decrease as much as the high tide does? Also, which tide is more significant, the low or high one?
Space Time: One of the speakers said that gravity is not a force but a fabric; what does he mean by that?
ReplyDeleteTide: There is high tide and low tides; will there ever be a 'middle' tide? For example, when the pull of the moon's gravity and the sun would have such a small difference no one will notice.
1.) Why is it that when the moon, the earth, and the sun form a straight line the tides become so much greater?
ReplyDelete2.) What does it mean when you can see the stars behind the sun because the moon is in front of it, and why?
Space Time: How does light be effected by gravity?
ReplyDeleteTide: What else does the moon's gravitational pull towards earth effect besides the tide?
1) space-time: During an eclipse, when space-time is bent, why or how does this allow us to see what is behind the sun?
ReplyDelete2) tide: Even though there is the 'neap tide', is there or can there ever be a tide that equals out the low and high tides even more?
Space-time:
ReplyDelete1) Why do they say gravity is not a force? I thought its called the force of gravity.
2) Are you literally able to see the stars directly through the sun? If so, how?
Tides:
1) How come when the moon and sun form a straight line, the tides become so much greater?
1. How is it possible for light to be bent around the sun?
ReplyDelete2. Does the moon's gravitational pull effect anything else besides the tide?
1) What can escape the effects of gravity? When objects get bent in the effect of gravity, do they change shape at all?
ReplyDelete2) What if the Earth had several moons? How would that affect the size of the low and high tides?
2. If the moon was in the same spot as it was a year ago, does it have creat the same tide?
ReplyDelete1. Since the ball with less mass orbits the ball with more mass, if a ball with a larger mass comes along, will the little ball continue orbiting the first ball, or will both balls orbit the bigger one?
1. If light can't even escape the affects of gravity, then what can?
ReplyDelete2. How come there is another gravitational pull/tide on opposite side of the earth away from the moon?
1.Why did Arthur wait until a solar eclipse to test his theory? Were there no other possible ways for him to test this?
ReplyDelete2. If there wasn't a moon would there be always be a low contrast between high tide and low tide?
Video: How is it possible that gravity is a "fabric" of space time instead of a force? If we are all just moving along the curves of space time... how does force come into play or make any difference?
ReplyDeleteAnimation: When the sun and the moon are perfectly aligned and are pulling the water from the Earth, how is it possible that there are tides on BOTH sides? There is no force that is pulling from the other side.
What does it mean when one of the astrophysicists says gravity is a shape of space and time?
ReplyDeleteDoes the gravitation pull of the sun and earth have any effects on the tides?
1) I thought that gravity is a force, but one of the commentators explained how gravity is a fabric, rather than a force. I'm confused about how it isn't a force, especially since we use the term "force of gravity." Also, what is a fabric?
ReplyDelete2) How/why is there a difference when high tides are compared to low tides when the sun, moon and planet Earth create different angles? Also,
why is it that when the moon and sun create a straight line, the tides are bigger?
1). If space-time is a fabric, wouldn't all the planets have to be on the same plane? Or are there infinite layers of fabric?
ReplyDelete2). For high tides and low tides, is there a set time of day/night for each tide? If not, why?
Animation: If we didn't have a moon, would the gravitational pull of the sun be enough to create a noticeable tide?
ReplyDeleteVideo: How does light bend around things?
If you look at a star on a path of light that goes right past the sun you would see it shift because of the gravity of the sun. why could you only see it shift in this situation?
ReplyDeleteWhen the moon is moving around earth the water follows it but there is still water on the opposite side where there is no moon. I know this has to do with inertia, as you told us in class, but i don't understand how?
How far back are the stars from the sun and how are we able to see them?
ReplyDeleteWhy are large tides created when the earth, moon, and sun are in a straight line?
For the tides animation, I understand that the moon creates one tide, and then centripetal force creates the other, but wouldnt centripetal force create a tide around the entire planet because its initially affecting the entire planet?
ReplyDeleteFor the relativity video, how much does it actually take for a massive body to distort space time enough to have an orbit/gravitational pull?
I'm a little confused about how gravity is a fabric/shape of space and time. so now its not a force? Or is it only a fabric when it is being used in space time?
ReplyDeleteDoes the sun, moon, and any other large masses in space time have affect the behavior of high and low tides?
In regards to the video: It is said that Einstein's theorems and discoveries have laid the foundation for modern day physics and how modern day scientists observe and extract upon new information; if one (or more) of his theories of relativity or astronomical physics were to be disproved (as such might be the case right now with an atom found in Switzerland which is said to move faster than the speed of light), how would such affect the history books and the way today's scientists look at our universe.
ReplyDeleteAre all tides set in stone in terms of time period/ do all tides, everyday occur at the same exact time?
How can you see the light from a star behind the sun? doesn't the sun block the light out then?
ReplyDeleteWhy are the tides at the highest when the moon and sun are perfectly alligned?
When the moon blocks the sun and forms an eclipse and results in a star's light being seen, how does the light travel past the sun and since it goes around the sun how much longer is the delay for it to reach earth?
ReplyDeleteWhy are smaller tides called neap tides, when the sun and the moon form a 90 degree angle with the earth?
^ Nick Martin
ReplyDeleteIn the video it says that Einstein established the concept of the fabric of time and space bending around everything holding everything up and keeping planets in orbit and such. This is probably just away to make some sense of gravity, but say it weren't. Say there really is a fabric of space-time about which I have many, probably unanswerable questions.
ReplyDeleteIf the fabric of space time really were a woven fabric of space and time, what would happen if that fabric were removed from existence?
Would the planets just fall forever? Would everything just be suspended? Would time stop and would everything live forever? Or would everything die?
Also would black holes be considered rips in the fabric of space-time?
Finally:
Are neap tides just the smaller differences between the high and low tides or are they the tides themselves?