Lisa Randall

Harvard theoretical physicist Lisa Randall joins us to discuss her book “Dark Matter and the Dinosaurs.” Randall thinks that dark matter is linked to the disappearance of the dinosaurs, and ultimately, humans’ appearance on earth. We’ll discuss Randall’s book and the connection she draws between the science of dark matter and the importance of empathy.

Guests:
Lisa Randall, professor of science, Harvard University; author of "Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe"

  • EIDALM

    Great topic ,the theory about the demise of the dinosaurs by a comet or asteriod was proposed first 1n 1980 by U C Berkeley Noble prize winner geologist Luis Alvarez and his son Walter ,they reach this conclusion when they found through their research a small layer of the element iridium deep underground deposited all across the world that corresponded to 66 million years ago ,iridium is extremely rare element on earth but abundant in asteroids and comets, so to have this uniform layer about 66 million years ago indicates it was a result of an impact of an asteroid or comet that time with the planet earth ,later on in 1983 another U C physicist who was student of Luis Alvarez Richard Muller who also a fiend and one of my classmate in the physics dept at U C ,Richard proposed that the demise of the dinosaurs and the periodic impacts of large objects with earth can be explained by an evil twin of the sun ,star he called Nemeses ,and he gave an approximate period of 35 million years of Nemeses to come close enough to the sun to disturb the orbits of comets in the distant part of our solar system that is called the Oort cloud that have trillions of moving objects ,some of them are very large ,and many are the size of a planet ,so every so 35 million years Nemeses getting close to the sun gets some of those Oort objects fly and hurl outward toward earth ,and that may be the case of that one that caused the demise of the dinosaurs .later on some physicist proposed that that periodic impacts on earth was caused by the the motion of the whole solar system above and below the plane of our Milky Way Galaxy and actually to explain the speed of stars in our Milky Way ,as well as in other galaxies ,and to explain the motion of all galaxies in the universe as well we had to introduce the concept of dark matter ,without which everything would fly apart and we would not have the universe all together.

  • EIDALM

    Dark matter is classified in two categories ,WIMPS ,and MACHOS , wimps acronym for weakly interacting massive particles ,and MACHOS acronym for massive compact halo object which refer to all of the invisible massive dead stars and other object in the halo of galaxies ,but WIMPS are much more interesting ,they are massive particles that do not interact with ordinary matter ,so right now you may be bombarded by billions of WIMPS but you don’t feel them at all….So of the 50 years many research work in the U S Japan ,Germany ,and other counties ,but so far no success in observing any WIMPS .

    • Jack Sarfatti

      So far there is no evidence for any of WIMPS or MACHOs. If dark matter is really a quantum vacuum effect of virtual particles inside it, rather than real particles outside it, all attempts to measure dark matter directly in the lab will fail.

  • EIDALM

    It is matter of when not if ,when earth going to be hit with a massive object ,we are sitting ducks in a shooting gallery ,if you look closely at the surface of the moon you will see what I am talking about ,we are surrounded by the Asteroids belt ,the Kupert and Oort clouds ,all add to trillions of objects millions many ,,,of them can strike earth and some without any notice ,….In the year 2029 on Friday April 13 the Asteroid Apophis named after the ancient Egyptian god of death and destruction is going to path so close to earth it’s path will be below some satellites ,and if it did not strike earth that day ,it will come back in 2036 ,with much higher chance of striking earth which will lead to massive destruction world wide

  • EIDALM

    Since you been talking about the demise of the dinosaurs and dooms day of the planet earth Michael ,you may want to ask your guests about Fermi paradox .,

  • Reed

    Why is it that physicists seem to be trying to create a new kind of religion?
    Science is supposed to be about experimentation and facts, not about wild speculation built on top of speculation built on top of speculation.

    • Sean Dennehy

      It’s probably to sell books, The average person wants a science book that makes them feel good about themselves, feel “connected” to the universe (whatever that nonsense means) and other stupid sentiments. They don’t want books about the cold harshness of reality.

      • practiCalfMRI

        From an Amazon review:

        The writing is engaging enough to lull you along, but the premise is
        patently absurd… Regardless of where you stand on the notion of “dark
        matter,” the entire book is merely a speculative, unfounded suggestion
        that dark matter pushed the famous comet into the Earth. If you happen
        to believe in dark matter, then every event would be intertwined with
        the action of this illusive substance— the selection of the dinosaur
        extinction is totally arbitrary. I would have been equally convinced,
        and twice as entertained, if she had instead titled the book “String
        Theory and the Watergate Scandal.”

        • Robert Thomas

          Since the point of the hypothesis is a claimed peculiar correlation between the periodicity of transition through a special dark gravitationally interactive region local to the Milky Way and, for example, the Chicxulub Event, the author of the comment seems disingenuous or confused.

      • Reed

        Sounds about right. And the cold harsh reality is, once the core of our planet cools to where it stops rotating, like already happened to Mars, all life on the planet will end permanently, with nowhere else to go and no gods to save us.

