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Martin Burrett

Gravity Simulator - 3 views

    Let your children explore the properties of gravity with this great gravity simulator.
Martin Burrett

Gravity Launch - 71 views

    A great game about gravity where players have to get the rocket to the right place in space.
Gareth Jones

Looking in the Wrong Places | - 5 views

  • We should be very careful in thinking about whether we’re working on the right problems. If we don’t, that ties into the problem that we don’t have experimental evidence that could move us forward. We're trying to develop theories that we use to find out which are good experiments to make, and these are the experiments that we build.   We build particle detectors and try to find dark matter; we build larger colliders in the hope of producing new particles; we shoot satellites into orbit and try to look back into the early universe, and we do that because we hope there’s something new to find there. We think there is because we have some idea from the theories that we’ve been working on that this would be something good to probe. If we are working with the wrong theories, we are making the wrong extrapolations, we have the wrong expectations, we make the wrong experiments, and then we don’t get any new data. We have no guidance to develop these theories. So, it’s a chicken and egg problem. We have to break the cycle. I don’t have a miracle cure to these problems. These are hard problems. It’s not clear what a good theory is to develop. I’m not any wiser than all the other 20,000 people in the field.
  • I’m still asking myself the same question that I asked myself ten years ago: "What is going on in my community?" I work in the foundations of physics, and I see a lot of strange things happening there. When I look at the papers that are being published, many of them seem to be produced simply because papers have to be produced. They don’t move us forward in any significant way. I get the impression that people are working on them not so much because it’s what they’re interested in but because they have to produce outcomes in a short amount of time. They sit on short-term positions and have short-term contracts, and papers must be produced.
  • The field that I mostly work in is the foundations of physics, which is, roughly speaking, composed of cosmology, the foundations of quantum mechanics, high-energy particle physics, and quantum gravity. It’s a peculiar field because there hasn’t been new data for almost four decades, since we established the Standard Model of particle physics. There has been, of course, the Higgs particle that was discovered at the LHC in 2012, and there have been some additions to the Standard Model, but there has not been a great new paradigm change, as Kuhn would have put it. We’re still using the same techniques, and we’re still working with the same theories as we did in the 1970s.
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  • That makes this field of science rather peculiar and probably explains why there hasn’t been much progress. But it’s not like we don’t have any questions that need to be answered. There are a lot of questions that have been around for decades. For example, what is dark energy? What is dark matter? What are the masses of the Standard Model particles? And what’s up with the foundation of quantum mechanics? Is a theory that's fundamentally not deterministic, where we cannot predict outcomes, the last word that we have, or is there something more to it? Is there maybe another underlying structure to reality?
  • but we haven't reached the fundamental level. Maybe we will never reach it. Certainly, the theories that we have right now are not all there is. The question is, of course, if we don’t have any guidance by experiment, how do we make progress? And are we doing the right thing?
  • We’ve reached this point where we have to carefully rethink if the criteria that we’re using to select our theories are promising at all. If one looks at the history of this field in the foundations of physics, progress has usually been made by looking at questions that, at least in hindsight, were well posed, where there was an actual mathematical contradiction. For example, special relativity is incompatible with Newtonian gravity. If you try to resolve this incompatibility, you get general relativity.
  • There are various similar examples where such breakthroughs have happened because there was a real problem. There was an inconsistency and people had to resolve it. It had nothing to do with beauty. Maybe beauty was, in some cases, the personal motivation of the people to work on it. There’s certainly some truth to this, but I don’t think it’s good to turn this story around and say that if we only pay attention to this motivation that comes from ideals of beauty it will lead to progress.
  • If we are working with the wrong theories, we are making the wrong extrapolations, we have the wrong expectations, we make the wrong experiments, and then we don’t get any new data. We have no guidance to develop these theories. So, it’s a chicken and egg problem. We have to break the cycle. I don’t have a miracle cure to these problems. These are hard problems. It’s not clear what a good theory is to develop. I’m not any wiser than all the other 20,000 people in the field.
  • The way that research is funded in foundations of physics and in many other fields just puts a lot of things at a disadvantage that are not pursued anymore. Typically, everything that takes longer than three years to complete, no one will start it because they can’t afford it. They can literally not afford it.
  • Who makes the decisions about the funding? Superficially, people say that it's a funding agency, so it’s the university who get to hire people. But that puts the blame on the wrong party. In the end it’s the community itself who makes the decisions. What do the funding agencies do if they get a proposal? They send it to reviewers. And who are the reviewers? They're people from the same community. If you look at how hiring decisions are being made, there’s some committee and they are people from the same community. They have some advisory boards or something, which contains people from the same community.
  • Even if that wasn’t so, what the people in these committees would be doing is looking at easy measures for scientific success. Presently, the most popular of these measures are the number of publications and the number of citations. And maybe also whether the person has published in high-impact journals. So, these are the typical measures that are presently being used. But what do they measure? They primarily measure popularity. They indicate whether somebody’s research is well received by a lot of people in the same community. And that’s why once a research area grows beyond a certain critical mass, you have sufficiently many people who tell each other that what they’re doing is the good thing to do. They review each other’s papers and say that that’s great and it's what we should continue to do. It’s a problem in all communities that grow beyond a certain size.
  • I later came to the United States and then Canada, and that gave me the opportunity to learn a lot about quantum gravity. I also figured out that much of what goes on in quantum gravity is very detached from reality. It’s pretty much only mathematics. Yes, the mathematics is there, but I still don’t know if it’s the mathematics that describes reality.
  • That’s the very reason why we don’t normally think of gravity as a weak force. It’s the only force that is left over on long distances, and the reason for this is that it adds up. It gets stronger the more mass you pile up. More precisely, we should say that the reason we find it so hard to measure quantum gravitational effects is that we either have a particle that has very pronounced quantum properties, like, say, a single electron or something like that, but then it’s so light that we cannot measure the gravitational field. Or we have some object that is so heavy that we can measure the gravitational field, but then it doesn’t have quantum properties. Okay, so that’s the actual problem.
Leslie G. Perry

