i open minecraft 1.7.2 and see this

Bootstrap (v5)
Current time is Nov 14, 2013 4:09:25 PM
System.getProperty('os.name') == 'Windows 8'
System.getProperty('os.version') == '6.2'
System.getProperty('os.arch') == 'amd64'
System.getProperty('java.version') == '1.7.0_45'
System.getProperty('java.vendor') == 'Oracle Corporation'
System.getProperty('sun.arch.data.model') == '64'

Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 2/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 3/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 4/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 5/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 6/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 7/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 8/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 9/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Downloading: https://s3.amazonaws.com/Minecraft.Download/launcher/launcher.pack.lzma (try 10/10)
Exception: javax.net.ssl.SSLHandshakeException: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
Recognized exception: the likely cause is a set of broken/missing root-certificates. Check your java install and perhaps reinstall it.
Unable to download remote file. Check your internet connection/proxy settings.
FATAL ERROR: net.minecraft.bootstrap.FatalBootstrapError: Unable to download while being forced
at net.minecraft.bootstrap.Bootstrap.execute(Bootstrap.java:95)
at net.minecraft.bootstrap.Bootstrap.main(Bootstrap.java:381)

Please fix the error and restart.