    • practiCalfMRI

      What I find more galling is a sensational headline that is then “walked back” in an abundance of caution once the bait has been taken. It’s really annoying. And unless Prof Randall can substantiate the link in her headline then the plain vanilla gravitational interactions, of the sort that cause asteroids to hit our planet very, very often, are a much more likely explanation.

      • Robert Thomas

        The element introduced, as I understand, is the particular periodicity of large object impacts and their correlation to the Solar System’s Z-dimension transition through a disk-shaped dark gravitationally interactive region obliquely associated with the disk of the visible Milky Way (the obliqueness being induced by the influence of the Magellanic clouds). A good question for Professor Randall might have been how this claim is affected by more recent calculations that the velocities of Milky Way stars are in fact explainable by conventional baryonic matter and that its dark mass is likely to be spherically distributed rather than oblately. Professor Randall (or anyone else working in the field) would be able to summarize an answer better than I, or any other commenters here, I’m sure.

    • William – SF

      I don’t see how she’s creating a new religion. Can you explain please?

    • Robert Thomas

      Although all theoretical work includes elements that are speculative – at least, as much as is required to suggest further investigation – on the contrary, from what I’ve read about Professor Randall’s hypothesis (I haven’t yet read her popular book) it’s based on observation and reason.

  • Ben Rawner

    If dark matter doesn’t interact with light what happens when a photon hits it?

    • Jack Sarfatti

      If dark matter comes from virtual electron positron pairs inside the vacuum then if the photon has twice the rest energy of electron, it could pull an electron-positron pair out of the vacuum as long as the energy and momentum can be conserved.

    • Sean Dennehy

      The photon doesn’t “hit” things The photon interacts with other particles through the four main interactions. In this case, the photon’s trajectory would change due to the gravitational interaction around the dark matter (light would bend). This is known as gravitational lensing.

      • Robert Thomas

        Photons travel on spacetime geodesics that are, in turn, affected locally by the presence of energy.

        I am unaware of any direct interaction between photons and the strong force. Are there?

  • Jack Sarfatti

    Dark matter needs to be distinguished from dark energy. Dark matter’s gravity field is attractive. Dark energy’s gravity field is repulsive which is why the universe’s expansion is speeding up. There is more dark energy than dark matter by a factor of 3 or so.
    Virtual photons inside the quantum vacuum act like dark energy would. Virtual electron-positron pairs inside the quantum vacuum act like dark matter.

  • Sean Dennehy

    What textbooks do you suggest for people with an undergraduate degree in physics to study Dark Matter and Dark Energy in depth?

  • David

    is it possible that dark matter is an explanation of phenomena that our theories (of gravity) otherwise do not account for? the point being, is it not possible that our theories are simply wrong and rather than posit something else to make them work, we should perhaps abandon the theories and come up with something else?

  • Jon Latimer

    Randal seems to be veiwing our current theoretical framework through a somewhat positivistic theory of ‘objective reality’. What is her epistemology? The history of science is full of radical changes in paradigms, dramatic revisions, abandoming of prominent theories, etc. Aren’t abstractions such as Dark Mater essentially constructs that help us explain some of the more bizare observations we have yet to explain otherwise?

    • David

      i wonder the same thing. i am not denying dark matter but i can’t help but think that dark matter may be making up for what our theories otherwise lack, namely explanatory power. and if we are to understand dark matter as really translucent matter, something you can’t see either directly or indirectly, then my skepticism kicks in with force.

      • TheAimless NeverMiss

        Yep. Dark matter could very well be “real”, but right now, I’d say it’s fair to call it a working construct. It fits the evidence. A lot of evidence. All we really know is there’s too much mass in our observations. Oh, right, also dinosaurs are dead, and every time we pass through the galactic halo everything dies. It’s a pretty good puzzle. Probably a great read;)

      • Robert Thomas

        The basic idea of dark matter precisely is that it CAN be observed indirectly, as being equivalent to loci of masses that assert gravitational influence where no matter can be seen, either to produce photons or to absorb them.

  • Bill_Woods

    We learned about atoms in the 19th century — long before we learned they could be split.

  • practiCalfMRI

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  • practiCalfMRI

    Worried about asteroids? Support SentinelMission (dot org). Ed Lu, Rusty Schweickart and colleagues want to find all the earth-bound objects lurking out there.

  • marte48

    Michael, I think that it was on your show that E.O. Wilson, the entomologist, pointed out that the ants were the most populous beings on the planet, but most of them live underground, and in locations where they will never be encountered by people. Another example of how we are unconscious of very important aspects of the universe.

  • EIDALM

    I wonder why Michael Krasny did not read any of my comments on the air which have lots of scientific facts about the subject ,so as to benefit his audience who has no access to on line comments ,I posted many scientific facts that his guest did not mention , I did hear Krasny make some statements from my comments without mentioning my name.

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