BBC News - Gravity satellite yields 'Potato Earth' view - 59 views

    BBC news report about the findings of the GOCE satellite in space that reveals uneven gravity distribution across the Earth

How to Make a Fork and Spoon Appear to Defy Gravity: 7 steps - 1 views

  • An alternative technique is to use two forks and put a quarter (or other medium-sized coin) between the middle slot of the two forks when they are held together and balance this in the same way
  • Yet another alternative: Create the fork and spoon "boomerang" with one matchstick as before. Stick another matchstick upright in the top of a heavy salt shaker. Balance one matchstick on the point of the other. If you're lucky, the center of gravity will work so as to allow you to balance the point of one matchstick on the point of the other at close to a 90-degree angle. This one takes a bit of experimentation.
Leslie G. Perry

ESA - GOCE - 33 views

    Story and animation of new data showing the uneven nature of gravity on the earth. 

Tricks Guys Can't Do | Girls Can't WHAT? - 4 views

  • Actually, it’s because of ‘center of gravity’. Women carry ‘weight’ literally in their hips. That’s where we balance from, that’s why the bones in our legs point outward from the knee up. Men and women aren’t that different in muscle strength, etc. BUT: The different center of gravity in a woman’s hips versus a man’s upper body will make it so its a cinch for women and men can’t rebalance their upper body while holding onto the chair.
Todd Finley

I just killed a social game mechanic | Gravity7: Social Interaction Design By Adrian Chan - 1 views

    47 Principles of game design. Many (all?) can be applied to education.
Martin Burrett - 27 views

    A great flash game where players must shoot a ball into a hole and use the magnets to help you. There is lots of science to learn in this game including about magnets, gravity and the orbits of space objects.
Steven Young

Demography and the Future of Secularism - - 1 views

    • Steven Young
      The American Enterprise Institute is one of the leading conservative think tanks. The AEI, and the conservative movement in general, have an interest in a more religious population, since religious voters are more likely to vote Republican and for conservative parties elsewhere in the world. Therefore, one needs to skeptical of research emanating from a think tank with a strong ideological bias; especially when that research serves the interests of the institution.
  • Across the world, "population change is reversing secularism and shifting the center of gravity of entire societies in a conservative religious direction." The same will be true here in the United States, where religious families have more children than non-religious ones.
  • It's easy to underestimate the role that population change can have in social change, Kaufmann says, but it can have a huge role, especially when differences in values drive differences in fertility
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  • -- demographer
  • Americans and Europeans
  • Americans and European
  • the fringe of ultra-Orthodox pupils in Israel's Jewish primary schools in 1960 has ballooned: they now comprise a third of the Jewish first grade class. They are gaining power: in Jerusalem, Haredim rioted in late December, demanding the right to segregate women on buses, and have already elected the city's first Haredi mayor.
  • the ultra-Orthodox may form a majority of observant American and British Jews by 2050
  • In the United States, Republicans have a similar values-driven fertility advantage -- an advantage, Kaufmann argues, which will outweigh the Democratic advantage of increased immigration, in part because many immigrants are conservative on social issues and maximalist in their family planning.
  • "In Seattle, there are nearly 45 percent more dogs than children. In Salt Lake City, there are nearly 19 percent more kids than dogs.”
    Summary of article from the American Enterprise Institute journal, "The American", that claims that future of the U.S. is more religious than secular due to the large family size of religious fundamentalists.
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